|
Need to get a couple of new tyres - front down to 3mm and rears 5mm - Assume the best thing is to put the new ones on the rear as this seems the recommended procedure on safety grounds. All agree?
|
|
Yes. It avoids the possibility of the rear having less grip than the front, and therefore your boot trying to overtake you in a skid.
|
|
CG - if you do a forum search you'll find lengthy discussion on this very subject...
|
CG - if you do a forum search you'll find lengthy discussion on this very subject...
>>
and this one will be as long?
The choice is for CGNorwich of course.
www.camskill.co.uk/products.php?plid=m11b0s0p0 has a little example near the end of what happens with best tyres on the front.
|
www.camskill.co.uk/products.php?plid=m11b0s0p0 has a little example near the end of what happens with best tyres on the front.
Is that the "Why you should fit 4 Winter tyres to your car, NOT 2 !" clip?
|
|
|
|
|
Thanks - More than adequately covered! Will put the new ones on the rear
|
|
|
|
|
I might be inclined to put them on the front, since there's reasonable tread depth on the back. However, putting two new ones on the back and the old back ones on the front would mean that the next tyre change wouldn't be so expensive...
Depends on how long you will keep the car, to some extent, and whether the fitter will swap 'em free.
|
And the rear tyres may need rebalancing when moved to the front. I think I'd just do straight replacement.
What car and tyre size btw?
|
Yup. I'd normally say put the new ones on the back (see the self-same thread you call attention to). However, he's got 5mm at least on the back.
The video shows someone testing a minimum-depth/new tyre set-up, and is obviously not the same as the OPs.
|
The video shows someone testing a minimum-depth/new tyre set-up and is obviously not the same as the OPs.
The VickiBH video is with new tyres at 8mm tread and part worn at 5mm.
|
I have 4mm all round at the last measuring (been rotating the tyres as per Honda's schedule) - This means I'll have to change all four come next month :-( I mioght change the car instead ! :-)
I always work on the basis that 4mm is the nearest I'll go to the bone - mind you the car has been peerless in this bad weather.
Edited by Pugugly on 12/01/2010 at 18:17
|
Putting four on the Mondy on Friday. It has 2mm on the fronts and 3mm on the back. Been a bit "loose" on the white stuff in fairness......Still quite good though.
PU, are you turning Irish ?
Anyway, if you do change, which BMW will it be then???
;-)
|
|
|
|
My fwd car had the new ones on the front i know the advice but stuff that i want best grip on front they did not bed in till about 600mls so in wet you just had to be carefull.
However remember when you buy a brand new car there all NEW! so you just have to get on with it.
That was last year before snow came and glad i did deffo improved the grip.
|
My fwd car had the new ones on the front i know the advice but stuff that i want best grip on front they did not bed in till about 600mls so in wet you just had to be carefull.
Those that question the sanity of choosing to put new tyres on the front of a FWD car always manage to miss that bit out.
The new tyres as you've demonstrated out arn't (with notable exceptions) a lot of good till up to a thousand miles on cars, i don't hear of disastrous rear overtaking front reports during bedding in time.
There has to be set of rigid one size fits all rules to follow these days, heaven forbid someone might have the nous to know how his car handles and tyre it up accordingly, maybe even taking into account the qualities of the various sets.
I usually end up buying them by the 4 anyway, swapping round to even wear out and change around 4mm or only slightly lower.
|
|
|
|
The VickiBH video is with new tyres at 8mm tread and part worn at 5mm.
I listened to the clip, but that wasn't said. How do you know?
Edited by FotheringtonThomas on 12/01/2010 at 18:22
|
>> The VickiBH video is with new tyres at 8mm tread and part worn at 5mm. I listened to the clip but that wasn't said. How do you know?
Bit of Sherlock Holmes! :-) If you pause the video when they are showing the worn tyre, you can clearly see the wear indicator blocks which are 4mm, the tyres haven't reached them yet.
|
I can clearly see the wear indicator blocks which are 4mm
Oh. I didn't know that the wear indicators on tyres are 4mm high. I don't think mine are.
|
>> I can clearly see the wear indicator blocks which are 4mm >> >> Oh. I didn't know that the wear indicators on tyres are 4mm high. I don't think mine are. >>
AFAIK 4mm is what you find on winter tyres.
Normal, standard, common, whatever, tyres are 1.6mm.
Some have an additional indicator at 3mm to indicate the tread depth is getting near the limit.
Edited by jbif on 12/01/2010 at 19:14
|
Indicators on mine are nowhere near 4mm. Fronts are at about 4mm and TWI hasn't been reached yet.
Edited by daveyjp on 12/01/2010 at 19:18
|
|
Perhaps the idea of putting snow chains on the rear wheels of a front wheel drive car isn't so laughable, if perceived wisdom is to have the newer tyres on the rear to prevent rear end drift.
|
Normal standard common whatever tyres (wear indicators) are 1.6mm.
Yup. Combined with the "... and yet completely legal" from the clip suggests that there's probably about 2mm on the back, and 8 on the front. In this situation, I'd switch 'em PDQ. For 8:5+ I wouldn't.
Edited by FotheringtonThomas on 12/01/2010 at 20:06
|
|
My impression of the VBH video was either the tyres were at 2mm on the rear or she tweaked the handbrake. In decades of new to the front motoring I've never managed (despite trying) to replicate that!
|
My impression of the VBH video was either the tyres were at 2mm on the rear
The "still legal" bit was stressed. I agree.
In decades of new to the front motoring I've never managed (despite trying) to replicate that!
As said before, I would not put nearly worn out tyres on the back and new on the front - but 8:5 isn't an issue.
|
>> Normal standard common whatever tyres (wear indicators) are 1.6mm.
Yep, my mistake, it's 4mm on winter tyres.
|
it's 4mm on winter tyres.
And Winter tyres have their fitting rules too... recently discussed here IIRC.
Edited by FotheringtonThomas on 12/01/2010 at 20:46
|
Why ever not? The road safety world - expert drivers, tyre makers, the police - say the better tyres should go on the back, so why would you say "I know better than them so I'll do it my way"?
True, FT's method would eventually achieve the correct balance, but it seems to be based on an assumption that rear tyres with 5mm of tread will never lose grip. But what if the car hit standing water on a fast bend, say the one near J8 of the M40? The new front tyres might plough safely through it, but the rear ones, even with 5mm, wouldn't clear the water so well and could aquaplane and spin the car. Wouldn't be fun with the 5mm tyres on the front but it would probably be recoverable rather than catastrophic.
To address a couple of minor cavils,
(i) I understand that a wheel-and-tyre combination is balanced only with itself, so the balance would not be affected by moving the wheel from back to front; and
(ii) I've always asked tyre fitters to move the old tyres to the front and none of them as ever suggested charging extra for it.
|
what if the car hit standing water on a fast bend say the one near J8 of the M40? The new front tyres might plough safely through it but the rear ones even with 5mm wouldn't clear the water so well and could aquaplane
except there won't be any standing water for the rear tyres to clear because those juicy 8mm+ fronts will have cleared the vast majority of it a fraction of a second before.
|
But what if the car hit standing water on a fast bend say the one near J8 of the M40? The new front tyres might plough safely through it but the rear ones even with 5mm wouldn't clear the water so well and could aquaplane and spin the car.
But, if, say, might, but, wouldn't, could - won't[1]. If that place was a problem, people on 5mm tyres all around (or even 2mm all around) would be spinning off all over the place for much of the time. They don't. QED.
To address a couple of minor cavils (i) I understand that a wheel-and-tyre combination is balanced
Yep.
would not be affected by moving the wheel from back to front
AOL.
True FT's method
It's not "FT's method". I have made it clear that I do not advocate mixing worn-out tyres on the back with new front ones.
[1] Unless you're talking supersonic.
|
GB, you're assuming the rear wheels follow the same path through the curve as the front ones, which they won't, so they'll always have some water of their own to clear.
And FT, you're missing my point about that curve on the M40. I didn't pick it as a blackspot for aquaplaning, merely as a curve fast enough to demand optimal water-clearing performance should there be standing water. Accidents tend to happen when several factors - high speed, standing water, traversing a curve, differential aquaplaning - combine to create an unmanageable situation. Why would anyone not take a simple measure to reduce the likelihood of one of these?
|
GB you're assuming the rear wheels follow the same path through the curve as the front ones which they won't so they'll always have some water of their own to clear.
Well as it was a fast curve scenario yes i did assume that, can't see how you could get the tyres into an aquaplane situation on a curve tight enough for the rear wheels to describe their own arc, a curve tight enough couldn't be taken quickly enough to raise a tyre up on the water....my opinion only obviously.
I agree they will always have a certain amount to clear but the bulk of water likely to induce such a thing will have been dispersed by the fronts.
|
Why would anyone not take a simple measure to reduce the likelihood of (problems).
When the reduction in likelihood of the problems is approximately 0 and it's not worthwhile.
|
|
|
|
|
