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Old 03-27-2020, 11:12 PM   #11 (permalink)
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Originally Posted by Ecky View Post
Although it wasn't stated explicitly, I gather that as some point, rolling resistance improvements diminish sufficiently as to not be "worth" the additional harshness and vibration.
Exactly! On flat roads top speed is limited by wind drag. Consider that a world class sprinter pro cyclist may be able to hit 40 mph in a sprint with a good leadout for a few seconds. A fully faired cyclist can reach 80 mph at Battle Mountain using very similar tire technology.

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The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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Old 04-01-2020, 03:11 PM   #12 (permalink)
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Originally Posted by Vman455 View Post
You might know the answer to this: Prevailing wisdom at Slowtwitch is that latex tubes are less resistant to puncture than butyl. Is that actually true?
I'll risk a guess that it's an anecdotal,urban legend type of thing.I have read where natural latex rubber has superior hysteresis characteristics compared to synthetics,but a puncture is a puncture.Under up to 51-psi inflation pressures now,unless a tire has an elastic,self-sealing membrane,passive 'healing' from a perforation would be hard to pull off.
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Old 07-28-2020, 03:57 PM   #13 (permalink)
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For bicycle tires see "High Tech Cycling" 2nd Ed. (2003) by Edmund R Burke PhD. For automobile tires look for papers from SAE.
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Old 08-07-2020, 04:18 PM   #14 (permalink)
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rolling resistance

After winning the World Solar Challenge, in 1987, the GM/ Aerovironment team commented that, had they run the entire race on bald tires, their margin of victory due to the superior R-R of the tread-less tires would have way over-shadowed the additional time they would have lost during the race to changing flat tires.The lion's share of R-R had to do with tire squirm of the individual treadblocks. Perhaps at 200-psi, there was virtually zero sidewall flexure, a common source of R-R.
Another reporting, having to do with LRR tires, commented that, the particular tire under discussion, simply lacked 25% of tread depth found in non-LRR tires. Or in other words, one would be paying full-price for a tire which was already 25% worn out.
In the mid-1990s, I called a California Saturn dealer to see about purchasing a set of LRR OEM tires for the EV1. The parts manager implored me not to do it. He said that the compound used was so soft that, tread life would be half what a conventional tire would have, and I'd end up purchasing tires twice as often, and would ultimately regret my decision.
A book on electric car conversion mentioned that, for every application, there would be an optimum inflation pressure, beyond which,no amount of over-inflation would result in reduced R-R.
Exactly what CAR and DRIVER said in another reporting, after doing the experiments at Chrysler Proving Grounds.
Race fans will observe that many racing tires are 'slicks' to begin with.

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Last edited by aerohead; 08-07-2020 at 04:20 PM.. Reason: add data
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