Bmw Big Change Of Mind On Tyres?

[foreign1]

Only just realised that new BMW1s seem to be sold now with 4 non-run-flat tyres and "a tyre repair kit" that I assume is a can of foam spray in the boot. Are they telling us something important about run-flat tyres?

Like they are very expensive, as already mentioned in this forum, even if you buy them from Asda.

And could it be that conventional tyres give a far more comfortable ride, with less bone shaking?

[M2 NPE]

hmmm...interesting. For me personally I'm going to stick with the run flats purely because the one series has no spare wheel or space to put one. I have no issue with getting my hands dirty and quickly changing a wheel if I get a puncture but I don't want the inconvenience of sitting at the side of the road waiting for recovery because I have a puncture and no spare wheel. I've heard of the cans of stuff that re-inflate and seal a punctured tyres, but I've also been with someone where they've tried to use the stuff and the can just didn't go off or do anything!

[Dizgav]

Ok all e46 m3 have no run flats and no spare wheel As standard we just have a small air compressor and a can of tyre weld.

It's never been a problem for me I've had a flat tyre the system worked to my satisfaction.i will never have run flats cont m3s for me every time! ;-)

The ride is far to hard with run flats any how

[btmaldon]

I agree that my run flats are very harsh on some roads, but in some cases the tyre weld is pretty rubbish. I keep a can in the boot just because I happened to have one but I also have another temporary repair kit that you can use for most punctures without having to take the wheel off.

http://www.ebay.co.uk/itm/CAR-VAN-TYRE-TIRE-PUNCTURE-REPAIR-KIT-WITH-10-STRIPS-/131230465044?pt=UK_Cars_Parts_Vehicles_Wheels_tyre_Trims_Trims_ET&hash=item1e8df1fc14

Not had to try and use it yet and hopefully never will.

[luckysummer]

whats the price difference for run flats to normal tyres

[btmaldon]

Run flats are from £250 each.

[Guest Mister Dabsy]

Don't get us started on Run-Flats :angry: :lol:

[foreign1]

We have already started on run-flats, but not finished yet, I'm afraid. It seems there is another big issue if you swop from run-flats (RFTs) to conventional tyres.

A tyre supplier tells me, " BMWs with RFTs have softer suspension to absorb these road shocks. Also the suspension allows superb handling provided that the tyres contact patch can be maintained. To do this the wheels vertical position (camber) is tilted, and along with suspension and geometry adjustments, allows both tyre and suspension to follow the same radii thus maintaining that all important tyre contact patch."

So, if changing to conventional tyres, do we have to get the suspension and wheel camber changed too? Sounds complicated and skilled work. Has anyone experience of getting this work done, please?

[Guest Mister Dabsy]

Nah, the camber maintains the optimum tread contact whether you fit run-flats or a bicycle wheel !

[foreign1]

How are you sure that the tilting of the camber, to which I referred above, and the suspension and geometry adjustments are the same for conventional tyres on BMW1?

[btmaldon]

The camber should only need adjusting if you are fitting a different width wheel and may have lowered the suspension. A wider wheel with no adjustment for camber and in some cases tow can cause it to wear on the inside. I took my Father in Laws car to a specialist near Wales to sort his out as he had bought a car that had been fitted with lowered springs and much wider wheels.

I cant see any physical reason why the camber would be changed if you just had a different tyre type. As far as having a softer suspension, I cant feel it on the M Sport.

[Guest Mister Dabsy]

Thanks you put it better than me lol

[foreign1]

Thank you, btmaldon, very helpful.