Optimum tyre pressure - Hybrid bike

[GrasB]

You ideally want 15% tyre drop give or take when loaded. Measuring this can be interesting if you've not got the right instruments but it has been done to a reasonable approximation here

 

[GrizzleyBear]

I have a 2010 Ridgeback Flight 02 and the tyres say "max inflation 7.0bar, 102psi".

I put about 90 in six weeks ago and have maybe covered 200 - 300 miles since, and I weigh 16 stones. I checked it today and was surprised that the pressures were only around 30 - 40.

How much should I inflate to and how often should I check them? I left it this long because they felt very firm each time I rode it.

For non-road and non-competition bikes (hybrid/mountain) - 42-46 psi (front) and 65-70 psi (back). You need to keep the back tyre under more pressure to have a better body weight distribution whilst riding.
For road and competition bikes - 90-95 psi (front) and 110-115 psi (back)

You also have to check you tyre pressure every 1/1.5 months to check if they are in range (above).