Over time I have been “sold” on the idea that from an aerodynamic perspective many of the major aero wheel manufacturers are close in terms of performance (Zipp, HED, etc). One thing I see little data on is the quality or impact of hubs. To pre-empt a bit I sometimes hear of quality concerns of one over another but my question is: Can one hub save watts over another?
I know that wheel oriented discussions generate controversy but I am getting close to making a purchase in this arena. As an aside, the advice here is always appreciated by the poster. In fact, just yesterday I picked up a new pair of the Specialized Tri-Vents (based on info from ST) . They had their maiden ride this morning and felt fantastic.
In my research of ceramic bearings I found that most of the manufacturers of quality wheels stick to the same tolerances. It seems that when I compare my race wheels to my training wheels I get just as much benefit from the race hubs as I do from aerodynamics. The bearings in my Heds are way nicer than the Mavics I train on. And the rear wheel mechanism is far superior. On the Hed site in reference to ceramic bearings I think they’re saying steel bearings and ceramic bearings of the same tolerance achieve virtually equal rolling resistance. The main difference is that ceramic bearings last longer.
One ceramic bearing hub manufacturer is claiming a saving of 4 watts.
Really? I’ve never seen that claim, although I don’t doubt that the claim exists. If it does, it’s total BS. What I HAVE seen is the 4% reduction claim–and 4% of next to nothing is, well, les than next to nothing.
As far as ‘fastest hub’, I think the Tour Magazine test of different wheels shows what is really ‘fastest’. The fact that the Ritchey wheel tests faster than the Velomax wheel (with identical rims, though the Velomax has straight pull spokes that ‘look’ more aero) makes me think what I’ve thought all along: the fastest hub is the smallest one.
If I were really that interested, I’d get an old-school dura ace hub (7400 variety) with the small shell and lace it to an 808. I think that would actually be the fastest way to go, based on all of the available information out there.
Just trying to calrify: Why would size have such a big impact?
Well, I don’t think it would have a BIG impact–that’s why I haven’t bothered (I’m just rolling a regular 808). What I DO think is that it would make a bigger difference than bearings. The Tour test I alluded to earlier showed a small, but tangible difference. As far as why? Smaller equals less front area. Less frontal area is typically faster. I’m sure how the hub interacts with the back of the rim has some effect (Zipp was selling this with the dimpled hub). Still, in the case of a front hub, I’d vote for smaller.
Funny, fashion has really dictated bigger hubs, ever since MTB hubs got bigger hub shells (to accommodate bigger, stiffer axles needed for suspension). I never understood it for road bikes, and I still don’t…