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Tech letters for June 10, 2003 - Answers #2
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.
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Campagnolo ten speed
Frame upgrade
Lance's bike at L-B-L
Mavic Helium Rim
Mavic Paris-Roubaix SSC rims
Pedals
Transporting carbon bikes
Wearing out tyres on trainers
These subjects were originally raised or last discussed in our last edition's questions or answers.
Campagnolo ten speed #1
In general you should try and use a gear that gives the straightest chain line. Typically there is a lot of duplication across the gears and you can get almost the same ratio using different combinations of front and rear gears. If you find yourself in the middle front ring and heading down to the smallest rear, then it's usually better to change up on the front and back and get a better chainline.
Frank Drennan
Wednesday, May 28 2003
Campagnolo ten speed #2
Although my setup is 3 steps lower than your setup - Devinci frame + Veloce 27spd - the geometry should be kinda similar. My ear tells me to avoid the biggest cog while in the mid-chainring as much as possible (too much chatter). The smallest cog I use a bit (and the chain deflection is not as bad as big cog), but by that point I can easily shift (from the hoods) into big-ring/6th-cog and achieve the same gear-inch/gain ratio.
As for small & big chainring, I'd avoid the smallest 3-4 cogs and the largest 2 or more cogs, respectively. Your derailleur may not be long enough to take up enough slack w/o chainrub in the small-ring/smaller-cog combos. You'll know when you to test that yourself on a bike stand or with the bike on the saddle & bars.
Leo Quan
Vancouver, BC
Wednesday, May 28 2003
Frame upgrade
This is a very individual question, one that I went through recently. I found that steel, carbon, and aluminum frames all felt very different from each other. I chose the feel of steel to replace my Colnago.
Then I looked at Colnago frames, found one, and almost bought it. I also looked at Strong frames (strongframes.com) and chose that instead. I did this for a couple of key reasons. One is that Carl Strong was willing to work with me over the phone and net -- answering many of the same questions that you asked. The second is that the frame actually fit me, and I can never over stress how much difference that makes! Third, he gave me exactly the ride that I wanted, better even than the older Colnago.
As to comparative weight, the 797 and Dural are good tubes, but the actual weight will depend on other factors as well. For instance: Lugged or not? Fillets inside or not? I would not trust any weights that you found on the net.
The three frames that you mention are good machines, but for real expertise I would suggest contacting someone like Carl and investing a few minutes chatting with him by phone or E-mail. If this is to be your last frame...
Peter Eva
Thursday, May 29 2003
Lance's bike at L-B-L #1
What you saw is Trek's new OCLV road frame. There are better pictures on Lance's website. From what I understand, Lance had been playing around with a compact frame as well as a sub-compact frame. In the end, he chose to stay with a standard set-up, but with some modifications. The current OCLV came out in 1992, so it's getting on in its years and needs an update. I wouldn't expect any groundbreaking low-weight (they already have it pretty light and have to be concerned with lifetime warranty issues), but needless to say it will be one sweet ride. Can't order one yet, they don't even have a part number yet!
Evan Solida
Emporia, KS
Wednesday, May 28 2003
Lance's bike at L-B-L #2
It's a new design from Trek that will probably designated a 5900 next year. Its an all new design using a new carbon fiber and uses technology to design it similar to the time trial frameset. You can see pictures in Cyclingnew's archives or at Lance Armstrong's website.
Phil Pulley
USA
Wednesday, May 28 2003
Lance's bike at L-B-L #3
"I cannot imagine Lance badging another bike as a Trek (I doubt the sponsor would be happy)."
Lance has done this in the past. Even as late as the 2000 tour, Lance's climbing bike was a repainted Litespeed Ultimate. They even put little bits of putty in the sharp angles in an attempt to give the bike a more rounded OCLV appearance, but if you look at pictures of Lance on the climbs in 1999 and 2000, you can see the difference.
That said, his bikes in 2001 and 2002 were all "stock" Trek bikes (though some of the componentry was obviously not…), so his being back on a welded frame is a little odd.
Matt Herz
Seattle, USA
Thursday, June 5 2003
Mavic Helium Rim #1
You can still get Helium rims from Mavic. I recently rebuilt a crashed front with a brand new red tubular Reflex (Helium) ordered from Mavic USA. It was over $80 though.
Jeff Werner
Massachusetts
Wednesday, May 28 2003
Mavic Helium Rim #2
Tubular Heliums use a Mavic Reflex Rim. Mavic only make a 32h and 36h rim these days.
Mark Rishniw
USA
Wednesday, May 28 2003
Mavic Helium Rim #3
Andy
I saw Helium rims this weekend at a shop in Alsfeld Germany. Just the rims that is. Try the shop's website www.neon-radsport.de or mail Marcus at info@neon-radsport.de.
He may be able to post them or even put you onto a source for them.
Also, apparently the Open pro rim is in fact a the same as a Helium rim(I may be wrong on this one).
Pierre Naude
Wednesday, May 28 2003
Mavic Paris-Roubaix SSC rims #1
Ebay is the best place for SSC rims. New and used rims are often available. If you're planning to ride on the rims regularly, go for more recent rims with yellow Mavic labels. The rims are great for specialist rides - I rode a pair at the amateur Tour of Flanders with no problems.
If you're looking for the ultimate, go for the much rarer but slightly wider version. They're designed for Special Pave tyres used in Paris Roubaix and Tour of Flanders.
Jerry Teague
London, UK
Wednesday, May 28 2003
Mavic Paris-Roubaix SSC rims #2
They are at La Bicicletta - www.labicicletta.com
Doug Smith
Bonny Doon, CA
Thursday, June 5 2003
Pedals #1
While I have not tried the Shimanos, I can tell you that the Speedplays are all I will ride with from now on. I spent 12 years on the original Time pedals, which I thought were great, then a season on the Ritchey SPD's (not as great). Speedplays are super light (less than half the weight of Time), best cornering clearance, easy to maintain, affordable (again, much less than Time), and are perfectly secure in the sprints. Plus, for those who appreciate float, it is the most free floating feel out there. Or, get the 'Zero's, which can be adjusted or locked out. You'll be glad you did!
Jeff Harr
Thursday, May 29 2003
Pedals #2
I am curious about this question because for the first time since 1988, and the subsequent years of cycling, I am having knee pain. In my left knee, and I suspect it might be related to my Look pedals. I am wondering, if there one of the pedal systems with a good reputation for being "knee friendly?"
Bill King
USA
Saturday, May 31 2003
Pedals #3
None of the above. Campagnolo pedals are a cut above any of these pedals.
Keith Shuey
Saturday, May 31 2003
Pedals #4
Dura Ace. No question. I just switched and they are much easier to use and much more secure feeling.
BD
Wednesday, May 28 2003
Transporting carbon bikes #1
I have a carbon Giant and use a rack that holds the complete bike with wheels attached and a clamp around the downtube. I have used it to and from a race only twice so far with no problems, but perhaps the question should be put to Giant re warranty exclusions?
Dave Coultas
Melbourne, Australia
Wednesday, May 28 2003
Transporting carbon bikes #2
I'd recommend using a fork-clamping rack, either a roof or trunk mounted type. If your fork fails due to the minor stresses of the bike swaying on the car, you have much bigger things to worry about as that fork is defective! A normal fork should be able to handle tens of thousands of pounds of clamping pressure from the skewer as well as hundreds of pounds of force from you hitting a pothole while riding your bike - a ride on a rack shouldn't affect it unless you drive incredibly aggressively a la Mad Max (and even then…). To be honest I have seen forks fail while on a rack. One scenario is the bike hits a low object (bridge, tree branch, garage door entrance, etc) and rips the whole rack off the roof. The other scenario is when the fork clamp is improperly tightened and the bike falls sideways, cracking, bending, or breaking the dropout in the process.
A high quality frame clamping rack is perfectly usable as well, but the user must take care in clamping the frame correctly. In a nervous or oxygen-debted state it's easy to make a mistake and overclamp your frame. Keep in mind that if the wheels are securely fastened to the rack and the frame tube cannot "get out of" the clamp, the bike will stay on your rack. However, be prepared for cosmetic damage to decals, clear coat, etc. As a general rule frame tubes should not be clamped if only for cosmetic reasons, whether for transportation or other purposes, i.e. a workstand.
If you look at a pro team car, they usually use both types - frame clamps on the outside, fork clamps in the middle.
Aki Sato
Thursday, May 29 2003
Transporting carbon bikes #3
All bikes should be able to be transported on car roof racks in equal safety. If the fork ends came out, then they would have come out anyway whether on the roof rack or riding along. As for the cracked down tube, I would guess that that was due to an ill fitting or too tight a clamp, ie user error! It takes quite a big force to crack a tube, so someone must have been a bit overzealous with their clamping. You don't need to tighten it that tight, just enough to be snug. On the very rare occasions mine goes on a roof rack the part where the clamp goes around the tube I protect it with thick cloth or similar - this ensures that the clamp isn't too tight & stops it from scratching the tube where micro cracks can start. After all that, I haven't ever heard of either of these problems on any sort of bike, let alone a carbon, so these stories you have heard are either urban myths, or very unlucky people!
Paul Thomson
Milton Keynes, UK
Wednesday, May 28 2003
Wearing out tyres on trainers #1
When considering tire wear on a trainer the first impulse may be to tighten the contact between trainer and tire, I found that loosening it is actually better. I experienced rubber deposits being left on the floor under the trainer - a sure sign of wear! Tightening made it worse, loosening made it stop happening.
Of course another option to save your tires is to not use your good ones on the trainer - save them for the regular season, and train/ride on some cheapies during the off-season.
David Connell
USA
Wednesday, May 28 2003
Wearing out tyres on trainers #2
Your best bet would be to get a cheap training wheel with a cheap tyre and use it on the trainer, and simply swap out the wheel for the road.
Mark Rishniw
USA
Wednesday, May 28 2003
Wearing out tyres on trainers #3
I have experienced far too much wear riding my good wheels/tyres on the trainer. I have a Tacx Grand Excel and Ksyrium/Gommitalia tyre combo. I rode these wheels about 200km on the trainer and went for my next road ride and guess what? I flatted! The tread delaminated from the tyre casing. I am told it's from the heat. Whatever the cause, I've learned to ride something else on the trainer, I bought a Tiagra rear wheel and ultegra cassette to use specifcally on the trainer. I use my old tyres that have the tread worn off that I can't ride on the road anymore - isn't "recycling" wonderful?
One thing I notice on the trainer is the heat on the tyre, not only is there constant contact with the steel trainer pulley, but there is no wind to cool things down. It does not take too many race tyres to pay for a cheap wheel and second cassette.
Richard D. Wile
Bedford, Nova Scotia Canada
Wednesday, May 28 2003
Wearing out tyres on trainers #4
Use electrical tape on the tyre to save it. One loop per hour of riding normally does the job.
Richard Riseley
Australia
Thursday, May 29 2003
Wearing out tyres on trainers #5
It is very important to have the roller tight against the tire. If the roller is loose, there will be a lot of friction. You can test this by feeling your tire. It will be slightly warm but any more than that means the roller isn't tight enough. I've seen rider wipe out expensive track tires warming up because they wanted less resistance in their trainer and accomplished this by not having the roller tight.
Jim Cushing-murray
USA
Wednesday, May 28 2003
Wearing out tyres on trainers #6
I've had the same problem. The solution is to pump the rear tyre up to
120psi, or thereabouts. The friction losses are reduced, the tyre runs
cooler and the black powder resulting from tyre wear is virtually
eliminated.
Gary O'Neill
New Zealand
Friday, May 30 2003
Wearing out tyres on trainers #7
I live in the Northeast and ride indoors during the entire winter. In the past I always wore out two or three tyres per winter. Then I found the ChainDriver stationary trainer www.chaindriver.com the trainer is chaindriven and replaces the rear wheel. The resistance is very smooth and I save my tyres and the trainers large flywheel really improved my power on the bike.
Chuck Simpson
Downingtown PA
Friday, May 30 2003
Wearing out tyres on trainers #8
My experience with using an indoor trainer is that the only way to avoid excessive wear on expensive tyres is not to use expensive tyres on a trainer!
Like many UK cyclist I have a winter bike fitted with mudguards, wheels and tyres designed to cope with what ever conditions are faced from October to April and a nice shiny bike with expensive bits used in the summer months.
The winter bike is used on the indoor trainer when it is to bad to go out due to weather or lack of light. The inexpensive tyres - inflated to at least 100 psi - don't seem to suffer any excessive wear. If the weather in Sydney does not justify a complete foul weather bike, use a spare wheel.
David Reid
St Albans, UK
Wednesday, May 28 2003
Wearing out tyres on trainers #9
Wearing out expensive tyres using your indoor trainer? The cheapest option is to buy a cheap tyre and use that on the trainer. A more expensive option is to by a rim trainer.
Anyway, cheer up - Sydney is finally starting to dry out!
Ritchard Longmire
Sydney, Australia
Wednesday, May 28 2003
