Bazza Posted June 30, 2015 Report Share Posted June 30, 2015 I've not long bought a 73 TR6 and it has Pirelli 205/70 ZR15 tyres and a look through the workshop manual says it came with 165 and it can take 185s but over this is not recommended. The tyres look new and the wheels look like original steel ones. Should I be changing them? Thanks. Quote Link to post Share on other sites
John Morrison Posted June 30, 2015 Report Share Posted June 30, 2015 If they are original Tr6 wheels, then YES! John. Quote Link to post Share on other sites
Marc R Posted June 30, 2015 Report Share Posted June 30, 2015 +1 with John, the original steel road wheel for an TR6 is 5.5J x 15' (maybe 5J x15' for the early early TR6 fitted with TR5/250 Wheel). As fare as I know the 5.5 wide wheel is not suppose to support 205 tyre. The typical range (by the charts available on the web) for; - 5 is min. 155, optimum 165 to 175 and max. 185 - 5.5 is min. 165, optimum 175 to 185 and max. 195 - 6 is min. 175, optimum 185 to 195 and max. 205 Regards Quote Link to post Share on other sites
Steves_TR6 Posted June 30, 2015 Report Share Posted June 30, 2015 Lots of people go for 195 65 15, including myself. Good and cheap choices available from regular tyre places. Steve Quote Link to post Share on other sites
Bazza Posted June 30, 2015 Author Report Share Posted June 30, 2015 Many thanks All. Great help Quote Link to post Share on other sites
TriumphV8 Posted July 1, 2015 Report Share Posted July 1, 2015 (edited) Things are more complicated than question might look! First normal rim size for 205/70 is 5-7". So from that the stock wheel fits. The original wheel is not designed to drive tubeless, what most of the people do not know. That is the biggest problem because the tire fits and the car runs but as the wheel is only H1 and not H2 it has not the required provision against sudden air loss on both sides. Should there be an accident there may be the question if that was the cause. The next more interesting point is the age of the tire. If its old it should be changed anyway. The often recommended 4 years are far to short for me as we do not drive our cars that often or that hard that they are worn after that time. 10 years seem to be a bit long to have them on the car, although at many annual meetings one can see older examples on the TRs. The last point is the question if they fit when steering is full to one side and when bumps are crossed. If something scratches there is a problem. I personally prefer 205/65 15 as they are very common, very cheap and very good. Looking for a 205/70 VR15 is a pain and maybe as they are for the Jag (ER/70 VR15 is the same) they might be very expensive without any benefit for us. 195/65 15 give a huge space between wheel and wing what I personally do not like. If you bring the TR back to normal space, it is too low and you will hit obstackles very often or have problems to enter the garage or parking lot. Edited July 1, 2015 by TriumphV8 Quote Link to post Share on other sites
Bazza Posted July 2, 2015 Author Report Share Posted July 2, 2015 Thanks. Very interesting Quote Link to post Share on other sites
PaulAA Posted July 2, 2015 Report Share Posted July 2, 2015 195/65 15 give a huge space between wheel and wing what I personally do not like. Agreed, Andreas, which is why the 195/70r15 size is worth considering. The rolling circumference is identical (certainly to the US model 185s) and they do a better job of filling the wheel arch. Admittedly, the choice of non-van spec options is less plentiful, but Yokohama A.Drives are available for about £40 a corner. Cheers Paul Quote Link to post Share on other sites
TriumphV8 Posted July 2, 2015 Report Share Posted July 2, 2015 Yes, would be a nice tire, but not easy to get. Did a quick search and found only few that are not for lorries and none of them was okay seen from speed index. The only Yoko I found was from 2010, so pretty old......... So if I had the car setup for that tire I would continue with them but if they are new choice I would opt for a more common size. All 195/70 are far better than the old ones but noise, wet and rolling are only medium quality..... Quote Link to post Share on other sites
PaulAA Posted July 2, 2015 Report Share Posted July 2, 2015 Fair enough, Andreas. My far less ambitious parameters are accommodated within the Yokohamas' limitations. As ever, a question of horses for courses! Cheers Paul Quote Link to post Share on other sites
Denis Posted July 2, 2015 Report Share Posted July 2, 2015 (edited) Hmmm...this subject always mystifies me why new owners of TR's think they need FAT oversized Tyres ! As I've said before if you had an Aston Martin DB6 would fit FAT tyres on it "to fill the wheel arches?" errrrr....I wouldn't! nor would I ever consider doing it to a TR6! The point is modern 165 tyres are miles superior to the 'wooden' tyres these cars were equipped with new and offer more grip than the already weak stub axles can cope with, and unless you've got a new chassis, our 40 year old ones are much weaker now! And then there's the extra weight and strain on all the steering components, not to mention the UJ's unless you uprated to CV type shafts...and then there are the insurance implications as you have to advise your insurers you've modified it. Nah, to me the idea of an old classic car is what the driving experience was like back in the day! If you want a more modern sports car, a Z4 or a J2000 Honda take a lot of beating for price, looks, handling, and performance! Edited July 2, 2015 by Denis Quote Link to post Share on other sites
Marc R Posted July 2, 2015 Report Share Posted July 2, 2015 Take care of the "Approved Rim Width Ranges", it is depending the serie. have a look on this link from Yokohama http://www.yokohamatire.com/tires_101/customizing/rim_wheel_width/ On my side I am like Denis, even if I used some wider tyres in the '90, for my TR6 PI CP now I am in favour of the original 165 or 185. Regards Quote Link to post Share on other sites
Tom Fremont Posted July 2, 2015 Report Share Posted July 2, 2015 (edited) +2 for Denis's PoV. I do see one benefit for the fat tyre preference: that of flotation when fording streams in flood . I recommend the Michelin XAS in the original 165 size for cars with 3.45:1 diff, and since it isn't made in 185 any longer I suggest the XVS in that size or the 180 in the XAS which is very close in diameter and tread with to the Michelin Redline tyre supplied to the U.S. market in the day ( this is a poorly rated tyre whose performance is night-and-day different from the XAS or XVS models ) - for cars with 3.7:1 diff. These options do carry a hefty price tag, but are terrific performers and period correct too. Cheers, Tom Edited July 2, 2015 by Tom Fremont Quote Link to post Share on other sites
Peter Cobbold Posted July 2, 2015 Report Share Posted July 2, 2015 (edited) Hmmm...this subject always mystifies me why new owners of TR's think they need FAT oversized Tyres ! As I've said before if you had an Aston Martin DB6 would fit FAT tyres on it "to fill the wheel arches?" errrrr....I wouldn't! nor would I ever consider doing it to a TR6! The point is modern 165 tyres are miles superior to the 'wooden' tyres these cars were equipped with new and offer more grip than the already weak stub axles can cope with, and unless you've got a new chassis, our 40 year old ones are much weaker now! And then there's the extra weight and strain on all the steering components, not to mention the UJ's unless you uprated to CV type shafts...and then there are the insurance implications as you have to advise your insurers you've modified it. Nah, to me the idea of an old classic car is what the driving experience was like back in the day! If you want a more modern sports car, a Z4 or a J2000 Honda take a lot of beating for price, looks, handling, and performance! Denis, Like you I drove the 6 for a decade and nearly 200k miles as a daily driver. On narrow tyres it was OK, but as the rest of road users were similarly shod they rarely braked too fast for me. The front end break away under heavy braking in the wet I did not relish, but weight transfer was built into the soft sprung stock design coupled with a rather high c.o.g. With stiffer and lower springing the nose diving can be eliminated and the car nowadays, on 205 sections, just clings and squats slightly to the road under hard braking. In my view it is safer amongst modern traffic to have better roadholding and braking than was the norm in the '70s.Traffic density, speed and performance has altered enormously. As for failure of stub axles - where the evidence? Peter Edited July 2, 2015 by Peter Cobbold Quote Link to post Share on other sites
TriumphV8 Posted July 3, 2015 Report Share Posted July 3, 2015 As I said at another place the TRs are used with semi slicks in many race series like the Triumph challenge. If there would be such problems with braking away of suspension they would suffer first. Honestly everybody should keep an eye on 40 year old suspension. There is a point where every men built system fails. Airplanes for example have a calculated lifetime for many parts and there is the reason: Would you make every part as strong to withstand lifetime it would never manage to get into the air. Our cars are somewhere in the middle between plane and Lanz Bulldog! The selection of 165 or 185HR15 tires is very limited. The Vredestein and the Michelin are both tested by me, having them on the car in former time. The result was definitely not satisfying. For some reason we do not find the now recommended labels on the tires for noise, wet and fuel! Many clubmates swap from these tires to modern size. For a 165 Michelin I would get more than two of the best 205/65 Dunlop Blue response, for the 185 HR 15 more than three! The result is a much more precise steering and that extra safety on breaking on dry or wet that might miss the other guy when required and make him stop with the rear of the front car or take the direct way out of the corner.... Would not play with the safety of my car, of my passenger and of me............ One of the reasons to buy the TR in the 70s was the mighty huge tire in 185HR15. With the 165HR15 it looks ugly in my opinion and to keep the height I like the 205 is required and as selection is limited in /70 size I took the /65. 205 in my opinion is far away from looking "wide" or fat. On my blue TR in the picture is 215/55 16 on 7x16 with wheelarch extensions what is a good idea for that fast car to go safely beyond 200 Km/h and also not "fat" what is indicated by nobody noticed that on any TR meetings wherever I participated. It can stand in a row with others and nobody of the normal TR owners could see from a far look the difference, so no reason to discuss wether this is too much....... Quote Link to post Share on other sites
Marc R Posted July 3, 2015 Report Share Posted July 3, 2015 Thanks' for all the comments, recommendations...very interesting. It is good opportunity, at least for me, to reconsider the various parameter and open my mind. Regards Quote Link to post Share on other sites
Tom Fremont Posted July 6, 2015 Report Share Posted July 6, 2015 Discussion of tyre pressures with these " fat " ones is an important detail. The Michelin 195/65s on my driver don't touch the pavement on the outer 3/4" of tread ( inside and outside edges ) at 28 psi. Remember, TRIUMPH's recommended pressure on the 185s was 24 psi ( less in front ). I would expect 215s at any kind of " normal " pressure to lack 3 inches or more of contact across the tread . To check, wipe rubber protectant across the tread and take it for a short drive ( in a fairly straight line, without rolling the tyre onto its edge ) and the untouched part will remain dark where the contact area is light. Oh, and the fat tyres are heavier too. Cheers, Tom Quote Link to post Share on other sites
OAF939M Posted July 6, 2015 Report Share Posted July 6, 2015 (edited) And a lot more friction, they slow you down! Edited July 7, 2015 by OAF939M Quote Link to post Share on other sites
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