CJG Posted March 30, 2010 Report Share Posted March 30, 2010 Hi, can anyone tell me the correct pressures for 165R15 tyres fitted with tubes on wire wheels (1962 TR4)? Thanks. Quote Link to post Share on other sites
stuart Posted March 30, 2010 Report Share Posted March 30, 2010 Hi, can anyone tell me the correct pressures for 165R15 tyres fitted with tubes on wire wheels (1962 TR4)? Thanks. 24Front 26 rear to start and then try it for a road test. Adjust up or down by a couple of pounds to suit the individual characteristics of your car/tyres. Then try again on the same bit of road for comparison. Stuart. Quote Link to post Share on other sites
Alec Pringle Posted March 30, 2010 Report Share Posted March 30, 2010 " Then try again on the same bit of road for comparison" Stuart, you forgot to add about the degree of understeer or oversteer being measurable by the depth of penetration of front or rear end respectively into the hedge . . . Even worse, you also forgot to add the caveat about not undertaking this exercise on the bit of road bounded by stone walls . . . . Cheers, Alec Quote Link to post Share on other sites
MadMarx Posted March 31, 2010 Report Share Posted March 31, 2010 24Front 26 rear to start and then try it for a road test. ... Seems to a bit low for street tires and normal road use. I would start with 32 psi at front and 30 psi at rear. Depending on the tire that would make the car a little oversteer but in most cases nice to drive. Cheers Chris Quote Link to post Share on other sites
stuart Posted March 31, 2010 Report Share Posted March 31, 2010 Seems to a bit low for street tires and normal road use. I would start with 32 psi at front and 30 psi at rear. Depending on the tire that would make the car a little oversteer but in most cases nice to drive. Cheers Chris At that pressure my 4a (solid axle variant) would just go straight on at the first corner especially as it has XASs on it. Stuart. Quote Link to post Share on other sites
MadMarx Posted March 31, 2010 Report Share Posted March 31, 2010 (edited) At that pressure my 4a (solid axle variant) would just go straight on at the first corner especially as it has XASs on it. Stuart. I think with a good sticky tire the main problem with the 165-15 size is the tire roll and occuring slipangle during cornering. To make the tire stiffer the higher tire pressure should be reasonable. I used that pressure on Conti CT21 tires and Vredestein Sprint 88 and Hankook 886. Cheers Chris Edited March 31, 2010 by MadMarx Quote Link to post Share on other sites
stuart Posted March 31, 2010 Report Share Posted March 31, 2010 I did start off at 30 psi and wasnt happy at all so arrived at my original figures after some trial and error. Maybe I dont drive it hard enough Stuart Quote Link to post Share on other sites
Alec Pringle Posted April 1, 2010 Report Share Posted April 1, 2010 32F/30R is fair enough for high speed track useage, but pretty damn twitchy on the road . . . and UK traffic conditions don't generally make for induced oversteer and throttle steering as the preferred cornering mode. 24F/28R was the original Triumph recommendation for 165/15 on TR4 - bear in mind that in the event of an accident the Police are likely to check tyre pressures. 32F would be difficult to justify to Police or insurers, and with good reason, which could prove an expensive error. Cheers, Alec Quote Link to post Share on other sites
Ade-TR4 Posted April 1, 2010 Report Share Posted April 1, 2010 24F/ 28R works fine on My TR4 with 165/80s Good balance between handling and ride comfort, especially on the sh4gged-out tarmac thats littering our area at the moment. I've tried higher pressures and found the car to be very twitchy, particularly in the wet/ damp Adey Quote Link to post Share on other sites
MadMarx Posted April 1, 2010 Report Share Posted April 1, 2010 (edited) Hmmm....are there different tire compounds between England and the continent? True that the owners manual is going for lower pressure but I suppose this was more for comfort than for fast driving. And not to forget that the modern tires are different compare to the Michelin X they had at that time. I would suggest to find a comparable car with about the same tire size and use a current tire pressure table or ask the tire manufacturer what would be the best.... BTW....all UK racers I've talked to do run on lower pressures than I use. Maybe the tarmac is different in England? ;-) Cheers Chris Edited April 1, 2010 by MadMarx Quote Link to post Share on other sites
Alec Pringle Posted April 1, 2010 Report Share Posted April 1, 2010 The Triumph figures covered a variety of 165/15 radials for the TR4/4A/5/6, 24F/28R for all but the later Michelin XAS fitment at 22F/26R. Tyre manufacturers generally don't concern themselves with recommendations for 40 or 50 year old cars . . . . and I can't think of many modern cars with similar suspension characteristics to our TRs by way of comparison. German and UK tarmac surfaces do tend to differ, road and track, and that is not anything new - in the 70s and 80s for German circuits we'd use maybe 10% pressure increase, on single seaters and saloons alike. Cheers, Alec Quote Link to post Share on other sites
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