Age Old Question... Wheel Choice

chickench

I know that this is such an old and thorny issue, but again I am troubled by the night gremlins that are causing a lack of sleep over the wheel choice for an upcoming race (how very sad is that!)

It is UK Half Ironman in Dorset/Somerset and there is around 4,000 ft of climbing on a very undulating course (http://www.bikemap.net/route/1529368#la ... ts_terrain)

I ride on power and am fairly light (68KG) with a power to weight ratio of around 4.4W/KG. My normal wheel set-up on my TT bike is a set of Zipp 606's (404 front and 808 rear) I also have a set of slightly older Zipp 303's. Including the power tap hubs, the difference in total weight of the 2 different wheel-sets is around 350 grams, and whilst I know that the 808 rear will be slightly stiffer than the 303, will the difference in unsprung weight (on the rim) baring in mind the amount of climbing involved make a big difference to the power needed to move them. IE here comes the old question; Aero or light weight on a hilly course!

dru

You've indicated that you ride with power.

If you are doing an IM, then surely its best to ride the wheels with the powertap so you can judge your efforts precisely over the course of the day - regardless of profile.

okgo

If the hills are steep go for lightness, if they're more draggy, go for aero!

Remember that you'll be going down hill too, the 808/404 will be a fair bit quicker down them...Forget stiffness, that's not relevant.

chickench

Thanks. Both wheel-sets have power.

Lots of short sharp hills with a couple of quite tough little lumps! A considerable amount of the decending is technical so i'm not sure that the more aero 808 will be of great advantage over the 303.
Does the stiffness not affect the power transfer capabilities of the wheel, or am I chasing ghosts?

okgo

Zipp 303's are plenty stiff, the difference will be small, and in time terms, not noticeable I would imagine. I'd go with the 303's based on what you've said.