Edited by John Stevenson
Confounded by carbon fiber? Need to sound off about superlight stuff? Tech letters is the forum for your gear-related questions and opinions. We'll attempt to answer all questions that don't require a PhD in astrophysics or industrial espionage.
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Quite a few appeals for help in today's mailbag, so hopefully there are some tech-savvy folks out there willing to pitch in with some advice. Chris asks about methods of dealing with different leg length, while Nick Peckio is looking for tips on adjusting his Look cleats, and Jonathan Dunne wants to know if his STI shifters can be repaired.
We've also had letters on Jacques Anquetil's pedalling style, cable routing on cross bikes, disk brakes, integrated headsets and more from the seemingly bottomless well of uses for old inner tubes. Keep them coming!
Leg length
Adjusting Look cleats
Cables & Housing
STI repair
Pedalling style
Cyclo-cross cable routing
Fit and frames
Disk brakes
Integrated headsets
Inner tube tips
Seems like my body was made like a cheapo bike and that might be giving me some fit problems. My right femur is 1/2" longer than my left. Should I use a shorter crank arm for my left leg? Something like a 170 for the left with a 175mm on the right? Or is there a better solution?
Chris
The usual way to deal with this problem is for a fit expert and a mechanic to build up the shoe sole for the shorter leg. We've not heard of anyone using different crank lengths to sort this out, but no doubt there's someone out there who's tried it.
Any tricks to adjusting Look cleats on Sidi Mega 3 shoes. I can put the cleats on but need help tweaking them.
Nick Peckio
Regarding your cable and housing tech advice; a nifty alternative to the aluminium cable end caps to stop cable fraying is commercially available electricians heatshrink. This is a plastic tubing that shrinks on application of heat, and is used to bind electrical cables or wires together. It comes in a variety of sizes, including one perfect for brake and gear cables, and should be available from your local electrical or electronics supply shop.
Simply cut a small length (<5 mm long if you're ultra weight-obsessed), slide it over the end of your freshly cut cable, apply heat (a heat gun is best, but with a little care a clean burning flame will suffice) and, with the miracle of modern technology, the plastic tube shrinks to fit snugly over the cable end. Sure, it probably doesn't offer many advantages over the aluminium end cap, but do you really want the look of a $200 kids bike on your thoroughbred racing steed? And it comes in different colours!! Red, white, or blue, for your USPS replica Trek, lime green for your Kelme team issue Look, clear for your ultralight titanium Litespeed. Not sure if you can get it in pink for your Telekom Pinarello tho'...
With kind regards,
Roger Dungan
Christchurch, New Zealand
I am hoping someone can help with a major problem I have with a pair of Dura-Ace STI levers, unfortunately just out of warranty! Until recently they have worked perfectly, but now I am completely unable to return the front changer (left lever) to the small chain ring. The smaller lever on the left hand STI lever moves but does not have any affect on the rachet mechanism, so no shift. Has anyone had similar problems, are they fixable, and if so what was the remedy? Thanks for any replies and suggestions.
Jonathan Dunne
Edinburgh, Scotland
I have no direct experience of this particular problem, but I know that STI mechanisms can be fixed by mechanics with lots of patience and dexterity. He's a long way from you, but Pete at Avon Valley Cyclery in Bath, Avon used to specialise in dismantling and reassembling mountain bike STI shifters.
Do any readers have any pointers for where Jonathan could get his shifters fixed?
Noel Crowley mentions Anquetil's pedalling technique, and I've heard other mentions of it in the past. Can anyone give a more detailed description of this technique.
John Morley
USA
The best description I have been able to find is this one, by Rod Gardiner of the UK's LVRC:
"More than anything it was the pedalling action that set Maitre Jacques apart; sitting very high in the saddle, his toes were pointed almost vertically down all the time. I challenge you to try it, on the turbo first. Just sit on the bike and 'click in'. Now, lift your heels, both feet, until you can't move them any more and your ankle is 'locked'. Now pedal, without ever lowering your heel - it almost feels like pushing forward, not down. Now's the hard bit. On the upstroke, pull as hard as you can, always without dropping your heel. You will find the amount of pull you've got now much greater than normal. Start to increase the intensity. After a few minutes, your calf muscles will give up.
"Anquetil himself reckoned that without toestraps - i.e. being unable to pull - he would have lost 5kph, because he pedalled like that all the time. ALL THE TIME. Now if you can do it, maybe you can ride as fast as he did in a time trial. "
For routing the front brake cable on small cross frames or handlebar stem configurations that have small distances from the underside of the stem to the cable hanger: run the cable up over the top the handlebar where it exits the handlebar tape and let it drop behind the handlebar to meet the brake hanger. That way the cable will not have to curve so much. Also look for a front brake cable hanger that has a lot of drop rather than one that sticks straight out from the headset.
Mark Legg
USA
Tim Rutledge from Redline here (Product manager of Redline Cyclo-Cross bikes since 1994).
We have used a Tektro 1272AF cable hanger stop for five years or so. I assume you are having trouble with the radius/bend of the front cable & housing. The Tektro cable stop solves this problem, & allows for quicker assembly/disassembly when travelling, plus we customize our race team bikes by drilling out the stop to fit an alloy adjustment barrel, so you can adjust your brakes to different rim widths.
I see that the Kona team has also adapted this method too. It still gives plenty of room for the cable carrier to pull-up, & mud clearance is not sacrificed because this all sits above the bottom of the fork crown. I suggest further modification to this stop, file the two top knobs off to make the stop sit exactly parallel to the head tube, this also causes it to grip the fork better & not slip around. The Tektro cable stop is designed for front or rear applications so it has the knobs for installing on a rear brake bridge.
Tim Rutledge
SBS-Redline
When you need something unusual, custom is great. My 54.5 cm bike has a 59 cm Top tube. Great fit. For me.
Luc Hamel
Canada
Don't forget that you can run road/cross sized rims and tires! They will fit since the circumference will be about the same as a pair of fat MTB tires. They will make the bike ride a lot better than 26" 'street' tires. And, for your own good, stick to the same type of hubs, or check the fit before you have the wheel built up.
Johan Kejler
Sweden
I'm not sure why a 700C tyre would ride 'better' than a slick 26in tyre, but it's certainly true that there's room in a mountain bike frame for a 700C wheel, as long as you can figure out some way to hook up the brakes. A disk-braked bike definitely offers this possibility, and has the advantage that fitting a 700C wheel with fairly fat tyres, say 28mm or 32mm (if we're talking commuting comfort) will slightly increase the gearing compared to a typical 26 x 2.0in set-up. That's definitely an advantage over fitting 26in slicks, which tend to be smaller than knobbies, reducing your gearing exactly when you need it to go up.
You will need identical hubs on the new wheels, and separate rotors for them as well. These bolts are not bolts you want to be installing and removing over and over. It will stress the material in the hub, rotor, and bolts, and over time is a really bad idea.
You will also need to purchase an inch-pound torque wrench if you were going to change them often, and that ain't cheap.
Michael Sylvan
Seattle
The C40 head tube is also a (carbon) lug for the top and down tubes. Something has to give even on a C40 so maybe the tubes were just ripped out of the lug? What happened to that bike anyway?
Kjetil Haaland
Norway
The market's a guinea pig. Integrated headsets are nice, but in the long run, how would a light aluminium frame handle it?
I'm lucky enough to be sponsored on dirt. I change bike yearly. Imagine the pros. At the slightest wear, new equipment come in. Integrated headsets look very nice. But for the long run, I'll let the guinea pigs check it out.
Luc Hamel
Canada
Road Tubes for 18-23c tires (particularly the heavy-duty butyl ones) make a perfect replacement for the rubber pads on which rests the hood of my 1973 Toyota Land Cruiser FJ40....
Brad DeVries
Squadra Coppi Racing
That clear film seems to wear through after a month or two of riding-with me at least; my best success protecting the frame from cables has been using the "furry" part of Velcro. Cut small pieces of self-stick velcro and stick them to the cable and it seems to work nice. Obviously don't use both parts of the velcro, just the furry (loop?) half.
Julio
I live in Canada, I'm used to the wet & cold too. I tried the trick for the headset. I destroyed my headset doing it. Moisture can't escape and it rusted in no time. Lizard Skins are neoprene and they breathe.
Luc Hamel
Canada