Tyre pressure, what should I aim for?

[Cockney Scot]

Origonal tyres fitted to my bike (700x38c) were City slickers rated to max70psi.
I initialy replaced them with (Budget £9.99) of road 700x 38c tyres rated to a maximum 60psi. Whilst the of road grip appeared initialy to be better , on road was a hard work and the lower presure made the bike feel less stable. I have now changed to Armadilo touring tyres and the pressures are 75 psi min and 100psi max. I have set them to 90 psi , but I have never come across a cycle tyre with such a high pressure. I take it that the rims and tubes will be ok to these pressures. Also if max is 100psi and min 75 what pressure should I use. In past tyres I have always inflated the tyres to the max.

 

[TheDoctor]

Aim for the maximum. And road bike tyres can run up to 130 psi or more...

 

[HJ]

What the Doc said...

 

[Cockney Scot]

Thanks for the prompt reply. i will inflate them to 100psi, only one problem, its bloomin hard pumping them at that pressure, any volunteers? would use the car pump but that only goes to 80psi

 

[Young Un]

Thanks for the prompt reply. i will inflate them to 100psi, only one problem, its bloomin hard pumping them at that pressure, any volunteers? would use the car pump but that only goes to 80psi

Get down to the gym

Just keep trying, have a little rest between each stroke.

 

[Dan B]

A track pump (floor-standing) is easier and faster than a minipump or even a frame pump

 

[Cockney Scot]

Get down to the gym

Just keep trying, have a little rest between each stroke.

Thats what i tell the wife (once a year).

 

[Joe]

Don't necessarily aim for the max unless you have seriously nice road surfaces where you are, or weigh loads. Go for lower pressure at the front too.

 

[mickle]

Generally speaking;

Skinny tyres will accept higher pressures than fat tyres.
Skinny tyres are faster than fat tyres.
The harder you inflate your tyres the lower the rolling resistance.

However, above about 110psi rolling resistance actually increases because the tyre is unable to flex over road imperfections.

Specialized were always very proud of the fact that when they tested their tyres to destruction it was always the rim which failed (at well over 200psi). I don't think Spez tyres are unique in this respect, any decent tyre which fits the rim adequately will behave in the same way. Tyres and rims are designed in such a way that the greater the pressure the less likely it is that the tyre will blow off.

I serviced a bike today, adjusted the brakes and then pumped up the tyres. The rim swelled so much from the pressure that it jammed in the brakes! Cheapo rims.

When establishing tyre pressure preference you should take account your body weight. At close to 100kg I inflate my 700 X 25c tyres to 100psi rear and 95psi front. Lighter folk should run less pressure if they want to retain a degree of comfort from their tyres.

Waffle waffle..

 

[Randochap]

What mickle and Joe said.

Ignore all advice to just pump tyres to maximum pressure. Most roads aren't the same as the steel rollers often used to test "rolling resistance."

Tyres on uneven surfaces will actually roll faster if they are wider and are inflated to lower psi.

Also take into consideration your total weight (rider/bike).