Tyre Pressures.

[Tony Smith]

Subtitled: "Everything I thought I knew was wrong in respect to modern tyres"


I had new tyres fitted to the GSA on Friday. As they were offering free fitting and balance I decided that I'd let them do the tyres, providing they let me watch.

Turns out that the tyre fitter is the son of the owner and has been fitting tyres to bikes for 25 years because the shop wants them done correctly. Not only did he not have a problem with me watching he invited me into the workshop so he would have someone to talk to while he worked.

As I have been very happy with the Pirelli Scorpion trails fitted to the GSA for the last year going with them again was a no-brainer, best of all the Scorpion 2 tyres they are now selling have a harder compound in the centre of the tyres to stave off the dreaded "squaring off" that prematurely kills tyres that do long highway miles.

I'd noticed some "cuts" on my front tyre and I asked the tyre fitter what he thought might have caused them to which he immediately replied "under inflation". I disputed that and said that I ran 34/36 solo and 35/38 loaded. The tyre man said that 38/42 unladen and 40/46 with a touring load would be closer to the mark (he also convinced me that my tyre gauge under reads by 2 psi by comparing it to his three quality gauges).

At first I thought he was having a lend of me so when i got home I spent time on the Pirelli site - he is absolutely correct.

The pressures I've been running the Pirelli city demons on the R65 were about correct, but the pressures I've put into the Shinkos is too low - I pumped them up to 34/38 but they are still terrible tyres.

What sort of pressures do others run their tyres? I'm interested in modern bike figures, not just R65s.

[tunnelrider]

For what it's worth I run my R65 tyres at fairly low pressures, 32 rear/30 front usually.  I had a wee slide in winter after over inflating (for me) the front to 40psi (had no working gauge with me) and lost the front in a shaded wet corner on a cold day in winter, which I thought happened way too easily.  Wasn't braking but coming out of the corner. The tyres were reasonably hard compound (Rinaldi WH21), good in summer, not so good in winter.  But in general I keep to the 32 rear/30 psi for the R65 no matter what tyre I've got on.

[Bob_Roller]

I run 40 psi front and rear on the oilhead, Michelin Power Pilot tires .
Also 40 psi front and rear on the Guzzi, 16 inch Pirelli MT 75 tubeless  tires .

[DonC]

Michelin Pilot Actives - 32 psi front, 33.5 psi rear.
From Michelin website, differs from owners manual which calls for 31 psi front, 36 psi rear.

[Matt Chapter]

I like higher pressures on my monoshock, I try to run 38 front and ~40ish rear (the rim leaks). If I remember correctly I'm running Avon Roadriders.

[Barry]

Michelin M45's. Solo pressures with 150lb rider 32 psi front and 36 psi rear