Tire pressure....

[cruisehard]

I have a question about psi's. My tires read: "max load 150kg (880lbs) at 250 kpa (36psi) cold". What the crap does that mean? When I got the bike back from the shop they inflated them to around 70 psi, so my gauge says. So is 36psi the minimum? My tires are 26x2.30

 

[user 135]

36psi is what is recommended. I would call the LBS and tell them the error of their ways.

http://www.sheldonbrown.com/tires.html#pressure

 

[icyuod2]

basicly it means this

they over inflated your tires.

 

[cruisehard]

basicly it means this

they over inflated your tires.

I kindda figured that...

 

[deorman]

Usually max load is given at max pressure. Most tires will become distorted, some will even pop at less than twice recommended max. Hope your tires aren't ruined. Maybe check again for any other pressure marking. Some do give hi and lo, some only give max, and some just say inflate to xx lbs or xx atm or bar(atmospheres, i.e., 2atm means double atmospheric pressure). Or, more recently, at least as far as bike tire are concerned, kiloPascal

http://www.asknumbers.com/PressureConversion.aspx

 

[cruisehard]

Mine just state what I posted above...at 40psi it rides sluggish, 60 psi feels good...I'm wondering why this dude at the lbs had the tires filled to 75psi? Or maybe the pressure gauge on my pump is wrong.

 

[X-RAY]

my guess is your gauge is wrong. i cant imagine it not failing at that much pressure. what kind of tire is it?

 

[deorman]

Old timey "flotation" tires run 22-35 pressure range. They're awsome easy on soft or loose surfaces, but they are truly a drag on smooth pavement. Thickwall moped tires often run low pressure also, but they weigh a ton, as well! Could this be what you have? I would expect most decent modern BICYCLE tires in that size to claim 45 lbs, or a range of 30-65 lbs, adjust to suit terrain and rider.
I thought about mentioning your gauge, the little hand held blow out kind are usually close, or they don't work at all. Dial gauges can be more precise, but can also be way off.

 

[66olds98]

The LBS prob. just used a compressor air chuck with no gauge, " yep thats full"

 

[StephenH]

If you have Schader-type valves, they have some digital air gauges that work pretty well for not too much.

I would assume the psi given on the tire was maximum psi.

I think you converted kg to lbs wrong...2.2046 lbs/kg.

 

[cruisehard]

my guess is your gauge is wrong. i cant imagine it not failing at that much pressure. what kind of tire is it?

It's a Chinese made tire from Chang Yang I think? I'm using a Schwinn foot pump w/ dial gauge. Here's a pic...

 

[user 135]

The LBS prob. just used a compressor air chuck with no gauge, " yep thats full"

That is how I do my mine most of the time. :mrgreen: But I bought a Prestaflator with the Schrader chuck. Best thing ever.
http://www.prestaflator.com/