Replacing just on tyre..
Replacing just on tyre..
Author
Discussion

xreyuk

Original Poster:

665 posts

176 months

Saturday 9th March 2013
quotequote all
Just curbed my wheel and popped my front right tyre, is it okay to replace just one tyre or should I get both replaced?

I've only had the one replaced because I've bought the same brand and model, and I had my service the other day and know there is still between 6/7mm tread left on the one on the front left.

However, the car is now pulling quite badly to the left. I obviously need to get the alignment checked as it could be this, but I was wondering if it could be the tyres? If it is I'll just go and get the front left replaced too.

Tyre fitters gave the suspension the quick once over and said there is nothing wrong that's easily identifiable.

wemorgan

3,583 posts

209 months

Saturday 9th March 2013
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IMHO 99% likely due to the wheel alignment

edit: as an easy test: swap the front and rear wheel around. I suspect the car will still pull to one side.

Camaro

1,432 posts

206 months

Saturday 9th March 2013
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Would agree, almost 100% alignment needs redoing.

craigjm

21,662 posts

231 months

Saturday 9th March 2013
quotequote all
You should really change tyres in pairs but if the other one has 7mm on it I wouldnt bother. Get the alignment checked

xreyuk

Original Poster:

665 posts

176 months

Saturday 9th March 2013
quotequote all
Thanks guys, I'll try and get it booked in.

Yeah it was serviced the other day and they were measured on the service and the two fronts before this were labelled as between 6-7mm



BOBTEE

1,034 posts

195 months

Saturday 9th March 2013
quotequote all
wemorgan said:
IMHO 99% likely due to the wheel alignment

edit: as an easy test: swap the front and rear wheel around. I suspect the car will still pull to one side.
This, but swap both rears to the front so they match. (Not sure if wemorgan missed an 's' smile )

wemorgan

3,583 posts

209 months

Saturday 9th March 2013
quotequote all
BOBTEE said:
This, but swap both rears to the front so they match. (Not sure if wemorgan missed an 's' smile )
yes sorry, it was a typo, I did mean both front and rear tyres smile

jamei303

3,084 posts

187 months

Saturday 9th March 2013
quotequote all
Note that a 1mm difference in tread depth equates to a 6.3mm difference in wheel circumference. That means for every 250 revolutions of one wheel, the other has to make 251 turns to keep up. This would happen over a distance of 400 metres. However if the difference is 5mm, the more worn tyre would have to make an extra turn every 80 metres.

As a rule of thumb you can double the tread depth differential to give you the deviation in degrees of the steering wheel from it's central position over the given distance.

A 1 mm difference in front tyre tread depth would give a 2 degree deviation of the steering wheel to that side over 400 metres
A 5 mm difference in front tyre tread depth would give a 10 degree deviation of the steering wheel to that side over 80 metres






clockworks

7,794 posts

176 months

Saturday 9th March 2013
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Can't see it making any difference at all on non-driven wheels, and very little difference on driven wheels (surely the diff would compensate?).

xreyuk

Original Poster:

665 posts

176 months

Sunday 10th March 2013
quotequote all
Just had alignment checked and they said it was only slightly out but still got a substantial pull to the left. Again they said suspension looks fine, and agreed with some posters above that they didn't think there would be much noticeable difference based on tread depths.

I did notice that when I held the steering wheel straight it was pulling very slightly left, but only very slightly. The rest of the pulling the steering wheel moves with the pull.

davepoth

29,395 posts

230 months

Sunday 10th March 2013
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xreyuk said:
Just had alignment checked and they said it was only slightly out but still got a substantial pull to the left. Again they said suspension looks fine, and agreed with some posters above that they didn't think there would be much noticeable difference based on tread depths.

I did notice that when I held the steering wheel straight it was pulling very slightly left, but only very slightly. The rest of the pulling the steering wheel moves with the pull.
Rotate the tyres. If the fronts aren't directional, swap them left to right, if they are directional, swap them front to rear. See if it makes a difference. If it does, it's the tyres. If not, it's still the alignment.

the_lone_wolf

2,622 posts

217 months

Sunday 10th March 2013
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Can you swap the left front tyre to the front right side and vice versa?

If the difference in tyre tread is the cause of the problem the car would begin pulling to the right, no?

Simple to do...

aw51 121565

4,773 posts

264 months

Sunday 10th March 2013
quotequote all
xreyuk said:
Just had alignment checked and they said it was only slightly out but still got a substantial pull to the left. Again they said suspension looks fine, and agreed with some posters above that they didn't think there would be much noticeable difference based on tread depths.

I did notice that when I held the steering wheel straight it was pulling very slightly left, but only very slightly. The rest of the pulling the steering wheel moves with the pull.
Did they check the castor (and camber) or just the tracking itself? My thinking is that the n/s/f axle has had a hefty belt and the wheel has moved back from its original position as a result of that (due to suspension derangement, or even chassis distortion which isn't unknown occasionally) - but I hope I'm wrong... smile

Stil, try swapping the wheels around, as 'pull' from a defective tyre (the way the cords are centralised can be incorrect on occasion) is much more likely (google "conicity" wink ) smile .

northandy

3,540 posts

252 months

Sunday 10th March 2013
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xreyuk said:
Thanks guys, I'll try and get it booked in.

Yeah it was serviced the other day and they were measured on the service and the two fronts before this were labelled as between 6-7mm
I'd be tempted to measure the tread myself, im my experience technicians do that by eye, and can be miles off, i had one set of rears reported as 4mm, yet they had only been fitted 3 weeks.

xreyuk

Original Poster:

665 posts

176 months

Sunday 10th March 2013
quotequote all
aw51 121565 said:
Did they check the castor (and camber) or just the tracking itself? My thinking is that the n/s/f axle has had a hefty belt and the wheel has moved back from its original position as a result of that (due to suspension derangement, or even chassis distortion which isn't unknown occasionally) - but I hope I'm wrong... smile

Stil, try swapping the wheels around, as 'pull' from a defective tyre (the way the cords are centralised can be incorrect on occasion) is much more likely (google "conicity" wink ) smile .
It was just the tracking, I'm going to have a proper 4 wheel hunter alignment done in the week.

It wouldn't be a pull from a defective tyre because it's pulling on the side opposite from the new tyre, and there was no pull before. The only reason I can think it would be related to the tyre is tread depth.

delmatt

506 posts

222 months

Sunday 10th March 2013
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I would be happy to bet my best underpants its not the tyre difference.Well tread depth anyway.
Have you checked the tyre pressure as well?

ModernAndy

2,094 posts

166 months

Sunday 10th March 2013
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How bad a knock was this? I know you had a pop-out but was it at speed or parking? What kind of car/vehicle was this on?

s p a c e m a n

12,140 posts

179 months

Sunday 10th March 2013
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What does it do when you brake/accelerate, make the pull stronger or weaker? Almost 99% certain that its not the tyre, unless you forgot to put air in it biggrin

xreyuk

Original Poster:

665 posts

176 months

Sunday 10th March 2013
quotequote all
Thanks guys.

Yeah pressures are fine, checked by them with their pump and then by myself afterwards at a petrol station.

It wasn't just a parking bump I was approaching a mini roundabout and it was a protruding curb, so I probably hit it somewhere between 10-20mph, definitely enough to knock the alignment out of whack. (I had good visibility that nothing was coming before anyone mentions I'm going too fast for a roundabout approach :P)

Braking seems to make it pull slightly worse as the brakes are applied, accelerating doesn't affect it.