Racing with your powertap wheel.

Thorman

If you go to analyticalcycling.com and run one of his calculators for weight on a hill climb you'll see just how insignificant a few hundred grams matters on most climbs you'll encounter in typical cat races in the US.

At just about every race I've been to you'll find racers lined up to "unload" more than a few hundred grams before the race so if you're that worried about it just get in line and do your business before the race.

I've found that having a set of Zipp 404 tubulars with a PT hub and another set of OP's for training is a good option for both aerodynamics on race day and durability while training during the week.

RapDaddyo

I agree. That's my 2nd choice, if I have problems putting together my HED3 (or just run out of time).

beerco

Scott,

I've read some stuff on your site and your posts here and say I'm very impressed with your evidence based aproach to training.

That being said, I'm very surprized that you picked tubs for your race wheels. What gives?

Thorman

I actually didn't stumble onto that data until this year, but based on it and a few short tests I've done I'm thinking about another tire option, especially since my rear Tufo has a hole in it right now.

Here's a very short test I did a while back. based on the data I posted to Topica a few months ago, the % difference between the Michelins and Tufos should be around 3.7% (I think the data came from Road magazine) and my test proved to be 3.2%.

I'm not sure what the repeatability is of a PT so this one time test is really nothing more than a comparison of two data points.


Comparison holding speed

Tufo S33 Special Tubulars:
Duration: 1:08
Work: 8 kJ
TSS: 0.2 (intensity factor 0.356)
Norm Power: 116
Distance: 0.292 mi

Min Max Avg
Power: 77 174 124 watts
Heart Rate: 97 106 101 bpm
Cadence: 53 88 68 rpm
Speed: 15.1 15.8 15.5 mph
Torque: 32 74 52 lb-in

Michelin Pro Clinchers:
Duration: 1:11
Work: 8 kJ
TSS: 0.3 (intensity factor 0.368)
Norm Power: 120
Distance: 0.302 mi

Min Max Avg
Power: 44 185 120 watts
Heart Rate: 99 118 105 bpm
Cadence: 51 114 69 rpm
Speed: 14.8 16.2 15.5 mph
Torque: 18 77 50 lb-in

peterpen

It's worthwhile to note that this is comparing some of the worst (for rolling resistance) tubulars and some of the best clinchers. The performance of something like a Veloflex Carbon or even a Vittoria Evo CX tub appears to be much closer to the Michelin clincher.