On that note CK, if you had ~9 hundred to spend, what wheels would you get? For all arounders....
J
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O.K. here's the dope: Rolling Resistance and Tire Pressure.
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Hmmmm....that is a tough one. Some great deals popping up on Chainlove.com lately on Rynolds wheels ( although I have some concerns. / questions regarding the shape of their rims....very pointy). Mavic has had some great deals as well, but closer to $1400.
I would have to give strong consideration to Williams wheels though. They are running a $999 special...wheels, Vittoria tires, carbon brake pads, etc. According to Williams data, they perform admirably well in the wind tunnel (and to their credit, they don't pretend to be the "fastest.")
http://www.williamscycling.com/Cycling-Power-Lab-Analysis_ep_46.html
Just say "NO!!" to WCP!
"Want to get faster? Work harder, eat better, cut the crap. Instead of talking the talk, work the work" -
Duh....totally spaced FLo wheels. CFD testing shows them close to Zipp and HED in terms of aero. They use a similar concept as the Firecrest / SCT designs from the big boys. LOTS of pele over at ST love these wheels.
Their next per-order opens tomorrow AM.
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I'd save $300 more and buy these.
Jam Econo -
http://www.novemberbicycles.com/rfsw-wheelset/
You could always show some love for our forum member.
It is his word versus ours. We like our word. We like where we stand and we like our credibility."--Lance Armstrong. -
Right. Soon, soon. Still in scanning mode. Ditched the idea of aluminum clinchers since I decided I have "decent enough" sets already. Just waiting to see what's out there and saving some cash (bonus season comes in March, thank goodness!).
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Keith, who would that be?
"To be free and to live a free life - that is the most beautiful thing there is."
Miguel Indurain -
That is dkri's company, November Bikes.
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There's a difference when you're sprinting. A tire with higher pressure reduces bouncing and increases power transfer from the pedal to the road. It's not the same as rolling resistance. For crits, high pressure is still better. The aerodynamics depends on the rims and the frame, not just the tire. With today's wider downtubes compared to the old steel bikes, a wider tire is probably more aerodynamic. Add a wider rim and the aerodynamics are better still.
I have been riding 25s and 28s for the last couple of years that have involved no racing. I'll only ride 23s if I know the road surface is smooth and the ride intensity is high. -
You got some studies to back that up? I don't see how a tire that has higher pressures, hence harder, is going to bounce around LESS that a tire with a bit of give to it.
Additional question...what to you consider higher?
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Since when does a wider leading edge equate to being "more aero"? Regardless of the tube shape for the frame, that argument doesn't make any sense.
Wind tunnel tests show that even with today's wider rims, a narrower tire is still more aero.
As for the "more pressure is better for crits" argument, leaving aside the suspect logic, you are forgetting critical elements like cornering, etc. You only sprint a few times during the race, but have to deal with surface imperfections, rolling resistance throughout the whole race, etc.
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Another piece of data to toss into the mix which just occurred....the new Mavic CX80 wheelset. If you use their tires and "gasket" to smooth the gap between the tire and rim, it is reportedly one of the fastest, if not THE fastest, wheelsets out there, across all angles.
Problem is that the tire has pretty poor Crr, which all but negates the aero advantage of the entire system. Apparently you cannot use their entire system with any tire except theirs. No idea how the wheels test with a normal tire and no "gasket"....
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Keith,
during high cadence high intensity pedaling, there is a tendency for the rider to bounce. When a bike's tires have less pressure, the increased magnitude of vertical bounce can waste energy. Some smooth sprinters may not suffer the same problem. I know a few crit riders that prefer 140 over say 110 psi, saying that they accelerate better. Some others prefer the better traction of lower pressures. Vittoria once put out (circa 2000) a set of Open CX tires in a Cipollini edition that could go to 170 psi. -
PSI on the sidewalls are not recommendations,mother are safety warnings. That is half the PSI required to blow the tire off a rim.
Riding with high PSI may "feel" faster, but it isn't. The idea that a lower PSI negatively impacts forward motion because of vertical movement is not based in any scientific thought. It also completely ignores all other aspects of the race, in which high PSI is a negative (Crr, cornering grip, comfort, etc)
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CK,
the vertical motion issue is only significant in the heat of the sprint. If you take a basketball and under-inflate it, it will take more effort to make it bounce as well as a properly inflated ball. More energy is lost in bouncing movement at a lower pressure. When it comes to cycling, this competes with energy lost rolling over a surface that's not smooth. What pressure works best depends on many issues. If you're a 2,000 watt sprinter, tire pressure is more important than if you're a 1,000 watt sprinter. -
Sorry, but that is a silly comparison. A basketball is supposed to bounce, a bike tire is not. Comparing the two as proof of efficacy in a sprint is pointless.
You also completely ignore the fact that the bike is already in (fast) forward motion and the direct vertical forces are minimal, even in a sprint.
If you wanna pump your tires up to rock hard levels, knock yourself out. But there is no evidence whatsoever that using a lower PSI, which decreases Crr across the entire race, somehow leads to negative sprinting performance.
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I'm a 200w sprinter
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