TYRE PRESSURES re Old Bikes - New Tyres!

[MGI]

Any suggestions reference Avon Road Riders on a  B33, one up at all times.

[Catz]

I've got them on my A10 and go with 42 rear and 36 front when carrying a pillion and 36 rear and 28 front when solo.
I'd forget what it recommends in the old service manuals. Modern tyres require modern settings.

[idie]

On my B33 I use 25 front and 35 rear. Best to find what suits you.

[Greenfield]

The original instruction manual says 17psi front and 18psi rear. That's a significant difference, but I think you find what pressure handles right for you.

[DAVE BRADY]

Hi,

The pressures in the manuals are usually for a 10stn rider with 1psi added to the front for each 2stn over and 2psi to the rear.
Also if carrying a pillion and luggage more is needed.

There is a chart on on page F18 of the A65 manual but I would think that as the weight of a B33 is about the same the chart will still be relevant.

Dave.

[Dean Southall]

Ignore the pressures given in original manuals/handbooks. Modern materials result in a much softer wall so higher pressures are required (even if the tyre is the same). For example the manual for the 19" tyres on the A10 are 18psi front, 20psi rear. With new tyres these should be increased to 26-28 front and 28-30 rear as advised by the supplier.

[MGI]

yeah, sounds about right...I was aware that the original specifications referred to tyres with extremely rigid walls (compared to todays products) which is why I asked for advice. Many thanks guys!

[DAVE BRADY]

Hi,

Don't forget that the manual gives a starting psi that is increased with the weight of the rider and then again with the addition of a passenger and luggage. It would be interesting to see what pressure would result from using the increase in psi recommended in the manual.  I would suspect that it would not be far off the 'supplier' advised psi.  I run 26psi front and 30psi rear on an A65 for me at about 12stn 7lbs plus bike gear, panniers with the usual stuff in them and some camping gear and if two up a bit more. The tyres last well and do not suffer any odd wear patterns.
It seems that for modern bikes the tyre pressures are not adjusted for load, for example a more modern bike that I have has 36psi front and 42psi rear for all situations.

Dave.

[neil1964]

I've found 25psi front and 28 on my '55 B31 with 600 motor works best for me (6'1" and 14 1/2 stone) using 19" Avon Road-riders front and rear

[yellow B31]

What ever pressure you decide on a good indicator that you have got it right is after a good run the tyres should be warm without being hot.

[Crazy Mike]

I've always wondered about tyre pressures on my 1961 B40 (Dunlop K82 3.25 X 18 Front and Dunlop K82 3.50 X 18 Rear) with the initial recommendations of 17 & 21 psi.

I have asked the question directly to the Goodyear technical team - this is their response.

"Depending on your rider style and required comfort, inflate

front within the 1.8 bar (26 psi)  - 2.0  bar (29 psi) bracket, and

rear 2.2 (32 psi)  - 2.5 bar (36 psi) ."

Hope this helps

[Jean-Luc]

Thanks for this info Mike.
And for the bars.

[maddogmargetts@yahoo.co.u]

that solves my problem as i was thinking the manual saying that they should be 18/20 psi was low. Must have been running
round with the tyres too low for some time! I shall pump them up.