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Fireman049

TYRE PRESSURES

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I once had two new tyres fitted to the front of my wife's car (not a TR) at our local tyre fitters.

On the way home as I entered a roundabout the car spun round full circle but luckily no damage was caused.

The tyre fitter had vastly over inflated the new tyres!  My advice to you is always carry your tyre pressure gauge and check the pressures before leaving the fitters.

I detest those air controlled wheel nut tighteners as they really overtighten the nuts and damage the wheels. I've always slackened the wheel nuts and retightened them

with the car wheel wrench.

Tom.

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Isn't the advice to fit new tyres to the rear of the vehicle?

Hence, if front tyres worn out, shift rears to the front and fit new tyres to the rear.

Ian Cornish

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They also need some careful driving initially to get rid of the release agent from the tyres that they put in the mould, especially on motor bike tyres. Certainly over inflation doesn't help

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Recently, I've needed new tyres on several of my fleet within the space of a few months. A pain in the wallet perhaps but definitely important.

Locally, my experience is you can rely on the tyre fitter to get the pressure roughly right but not spot on. Some ask what pressure I would like, as they don't see a 50 year old Triumph every day.

As for the wheel nuts, recently they tighten by hand then finish with a torque wrench. I've got into the habit of giving the tyre fitter a note of pressues and torque before he starts.

Nigel

Edited by Nigel Triumph
Typo

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My local Kwik fit in CONGLETON are ace. 

They do all my tyres. 

They alway torque the nuts typically peer reviewed as a 2nd person does the torque. 

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56 minutes ago, Hamish said:

My local Kwik fit in CONGLETON are ace. 

They do all my tyres. 

They alway torque the nuts typically peer reviewed as a 2nd person does the torque. 

Same here in Rugby.

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I could be wrong and stand to be corrected but I thought that if fitting 2 new tyres these should be fitted to the driven wheels, so in the case of all TRs this would be on the rear but for more modern front wheel drive cars then on the front. 

Chris

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I understood the reason to be that the newer tyres will give better grip - so putting them on the front tends to encourage oversteer, which is frowned upon, whereas on the back they encourage understeer which is regarded as safer.

When I last had tyres on my daily driver the mechanic duly tightened the nuts with a torque-wrench, but continued to lean on the thing long after it had clicked. I had to re-set the torques when I got home. 

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On my modern, new tyres go to the front.

I always assumed this was because the front tyres see more water, and a new high profile is better to encounter aqua planning.

And secondly: putting half worn tyres on the front axle will affect steering.

But not sure if my assumption is correct.

Waldi

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I'd put new tyres on the front of a modern, since most are front wheel drive, and the back end is only there to keep the boot from dragging on the ground! :D

Pete

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Nope...if you go downhill in the wet with new tyres on the front at the limit of adhesion, and come to a corner the back end will be lost (the older harder rear tyres (even if the same tyre as the front will have less grip) oversteering you into a tree or oncoming traffic. Doesn't matter if front or rear drive, when limit is met the rear tyres will still have less grip, the rear tyres become hard in use with multiple hot/cold cycles.  Even Michelin think so Ha...what do they know.

 

Edited by Motorsport Mickey

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Hello,

when I participated at several "safety trainings" by the ADAC (similar to your RAC) the instructors always told us to put the better tyres on the rear.

Why?
Because the rear axle is fixed to the body and so the direction of the rear axles is identical to the movement of the body. The front axle is indepedendant and its direction is modified by the steering wheel/ driver. So if you loose grip at the front, then the car moves into the direction of the body (rear axle) - if you loose grip at the rear, the car may move into any direction. Therefor it should be better to put the better tyres on the rear axle - independant from front/ rear wheel drive.

This is said to be valid for normal day driving and situations - not for forced drifting or driven on a track.

 

Regards, Johannes

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Thanks for posting the video, Mick - good demonstration of the reasoning.

Why do Americans state 2/32" when 1/16" would do?  And I didn't know that we drive V - hickles.

Ian Cornish

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I saw a long debate on another forum some months back and it turns out that pretty much all tyre manufacturers say the newer tyres should go on the back. I changed my new tyre habit of many years after reading it and seeing the sense.

The same thread also highlighted that British cars tend to wear out their nearside front tyres before the offside. Anyone care to guess why? (no Google cheating).

 

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Road camber.

Mick Richards

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We tend to go round right hand corners a tad faster because we 'See' them earlier

compared to left hand.

John.

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A few years ago I bought a 2 door Triumph Toledo with very new tyres on the back, can't remember what make but I think they were eastern European, and a very old set of Vredsteins on the front which were starting to crack on the sidewalls.

A week or so after buying it, I managed to spin it on a wet road, ironically on the way to the Stoke group TR register meeting. I managed just over 270 degrees before I slithered to a halt with trees either side of the road. The trees and hedges are festooned with number plates, glass, bumpers etc so it is obviously a slippery bit of road!

I realised very quickly that the new tyres were absolutely lethal after swapping them to the front end and finding the car ploughed on in a straight line whenever a corner was encountered.

I very quickly fitted a new set of quality tyres all round (on Dolomite Sprint alloys) which removed the terror factor, apart from the fact Toledo's are so poorly damped they are dangerous at speeds of over 50mph unless on a smooth road.

My conclusion is that by all means fit new tyres to the rear, but not if they are economy specials!

Neil

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All (or most) of the above ignores braking.

I wpuld always put the newer ones on the front on the basis that they will have more grip in an emergency braking situation. And I still will.

Jerry

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Your priority seems strange Jerry. You go round corners much, much, more frequently than carrying out emergency braking.  :rolleyes:

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2 hours ago, jerrytr5 said:

You haven't seen the way I drive.........

I have! :lol::lol::lol::lol:

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Having read all the posts and conceeding to the opinion of the professionals who say new tyres on the rear I am left with the following observations.

1. Fitting new tyres on the back is good.

2. Moving rear tyres worn flat onto the front is bad, awful steering low grip.

3. Regularly changing all the tyres  round to equalise the wear is the way to go so then no problem moving the rears to the front. Just a pain to do!

4. Alternatively always buy and fit 4 new tyres, ouch ! £££

Chris

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When I was poor and could barely afford to keep a TR on the road I bought tires in pairs, occasionally.

Otherwise, unless one gets an irreparable puncture early in its life I buy 4 or 5 at a time ( per Chris's #4 above ).

 

Tom

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My daily driver is a Ford S Max 2.0 litre diesel...heavy car about 2500 kgs in loaded condition with front wheel drive. I bought this car from my firm after driving it for 4 years as my company vehicle, (now at 11 years old with 164,000 miles on the clock) at first I left the tyres Michelin Primacy in their original positions and the steering tyres (front) wore down to 2mm after 14,000 miles near enough on the button. The rear tyres were at 5mm and I put a new pair on the rear moving the rear tyres onto the front, and after a further 8,000 miles I again moved  tyres at the rear moving them onto the front, and again after a further 8000 miles etc etc .

The rear tyres on all cars and especially front wheel drive cars have a much easier life than the front tyres. The fronts obviously have braking, steering and driving the car to contend with whilst the rear tyres merely suspend the weight of the car and have corning and braking forces (less than the front) but no steering or drive forces to contend with. Also the front engine positioning means weigh upon the front axles is about 15% more than at the rear.  Hence the rear tyres wear down considerably less but if the front tyres are not rotated front to rear the rear tyres receive many cold/hot/cold cycles which bleeds the oils out of the tyre and the tyre suffers from advanced aging (becomes harder) which again promotes less wear year on year (but less grip).

This leads to the scenario where new tyres on the front with their fresh rubber full of moulding oils and of softer compound (even if the same compound as the rear just years younger and with thousands less hot/cold cycles which hardens it) has considerably more grip which leads to the examples as shown in the Michelin video, when the front wheels get to the limit of their grip (front wheel drive or rear wheel drive) the harder rears exceed the tyres grip coefficient and off into the boon docks you go...dangerous. Driving safely is a percentage game, the number of times throughout the life of a set of tyres an emergency stop happens is very low, but the number of times you've driven in teaming rain becoming aware that even lifting off will cause a dangerous situation because of weight transfer, or a corner causing a side force or even the side draught from a HGV pushing your car out of line over a 2 or 3 year period will vastly exceed it...you think not ? it may well be because you are not aware of it, which should make you think again.  

The best mileage I got out of my Michelin Primacy was a combined mileage of 38,000 miles from a set of 4, which spread the tyres aging and hardening forces as equally as I could amongst the set whilst still allowing good grip for braking and steering available for the front axle. If I had continued to run new tyres only on the front the best mileage I would have recorded would have been 28,000 miles for a 4 tyre turnaround, whilst I would have risked having rear tyres which would have degraded in grip by a much more considerable amount than that available at the front. Interestingly the car leasing company phoned me after the first tyre change asking why I had instructed their tyre fitters to fit the new tyres on the rear after moving the older tyres onto the front, (there was a £10 extra labour charge involved) they listened to my explanation (as outlined here and after gum sucking said ok they'd monitor it). When I again spoke to them after reaching the 38,000 miles mileage for the Michelins apparently it had become company policy after seeing the tread life extension where their company expectation was 30,000 miles on an S Max, what can you teach young tyre fleet engineers eh... well apparently a great deal !). 

As a professional driver I was expected to drive to the conditions and if that meant slowing down an extra 5mph or expecting the unexpected that was part of the job. Driving to the levels of grip both cornering and braking was an expected skill... and yes having an unseen car or object in front which caused you to have an accident was not necessarily absolved as "that's life" without questioning and objective examination of what caused it..and no I didn't have one, but I know drivers who did.  

As a clincher for anybody who questions what Michelin (and other tyre manufacturers say, this advice is now universal) their advice actually removes money from their pockets ! Eh...what how come ? If new tyres are fitted to the front of a vehicle because they are softer (even if the same manufacturer and compound) and share braking, steering and acceleration forces they wear out quicker than if they are fitted to the rear, hence the tyre manufacturers recommendation of fitting them to the rear reduces their tyre sales with the increased mileages covered because nobody replaces worn Michelins with new Goodyears (unless a disaster has occurred).

So driving experts (as well as me) and tyre manufacturers say fit new tyres to the rear, now I'm not against the idea of ploughing a lonely furrow I've done it many times...but really ?    

Mick Richards   

Edited by Motorsport Mickey

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