Tyre Pressures on a Small Trailer?

[Cleggy]

I bought a small trailer (5' x 3') secondhand and there's no maker's info on what the tyre pressures should be. It's used very infrequently, mainly for short trips to the local tip.  Mr Google is not being helpful - can anyone advise what typical values are?

Thanks

C

[Eddystonepete]

Hi Cleggy, this might help


http://www.tyresafe.org/tyre-safety/cara...re-safety/

Peter

[Cleggy]

Thanks for that, but the smallest wheel size of their chart is 13" (and typically inflated to 30+ psi) and I've got 8" -but perhaps that doesn't matter?

The tyre sidewall shows a maximum rated cold pressure of 60 psi. Most cars these days seem to run at about ~30psi, but I remember my old 1970's Viva with 12" wheels ran on just 22psi (even with radials).

C

[pwdrive]

I have an Ifor Williams P5 trailer (Approx 5ftx3ft) 145/80B10's at 36 PSI.

Lawrence.

[Cleggy]

Well, from everything I'm hearing it does look as though 36psi (or more) is correct. Just sounds a lot for a tyre that would fit a wheel barrow!

C

[Mark Hennessy]

I'm thinking it must be related more to the width than the diameter?

Car tyres are a lot wider, so have more square inches in contact with the road. To give an extreme example, I put 90psi in my bicycle tyres! These aren't the extremely skinny racing tyres that serious cyclists use - these are 32mm wide.

[pwdrive]

My logging arch has small wheels, just a bit bigger than wheelbarrow size, tyres are at 40 PSI as per the instructions:

   

Lawrence.

[Herald1360]

Probably easiest to go with max rated pressure for the tyre with the lower rating if they're not identical. (Not all trailer tyres have same ply rating.)

 Think about the size of the contact patch of the tyre on the road, half the gross trailer weight, and relate the two to the pressure.

[pwdrive]

If in doubt stick 30 PSI in and see how it sits fully loaded.

Lawrence.

[Cleggy]

Thanks for the replies. I get the impression that 35-40psi seem to be a figures which are cropping up a lot, so I think I'll probably stick to that range. It seems that I was wrong to be influenced by the pressures on my old Viva and I need to be running higher pressures than I have been doing.

C