I don't have the literature in front of me but I'd suspect that in theory the 3sp/disc combo might be more than your estimated 5 minutes faster than the Vector pros based on the wind tunnnel tests. Your best bet might be to look on the Hed site, Kraig Willet's pay site or Jim Martin's bike aerodynamics site. Do a goggle.

My wife races/trains on VP's and is happy with them. She tried a HED Deep/60 combo on windy days and found that it a bit too much for her 118 lbs. Something to consider with the 3sp as a front.

I don't know the gradients of the hills you mention but the extra wt will likely of little significance when weighed against aero advantage. If you know the numbers you can get the theory by using the computer on this site. In general, areo wins out every time except on extreme gradients.

http://analyticcycling.com/

Quote: " In general, areo wins out every time except on extreme gradients."




cerveloguy,

I agree. I think Kraig did an analysis of Chris Horner's? win in a time trial at Redland's one year and his choice of aero wheels and a time trial frame versus a regular road bike. The course had a number of climbs but were less than 6% grades.

According to the analysis, the more aerodynamic wheels and time trial frame were a better/faster choice until the climbs exceeded 6% grades and represented some percentage? of the total ride.

The analysis was pretty in depth and examined a number of what if scenarios after the analysis of the actual conditions. It was pretty neat. A good read for anyone interested in bicycle aerodynamics and an education in real world considerations.

---

Ben Cline


Better to aspire to Greatness and fail, than to not challenge one's self at all, and succeed.

You will benefit far more from the aerodynamic wheelset over the course of the 100 or so non-climbing miles than you will be hurt by the extra weight on the climbs. One to two pounds isn't going to make that big of a difference.

Here's a non-specific model from analyticcycling.com:

Long Climb

Our riders are doing a long, 5 km climb on an 8% slope. Our Standard Rider is on 32 spoke standard wheels. Out Test Rider is on Specialized tri-spokes. Both riders start at the same time with the same initial speed. They are identical in all other respects. Which one gets to the top first?

The Specialized rider would be ahead by 2.5 meters or 0.5 second at the top. Change the slope to a 13% slope and the Specialized rider would be behind by 1 meter.

Here's a fairly specific model I ran for more specific data:

Richter Pass = 11km @ 7% average grade:
- Rolf vectors: ~1,700 grams (3.7 lbs)
- Hed Disc/3 combo: ~2,100 grams (4.6 lbs)
- Rider weight: 160 lbs
- Bike weight (sans wheels): ~17 lbs
- Additional weight (water bottles, spare tires, helmet, shoes, et cetera): 10 lbs
- Total rider weight with Rolfs: ~190 lbs
- Total rider weight with Hed combo: ~191 lbs
- Increase in time to climb Richter Pass using Hed combo assuming an average power output of 250 watts: 14.93 seconds (complete model below).

Breaking it down into the total weight you're pushing up the hill really makes clear how silly it is to worry about the extra weight from this combo - it's < than 1 lb which only about .5% difference in total weight. Rock the disc/H3 combo.

Benefit From Less Weight
This Much Less Weight 0.5 kg Over This Distance 11000 meters On Hill of Slope 0.07 Decimal Faster by 14.93 s Ahead by 57.20 m Frontal Area 0.5 m^2 Coefficient Wind Drag 0.5 Dimensionless Air Density 1.226 kg/m^3 Weight Rider & Bike 86.8 kg Rolling Coefficient 0.004 Dimensionless Power 250 watts

Some great answers folks and thank you. There's nothing better than supportive fellow athletes helping one of their own justify spending $1000s on a few minutes time savings ;-). It might help me qualify for the big dance.

Graham

The specific model I ran doesn't take into account the aerodynamic benefits of the disc/H3 combo (which is probably quite small) - only the weight penalty.

For what it's worth, the first 5 riders to roll through this year, between Richter and Yellow, were...

- Tom Evans (zipp disk, deep dish front)

- Stephan Holzner (colagno disk and deep dish front)

- Matt Seeley (no-name disk and deep dish front)

- Gordo Byrn (botrager disk and HED tri front)

- Jasper Blake (rear disk and 4-spoke front)