Originally Posted by
Bikerider007
Wow, "err on the low side". " Under 100 faster than 100-120". Interesting.
But I only listened to about 30 minutes, did they mention anything about front vs rear?
Jan published
this article 10 years ago, and Frank Berto's chart with it:
Jan has also published about 2 dozen tire pressure articles since then.
A lot of people use this chart as a starting point and often find themselves backing off from these numbers.
The front/rear tire pressure difference is all about the weight distribution. It's going to be somewhere between 45/55 f/r for a road bike, and 30/70 f/r for fully upright.
If you ride really big hills and find yourself hitting 35-40 mph (and higher) you're going to need to run a little higher pressure than normal road shock and vibration tell you that you need. This is because centrifugal forces stretch the tire, and the tire is actually running at lower pressure at speed - you feel it as a lateral squirm and maybe even a spooky sideways vibration at high speed.
Conversely, when going to gravel, I drop down from my normal set points by 5-10 psi. It improves the endurance of both me and the tires.