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Acceptable tolerance for wheels


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I am about to refurbish the steel wheels on my TR6, it was a few small dents on the edge of a couple of the wheels which I made good with heat and a hammer. I want to check if the wheels are true before I go any further, I got a dial gauge but no stand so just ordered one.

 

What is the acceptable wobble on a wheel? I would guess that depends on the speed, how bad would a 1mm wobble be?

 

 

Magnus

Edited by TRseks
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I would have thought that any 'wobble' would be taken up by wheel balancing? Unless of course the wheel is totally out of true?

If you take the offending wheels down to your local tyre place & they put them on their machine it will be pretty obvious if they are out?.....................................................I stand to be corrected mind you!

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I saw a Marcos the other day where the rear wheel seemed to be wobbling about half a inch.

The driver seemed happy but I would have tolerated it!

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I struggled with this last year. The car would begin to feel unstable with speeds above 60 miles/hour... Had the wheels balanced two times but the problem stayed. The second time I was there when they balanced the wheels. After putting on a fair amount of weights the machine indicated it was perfect despite the fact that two of the wheels had a wobble of about 5 mm....

 

So not being happy with the car unstable at speed I decided to get some new wheels (minilites)... and the difference is enormous. The ride is much smoother... at every speed

 

I doubt if a wobble of just just 1mm would be noticeable but 5mm is too much in my opinion ..

 

Cheers,

Edwin

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One thing I learnt when I had a lotus élan was the difference between balancing wheels on and off the car. I always had a wobble at speed even when the wheels were balanced off the car. I then heard of a place near silverstone that could balance on the car. The difference was amazing!!

Cheers

Tim

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Tim, I am currently plagued with a severe wheel wobble, usually around 57 to 65 mph. It has been like this since I rebuilt the car, frankly I'm getting desperate and considering having the on the car balancing done, but the nearest place I could find was Bicester! Much further than silverstone. I've done lots of fruitless google searches, do you know who the company near silverstone are? Or indeed does anyone know of another company nearer to me in Essex? Bob.

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Like Edwin, I went through this exercise also when i refurbished my steels (before the accident!)

 

I had it pointed out that wheel wobble (that shaking you get through the car) and the subsequent correction with weights is the wheel + tyre being unbalanced as far as radial weight distribution (think unbalanced washing machine drum)and NOT bent wheels/rims.

If the wheel deviates left to right when looking from behind, then weights etc wont fix this issue, you need to get the wheels straightened..THEN put the tyres on and get it balanced.

As for run out, Id say any more than +/- 5mm is verging on unacceptable.

It would also surely wear tyres out quicker too?

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The chaps I used were.

 

http://vibrationfree.co.uk/

 

I think these are probably the people on Bicester that you mentioned. I guess from me that counts as near silverstone!

Cheers

Tim

Edited by Tim D.
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Thanks for that Tim. Yes they are the people, who I am beginning to think are the only people in the UK who do still balance on the car. Even then this is just a small part of what they do. Bob.

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A point to bear in mind the tyre contributes hugely to whether your wheel is in our out of balance and requires lots or even no weights.

 

I've used Michelins on wire wheels and because of the wire wheel is inherently in balance when a Michelin was fitted no weights were required, conversely when Pirellis were fitted the same wheels (still in balance) needed huge gobs of lead to remove vibration. Mr Michelin makes tyres which are concentric, not all makes do.

 

Mick Richards

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When I got my lotus done these guys said they were the only people in the UK doing this.

I had to say I never found anyone else. The reason I used them on the lotus was that the wheels located on the pegs as they were centre lock and tyre fitters cannot handle this as they use the central hole for location. If you do use these guys mark the wheels for position on the car and orientation on hub

Tim

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  • 6 years later...

I am in the process of restoring (frame off) a 1971 TR6.  Disassembling the rear hubs turned out to be a tremendous task.  The first hub (from the RH side) popped apart fairly easily with my 20 ton press.  But the LH side refused to come apart until I went to a machine shop and used their 50 ton press.  Problem is, even with my fixture (a 7-1/2 inch long piece of steel pipe) which held the outer flange  very evenly near its outer diameter (except at the stud bosses  where I had cut reliefs) , the press bent the flanges.  Also, the first flange was bent from previous activities (by a "jack leg" mechanic, to be sure -  I have seen too many other examples of his/her work on this car).  The flange on an axle assembly I bought on eBay was bent similarly.  I measured the planarity of all three flanges using a dial indicator and a fixture I built to allow me to spin the axle with the flange on it while measuring the face of the flange. 

Bottom line of all this is: if you (or anyone else, for that matter) have ever disassembled your rear axle hubs, you have very likely bent the flanges.  There are many posts and warnings on the internet telling of this.  It happens because (apparently) after 40 years or so of these parts being together, they have become very good friends and to not want to part (as is the case with just about any taper fit).  A deviation of as much as 0.047 inches between one point on  the flange and a similar point ont the other side, when multiplied by the ratio of the tire diameter  (26 inches at the tread face) to the flange diameter (4-3/8 inches at the stud centers) will result in a wobble of just over 1/4 inch.  This may not seem like much, but at high speeds, I'm sure it will  be noticeable.  

I'm going to try to improve my flanges.  Wish me luck.

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It's worse than you think Tom. The bent flanges are not the main problem but the processes used to split the hub off the tapers are, it often does this to the hubs

1946300104_StagHubfailure.jpg.bd527617e00477509889d87e2c4239d0.jpg

Then when you do the other one it does this

1184405796_StagHubfailure2.jpg.af4455a4a258bea21cc2be32ec098f99.jpg

Now these are off a pair sold to a Stag owner that had been reconditioned by a specialist, and after the first failure the second hub failed within 18 months. If you search on this forum under Hubs failure or the like you will find many posts where owners have posted of problems and where we have had cars inverted because of it. The hubs and rears "Innsbruck" suspension designs are shared between Stag, TR4a/5/6 with the independent suspension, and Triumph 2.5 saloons and all have the same problem...age, the hubs and components are...dying. Many years of being bumped over kerbs or used for racing at weekends (race on Sunday drive to work on Monday) old saying used by dealerships to sell Triumphs, and being split on varying sizes of presses to replace worn bearings are causing fractures in areas that cannot be adequately crack tested...but found out later when being used.

Do not buy replacement old hubs that have been refurbished, NOBODY can check whether they are safe or not, only you by driving, NOT the way to do it. These old hubs owe TR owners nothing, after 50 plus years they have exceeded their original design life by many times, if you asked a modern BMW or AUDI design engineer what condition their hubs would be in after the same time and usage they would not put their companies reputations to the test. There are new hubs from a variety of sources, again they will be found in the search function, fit these with new driveshafts whether CV or normal sliding design for reasonable prices and assure yourself of further long, reliable and most importantly safe motoring into the future.  

Mick Richards   

 

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Magnus--

 

I don't know if there is a spec on wheel runout, but when I checked my original wheels on my '74, four of the five were 0.035" or better.  The fifth one was almost triple that.  It's my spare now.

Ed

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On 6/12/2013 at 8:39 PM, Motorsport Mickey said:

A point to bear in mind the tyre contributes hugely to whether your wheel is in our out of balance and requires lots or even no weights.

 

I've used Michelins on wire wheels and because of the wire wheel is inherently in balance when a Michelin was fitted no weights were required, conversely when Pirellis were fitted the same wheels (still in balance) needed huge gobs of lead to remove vibration. Mr Michelin makes tyres which are concentric, not all makes do.

 

Mick Richards

Surely that is what the 'coloured spot' on the side wall is all about?  

It is placed there by the tyre maker to identify the light side of the tyre and should be adjacent to the valve stem when the tyre is fitted.

At least that is what I was taught when fitting aeroplane tyres in the 1970's.  It also gives an idea of tyre creep around the rim due to braking/accelerating, on the assumption that the tyre was fitted with the spot next to the valve to start with.

An American view on the subject. 

https://www.tires-easy.com/blog/what-are-the-red-and-yellow-dots-on-my-tires/

 

Cheers

Peter W

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33 minutes ago, BlueTR3A-5EKT said:

Surely that is what the 'coloured spot' on the side wall is all about?  

It is placed there by the tyre maker to identify the light side of the tyre and should be adjacent to the valve stem when the tyre is fitted.

At least that is what I was taught when fitting aeroplane tyres in the 1970's.  It also gives an idea of tyre creep around the rim due to braking/accelerating, on the assumption that the tyre was fitted with the spot next to the valve to start with.

An American view on the subject. 

https://www.tires-easy.com/blog/what-are-the-red-and-yellow-dots-on-my-tires/

 

Cheers

Peter W

Agree Peter, but the point I hoped was made (it was back in 2013) was the wheel once balanced, if it has a concentric and density controlled tyre placed upon it should not require further weights. A balanced wheel with a concentric and evenly weighted tyre (due allowance in fitting it for any sidewall coloured dots to allow for uneven valve weight discrepancies on the wheel included) should not require extra balance weights. In my experience Michelin tyres do, not all others can claim the same.

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0.040" = 1mm TIR is the maximum runout according to Uncle Bentley if I recall correctly ( the source, not the value - I'm sure about that ).

The best of my original TR250 wheels was at the limit; the worst was about 2X.

When they were in production, at least here in the  'States it was unusual to find a TR whose front end didn't shimmy at 60-70 mph ( some said they were trying to attract mates ^_^ ).

I've been using Panasports for the last 30 years. Michelin tires are what I've been using for the last 20 ( apart from a dalliance with Dunlop here and Avon there; don't bother ) and while they don't require much in weights they aren't perfect that way. The bigger problem is keeping the weights stuck to the compound curves of the wheels. Because I've become accustomed to perfectly smooth operation at any speed I get upset when they don't behave, which has been due to weights falling off, usually in the garage.

It is possible to get smooth operation with a bent hub if balanced by the best shops; I got a vibration after rotating tires much later. Watching over the specialist slaving away in vain I thought I spotted a bent flange, mentioned it and got a replacement - end of.

 

Tom

Edited by Tom Fremont
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