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20" E70 Tyre Change

Posted: Sun Mar 10, 2013 9:52 pm
by 55NF
I'm changing to Non RFT as the ride on RFT with Sport Suspension is shocking.  I was told all four tyres  have to be changed at the same time, or is this total garbage?  Sounds it to me, I only need two fronts

Re: 20" E70 Tyre Change

Posted: Sun Mar 10, 2013 9:59 pm
by Chompers
Yep bollocks  >:D however the tyres must be of the same design/construction on the same axle i.e. change both fronts together and both rears together. Did this on my e61 and no body said anything about doing all 4 together. 2 were done by BMW and 2 by Micheldever.

There is another thread running about informing your insurance company as you are changing the vehicle fro how it was original built. Worth checking with yours I would guess  ;)

Re: 20" E70 Tyre Change

Posted: Sun Mar 10, 2013 10:03 pm
by 55NF
[quote="Chompers"]
Yep bollocks  >:D however the tyres must be of the same design/construction on the same axle i.e. change both fronts together and both rears together. Did this on my e61 and no body said anything about doing all 4 together. 2 were done by BMW and 2 by Micheldever.

There is another thread running about informing your insurance company as you are changing the vehicle fro how it was original built. Worth checking with yours I would guess  ;)
[/quote]


That explains it !  just two identical on the same axle.  So if you rip a tyre, you;re saying you have to change two?  Just looked at the Insurance thread & replied.

Re: 20" E70 Tyre Change

Posted: Sun Mar 10, 2013 10:08 pm
by Chompers
[quote="55NF"]
[quote="Chompers"]
Yep bollocks  >:D however the tyres must be of the same design/construction on the same axle i.e. change both fronts together and both rears together. Did this on my e61 and no body said anything about doing all 4 together. 2 were done by BMW and 2 by Micheldever.

There is another thread running about informing your insurance company as you are changing the vehicle fro how it was original built. Worth checking with yours I would guess  ;)
[/quote]


So if you rip a tyre, you;re saying you have to change two? 
[/quote]

No if you get a puncture or damage one tyre you have to replace it with a tyre of the same construction as the one on the other side of the car and presumably the damaged tyre.

Re: 20" E70 Tyre Change

Posted: Sun Mar 10, 2013 10:09 pm
by X5Sport
Not if you're replacing like with like.

It came in when the change from cross-ply to radial was ongoing.  As everything is radial these days, it's more about making sure that if you have directional patterns then these are maintained along with speed & weight ratings.


@ Chmoers - you beat me to it.. :)
Richard

Re: 20" E70 Tyre Change

Posted: Sun Mar 10, 2013 10:12 pm
by Chompers
[quote="X5Sport"]
@ Chmoers - you beat me to it.. :)
Richard
[/quote]

Too much red wine  :drunk:  ;)

Re: 20" E70 Tyre Change

Posted: Sun Mar 10, 2013 10:13 pm
by X5Sport
I wish.......... :))

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 5:07 pm
by davyk31
Mixing runflat on rear with non runflat on front would certainly not be advised. Never heard of it on an X5 but certainly people who did it on 3 and 5 Series reported very odd handling characteristics. You need to swap all 4 at once if going away from runflats.

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 6:26 pm
by Don Coffey
I would agree Davy, I would only consider either run flat or non run flat if all four tyres were changed at the same time.

Don

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 7:21 pm
by Chompers
[quote="davyk31"]
Mixing runflat on rear with non runflat on front would certainly not be advised. Never heard of it on an X5 but certainly people who did it on 3 and 5 Series reported very odd handling characteristics. You need to swap all 4 at once if going away from runflats.
[/quote]

Sorry but that's bollocks!!! I changed my rears to non RFT's 5k before the fronts and had no handling issues what so ever. They were also changed by a BMW dealer who when asked said ther would be no issue what so ever. I would also defy any normal driver to differentiate between the 2 types of tyres in handling terms.

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 7:23 pm
by 535dboy
+2

You will have potentially quite different characteristics and if you had to do an emergency stop it could throw the car in a wobble as one end reacts differently to the other

Also are far are the rears actually gone

I used to think it was only ever the fronts that needed doing but if you check the inner edges of the rears you may find they are closer than you think - caught me out a few times

Finally there is the old though thought that too greater variances in treads between front and back can cause transmission problems too

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 7:24 pm
by 535dboy
[quote="Chompers"]
.... I would also defy any normal driver to differentiate between the 2 types of tyres in handling terms.
[/quote]

...hello

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 7:53 pm
by Chompers
[quote="535dboy"]
[quote="Chompers"]
.... I would also defy any normal driver to differentiate between the 2 types of tyres in handling terms.
[/quote]

...hello
[/quote]

Differentiate between handling is different to ride quality. Changing my 19" RFT's to non RFT's has vastly improved the ride comfort but has had no impact on the handling of the car, infact I would comment that the rear feels more 'planted' than on the RFT's. My non RFT rear/RFT front set up was over the wnter months as well for info.

You are very right to point out the excessive inner shoulder wear. My rears had 3-4mm across the 3/4 of the tyre, however the inner shoulder were  :rip: :yikes:

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 7:58 pm
by leosayer
I can honestly say I didn't notice any handling difference between RFT and non RFT when I changed all 4 tyres on my X5. My X5 handled superbly before and after the change.  The only difference I noticed was how much better the car was at absorbing larger bumps.

I don't see how the car could become unsafe with RFTs on one axle and RFT on another, but I'm a bit anal about matching tyres so I would change them all and sell any with remaining tread on ebay.

Re: 20" E70 Tyre Change

Posted: Mon Mar 11, 2013 9:08 pm
by X5Sport
[quote="535dboy"]
[quote="Chompers"]
.... I would also defy any normal driver to differentiate between the 2 types of tyres in handling terms.
[/quote]

...hello
[/quote]

You're disqualified...........you have an......Audi