Tire pressure

velardejose · #1 (**permalink**) 10-25-2008, 10:38 AM

I bought a pcl tire pressure manometer yesterday
Checked my tires today
They were at ~25 psi
Brought the tire pressure up to 40 psi
MB is quicker than before
Jose

tyrslider · #2 (**permalink**) 10-25-2008, 11:22 AM

Lower rolling resistance = faster ride!

cachehiker · #3 (**permalink**) 10-26-2008, 12:39 AM

All tires have an ideal pressure for the conditions they're being used for. My mountain tires are typically inflated from 35 psi (beefy knobbies on rough trails) to 70 psi (narrow semi-slicks on pavement).

In general, higher pressures mean lower rolling resistance. However, there exists a point where higher pressures actually result in higher rolling resistance. It takes energy to lift a bike up and over a bump in the road and unless you're at the velodrome, at some point the energy being used to lift a bike up and over the bumps exceeds the energy being lost to tire deformation.

The difference in speed vs. pressure vs. terrain is especially obvious on my cyclocross bike. On a race course, 35-40 psi rules as it sucks up all the surface irregularities and allows you to ride faster. On the road, 35-40 psi is like riding my mountain bike whereas 65 psi is actually pretty quick.

velardejose · #4 (**permalink**) 10-26-2008, 01:24 AM

I was scared because of a post about apparent spontaneous tire exploding
Recommended pressure is 40-65 for my tires (Cheng shin c917-12)
I think I will stick to the min value
Jose

**Bikeguy Joe** · #5 (**permalink**) 10-26-2008, 02:29 AM

Link to those posts?

brisbane_boy · #6 (**permalink**) 10-26-2008, 04:40 AM

Yer i pump my motored bike tyres to 40psi. and on my racing bike i pump them between 80psi and 120psi.

Yer probly better on the motored bike to not have then so hard because if they are like 60psi they are very easy to puncture.

velardejose · #7 (**permalink**) 10-26-2008, 10:27 AM

This is it
Tire Quality 101
I ride to and from work, that scared me
I will keep on riding my mb, but not as I stole it...
Peace

Motormac · #8 (**permalink**) 10-26-2008, 10:41 AM

Scares me too Jose,I think about my tires all the time while riding.

**Bikeguy Joe** · #9 (**permalink**) 10-26-2008, 12:42 PM

Alrighty, that thread is an older one, and it was just one tire in one instance.

I wouldn't worry TOO much, but, like with some early hang glider designs- "never fly higher than you want to fall" or "Never ride faster than you want to crash."

**fairracing31** · #10 (**permalink**) 10-26-2008, 12:47 PM

Our Chinese motors are like a model T, Easy Riders is like a Ferrari