Tech
letters for November 2, 2001
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 questions that don't require a PhD in astrophysics
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Contents
Wheels Light, strong, cheap?
What's the deal with carbon wheels and rims?
I'm a 166lb cyclist competing at the national level in Switzerland and
I can't seem to find an answer to my problem/question.
My race bike is a 5500 Trek with Mavic Ksyrium wheels. I would want to
have lighter and profiled wheels while having at least the same stiffness
and durability of the Ksyriums. (The Mavic Cosmics are good but they are
at least 200 grams heavier than the Ksyriums)
I have looked everywhere and found a number of products at various prices
yet none of these ADA, Lightweightwheels, lew (Sydney), Zipp, Corima
(Medium) seem to be durable enough while all the Shimano, Ambrosio
(X-carbo), Spinergy (Xaero), Fir (Antara) and so on are all too heavy,
with the exception of the new Campagnolo Hyperion; slightly too expensive
(USD 3,500)
What's your opinion on my dilemma? Can't I find a decent carbon wheel
which I can take for tough road race (not time trial) without throwing
it away after the finish?
Tom Maxwell, Geneva, Switzerland
Tom, my opinion on your dilemma is to quote tech guru Keith Bontrager:
"Strong, light, cheap pick any two." You want
strong, light wheels, and the only way to create such wheels currently
is to throw some expensive materials and construction techniques at
the problem. And that's not likely to change any time soon. Even when,
say, the Campagnolo Hyperon wheels appear in a form that costs less
than a secondhand car, there will be something else lighter and just
as expensive filling the vacuum at the top of the price heap.
I can't help wondering just how marginal an advantage you get after
spending a couple of thousand bucks on a pair of wheels. As a tech ed,
it's partly my job to encourage this sort of rampant consumerism and
lust for shiny techo-goodies, and I freely admit to suffering a bad
case of tecnho-desire when I was handed a pair of Hyperons at the recent
bike shows. But the older, wiser, practical part of me says that a hell
of a lot of coin that could be 'spent' indirectly on time off work to
train or directly on the services of a really good coach.
Campagnolo steel
Being a gram head, I was wondering why Campy uses a steel plate as the
back piece of the pulley cage on the Record (Chorus also) rear derailleur?
Do you guys know of a way to replace/modify/delete this heavy chunk on
an otherwise perfect component?
Mark Cole 13.4lb Calfee Luna Pro owner
Mark, I suggest you try and bulk up at 13.4lb you're going to
get blown over in every cross-wind, and you have no chance in shoulder-to-shoulder
criteriums.
Smart-assedness aside, just because something is steel, doesn't necessarily
mean it's heavier than it can be. Campagnolo probably uses steel in
that application because for a less dense material to be as strong you'd
need just as much of it in gram terms, and even if you could make thepart
lighter in, say, titanium, it would have to be thicker to be strong
enough. Making that plate thicker is something you don't wantto do -
there's precious little space between it and the spokes as itis.
I'd look for other places to save weight, though I'll keep en eye out
for carbon fiber replacement plates
Reader
suggestions for ways Mike can shed weight from his derailleur are
welcome.
The 10.5lb bike
Re: The 10.5 lb bike: What would
this retail for?
Mike Entwistle
Mike, if you have to ask
Since we can't possibly afford this bike, we did ask. Here's Richard
Bryne's response:
"I do not have a good answer on the price and I like your answer.
The bike went together slowly so I never really added it up (and neither
did my accountant, thankfully). I also don't think Bill Holland would
ever build another bike like this one again. Bill said that it took
him five times longer to build than any other bike he has ever built
(so the frame would probably pencil out at over $10,000 at his going
rate just for starters). Also the url for the Cat Cheetah cranks is:
www.catbikes.ch/
and the Smolke bars are available from Tune
in Germany."
An even lighter bike
I read your article about the lightest road bike presented by Speedplay
with interest. I read however in a French cycling magazine named "Top
Vélo" (September 2001 issue) that a lighter road bike (4.68kg
- 10.2lb I believe) was built and put together by Emmanuel Dehan (the
cyclist) and Fabien Boitelle (mechanic, project manager, French Somec
importer). The specs are as follows:
Frame: 51.5 Somec Dedacciai US Special Series Aluminum
Fork: Aviotech Custom Carbon
Seat Collar: Somec
Headset: Modified Stronglight A9
Stem: 1" ITM The Stem, polished
H/S Top Cap: Dia Compe
Fork Expander: PMP
Handlebar: 42cm (c-c) Carbon Schmolke
Handlebar tape: Somec
Seatpost: Carbon USE Alien
Saddle: Modified Tune Speed Needle
Crankset: Titanium Morati
Chainrings: Pierced 46-tooth Vuelta and 34-tooth TA
Chaniring bolts: Aluminum Omas
Crank bolts: Aluminum
Bottom Bracket: PMP
Pedals: Titanium Speedplay
Rear Derailleur: Campagnolo Record
Front Derailleur: Shimano Dura Ace
Levers: Campagnolo Record rear + Super Record downtube shifter
(front der.)
Cassette: TA Kheops + aluminum lockring
Brake Cables and Housing: Aluminum CLB housing + cables
Derailleur Cables and Housing: Gore Extralight
Chain: Campagnolo 10sp
Brake calipers: Titanium CLP
Wheels:
Rims: LEW Custom Competition
Hubs: White industries (front), Tune (rear)
Skewers: Titanium SRP, no quick releases.
Tubulars: Clément Pista Seta
The guys said it took 2 years to finalize the project, involving up to
thirty people and the goal was to build the lightest bike that you could
race on. They decided to use parts that were known for their light weight
but also their race performance and left out a lot of lighter equipment
for safety concerns. You gotta check out the pierced chainrings though,
and the derailleurs...
Franck Abate
Franck, thanks for that it's good to see there's more than one
mad weight-weenie out there.Does anyone else know of anything lighter?
Sub 10lb perhaps? Let
us know.
Bike weight
Hi, thanks for the Interbike report and the "Weighing up the options"
piece.
Could you tell me, is 20lb for a complete road bike with double chainring
Dura Ace and a steel frame (like 853) and tubular tires still considered
'light' ?
John Stow
That is still considered sensibly light unless you're trying to win
a hill-climb or mountain stage.
The push to ultra-light worries me. I come from a mountain biking background,
and I watched the lightweight fad in mountain biking produce some extraordinarily
dodgy components back in the early '90s, including a 130g aluminium
handlebar that at least one racer sponsored by the manufacturer refused
to use. I still have the scars from a failed carbon fiber handlebar
but happily the magnesium saddle rails and carbon seatpost that also
broke under me back then didn't leave scars.
20lb sounds like a good, reliable weight to me.
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