Showing posts with label folding bikes. Show all posts
Showing posts with label folding bikes. 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! 

Sunday 7 August 2011

Time Trial on a Raleigh Twenty and a steel Iceni

I decided to revamp the Iceni into a dedicated TT bike. I enlisted the assistance of AWCycles who did a great job (I can highly recommend them). It cost me around £200 to do that - see photo above - whereas a new TT bike would've cost ten times that price. She weighs in around 10.4kg and my best 10mile TT so far on her is 25:51. Whereas the TT mean machine below weighs 16.0kg!!

I fitted basic new tyres to the £25 Raleigh 20 (Stowaway model), an alloy seatpost, modern saddle, but everything else is as original. I rode this bike, exactly as shown in the photo above, in a 10 mile TT, clocking 31:28. Great thing about riding a shopper at an evening club TT is that it seems to cheer everyone up! Afterwards, I did catch myself thinking "Sub 30 min is possible if I lower the bars to get more aero, fitted alloy rims, slicks, service the bb and hubs, new chain, lose the rack, mudguards and kick stand, etc... :)

Saturday 5 March 2011

Raleigh Twenty: Sturmey Archer Hub Gear Cable Adjustment - Indicator or Toggle Chain

People have asked me how to adjust the gear cable on a 3 speed Sturmey Archer hub. Indeed, some folks are a bit perplexed by the dangly chain bit, knurled parts, and the somewhat "mystical" operation of the whole affair. This sequence of photos attempts to explain cable adjustment in easy steps. So, assume you've picked up a Raleigh 20 or other bike with a 3 speed Sturmey Archer hub gear. This one is from 1980 (pictures in a previous blog). I'm also going to assume that the short chain part shown below, called the "indicator", is the right type for the particular hub. Why it's called an indicator will become apparent later.
First step is to loosen the knurled nut at left in the photo above (untwist it a few turns). Then undo the knurled tube connector (far left in the photo above). Once disconnected, carefully take the plastic cap off the axle nut, to leave what's shown below:
Now, the dangly chain part is the indicator. The part on the left still attached to the cable is what I'm calling the knurled tube connector - it's also called a "barrel nut". Grab the indicator by the chain, lift it gently (upwards in the photo) and untwist it carefully from the hub. Hopefully, it will be free to turn. Take it out and clean it up using, degreaser or whatever you like really.

It's worth looking at it carefully - see below. The tip (top right) is shaped into a cone - this is to assist when screwing it back in. Then there is a uniform rod, the chain, the threaded part on which runs the knurled nut and the knurled tube connector (not shown in the photo below):
Grease both threads. Oil the chain links. Put the gear thumb lever in 3rd (top gear) in order to slacken the cable. Then insert the tip back into the hub and tighten it very slowly and gently. When you feel it become just hand tight, then unscrew it by half a turn - no more. Put the plastic cap back on and tighten the knurled tube connector back on to the threaded rod of the indicator. A few turns is fine initially. Now put the thumbshift lever into 2nd gear. It looks like this:
Look through the viewing hole in the axle nut and you can see that part of the uniform rod is showing. Meaning that the rod is jutting out from the end of the axle tube. Now, the aim is to get that uniform rod end LEVEL with the end of the axle tube. Turn the knurled tube connector one way, and see what happens:
In this case, the rod has come out even more - see the yellow arrow above. Now you can see why it's called an indicator, and what the viewing hole in the axle nut is for. So, turn the knurled tube connector the other way...
In the photo above, the rod has gone inside the axle tube. Remember, you want it level with the end of the axle tube. Just to reiterate, the thumb shifter must be in 2nd gear while you do this adjustment - which is in essence cable length/tension. Keep twiddling the knurled tube on the threaded rod until it is level, like this:

Now spin the pedals a few times, change gear up and down and back to 2nd, and re-check that the indicator rod is level with the axle end. Then tighten the knurled nut against the knurled tube connector, to lock down the cable length and replace the plastic cap, thus:

Go ride! It should all be hunky dory now, and shifting should be fine. If not, it probably means that the indicator is not the right one for the hub. You can sort that out by getting the right one from a good supplier, like Oldbiketrader, or if not, then you have to adjust it by careful and gentle testing. If you end up having to go through the testing route, remember that the cable should not be too tight in first gear - you may feel too much tension at the thumbshift lever - and gears should change smoothly, with no free-spinning in second. You should be able to see the uniform rod on the indicator moving in and out as you change gears. That indicator is also known as a TOGGLE CHAIN, and here's a great site for cycle touring and hub gear afficianados:
The planetary hub gear was a wonderful invention!

Thursday 16 December 2010

Tyres: Raleigh Twenty 20, Shopper, Stowaway, Triumph 20, BSA, etc

Most Raleigh Twenty bikes had ISO 451 diameter wheels. Despite the 20 name, this is closer to 21" than the common 406 BMX size wheels. So, is there a decent selection of modern tyres to fit the Raleigh Twenty wheel (451 diameter)? I've been looking out for them and here is a list (if you know of further ones, please post a comment with details - thanks!):

KENDA
- Kompact (hard packed race)
- K-West (road, commute)
- Small block eight (photo left: hard packed race and trail, well regarded by MTB and cyclocross riders)

MAXXIS
- Drop the Hammer (hard packed race)
- Holy Roller (pavement and hard packed race, staggered block pattern, see photo below)


PANARACER
- Minits Lite (fast road, commute, baldies pictured at the end of this post)

PRIMO
- Comet (fast road, commute)
- Champ (file tread)

RALEIGH
- Record (traditional)
- Shopper (traditional)

SCHWALBE
- HS110 (traditional style)
- HS371 Mow Joe (knobbly, photo below)
- HS377 Road Cruiser (heavy touring, 457, not 451, but would probably work)
- HS399 Durano (high mileage road)





SHYH HWA
- Traditional style 37-451 (SJS Cycles ebay shop)

TIOGA
- Powerblock (bmx racing)

Most of these are either 28-451 or 37-451. You can get full details from the manufacturer's websites. As to retailers, you would have to search around, for example: Chainreactioncycles, SJS cycles, Winstanleys, Dereks Cycles on ebay, West country recumbents and Mailorderbikes, to name just a few.

Rejoice in your rubber!

Chuck

Wednesday 1 December 2010

Dahon Wheels but better

I ride a Dahon folding bike regularly. However, the factory wheels have been problematic. Every few months I break a spoke. I'm no spring chicken, mind you. Total weight including baggage in the morning is under the 105kg specified max for Dahon bikes, but not that much under!

So, I tried to find a solution. And I think I may have found one. Paul Hewitt Cycles. They have a great reputation for wheel building. I sent them my Dahon wheels and for a reasonable fee, they serviced and re-built them for me. Apart from spokes and bearings they re-used all the parts that I sent them. Yes, a re-cycled cycle wheel.

I've been riding it for about a month and it has been superb. No broken spokes. Also, an improvement I didn't expect - a more planted assured feel to the ride! Highly recommended.

Saturday 30 October 2010

Renovating a Raleigh Twenty Again: Part 1 - "new" machine

UPDATE Feb 2012: I've given this vintage Raleigh Stowaway folding bike (Raleigh Twenty style) away to a relative for use as a commuter. Eventually, when it returns, I'll strip it and get it powder coated probably in DARK PURPLE....lovely...

For a paltry sum, I picked up another Raleigh 20 folder. This time she's a yukky beige STOWAWAY. Frame number and hub stamp indicate that she was made in Nottingham in the Summer of 1980. This was the time of Blondie (Call me), Michael Jackson (Off the wall) and Pink Floyd (The wall). Lots of photos below:









Thursday 15 July 2010

Raleigh Twenty on a train

Well, she's not as small as a Dahon and nowhere near the compactness of a Brompton. Here, I haven't dropped the handlebars, or seatpost, so the folded package could be smaller than in the photo. Definitely useable, but not in a busy train I'd suggest. Fairly easy to fit inside the boot of an average car - I have managed to pack both a Dahon Speed D7 folding bike and this Triumph Twenty into the boot of an estate car, without the rear seats folded and with quite a lot of space to spare. This photo was taken before I'd changed the pedals and serviced the bottom bracket.

Wednesday 7 July 2010

Raleigh Twenty Links

Here are some of my favourite sites about the Raleigh Twenty:

1. Fabulous Raleigh Twenty to Life site.

2. Sheldon Brown's pages which I am sure are responsible for causing a number people to develop Raleigh Twenty addictions!

3. The history of the Twenty by Tony Hadland.

4. A super site by Hartley Martin collecting information from many Raleigh Twenty owners round the world.

Sunday 4 July 2010

Renovating a Raleigh Twenty: Part 3 - Progress Update

So here is a photo of where I've reached so far. She's ready to roll. For comparison, below is how she looked when I bought her.

So far, I've done the following:

1. Cost of bike: £10
2. Remove kickstand and chainguard
3. Washed her. Removed down tube and seat tube labels. I'm still rubbing off the gummy sticker backing. It comes off with meths and elbow grease - doing it bit by bit
4. New gear cable and indicator protector cap: £5
5. Adjusted gear cable and lubed hub for smooth shifting
6. Dismantled forks and headset, spray frame saver inside forks, steerer and head tube
7. Serviced headset, with fresh ball bearings: £1
8. Changed pedals (I had some in my parts box)
9. Replace front rim and serviced hub: £18
10. New tyres front and back: £20
11. Alloy seat tube (the saddle is one I had lying around): £10
12. New rear brake cable: £5
13. Cleaned front brake cable and fitted new Dia Compe dual pivot calipers (photo below): £12


She's now a real pleasure to ride. Weight has reduced by 1.1kg so far (is currently ~14kg including the rack and pedals). Front braking is very good now and the back brake is satisfactory too. My 8 year old son and my wife love just riding about for the sake of it.

To dos:

1. Rear rim replacement
2. New rear brake
3. Strip and service bottom bracket
4. New chain

Still not sure about replacing the handlebars - they feel so chrome cruiser cool!

Renovating a Raleigh Twenty: Part 2 - Replacing a Bicycle Rim

This is a sequence of photos to show how to replace a rim. Old wheel, new rim a Sun ICI-1 alloy job, some basic tools and some engine oil. The rim is 451 diameter - that's about 21" and is bigger than the normal folding bike 20" which are usually 406. The upside is that pedal clearance stays as original, and being tall, I like the bigger wheels. The downside is that tyre choice is limited.

After removing the tyre and tape, this is what I saw! A rotting rim - definitely dangerous. I wondered whether it was possible to re-use the nipples though. Liberal spray of WD40 to loosen things up.


Quite rusty nipple heads. So, out came the wire brush....


And the wire brush worked wonders. As you can see, I've loosened all the nipples now, so that the spokes are not under tension and I know that each nipple unscrews.

Now using masking tape, fix the new rim next to the existing one, like the photo above.


Tape it up, new rim to old, in a few more places.


Start off by transferring the spokes that are nearest to the new rim. In this case, 28h, that means every other spoke.


After that, start transferring the other spokes. Here at the top left, you can see the first spoke transferred over to the new rim.

All spokes now transferred over. It's now laced up. Cut the tape off and tighten up all spokes so that the tension is even all round. You can use a spoke nipple initial setting tool for that. I don't have one, so I just used a screwdriver to bring the spokes up so that they were level with the bottom of the slot in each nipple. Then felt them all by hand and adjusted by feel. That was how I set the initial tension. It's really important to get that starting point right, because it helps to ensure that the rest of the tightening up procedure goes smoothly.


Before starting to tension the wheel up in earnest, it was time to dismantle the hub. The ball bearings were bone dry, but they were all there and in pretty good condition.

So this is the hub dismantled. A simple and quite well made design, I reckon. One cone moves, the other screws down to a bedding ridge on the axle. The cups were really dirty.

I've cleaned up the cups and all the parts, ready for greasing and re-assembly.


Assembled. All I need to do now is wipe off the grease outside the hubs, put the wheel in my truing stand and tighten it up progressively and steadily.

Here is my truing stand! The stool is to sit on. It's a pleasant and relaxing job, I find. I start off with whole turns on each spoke, then spring the spokes by hand (wearing leather gloves helps for that), and check for hop and wobble. If either are present, remove them. I try to work out why the hop or wobble exists - at early stages, it's normally that one or two spokes are too tight or loose. The idea is to get them all even tension and the rim nice and circular. So after some full turns, then I move to half turns, and finally quarter turns on every spoke.


I use the brake pads as a guide for working out where the wheel needs some work.

The finished wheel, shod and ready for fitting to the bike. The whole sequence above took me about 2 hours in total. It went very smoothly and is incredibly satisfying to build an smooth running wheel that is fast and true. I've now made four wheels in total over the years (two involved lacing up from the start and the other two were rim replacements). This was the easiest and the best yet!

The original steel rim weighed 550g, while the new alloy rim was 320g. That means I saved 230g just by replacing the rim! That's the same weight as a packet of butter rotating around the perimeter of the wheel.