When is frame weight for a Tri bike an issue? Does it differ when comparing to different distances?
anyone?
http://www.cervelo.com/viewkb.aspx#3
All you need to know …
edit: sorry, can’t link directly. Just click on the weight and aerodynamics radio buttons and search. There will than be an article about weight vs. aero with lots of rationale, data and more to read, understand and digest.
Distance doesn’t matter in the tradeoff between weight and aerodynamics; all that matters is course profile. A lighter frame helps if the course is hilly, and or has lots of braking/reaccelerating (ex. criterium style). That being said, a course has to be seriously hilly (we’re talking sustained climbs of several miles over 5% grade) before the kind of weight differences you see between frames makes any real difference. A light frame might be 2lbs., and a heavy one 3.5lbs., so we’re talking about <1% of the total bike/rider weight. Very small reductions in air drag will easily eclipse any weight difference. People tend to like the feel of a light, responsive bike over a heavier one; but it doesn’t correlate with speed very well. Triathletes use deep rims, disks, and aero helmets; all are much heavier than “standard” components, but much faster. All that being said, thanks to carbon fiber lots of bike can be uber-light and still have great aerodynamics, so you don;t necessarily have to make a trade (Scott used to have an ad about how Simoni’s TT bike will a disk and full aero gear clocked in under the UCI’s 15.5 pound limit…he was actually delayed at the '07 Tour of California ITT while they added a bottle cage to get the to “legal” weight). As a general rule get aero first then cut some weight if you can.
Regarding the two Cervelo’s; the pros would ride the P3 for everything but an uphill moutain time trial, even a hilly course like Lanzarote or Wildflower.
Ive asked myself this question a bunch of times when switching from bike to bike.
For TT bikes, I decided the feel of power transfer, acceleration and stability on the road were the main buying points for me.
I test rode an e-112 a few months ago and loved it. I wish it came in black though…
did it feel heavy? The e-114 is a HEAVY bike
The 112 I test rode felt about 17ish.
The E-114 definitely had better power transfer with the solid front end. Both had stiff, beefy rear stays that sold me. If I could afford today, it would be mine.
A e114 with DA 10 in the shop was a tad lmore than 18lbs training wheels seat post uncut, which was fine. It wasnt noticeable on the climbs or flats during the test ride.
Both had responsiveness and ride quality. Match it with aero wheels that can hold speed (i.e. nice hubs, bearings, etc.), it would be a beast!
Good luck,
Keau