Just a side note, this exists quite some time. For example, we have 2 SRM track PMs with track axle, Wattshop crankarms and Kappstein 144bcd chain rings. The Q Factor is even narrower than 136mm. Not a bargain, but hey, everyone only lives once.
yes! Joe Skipper has been on the Wattshop SRM cranks this year and truly love those, as they’ve provided ease to test crank length effects on his quad vs glute engagement.
Zipp claimed 9s over 40km for the Vumachrono https://www.slanecycles.com/zipp-vuma-chrono-crankset-1725mm-x-5442t-p-21646.html
I can’t find the episode now but on the marginal gains podcast Josh says that this is below the real saving, because they didn’t think people will believe the real numbers.
I expect Aerocoach will have numbers when they are ready to sell the brute crankset.
As stated above and by Escape Collective, a narrow q-factor is not new at all.
Here on slowtwich someone (I don’t remember the name) got a narrow q-factor, I think below 130 mm, with Campagnolo track cranks, I believe on a Cervelo P3. He stated rather big aero gains.
Walser had a frame version with a very low q-factor (and it was long and low in addition).
The FES track bicycles of the German national track team have narrow q-factor and they have proprietary crank based power meters with narrow q-factor.
I think it would be interesting to isolate variables on these for testing. Keep q factors consistent and show results of just the aerodynamic design and machining.
Then seperate analysis with q factor.
Also would be interesting to see what the difference is with just swapping rings to something solid like the absolute blacks, etc.
It’s a big amount of money for something that doesn’t have a lot of evidence.
Also curious what the drag savings of removing the front derailleur is. Would seem that big old block hanging out in the turbulence would be an easy gain if practical.
The q -factor can make a big difference. However, how you pedal matters a lot.
Some people switch to a narrow q-factor, but their knees splay out wide when they pedal hard – in which case the narrow q-factor doesn’t help at all. You have to have good “knee discipline.”
P3
Well actually 0.179, in Sunday morning’s weekly Chung test.
That was with a slightly slower front wheel and no shoe covers or trip socks. So maybe I can get to 0.177 with those enhancements.
I thought I’d let you all in on this after seeing how much fun everybody was making of the poor guy with Morf bars on the Kona thread. My rough guess from testing is that I’m saving about 10 watts from the Mantis and about 5 from the no-basebar. Unfortunately, I have significant power loss in the Mantis position. I haven’t figured that out, as my elbows are at the same height as before.
One warning here is that several people have found that going narrower can actully increase drag until you get past a certain inflection point. So going from 160 to say 140 could actually be worse.
For my part, I didn’t see a significant advantage until I got real narrow (120s).
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