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Old 04-17-11, 01:18 PM
  #108  
njkayaker
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Originally Posted by garage sale GT
Show me where.
Here.

You are saying basically opposite things in these two paragraphs.

Originally Posted by garage sale GT
Gauging from what you said so far, it's not particularly amazing that you never noticed that narrow tires at a given pressure vibrate less also.
That is, you are saying using the same pressure in wider and narrower tires reduces "vibration" comparitively. You are basically describing the case where the narrower tires is "under inflated" and the wider tire is "over inflated" (more or less). What you are describing is the same effect as using a lower pressure in the same tire (that is, reducing pressure reduces "vibration"). The problem with running a lower pressure in narrower tires is that it reduces the load that can be accommodated (eg, for a given tire, heavy people use higher pressure and lighter people can use less).

Originally Posted by garage sale GT
That's why narrower tires are good, incidentally. They can be run at a higher PSI without bouncing or shaking. This factor is not testable by the steel drum tests in the picture on the first page of this thread.
That is, you are saying using a higher pressure in narrow tires reduces "bouncing/shaking". But narrower tires run at higher pressures are less comfortable.

====================

Originally Posted by garage sale GT
I am assuming that is because the pressure is so high it starts to bounce over the aggregate in the asphalt rather than conforming to the road.
The tires have to "give" enough (but not too much) to absorb shocks and variations in road surface. The pressure certainly can be too high.

Interesting graph (let's assume it's accurate for different tires).

I suspect that the upward turn in RR with increased pressure occurs earlier on rougher roads. If so, that's why one uses wider tires for rougher roads. The basic effect is the same with cars: race cars driven on smooth tracks have stiff suspensions.

http://en.wikipedia.org/wiki/Suspension_(vehicle)

Last edited by njkayaker; 04-17-11 at 01:55 PM.
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