The Triumph Dolomite Club - Discussion Forum

I'm just back from taking the 1850 out for a long overdue blast.

It sits on Sprint alloys. The tyres were very soft so I stopped off at the local service station to pump them up. I normally have my tyres around the 30/32 mark for each wheel but they still seemed pretty soft so I gave them a bit extra. What is the standard pressure for Sprint alloys?

22 front and 24 rears I think


Modern cars using same size tyres with a similar weight use 30 ish psi so thats what I used to use

22psi in the front, 24psi in the rear. Your pressures are way too high.

Seriously?

Anything below 30 has me pulling my arms out of their sockets turning the wheel while turning/parking! Hmmm. Have to admit it was much better at the pressures I have them at now. Thanks for the quick replies Adam/Carl.

Garfin wrote:Seriously?

Anything below 30 has me pulling my arms out of their sockets turning the wheel while turning/parking! Hmmm. Have to admit it was much better at the pressures I have them at now. Thanks for the quick replies Adam/Carl.

Yup, definitely 22 front, 24 rear. It makes it harder to turn the wheel, but that's just the car's way of saying either:

a)Don't turn the wheels while stationary

or

b)It's much easier to make tight corners with power oversteer.

Ah well, by the time I get another chance for a run in it the pressures will be back down to 22/24 anyway!

I have only been running mine for a few weeks but have been expirementing with different pressures.
The standard recommended pressures feel far too soft to me and I have settled on about 28 psi at the moment and it feels good for me.
I think a lot of it is personal preference, go with what feels right.

alolympic wrote:I have only been running mine for a few weeks but have been expirementing with different pressures.
The standard recommended pressures feel far too soft to me and I have settled on about 28 psi at the moment and it feels good for me.
I think a lot of it is personal preference, go with what feels right.

Your insurance company will not see it that way. If your tyre pressure is wrong and you have an accident they may decline to pay out because you have made an unauthorised and dangerous modification.

Bear in mind that the pressures suggested are cold pressures. it's likely that from cold to normal running the pressure will up by about 4 PSI, so if your tyre reads 28 after a run then you are pretty much spot on.

There was a previous thread on this topic. While many people reported that they preferred higher pressures for various reasons, the fact remains that you are on very dodgy ground legally if you run at anything other than the manufacturers recommendation.

And it was noted last time we discussed this topic that the manufacturer's recommendation (from the 1970s) was when the car was running on tyres of the period (i.e. the 1970s). If you think a modern 175/70/13 is the same as one you would have bought in the 70s then you are mental. But the avoid-paying-out-at-all-costs mentality of insurance companies makes it ill-advised to deviate from the published figures, even if a higher pressure may happen to be safer, for example if running a modern 175/70/13 at 22psi is dangerously under-inflated, leading to possible overheating and blow-out.

All very interesting. 22/24 does seem way too soft for modern tyres, almost dangerously so. Even 30 feels soft but I think I'll go with 28/30 and see how that works out. Thanks again for the feedback.

old 1970's tyres had far stiffer sidewalls so could run lower pressures.

I tried standard pressures on my Sprint which has modern 185/60 13 tyres. It felt awful & the tyres would flex just by rocking the car with my knee on the bumper. I gradually increased pressure untill it felt good which was 28 front 30 rear, cold.

I ran 30/28 in pretty much all of mine. Anything less was noticeably underinflated and gave unequal wear across the tread. And felt awful.

My 306 Diesel, approximately the same kerb weight as a Sprint, similar axle weights, no PAS and running on 175/70/13 tyres recommends 33 front and 35 rear. There has to be something in that.....

Diesels always seem to quote higher pressures.

If at 22/24 you have trouble steering whilst moving I would suggest you have other steering problems elsewhere, for RWD the Dolomite is surprisingly light on steering. I'd look for a seized upper UJ, contaminated rack mounts allowing sideways movement of the rack, a knackered lower UJ or missing bulkhead bush followed by track rod ends and ball joints.

In the absence of any other advice from the manufacturer, divergence from the standard 22/24 set up will put you at risk; this is not a decision you can make. The reason why the steering lightens is because the tyres overinflate, balloon and thereby leave less tread in contact with the road. In an accident, the tyre pressures will be checked and could easily be used to move any pointed finger...ask Chrith Eubank!