Showing posts with label chains. Show all posts
Showing posts with label chains. Show all posts

Thursday 1 April 2021

Chuck's Tech Opinion: How to decide what to keep and what to change on a Raleigh Twenty, and Pedals!

As you work on a Twenty, you start to get a feel of the engineering. I find it useful to categorise: some parts are really well thought out and function well, others are merely adequate for their job and there's another category of redundant, useless, or poorly designed stuff. Then layered over that, some parts have elegance, possibly even beauty, while others are downright ugly. Add yet a further layer, namely weight, and a recipe emerges as to how to go about deciding what to keep and what to change. 

Take the pedals. In the photo below (starting top left and going anti-clockwise): originals off a BSA 20, modern MTB style polymer flatties (BBB brand) and a generic polymer trap-type pedal:


Both the modern pedals have reflectors, today a legal requirement for safety, whereas the R20 pedals do not. Now, this R20 pedal has a certain elegance, it's true, but it's also narrow. Uncomfortable over a length of time, especially in soft soled shoes, as your feet curl over it. The weights add another factor:

Pedal type g per pair
R20 651
MTB Flatties 336
Polymer Cage      286

I think it's remarkable that the old R20 pedals weigh so much, nearly 1.5lb! I discarded the polymer cage, for two reasons: the bearings on one were notchy and I didn't like the style for this bike. I thought it would be funky to have the MTB flatties. Apart from the beautiful wide platform they provide, the reflectors for safety and the weight saving (a stonking 315g), they are also shorter (12.1 cm v 11.0 cm from crank to pedal tip) and thinner, both of which reduce the chance of a pedal touching the road in a corner. So, my choice is made to switch to the MTB Flatties. 

That all sounds great, but then I tried fitting the MTB Flatties and to my surprise while the diameters were comparable (9/16"), the threading was different! I wondered whether the cranks had some old English threading, but that seems like an odd explanation, because I've managed to get modern pedals on a R20 before and know that others have too. More likely, perhaps the threading tooling that Raleigh used was slightly different to modern standard. It could be just some R20s that were like this. I tried a few pedals and I found that most of them were too tight, but one or two modern pedals went in ok, but only on one crank. Whatever the reason, after playing about a bit with modern pedals, I now feel that for this project, I will stick with the original pedals. They are a basic, but serviceable design. The end cap prises off carefully with a thin screwdriver. Underneath, two spring clips and a washer to remove:


There are no BBs just a plain bearing. The axle at the top simply slides into what looks like a tapered sleeve in the pedal, then the washer with flats is added and the two spring clips to hold it all down. This one was gummed up and a quick clean and regrease worked wonders. They spin super smoothly now. At least they are hardly worn and have plenty of service to give. They'll clean up ok and add to the retro look. 

Now consider the light bracket:


What an ugly lump that is, and given modern lights, it's redundant too. It serves a purpose in the headset, that is to increase stack height by a few mm in order to prevent the top lock nut from bottoming out. But that function can be easily achieved with a small standard spacer. How much does this monstrosity weigh? 77g! That's about the weight of SEVEN AAA batteries! Wowsers. Guess where that's going? Yes, in the recycling bin. NB, you have to remove the front brake caliper to get the stem out in order to lift this off the headset (see my post a few days ago on that wire loop thingy that restricts the movement of the stem vertically).

Note that by just by changing pedals and ditching the light bracket, you could save nearly 400g. Astonishing. 

You can repeat this thought process for every other item on the R20, using the factors I suggested at the top of this post (I'm not considering maintenance items, such as brake pads, tyres, BBs, chain and cables):

Sturmey Archer hubs (both the front one and the rear epicyclic AW gear unit): 
Elegant, well thought out, very functional, design kudos, unique, a bit heavy, but worth it! Pretty when clean and polished! I would keep these in nearly every case, unless there was a radically different vision for a particular build. 

Chainset: 
They are not all the same. Some patterns are indeed beautiful, others look more functional, but they have some eye appeal, I like the stamped "Nottingham Knight". They function well if you can deal with cotter pins and can live with the heavy chromed steel.

Bottom bracket:
It's perfectly functional, and isn't heavy, so in my view, this comes down to condition, and how important it is for you to change the chainset/eliminate cotter pins. The axle is a solid thing, and very rarely needs replacement. So, a good service with new BBs is usually all that's needed if you stick with cottered cranks. However, if you want to open up the world of square taper chainsets, then I believe that the simplest and best option is to find a square taper axle that fits and retain the same bottom bracket cups and 1/4" BBs. If that's not possible, then face the shell to 73mm or even 68mm (the width of my BSA 20 shell is 77mm as best as I could measure it), and rethread to standard 24 tpi. Some say that you should fill the threads with with a suitable molten metal before re-threading, but I've also read that many people have had success just rethreading directly, but slightly deeper than the original threads. Clearly a specialist's job. Failing any of those, then a problem solver may be a new threadless (friction fitting) unit. 

Saddle:
Really ugly, uncomfortable for me, and enormously heavy! It's gotta go. 

Seatpost:
Ugly, too short for many people, and very heavy, especially being steel with the steel clamp. Easy swap out to a modern one 28.6 usually. It's gotta go. 

Chrome steel Handlebars and Stem
Function ok, and have a certain elegance. However, they are really rather heavy and often this is were customisation and your personal vision take over. A quill stem, with alloy riser bars, or bullhorns, etc. 

Hand grips:
Yeuk! Hard ugly plastic and short. The only positive thing I can say about them is that they are hard wearing. But, I really think they have to go in just about any project (save for a restoration to original spec). 

Chrome steel rims:
Work ok, but do not brake as well as alloys, especially in the wet. Look nice when clean and polished up. Heavy! My front wheel without nuts, rim tapes, or tyres weighs 940g. With rim tapes, tyres and nuts it weighs 1547g. Go or stay? It's really one of preference and also considering the condition of the steel rims that you have, the hassle of doing a rim swap, or finding/building another wheel that fits and also brakes that work with them. On the other hand, if you're not accelerating and braking a lot then, a heavy wheel provides a nice flywheel effect for steady riding - which is what I tend to do on a Twenty. 

Nylon bushing top part of the headset: 
Functions just about adequately, especially if you get a chance to clean it and lube the surface that touches the steerer, and adjust the headset properly. Once the light bracket is off, there's not much in the weight. So this one is a matter of preference again. This photo is of my current project, rust cleaned off and polished. I've kept the Nylon bushing, but ditched the light bracket (hence the black spacer):


Another approach is to remove the Nylon bushing and install the top half of a 1" threadless headset. When I do that again in the future, I'll be sure to take enough photos and post them on this blog. 

Frame: 
It wouldn't be a Twenty without one! It's a classic, has got to stay.

Forks:
They are designed to fit the cone flanges of the Raleigh Sturmey Archer front hub and they work well enough. A bit heavy. I think this one is mainly down to whether you keep that front hub or not. Also whether you want to do something funky, like BMX forks for 451 or 406 wheels or suspension forks. In which case, you can also change the whole headset. 

Paintwork:
What condition is it in, and do you like it? Will it clean up nicely (after a wash, T-Cut and car polish)? Simple as that. 

Clamps and Locking levers on steerer and seat tube:
These function adequately if well-maintained and positioned properly (evenly over their respective tubing slots). They add a bit of weight, but also provide easy quick adjustment. Also, if you are fitting a quill stem, the front clamp becomes unnecessary and can go (or stay!). So it's really up to you. 

Brake caliper units:
Can function adequately if you take the time to set them up well, and they polish up ok too. Remove rust with WD40 and 0000 steel wool, chrome polish, lubricate and fix and adjust them properly. Use fresh cables. In many instances, I've changed only the inner wires, as the outer cables were fine. If the ends of the outer cables are kinked, you can snip off 5-10mm cleanly and that will improve the performance quite a bit. Modern alloy units would be an improvement and weigh less, but I think this one is really a matter of preference.  Here's a front caliper, with rust cleaned off one arm, but not yet the other one:



Brake levers:
In my view they function adequately, and being steel are better than plastic levers! But there are lighter and better modern alternatives. So, it's a matter of preference for your particular build I think. 

Mudguards (Fenders):
Functional, but do not have the break-off arms for safety as modern ones do and are relatively heavy. Must mount them properly and securely, or those beefy mounting arms could foul a wheel and cause a bad accident. I'm powder coating mine on this build.  

Chainguard:
Serves a function (keeping your trouser leg clean!) and has a certain appearance. Don't weigh a great deal, but grams are grams. It's up to you! I'm powder coating mine on this build.  

As I've said before, the Raleigh Twenty is like a blank canvas to a bike builder! The Raleigh bronze green BSA 20 that I'm working on at the moment is going to retain most of its original components, but with modern contact points (pedals, saddle/seatpost and hand grips). The next one may be a light weight with funky bars and alloy rims, but I haven't clearly figured out my direction on that one at this time.  

Go with your heart and desire, enjoy the process, and all will be ok. Be creative, be artistic! 

Wednesday 31 March 2021

Chuck's Tech Opinion: Shimano Uniglide cassettes, replacing cogs/sprockets

Just before Shimano came up with the Hyperglide (HG) cassette system that we know and love today, it introduced the Uniglide (UG) arrangement. It was an 1980s effort to provide not only a cassette system, but also teeth features to improve shifting (especially for the indexing 'click' that is pretty much standard now). I happen to have such a cassette in 6 speed - they were produced in 5, 6, 7 and 8 speed. Generally, UG cassettes are rare these days, while screw-on freewheel types remain relatively abundant. This post is about cleaning and re-jigging my Uniglide cassette, currently 13-14-15-17-19-21T, and my thoughts about it. I want to dismantle, clean and swap out one of the cogs to allow me to put in a bigger 24T. Photo before I started work:

Yes, it's dirty, and the grime is stuck hard! If you've never seen a Uniglide cassette before, then it could be confusing. It has neither Hyperglide's splined lockring nor the spline socket that screw-on freewheel types have. It does have a freehub body, much like the modern Hyperglide, but all the splines are the same width. Instead of the HG lockring, the topmost cog is screwed down on to the upper part of the freehub body, which is partially threaded, to hold everything together. The 24T cog that I want to add is the black one in the photo. To dismantle, you use 2 chain whips to hold the wider cog, while unscrewing the topmost cog (13T):


Thankfully it unscrewed fairly easily. Turned over, you can see the cutouts for weight reduction and the three small bolts that hold the unit together. The top locking cog (13T) has an inbuilt spacer and is threaded on its inside. 


View from the other side, there is a thin washer under the top locking cog (13T), and you can see the bolts engaged in the three small threaded holes in cog 14T:


The bolts need to come out. The bolts have a smooth shaft and are threaded at their tip. They screw only into the matching threaded holes in the 14T cog: 


Taking off the 14T cog, there are identical plastic spacers between the remaining cogs:


I cleaned up the parts and started to refit. In this photo you can see the threading on the upper part of the freehub body. Apparently, it's possible to change that body for a HG one, but why bother when this seems little worn and is functioning beautifully. Also, I think the threading on Dura Ace is different - presumably an attempt to keep it "exclusive" and apart from the mass market! I've placed the new 24T on first, then a plastic spacer:


Looking at the splines on 19T, note the absence of the wider notch and narrower notch. Also note the three holes for the bolts - these are present in everything, spacers, washer and cogs. I'm not going to use the bolts as their main purpose is to hold the cassette together for easy fitting. 


In the photo above, you can see two teeth features designed to improve shifting. Firstly, two opposing teeth on the 17T cog are shorter. These provide avenues for the chain to dismount as you shift. Secondly, you can just see the twist of all teeth. These features are the precursor of Hyperglide teeth shaping. Place cog, spacer, cog spacer, etc... until you reach the penultimate one, then the thin washer goes on:


Now you can clearly see the threading on the freehub body to take the last locking cog 13T. Put that last one on carefully by hand, to ensure threads are not crossed! Then tighten it with a chain whip, but it's not really necessary to strain yourself doing that, because the process of pedalling will tighten it. In fact, when I put it into top gear while riding, I felt the slight slip as it tightened into position. Here's a pic of the removed bolts and 14T cog, which I'll be putting away carefully in my bits box. Only some cogs had the shorter opposing teeth pairs:


The finished cassette. Not so dirty now! Can you spot the shorter teeth in the picture below? Hint: there are none in the top locking cog (13T). Notice that the 24T cog has them, which means it's not really intended to be a last cog - contrast with 21T (see photo above) which is stamped 'Low' and doesn't have the shorter teeth. I don't think it really matters, and presumably, having the shorter teeth on the biggest cog will help switching from 24T to 21T.  


Now a photo of the bike in which this wheel goes, my Dawes Impulse (see previous posts): 


And a closeup of the cleaned cassette newly configured to: 13-15-17-19-21-24T, with the vintage super-cool Shimano 105 mech:


One thing you need to check for is that the chain is long enough to handle cross-chained big-big. Even if you're not supposed to use that gear, it is wise to ensure that the chain is long enough for it to be engaged otherwise you can break things. To my relief, it was long enough.  

CHUCK'S TECH OPINION ON UNIGLIDE

I thoroughly enjoyed working on my Uniglide cassette, because the quality of manufacture is superb, and everything disassembles and fits well. It was easy to remove the bolts (using quality pliers). This is better than those annoying rivets in modern cassettes, but I can understand that rivets would be much cheaper than those three bolts when it comes to mass production. 

Test riding was magic! It shifted positively, flawlessly, and the indexing was spot on. Definitely the crispest shifting bike with down tube levers that I've ever owned and I'm comparing here to both screw-on freewheels and even more modern 9 speed Hyperglide hubs. (Perhaps that's because the tolerances, both cog-spacing and lever-indexing, for 6 speed are more forgiving compared to the narrower 9 speed?). 

Another great advantage is that the uniform spline widths allow you to invert each cog. Useful to maximise working life, as worn cogs may be simply turned around. While I like this and it resonates with today's re-use, up-cycle culture, it is not the ideal situation for the capitalist mass-producer who wants sales (think Apple iPhones and OS upgrades that render one's device slow). I think that is part of the reason why we have modern riveted cassettes and non-reversible cogs today.  Also, I suspect that with different width spacers, you may use the same freehub body to build up a 5, 7 or 8 speed cassette, but I haven't tried it and would have to research the standards for that (i.e. spacer widths, cog thicknesses and overall hub body height).  

In its time in the 1980s, Uniglide was top-end and a step-forward in smoothness of shifting and ease of indexation. I can appreciate why. Uniglide hubs are ultra-rare nowadays, so the information in this post is really for bike nuts, the sake of history, or those who accidentally come across one. Feel lucky if you do though because from what I've seen, a new old stock Uniglide cassette can sell for £60-£100!

Saturday 28 April 2018

Park Tool Derailleur Hanger Alignment tool DAG 2.2 - Review

Why didn't I buy this earlier?! Yes, it's relatively expensive, but within a year I've used it on 6 bikes and am very happy with the results. Why? Because it improved rear mech changing performance hugely. In some cases, transforming a noisy, crunchy, chain-scruncher to a beautifully efficient "click-whirr"! In my view the tool has easily paid its way already.



I had bought the tool for when the bike may have pranged on something, or fallen on to the drive side, putting the hanger visibly out of alignment. But to my surprise, it's been very helpful for new bikes too. Which tells me that alignment is not always (hardly ever?) checked when a new bike or frame goes out the shop-door to a customer!

The purpose of the thing is to ensure that the rear mech is well-aligned with the sprockets on your back wheel. More precisely, the tool ensures that the plane of the cassette's sprockets is normal to the rear mech fixing bolt hole axis in the derailleur hanger.

If you have trouble adjusting rear mech cable tension to get smooth shifting in both directions, or an otherwise sub-standard rear transmission, just take a quick look at the alignment of your rear mech pulleys and the sprockets. If they are not coplanar, then use this tool to fix it. In the past, I tried realigning by hand, and while it can improve things, the tool allows you to align accurately. Once that alignment is decent, the rear mech can do its thing properly. Suddenly, your transmission works beautifully.

Although it's a simple-looking tool, I can see that a lot of thought has gone into its design. There are various factors to consider in the design of such a tool:

1. Robustness and longevity. The lever needs to be stiff enough, and the attachment to the hanger strong enough. This is because the lever is used to manually bend the hanger. No problem here with the Park Tool. The lever is strong and the rotating bolt is a good tight fit in the heavy housing. Moreover, the threaded end bolt can be removed (it has an allen key socket in it) and replaced. Here's a photo of the main bolt pin removed (need to remove a grub screw):



2. Must fit. Look at a bunch of bikes in a shop, and you'll see a variety of positions of the derailleur hanger bolt hole with respect to rear dropouts, wheel axle, etc. So, the tool has to be able to attach to all these types. I've had no issues with this so far, and I think this is because the part of the tool that houses the bolt is fairly narrow diameter.

3. Ability for the indicator to be moved in and out without losing the setting. The tool has to be used while on the bike (because the hanger is on the bike!). Therefore, the indicator has to be moveable to get around at least, the chain stays and then any other parts hanging about, such as racks, mudguard arms, or even the derailleur itself (if all you've done is unbolted it and let it hang free). The indicator on the tool achieves this with a small knob, and small O-rings to keep the setting as you move it in and out.

Tips and Learnings


1. What I've learned recently, is that even small improvements in hanger alignment can cause big improvements. These kinds of misalignment are not that easy to see with the eye alone, but the tool can detect it. I suppose this is because the indicator looks at the rim positions which is a long distance from the sprockets.

2. I put something on the wheel in the bottom dead centre position, e.g. the tyre valve. Throughout the testing and alignment process, I ensure that the valve remains in that spot.

3. Take off the rear mech. If the hanger is removable, unbolt it and clean it. Grease the bolts and refix it securely before you start the alignment procedure. Sometimes, the issue is not alignment, but rather hanger tightness!

3. CAREFULLY screw the tool into the mech hanger hole - really really really don't want to cross threads here!

4. The procedure I've used that has worked well starts with first using the indicator to look at the top and bottom of the wheel rim to work out which way the hanger is bent in or out from the wheel. (This requires sliding the indicator housing, because the rear mech hole is not in the wheel centre). Then look at the back of the wheel rim and front of the wheel rim (which requires maneuvering the indicator around the chainstay) to figure out which way the hanger is toed in or out from the wheel's plane.

5. Then, spend a few seconds (minutes?!) to visualize how the hanger is aligned with respect to the wheel in your mind BEFORE you bend anything.

6. Make the first bend. So far, I have gone for a horizontal and vertical approach: (1) with the lever horizontal to correct toe-in/out, and (2) with the lever vertical to correct push-in/pull-out. In other words, I get the alignment satisfactory with the lever vertical or horizontal, then get the alignment satisfactory in the other direction (lever horizontal or vertical).

7. I try to minimize the number of bend attempts, because metal fatigues! A couple of mm difference in the indicator positions at the rim doesn't seem to make much impact, so it doesn't seem worth bothering to get mm perfection. Remember that whatever the "gap" is on one side, you only have to bend the hanger half that amount to get it aligned.

8. After correcting both vertically and horizontally, I go back to 4 above and quickly recheck all is good and that the hanger plane is close to parallel to the wheel plane.

9. The knob on the indicator slider and the small O-rings on the indicator work fine. However, I've found that the O-rings will disintegrate over time. I need to get more of them, but at least O rings are easy to find online and cheap.

10. Clean and grease the main bolt pin (see photo above), or perhaps a drop of oil every now and then to keep the bearing smooth. A good idea to keep it easy to screw into the mech hanger hole.

Here's a video from Park Tool of the thing in use.

Park Tool have done a super job with this tool and I recommend it highly. Just get a small bag of replacement O rings.

Sunday 11 March 2012

Peugeot Lautaret Single Speed project - build log

Following on from my earlier update, here is how I built the bike. First of all, I took apart the headset (I've explained in previous posts about the quill-Ahead stem adapter, and funny French sizes):
I want to ditch the ball race cages and use loose balls. With loose balls, the pressure is spread out more within the cups because you can pack more balls in. So, using calipers, I measured the ball diameters:
Definitely 5/32", which is great, because I have some. Reassembled headset with loose balls (this is a view of the bottom cup - the frame is upside down):
Although with a cartridge bottom bracket, a plastic sleeve is not strictly necessary, I cut one out anyway from the Boss's old oregano spice packet:
Trimmed it down to size, making sure that the overlap is at the bottom so that water can drain out through the somewhat massive cable guide hole. Fitted square taper Shimano UN54 113mm cartridge bottom bracket:
Once that was in, I enjoyed some time gleaming up the frame with Simoniz car polish:
Tyres on, wheels on - Tiagra 32h on Omega Mach 1. Fitted the chainset, a Sturmey Archer 44T ally job with steel teeth. This was cheap yet good quality and also had a right side chain guard. Utilitarian, as I intend to use this for commuting. Pedals are MKS resin types for now, again chosen for practical reasons - I could ride this in flip flops - (later I may stick some single-sided SPD touring pedals on):
Using a steel ruler, I measured front chainline, which is from centre of seat tube to plane of chain ring teeth. It was a pretty lengthy 49mm. So, that means the rear cog position would be 16mm from right OLN ((130/2)-49mm). I'm using a Shimino 18T sprocket on a standard cassette type hub to give a gear of around 65 inches. The Velo Solo shims are great, because you can use different thicknesses to set the rear chainline. This is how I measured the rear cog position using two rulers:
After doing that, I did a secondary check on the chainline with a long steel ruler:
Much to my surprise, it was spot on, so the calculation had worked! Then I put the handlebars on. The front brake was a cheepo steel side pull unit off eBay. Rear was an alloy side pull unit (from my box of old unused bits). I also needed some bolt spare parts, again sourced cheaply from eBay. I fitted the brake levers in a position that suited braking from the hoods, as that is mostly how I will ride this bike. I don't want flat bars because I like the greater number of hand positions of drop bars. Fitted the cables, the only interesting thing here is that the rear cable runs into the top tube. I used a hook to pull top tube cable out of interior cable run. You can just about see the rear cable entering the top tube in the photo below [I'll need to get a better photo of that]:
I hooked up a SRAM 8sp chain, estimating length by running it around with the wheel in a forward position in the dropouts, taking account of the length of the Powerlink joining link. I decided to keep the rear hub QR skewer, because when I lock the bike I always run it through the back wheel:
On the front, I fitted a bolted skewer from Halo. Fitted saddle - I'm still umming and ahing over black or green (Charge Bucket, which is a cheepo one that looks a bit like a Turbo). Steel chromed 22.2 seat post. Handlebar wrap with Trek red light bar end plugs - once again, a practical thing for late evening commuting.
The only hitch along the way, was a problem with the seat post slipping (it went down about 1cm during a 1h ride). As a temporary solution, I did the "good old coke can shim thing". First, drink some coke, then rinsed the can and cut it:
Trimmed to fit and inserted inside the existing seat tube shim. Shoved the post in, taking care not to let the shim slide in fully. I did that by cutting slits in the top of the foil, to make tabs that I hooked over the edge of the shim. After tightening the bolt, I then unfolded the tabs:
So that I could trim off the excess carefully with a serrated knife:
Lovely jubbly! So far, the temporary solution has worked well. I've ordered a slightly thicker seat tube shim anyway, but hopefully, I'll never have to use it. I'm guessing that the original seat post would have been around 24.2mm. What a weird size. Let's see how it goes. To continue with the practical theme, I will probably fit some mudguards, but will keep them low profile!

Hope you enjoyed this build - click on single speed conversion project on the right for all the posts on it. It's very satisfying to get an old frame running again. It feels light and comfy and has cheered up my commute a great deal. So far I've got up to about 44km/h on it and at that speed it seemed sure footed enough, although not rock solid like a modern bike. I've surprised myself at the versatility of the 65 inch gear is - I've ground up some decent grades with it now. But most of all, I'm impressed by how efficient and quiet it is to pedal. So silent, that on one ride I was bothered by the noise of a crease in my jersey fluttering in the wind! Never thought that would ever happen!

Thursday 5 January 2012

Commuting bike for £15

Here's a photo of the Concept Excelsior that I bought on eBay for £15, on its first day as a London commuter. 

I fitted mudguards which were lying around unused at home (you can see that they were for 700c wheels, not 26", but they will work fine). Other than the longer seatpost and cheepo saddle, no new parts have been fitted. Since the front shifter was knackered, I removed the gear cable and adjusted the mech to middle ring (38T). After lubrication and cable tension adjustment, the 5 rear gears work reliably now. Basically, very little cost and work to get this roadworthy and working at an acceptable standard. The chain had surface rust, but was not stretched - in fact, it seemed hardly used. So, I wire brushed it and thoroughly oiled it. Gearing is perfectly sufficient for London. First impressions are that it rides well, but is heavy. After winter, I'll fit lighter, narrower, touring type tyres, and that will help a fair amount. 

Thursday 15 December 2011

How to service a bicycle

I'm about to sort out the Concept Excelsior hybrid bike, which let me gloat again, I bought for only £15 (see my previous post on that). I thought it may be useful to jot down a checklist of things to do. Now, there's no real need to do these all at once. Actually, I see this exercise as a fact finding mission, so as to understand every part of the bike. I then prioritise the areas to service first. In this particular case, I do not want the bike to look pretty, as it's going to be used for commuting and parked in various locations in town. So with that background, here's the full list:
  1. Frame - external: Inspect it all over, look for cracks, dents, corrosion, twists, bends, any defects really. Special care around the fork areas. It may be convenient to do this while washing the bike with a sponge and soapy water. Do ensure that it's rinsed well with clean water though, as most soaps contain salt that encourages corrosion. At worst, you may have to get something welded if steel, or end up chucking the frame because of a previously unseen crack.
  2. Frame - internal: Look inside, where ever possible - down seat tube, look at drain holes in the forks and stays, inside the head tube. When bike is completely dry, spray frame saver inside, or at least Waxoyl. Remove bottle cage bolts to get the spray tube into the down tube.
  3. Saddle and seatpost: Is the saddle tatty, comfortable, or hurty? Loosen the seat post bolt, take the post out. Hopefully, that will be easy, but sometimes it's jammed. In which case, spray some WD40 or Plus Gas around the top of the seat tube, allow to penetrate, then try again. Once out, clean the inside of the seat tube with a rag using a stick as a ram rod. Clean and grease the seat post, bolts and nuts, apply a bit of grease inside the top of the seat tube too, then re-assemble and adjust to the right height and angles. In a year's time, you'll be thankful you did this!
  4. Steering: For a quill stem, do as for the seat post, ensuring especially that you grease the long bolt. I also grease the faces of the stem and the expander wedge where they slide together and very sparingly around the post and in the tube. The idea is that it should not jam later, when you want to remove it, but also, should not slip when you tighten it up. For Aheadset type systems, you need to check that the bolts at both ends of the stem are tight - but rather than stripping them by overtightening, it's probably much better to loosen them all, grease and then tighten up. The bars should turn fully and freely in each direction.
  5. Headset: May well be fine. Stand over the top tube, bend over the handlebars, put the front brake on, and rock back and forth, with your weight on the bars, checking carefully for play in either top or bottom bearing. Turn and feel for roughness. It may be easy and perfectly sufficient to wind the lock rings up a few turns, squeeze some grease into top and bottom bearings and tighten it all up. A more thorough service may be fairly easy - dismantle it, clean, grease and rebuild, and you may have to change the ball bearings or races. It's up to you! At worst, you have to change the headset, which can be a pain if you can't seat the crown race or top and bottom cups easily, but in that event, your LBS should be able to help you out if it needs a full replacement.
  6. Wheels: Loose, or much worse, broken spokes should be sorted out sooner rather than later. Check condition of the rims - how worn are they, how much life is left in them? Never risk running rims that are wearing out - look for wear lines or other indicators. Examine the hubs carefully, especially around the spoke holes. Any cracks or signs of imminent breakage? Are the bearings ok? Waggle the wheels - is there any play in the hub bearings? Again, you may need to strip and rebuild, but a quick tighten up of the axle nuts may be enough for now, the full service not being urgent. Next time you get the tyres off, check the rim tape and the spoke heads too. It may be worth oiling them, to make tension adjustments easier in future. Is it too obvious to say that you must check that the wheels are firmly fixed to the forks?! Track nuts, quick releases, whatever. Grease and lube wherever you see fit!
  7. Tyres: Check for cracks, splits, holes and general wear and tear. Nowadays, I tend to make a washer out of an old inner tube, and put that on the valve before fitting it in the tyre. This stops the edges of the valve hole in the rim cutting into the valve base. But these things can wait until the next time you take the tyres off.
  8. Brakes: Very important area this. Pads must have some decent thickness to them. Old pads can be revived with a file, or just rub the face on a cement floor or brick side. Need to get any bits of metal that may be embedded in them out! Oil everything that has a pivot - including the brake levers. I also oil cable entry points. Adjusting angle of the pads and ensuring that they move uniformly and hit the rims evenly can take time, especially with cantilevers, but it's well worth it. Toe in if you have to eliminate squealing. I use a bit of card at the back of the pad while tightening it up.
  9. Pedals: Ensure they spin freely and aren't mangled up. Angle them and try to dribble some oil in the bearings. Do they suit your shoes!?
  10. Bottom bracket: Grab hold of the crank arms and wobble them, holding the frame still. Do it while riding the bike too, with your feet on the pedals. Examine rings and cups to check they are tight. At best, it'll be fine, especially if it's a cartridge type. If not, either change the cartridge or service the axle and bearings.
  11. Chainset: Clean, inspect the teeth for wear. Are rings bolted on securely? Check the cranks for cracks, especially around the pedal axle area. Are the cranks well secured to the bottom bracket axle? It's worth releasing them, cleaning, and re-fitting them securely. This will stop you cursing later when you want to get them off but can't.
  12. Chain: Clean, inspect, lubricate (see my earlier post for full details).
  13. Front and rear mechs: Clean and oil, ensure they move back and forth smoothly. It's very important to ensure that the L and H settings are adjusted properly, for safety. Otherwise the chain can come off and jam somewhere, causing injury possibly.
  14. Shifters: Clean, and lubricate, but with care! Putting oil in the wrong places on some shifters can cause problems - e.g. slipping. Seek expert help for tricky things like STIs or Ergos. Check condition of cables, replace if necessary, and lube or grease cables at entry points. An easy one is the under bottom bracket cable guide - clean it and oil it.
  15. Freewheel/Cassette: Remove debris, clean up, inspect for wear. Are teeth worn down or fresh looking? Try to lubricate freewheels with a good quality oil - need to exercise some gymnastics to make it dribble around inside to get to the moving parts.
  16. Make notes: I think this is worth doing, and easy as you go over the above items. Frame number, dimensions, gear teeth numbers, all useful information that you may need to refer to later. A few years ago, I started to log my maintenance work in a spreadsheet document on a pc. I've found it more useful than expected - like informing me as to spoke breakages on a particular wheel, and creaking noises - information that gave me clues about other matters that needed to be fixed. 

Sunday 11 December 2011

Peugeot Lautaret and Hybrid commuter projects

Found a couple of bargains on eBay. Here is a lovely Peugeot Lautaret frame (£13.10):

After studying it carefully, I'm pretty sure it's from 1987, as this is the date stamped on the Sachs Huret down tube shifters, and according to brochures online, the rainbow paint scheme is from that era. It's marked 12 vitesses, and the tubing is Peugeot own brand HLE, neatly internally brazed (no lugs). Paint is in great condition. The BB seems to be English 68mm, the seat tube is weird size, probably a 24mm diameter, and the stem is a 22.0 French jobbie. Rear dropout spacing was 120mm, but it was pretty clear that someone had cold set it unevenly. By sighting down the seatstays, one could see that the right hand stay had been pushed in. I gently pulled it back to its original 126mm spacing. Now to figure out how to build it up - single speed or 6 speed? I'm certainly going for a single chainwheel up front. Options, options...

Second bargain is a Concept Excelsior 15 speed hybridy mtb type thing (£15):

Judging by the condition of the chainset, sprocket teeth, tyres, rims and brake pads, it's HARDLY EVER been ridden! A label on it says "Designed in England by Concept Cycling Ltd" and another "Mega Carbon Steel". The frame feels bomb proof. I know nothing of Concept Cycling Ltd, but a quick Google search tells me that it went bust in around 2005 and is now part of the Avocet Group, with Viking and other brands. The chain was rusted and wrapped round the 5 speed block. But it was simple to unwind it, lube it and in 10 minutes, it was back in rideable shape. It rides fairly well actually. Front twist grip changer is knackered completely. I adjusted the L set screw on the front mech to put the chain in the middle ring (38T) for now. Rear twist grip shifter is ropey, but seems to work in a fashion. There's a straight chainline with the middle ring at the front and the second smallest sprocket at the back (17T), which is ~58". I'm wondering whether to lose the rear mech completely, fit mudguards and make this a single speed commuting hack using existing cogs and rings (it has sloping dropouts). But I'll need a longer seatpost first. At least it's a standard ish size: 25.4mm.

Will post more photos as I sort these out. But first, allow me to revel in getting a frame and a functioning bike for a grand total of ~£28. I feel smug! Marvellous. Thanks eBay!

Wednesday 10 August 2011

Bike chains: how to inspect, replace, fit, clean and lubricate

Figure 1. The Shimano Length Check (see 2(a) below).

Fitting a new chain should be easy and satisfying. Yet, it's possible to make a miserable, muddlesome meal out of it. I know, I've been there! Generally, the objective is to ensure that the chain is as short as possible and suits the gearing system on the bike. So, after all my trials and tribulations on the subject, here's how I've learned to go about it:

Derailleur equipped bikes

1. Assess the chain's condition. Is it enough to merely clean it up, or should it be replaced? Is there a special joining link? What kind of chain is it? Buckled links, damaged plates, or severe rust point to changing it. I measure the wear, or "stretch" as its sometimes called, using a steel foot ruler. I put the zero mark on the centre of a rivet pin. Measure 12" and if the chain is not worn, there should be the centre of a rivet pin at the 12 inch mark exactly. I put a bit of pressure on the pedal with my free hand while I do this, to ensure that slack in the chain is taken up. If the centre of the pin is more than ~1mm past the 12" mark, then I replace the chain. If it's greater than ~1.5mm past the 12" mark, then I'd replace the cassette too. Otherwise, the chain may slip on the old worn cassette. It can get expensive if the chainring teeth are worn as a result of a knackered chain, so it's wise to assess chain stretch regularly.

2. Is the current chain the correct length? On a bike I'm not familiar with, I do all three of the following length checks:

(a) The Shimano length check. With bike on level ground, shift the chain on to the biggest chainwheel and smallest rear sprocket. The axes of the jockey wheels on the rear derailleur should line up vertically (or close to vertical), one above the other, with the line perpendicular to the ground. See Figure 1 above.
Figure 2. Tautest Setting Check.

(b) Tautest setting check. Change shift levers so that the chain is in its most taut setting, that is on the biggest chainwheel and also the biggest sprocket. If the chain is too short, this setting cannot be achieved without something breaking! Although the big-big combo should not be used in practice, I think it's very important that it can be engaged, or damage could occur when shifting into that setting accidentally. The rear derailleur will be angled forward and the chain should show at least a slight S bend as it goes around the jockey wheels. The chain should not be too stretched out through the wheels. See Figure 2 above.

(c) Slackest setting check.
Change shift levers to put the chain on the smallest front ring and smallest back sprocket. The rear derailleur should be coiled up, the chain should Z bend round the jockey wheels. There should be minimal slackness in the bottom run of the chain and no interference between jockey wheels, derailleur arms and the free runs of the chain. Again, the small-small combo should not be used, but it needs to work without fouling or excessive chain slackness. (Figure 3)
Figure 3. Slackest Setting Check.

Ideally, the chain should pass all three length checks, but the Tautest and Slackest ((b) and (c) above) are the most important ones! Doing them all gives me a clear idea as to whether the current chain is the right length, too long or too short.

3. Decide which chain to buy. This means thinking about its size, type, brand, quality and joining method. If I know the bike is going to be muddy and wet frequently then I would go for one with corrosion resistance - e.g stainless steel, or at least nickel or brass coated. I choose the speed and the brand, the big boys are Campagnolo, KMC, Shimano, SRAM and Wippermann, and then there are a whole host of smaller suppliers. I've tried all of the big brands and have found something to like in each of them. How do I choose the type? Well, past experience is a good guide, as are the views of others, although I don't always agree with them! Generally, I find that very cheap chains tend to be poor quality, deform easily and wear out quickly. Price is a big factor. Another is the joining method - personally I like SRAM powerlink/powerlock connectors (you pinch them), but they are not the only option for quick links. Joining with rivets is not a problem, but is less convenient for taking the chain occasionally for cleaning or access.

4. Remove the old chain. In step 1 above, I checked whether there was a joining link, right? If there's no quick link joining mechanism, I'd resort to a chain tool. It needs to be a suitable size (and speed) for the chain - it's basically a rivet extractor that uses a screw mechanism. Clean up the derailleurs, chainwheel teeth, cassette and any other bits that need sprucing up. I lube the derailleurs at this point because access is easy.

5. Cut the new chain to the right length. Measure, measure and measure again before cutting! If the original passed all three length checks, then count its links (do it a few times to check!) and cut the new chain to the same length. Otherwise, I use the Shimano length check (see 2(a) above) and/or the following easy one:

(a) SRAM length check. Put the chain on the biggest chainwheel and biggest sprocket. Do not run it through the rear derailleur. Take up all the slack and bring the ends together tight. From where the ends would join up, add a further 2 links and the powerlink. This usually works, but it may depend on the on the derailleur design, so be careful - I use the SRAM length check and/or the Shimano length check just to establish an initial guestimate (see Figures 1 and 4).

Figure 4. SRAM Length Check.

6. Join ends and do the three length checks. This is where a quick link is great, because I can connect the chain, test it using the Tautest setting and Slackest setting length checks above, and if necessary change its length, taking apart and re-joining easily. Note that 10 speed SRAM powerlock connectors are one time only, whereas 9 and lower speed powerlink ones can be re-used. When joining Shimano chains use their special joining rivet and remember to check the manual to ensure it goes in the correct orientation in the link. Whatever the manufacturer, read their instructions for connecting and adhere to them.

7. Lubrication and cleaning. I leave the manufacturer's lubricant on the chain for as long as I dare. Keep the chain clean and lube it only when it's clean and dry - because dirt can act as a grinding paste in the oil. If you clean with soapy water, then make sure you wash it off thoroughly with clean water, because many soaps (e.g. washing up liquid) contain salt, which stimulates corrosion! Degreaser, paraffin, white spirits are all possible cleaners depending on the state of the chain. I use one of "the boss's" discarded baking trays as a washing pan for the chain. Let it dry off well.

Chain cleaning and lubrication is a subject that can generate much discussion and spark heat among cyclists! There are many different schools of thought on it. I find that astonishing for an invention that's well over a century old! Personally, I oil each link joint on the inside of the chain (that's the side closest to the chainwheel teeth) along the bottom run of the chain. That way it does not go all over the place, only to where it's needed. Then rotate the pedals backwards a number of times to work the oil in. Wipe off excess oil along the chain using a clean cloth - I put my hand in an old soft sock and hold the chain while pedalling backwards. I agree with the experienced time triallists who tell me that a clean, oiled and unworn chain is worth many seconds in the race of truth!

Single speed or hub gear bikes

The general objective and thought process is very similar to that described above, but since there is no sprung derailleur and only one sprocket and chainwheel, setting chain tension can be tricky. So note the following additional point:

8. Look for tension adjustment. When assessing the chain's condition - along the lines described at 1. above - I would also inspect the bike for methods of chain tension adjustment. For example, by sliding the wheel axle back and forth in the rear dropouts, an eccentric bottom bracket system, a chain tensioner or even a jogged link (half link). Indeed, it may be worth considering a half link chain (that's one made entirely of jogged links). This could be handy where there is little other provision for chain tension adjustment. They also look dead cool!

There's something therapeutic about a new, or freshly cleaned, chain. It feels cathartic to ride off on the bike afterwards - not to mention a little nippier!

Thursday 15 July 2010

Renovating a Raleigh Twenty: Part 5 - Chain

I decided to break the old chain at the half link. Although I'd cleaned and oiled it and it was ok in practice, it was stretched/worn beyond acceptable limits. I counted 93 links in the old chain.

Then I attached a fresh half link to the new chain. I'm replacing with a Wippermann Connex 100 1/2" x 1/8".

Here's a photo of the chainwheel (which as I mentioned earlier I'd straightened a tad). The cotter pins are new and I had applied just a little grease on their flat faces in a bid to prevent them seizing up in future. I tapped them in, rode it, tapped them in again, rode it and finally tapped in again and tightened the nuts. I'm happy that they are in properly now, but not stupidly tight.

The connector link is now in place. This is really so much easier than using a chain tool to re-connect. There are 93 links in the new chain too.

The outer plate goes on next.

The spring clip is then placed in position. With a screwdriver, just slide it so that it clips in place. NB: A reader, JJ, pointed out that the clip is the wrong way around. I think he's right! The closed side should be facing the driven side of the pedals - I must have been confused because the bike was upside down. However, it doesn't matter now, because since then, the bike was stolen from my student cousin to whom I loaned it.

The joined chain. Lovely! One thing I noticed is that since the wheel axle is now nutted a bit closer to the chainwheel (because the new chain is shorter than the old stretched one), the gear cable tension had to be re-set. It didn't take long, but I hadn't thought of that effect of the new chain.

Anyway, she rides so much better now. I could feel the increase in efficiency first from the serviced bottom bracket and then another incremental improvement with the new chain.