Bike frame material: Is steel better than aluminium, carbon, etc?

Which is the best: steel, titanium, aluminium alloy or carbon? For that matter, what about bamboo and wood?!

Such questions have vexed bike designers for many decades. This post is not about the relative merits of each of these materials for bike frames, as there is plenty of information about that already (one of my favourite resources is here). Rather, I give my views on fitness for purpose and ride quality. I used to believe people who said that aluminium gives a harsh ride, until I bought a good alloy road bike, alloy front forks and thoroughly tested them in cyclocross. In my view, in practice, neither were harsh. I used to believe people who said the type of steel tubing really matters, and those who said 531C is the best, until I realised that it is not that simple. In the 1990s 7 steel bikes, identical except for the tubing, were built and blind tested (see this fascinating article). After much riding and reflection, the reviewer commented that the differences between the steel alloy bikes were very subtle - really rather minor. 

There are many ways to create a bike that works well and suits its intended purpose. Factors such as weight, shape, stiffness, tyres and saddle have a huge impact to how a bike works and feels. Ride quality is determined by so much more than frame material. I think there is a good way to look at this. First of all, think of all the things that make a bike efficient. What makes it go further, faster for less work input by you, the engine?! Then list the things that make your life on the bike more comfortable. After doing that, note that some of the comfort enhancing aspects serve to reduce efficiency, but even so, the increase in comfort may be worth it. So here's what I mean:

EFFICIENCY FACTORS

1. Bearings smooth. To put it another way, a jammed wheel would give atrocious "ride quality"!

2. Stiffness. Frame doesn't flex around when you push the cranks, descend at speed or turn

3. Wheels don't wobble, hop, or flop

3. Tyres have low rolling resistance 

4. A decent engine: rider has appropriate fitness and technique (my grandma ain't as efficient as Bradley Wiggins!)

5. Shape and size

6. Fitting is good, proper muscles engaged

7. Clipless pedals

8. Light weight

9. Aerodynamic

10. Components function efficiently 

Some of which work against the following:

COMFORT FACTORS

a. Tyre size and pressure - fatter, softer are more comfy

b. Saddle type

c. Suspension, whether through flexy frame or actual springs/dampers (which also add weight)

d. No nasty resonant effects - from high frequency teeth rattling vibrations, to scary front wheel shimmies

e. Relaxed seating position and rider view point

f. Contact points feel nice, allow subtle body shifts and position adjustments while riding

g. Components are convenient and comfortable to use

I hope you can see where the frame material fits into this. Basically, it contributes to 2, 8, a bit of 9, c and d. But any of the other factors could ruin the rider's experience of what is otherwise a great frame. Thus, all of the materials listed at the start of this article may be used to make a lovely bike frame that functions very well  - but only under particular conditions. Heavier tubing will make a stiffer bike. Both the load lugging touring cyclist and the road racer want a light, stiff bike but suitable frames are not the same in each case. Carbon fibre is great until it gets whacked or even scratched, when a small defect could make it dangerous through risk of catastrophic failure. Bamboo is natural carbon fibre! Modern super-steel alloys like Reynolds 953 undoubtedly make light, comfortable, strong, stiff, corrosion resistant frames, but so can carbon fibre composite, titanium and aluminium alloys. To underline my point, last season, Zdenek Stybar and Ian Field (world and national cyclocross champions) both used aluminium alloy bikes, while many of their world class competitors opted for carbon frames, but I don't know of any champion racers who used a steel frame. 

Ideally, your choice should be a personal one, based on real evidence and your preferences after test riding. After all, you will be riding the bike, not the person who gave their opinion on the frame material!

Toe overlap

Is it a disaster if you have toe overlap?

Obviously, wearing winkle-pickers on a small bike with mudguards does not help! But usually, a bit of overlap is not a disaster, because for general riding, steering inputs are small. However, toe overlap can be very irritating, especially at slow speeds where handlebars are turned more. For me, the worst situation is climbing a twisty road. I'm out of the saddle, putting the watts down, going round a hairpin bend, when whack! At worst, I could fall off.

Over the years, I've developed a sense of the front centres measurement that allows my toes to clear the front wheel. Front centres (FC) is the distance from the centre of the bottom bracket to the centre of the front wheel axles - measured very simply with a tape measure. For me when FC~595mm, then I know that in normal cycling shoes and tyres up to 28mm, toe overlap may be marginal. That is, it may be present, or it may not! I also know that when FC~600mm, clearance is more likely.

If you have a bit of toe overlap and want to get rid of it, you could try changing a few things, for example:

• move your cleats forward a bit, but of course, this may affect comfort
• use narrower tyres
• change cranks to shorter ones - not an ideal solution for a few mm gain
• more radical would be the change the front fork to one with more forward rake

So, toe overlap is not a disaster, but it can be irritating and possibly dangerous. Personally, I don't like it. I try to ensure that there is no toe overlap on any of my bikes, but that said I will keep a bike that I enjoy even if it has a slight toe overlap. 

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!

Are integrated headsets inferior?

I don't think so. I'm talking here of fully integrated headsets, where the bearings drop directly into the head tube with no pressed cups to sit in.

In 2002, Chris King published an article called Integrated Headsets Explained which vigorously attacked these kinds of headsets. In his view, they were a flawed design. Note however, that his firm were not producing any, so a cynic might say that he was attacking a competing product type. There was a hot debate about them in the years that followed, for example here. Many took Chris King's side and I can understand that, because his products are lovely and he clearly knows a thing or two about headsets. However, many did not agree with him. At that time, I stayed on the fence, not really knowing who to believe, but more importantly, looking for evidence supporting either side's arguments.

Since then, I've used integrated headsets a lot. After riding them for some years, I've no issues to report. On the contrary, the ease of fitting, smooth running replaceable angular contact bearings, and the clean finish are all superb benefits. Indeed, nowadays, many top notch frames are designed to take them, Colnago, Hope, Cane Creek, FSA, Ritchey and other great bike brands make them.

Most importantly to me, I haven't found any evidence that proves Chris King's allegations against the integrated headset design. In my opinion, for any kind of headset, what really matters, is how well it is fitted, adjusted and maintained.

Peugeot Lautaret single speed project

She's on the road, posing on the verge! These photos were taken on her maiden voyage. The roads were wet, but there was late evening sun. More later, including build details.

She feels light and lively. Just like any lightweight steel frame actually. But the thing that struck me most was the quietness while pedalling. As your legs turn the cranks there's no noise as the chain does its thing. 

Butyl or Latex inner tubes?

I thought it would be fun to write short opinions on technical subjects. Here is the first one.

Latex tubes roll better than butyl ones. The improved rolling resistance is measurable, quantitatively, for example here. The improvement is real, but relatively small - you could achieve comparable rolling resistance reduction by pumping up the tyre more, or through changing tyres. The competitive edge of latex will be of use to the really top flight racing types. The rest of us have much more to gain through training and improving aerodynamics. There is no weight penalty between the two types of tube, because lightweight butyl tubes are available that compare well with latex ones in grams. In qualitative terms, I find latex tubes more comfortable. They have a wonderful "squishy, yet fast" feel to them. In contrast, butyl tubes give a "harder, harsher" ride. Another factor is that latex tubes need to be pumped up more regularly - pretty much every day - as they do not retain air as well as butyl tubes. I've also noted an odd wear issue with latex tubes. See the photo below which shows some kind of plastic deformation on the inside of the tube - I never figured out the cause.

I had to chuck this one after just a few months use, despite the fact that I had run butyl tubes in the same wheels and tyres for much longer with no issues.

So, if you want fast, comfy tubes with improved rolling resistance and can put up with the extra maintenance hassle, then go for latex. But if you can't be bothered with the extra maintenance (both in terms of time and expense), then stick to butyl.

Cutting a steerer tube

Before and after photos of the steerer on my Iceni TT bike. It was too long, but I wanted to leave some spacers above the stem, in case the bike ever is converted back to a road bike. Before:

 After. Now that's much safer!

 

After removing the required number of spacers, I scored the steerer tube. Then put the pipe cutter in place, 3mm below the scored line. 

 Had to remove the stem in order to be able to rotate the pipe cutter.

 

Took the fork out (carefully placing the headset parts on a sheet, so as to not lose their order). Then, knock in a new star fangled nut. I use an old screwdriver in the hole, but there are great dies for it. Also, when hammering it, I support the fork in my hand under the crown. That way, you are not risking hammering when the forks are braced against the ground!

 I love this top cap. I had a Ritchey one before, but this looks way cooler. I'll need that when I'm sweating on top of it during my next TT!