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Just fitted Bridgestone Turanza 195/65/15 to the 4A. Nicer feel than the same sized Falkens on the 6. Nice ride and good wet/dry grip. This size is readily available from many manufacturers which gives a range of prices. 

Thats as wide as I would go. Steering gets heavy and wider wheels / spacers needed. 

Some advocate originality calling it handling. Personally I interpret that as lack of grip. But that’s a personal preference. Original sizes in quality rubber are expensive.

 

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7 minutes ago, Andy Moltu said:

Original sizes in quality rubber are expensive.

But isn’t it worth matching the car’s value?

Regards

Bill

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1 hour ago, Motorsport Mickey said:

"My favourite was the Firestone 560 - but they are no more."

AAaaaahhh the fabled "Ditchfinder Generals" of yore, lol.

Mick Richards

 

Hi Mick,

on my 4A they worked well but then I'm running at touring pace not flat out.

 

Roger

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I'm running 165/80 15's, I love the way they feel, but also as important they look so right on the car, I can't stand the over tyred square tread of 195's.

But as they always say, it's your car do want you want to it. 

Gareth

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1 hour ago, DRD said:

Indeed - all the US ones had 185 tyres. I really can't see any evidence that anything larger than 165 will increase stress on the suspension.

That's what we need, somebody presenting a reasoned argument !

Of course all owners fitting wider than 165 tyres can't prove any technical benefit in fitting the wider tyres. S'obvious.

If you fit 195 tyres you don't gain any grip...right ? Oh...I think you'll find many owners here running 195 tyres might disagree, just check out some of the posts. It's a truism, wider tyres=more tyre on the road=more grip=increased stress on the suspension, the G force on cornering must increase if you use the increased grip...otherwise why bother to fit them. ? 

Mick Richards

Edited by Motorsport Mickey
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1 hour ago, Andy Moltu said:

Some advocate originality calling it handling. Personally I interpret that as lack of grip.

Don't confuse handling and grip; they are quite different. Greater grip usually equates to more abrupt breakaway rather than the easily managed drift caused by tyre deformation. With my 67 year old reactions I'm not a good enough driver to cope with abrupt changes in grip. 

Here's some food for thought though:

Friction is independent of surface area.

Wider tyres increase unsprung weight and  reduce acceleration. Weight on the wheels is much more of a disadvantage than weight in the body as it has to be accelerated forward and in rotation.

 

Edited by Drewmotty
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Yep. As ever a controversial topic. I run 195s on the TR and for the record 185s on my stag. Not had the TR break away yet and that included some very spirited driving at spa. Think the "sudden" breakaway myth is really more associated with the "rubber band" tyres used on pimped modern cars. Certainly  195s may break away slightly more suddenly than 165s, but you have to push them a lot harder than for 165s for it to happen and in my case I never reach that limit. I did drive a TR4a on new 165s and it felt more lythe but also more scary. Back end was much more mobile on corners. Kinda fun, but might be waring on long drives. 

However,  whatever the choice the main thing to think about is will you be able to afford to replace them every 5 years when they get too old. I don't have the depth of pockets for doing this with a set of XAS but can with the more reasonable 195s. If you do go 195s consider uniroyal rain expert. Very popular with midget owners as they are a bit softer. Means they wear quicker but I replace every 5 years so don't care. 

Tim

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7 hours ago, Motorsport Mickey said:

That's what we need, somebody presenting a reasoned argument !

Of course all owners fitting wider than 165 tyres can't prove any technical benefit in fitting the wider tyres. S'obvious.

If you fit 195 tyres you don't gain any grip...right ? Oh...I think you'll find many owners here running 195 tyres might disagree, just check out some of the posts. It's a truism, wider tyres=more tyre on the road=more grip=increased stress on the suspension, the G force on cornering must increase if you use the increased grip...otherwise why bother to fit them. ? 

Mick Richards

I dont see much of a sound argument from you other than dodgy assumptions. Show me the stress calcs that show values exceeding the design specs for the suspension or any other demonstrable engineering evidence for this. If I had the time I'd do the dynamics calc myself, but I presume Triumph did something similar at the time when they fitted 185s to the Federal cars and found everything was within acceptable safety limits.

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"I don't see much of a sound argument from you other than dodgy assumptions."

Nope...all I hear there is you thrashing around and doubling down on your original unthought assertions "I really can't see any evidence that anything larger than 165 will increase stress on the suspension." ! ! !

If you can't see that my comment repeated below 

"It's a truism, wider tyres=more tyre on the road=more grip=increased stress on the suspension, the G force on cornering must increase if you use the increased grip...otherwise why bother to fit them. ?"

Is proven by it's very virtue of the wider tyres with more grip extending the contact patch away from the centre of wishbone rotation, and by so doing increasing the applied force lever length thereby transferring increased stress to the suspension components and through them the bracketry and into the chassis.

Then supplying you with a few pages of calculations to prove the same thing is unlikely to be accepted by yourself.

Perhaps you'd like to present us with your calculations (if only you had the time) proving the unprovable that increasing lever lengths DOESN'T increase the forces applied by the wider tyre widths. 

That's what we need, somebody presenting a reasoned argument !

Mick Richards

Edited by Motorsport Mickey
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Surely DRD the US tyres were 185 x 15 therefore had a higher profile and that would put less strain on the suspension components than if BL had fitted 185/70/15. The higher the tyre the more the tyre takes up loading on suspension components whereas the lower aspect tyre will always place more strain on anything behind the wheel and tyre itself.

Thats my take on the matter anyway and no I would not fit 195/65/15 tyres onto standard TR6 wheels. I will stick with the 165 x15 that the car came with.

Alan G

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46 minutes ago, Motorsport Mickey said:

"I don't see much of a sound argument from you other than dodgy assumptions."

Nope...all I hear there is you thrashing around and doubling down on your original unthought assertions "I really can't see any evidence that anything larger than 165 will increase stress on the suspension." ! ! !

If you can't see that my comment repeated below 

"It's a truism, wider tyres=more tyre on the road=more grip=increased stress on the suspension, the G force on cornering must increase if you use the increased grip...otherwise why bother to fit them. ?"

Is proven by it's very virtue of the wider tyres with more grip extending the contact patch away from the centre of wishbone rotation, and by so doing increasing the applied force lever length thereby transferring increased stress to the suspension components and through them the bracketry and into the chassis.

Then supplying you with a few pages of calculations to prove the same thing is unlikely to be accepted by yourself.

Perhaps you'd like to present us with your calculations (if only you had the time) proving the unprovable that increasing lever lengths DOESN'T increase the forces applied by the wider tyre widths. 

That's what we need, somebody presenting a reasoned argument !

Mick Richards

You still haven't provided any evidence that the forces on the suspension for 185 size re. 165 are going to be a problem for the suspension - just hearsay!!

I don't dispute the forces will change, as they would for any other alterations. Show us the tangible data that these forces will exceed original design/safety parameters.

If you can't stop postulating your opinions as if they are facts!

 

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Damage to steel components from fatigue failure is cumulative and related to stress levels and time (number of stress cycles) .   If Triumph did such calculations originally, they would have been based on the expected life of a vehicle at that time - maybe ten or fifteen years?

Fifty + years later we have instances of failure of rear stub axles on the IRS cars.  I wonder whether that is related?  While the initial damage may be due to incorrect repair methods, the subsequent stress loading could be a factor in this. 

http://www.mg-cars.net/triumph-tr6-bbs/rear-stub-axle-failures-on-tr6-199902280025340.htm

 

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50 minutes ago, DRD said:

You still haven't provided any evidence that the forces on the suspension for 185 size re. 165 are going to be a problem for the suspension - just hearsay!!

 

 

I’ve never claimed the forces on the suspension “are going to be a problem” you are trying to make your assertions fit a claim I never made. 
Thankyou for accepting that the larger tyres will change the forces on the suspension, which is what I said, that at least we both agree about.

 

Mick Richards

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Were 195/65/15 or 185/70/15  tyres common when the TR6s were conceived? In that era crossplies were still pretty common. Would Triumph have fitted lower profile ones if the 6 was around in the 1990s - probably as they did to the Jags & Rovers of the era.

Lower profile tyres are a "relatively"  modern thing on production cars with a seeming steady progression to the modern ultra low profile tyres on modern performance cars, the thoery presumably is that the tyres are to provide the grip and leave the rest to the suspension.

The stub axle failures are not new. Occured relatively early on on the estate cars that were heavily loaded.

Metal fatigue occurs, the bigger the forces the faster it occurs.  The key big force on the stub axle is that needed to separate the bearings during rebuild (much more than the loadings from tyre grip in road use - not absolute as hefty kerbings may be relevant) Probably why hubs with the original bearings rarely fail and quite a high proportion in my experience have been rebuilt ones that have not replaced the stub axle as part of the rebuild.

If you are concerned your driving and the forces from the tyres might break the hub I would advocate you replace them. I have concerns about the quality of the current "new original design hubs" being supplied so personally fitted the Classic driving development ones on my TRs & Stag which use a modern hub & bearing of Japanese origin. (There are other after market ones, such as the ones supplied by Dennis Vessey which again use a modern proven hub I think of Cosworth orgin adapted to fit the TR trailing arm).

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On 7/19/2022 at 3:26 AM, nickw71 said:

Ah yes, the chap (owner) of Blockley tyres was explaining away that report on his stand at the NEC resto show back in March. 

I have no direct experience so only repeating favorable comments from this forum and the e-Type owners club (father in law) as they seem popular with that mark. 

Interesting to hear Gavia's comments above on the Pirelli CN36 as I've considered those as an option. It's a period profile and 185 width (as fitted to US cars).

Nick  

Nick, my car and I are located in Canada, (NA Spec vehicle) the only tires its ever worn are the original Goodyear 185-SR-15, Dunlop 165-80-15, Michelin X 185-15, and awful set of Falken 205-65-15, and finally the current Pirelli's.

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Just bought 4 165 x 15 Pirelli CN36 tyres from Longstone as the Michelin XAS are now 8+ years old. Nothing visually wrong with the XAS but I value my life and possibly someone else's so they have been retyred, if you'll excuse that worn out pun, oh there I go again!

Not cheap but neither is my life, just get it done and do the crying later! 195/65/15 tyres are evidently a lot cheaper but take away from what the car is and does, I have been down the 195 route and they are not for me.

Alan G

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There is a huge difference in feel between different makes of tyres in the same size.  

Bear in mind when fitting modern tyre sizes, some are intended for heavier vehicles.

Over the years I have run the 6 on 165 Mitchelins (can’t recall the exact spec as it was 35 years ago) and my verdict was between s***te & shocking. Then 185 Goodyear which were ok. Then 195/65/15 Kelly which had good grip but the sidewalls were a bit soft which gave a strange feel. Avon ZV1s 195/65/15 which were lovely both in the dry and the wet. Replaced by the Falken 195/65/15 which are just a bit hard feeling.

The 4A had 165 Mitchelin (XAS I think) which were shockingly devoid of grip. Not great in the dry but frankly dangerous at 30mph on a wet road. Yes they were past their best but barely used and negligible exposure to UV light. Now on Bridgestone Turanza 195/65/15 and infinitely nicer to drive.

I am not concerned that it is overly heavy to drive let alone thinking about a PAS conversion.  Having said that I. Can appreciate that those who have never experienced cars without PAS might find any of the TRs heavy at low speed.

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Andy,

You specify the CDD hubs have Japanese bearings, if it’s stamped on them they may be, ( Timken are a world wide operation with factories across continents). But Timken bearings are acknowledged as being extremely good, and a Timken bearing meets the right spec no matter where it is made.
CDD Specify as follows

“Genuine Timken / SKF taper roller bearings widely spaced, larger than standard and solidly shimmed.

Bearing design and layout developed in conjunction with Timken UK.” 
I’m happy with that.

Mick Richards.

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I was referring to the origin of the hub I think was a Nissan or Hyundai so used the generic “Japanese” term. No problem with using Timken bearings at all.) I was just giving examples of the alternative hubs’ derivation rather than specifically the bearings in them. Apologies if this read erroneously.

 My concern is that not all rebuilt standard hubs have new stub axles and that even the brand new remanufactured ones are put together too well as Chris Hale found out as he pulled into the campsite at Malvern last  year and his hub came apart. If the assembly can’t be trusted then the make or quality of the bearings becomes academic.

The problem with the original hubs wasn’t the bearing but the terminal force used to separate them. (The stub axles will cope with low level forces an almost infinite number of times, but as the forces get higher the fewer times it can be taken without fatigue fractures. The one massive force used to separate a 50+ year old hub may prove critical in terms of accelerating the terminal fatigue. One of our local members lived in Guernsey for a while and a 60 ton press in a marine engineer’s workshop wasn’t enough to do the job!

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On 7/19/2022 at 12:13 PM, Bill944T said:

Bill - wonderful Carlos Fandango memories...the other Panama advert of not involved the strap line "fit zees skis and you will be the sensassion of the sleupes...."

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I thought it summed the topic up quite well especially with the six appeal link! There’s also the one with the photo booth that’s funny as well!

Regards

Bill 

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On 7/23/2022 at 12:10 PM, Andy Moltu said:

There is a huge difference in feel between different makes of tyres in the same size.  

Bear in mind when fitting modern tyre sizes, some are intended for heavier vehicles.

Over the years I have run the 6 on 165 Mitchelins (can’t recall the exact spec as it was 35 years ago) and my verdict was between s***te & shocking. Then 185 Goodyear which were ok. Then 195/65/15 Kelly which had good grip but the sidewalls were a bit soft which gave a strange feel. Avon ZV1s 195/65/15 which were lovely both in the dry and the wet. Replaced by the Falken 195/65/15 which are just a bit hard feeling.

The 4A had 165 Mitchelin (XAS I think) which were shockingly devoid of grip. Not great in the dry but frankly dangerous at 30mph on a wet road. Yes they were past their best but barely used and negligible exposure to UV light. Now on Bridgestone Turanza 195/65/15 and infinitely nicer to drive.

I am not concerned that it is overly heavy to drive let alone thinking about a PAS conversion.  Having said that I. Can appreciate that those who have never experienced cars without PAS might find any of the TRs heavy at low speed.

 

Hi,

my 2 cents on a topic that could run forever...

I run my 4A on 165 Michelin XAS and find them very good in the dry, i still have to try them on the wet.  They are not "shockingly devoiding of grip" to me.

Yesterday i tried a higher pressure as we have a long trip planned.  at 2 bar (29 psi) rear, i already feel it is too harsh for the chassis and suspension and the ride quality suffers.  I cannot even imagine driving 65 stiff modern profiles.  The chassis designed in the 60's calls for high profile tires at low pressure.  That way you have a smooth, predictable behaviour which i like.

But the 4A is a touring machine for me, i don't have to drive it very fast to enjoy driving it.

cheers,

Laurent

 

 

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Been in the tyre came for 40 years plus and always tired to fit Michelin tyres my 6 got 19 65 h15 Michelin tyres they old the road very good in all weathers plus at high speed 

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