Tire PSI

[Bill]

(10-18-2010, 03:44 PM)xerxes Wrote:  A really hard tyre on a 20" wheel would probably give a vary harsh ride; smaller wheels are stiffer and have less give than larger ones. In addition wider tyres have less rolling resistance than narrow ones, so a very high pressure may be disadvantageous, providing less less comfort and grip. Small wheels also have more rolling resistance than larger ones, so it's probably impossible to get a 20" wheel to roll as well as a 29" with similar tyres.

Take a look at these:
http://www.schwalbetires.com/tech_info/rolling_resistance

http://www.sheldonbrown.com/tyres.html

This is very true. To think about it BMX was originally intended as an off road bicycle if memory serves me. The only way to get less rolling resistance is to go with with thinner tires. You can also make sure your wheels are maintained properly with undamaged parts i.e. bad bearings, bent axle etc. As far as anything else I can thinking of is make sure your wheel are true!

Hope this helps,
Bill