Run Flat Tyres

[mopardave]

Hi all.......can anyone settle an argument.......well, discussion actually. My brother has a 2008 BMW Z4 coupe with run flats. One of them (front) is bald. He's getting conflicting advice....some say fitting a conventional tyre is ok (but only if he also changes the other front at the same time).
So:
1) Can he do this safely......two conventional on the front......two run flats on the back?

2) Advantages/disadvantages of run flats versus conventional......apart from the obvious.

He's getting all sorts of conflicting info!

Help?

 

[RattyMcClelland]

It really is an easy choice.

Standard tyres with a can of tyre weld.

The only advantages of run flats is that upon a puncture during driving you don't have to pull over or stop. The Tyre is still ruined.

Try are expensive, harsh ride and limited to specific tyres do you cannot choose compound or tread to suit driving style.

Imo fit the most expensive normal tyres you can afford. Get rid of the runway ditchfinders.

My friend has a e92 335d with runflats.

We replaced with rainsport 3 tyres and now the traction control never kicks in, so much grip as it's producing over 600nm of torque. Ride quality is night and day different.
He lost Tyre pressure monitoring but that's just lazy anyway.

 

[mopardave]

Thanks mate.....I get what you're saying. I just thought that the wheels were specific to run flat tyres and that you couldn't choose conventional tyres for run flat rims?

 

[Caravellet6]

Our Yeti has run flat tyres had a puncture in the first few months, £140 for a sodding 17" tyre!

As soon as they wear out I'm going to normal tyres, waste of money, plus u need TPS cos u cant tell they are low on air.....

 

[former member]

Run flats are the hateful work of the devil; heavy, wreck the ride, nasty.
I got rid of them on our old 335d within three months of getting it. Luckily the M135i is deemed "sporty" enough by BMW to come with normal tyres.

But if you really have to, match axles but do NOT have one of each on the left and right.

Get shot of them ASAP!

 

[Vinci]

I was very impressed with Bike-Seal ......it has a NATO parts number, and apparently the police stinger tyre deflator had to be redesigned (this seals holes upto 10mm or something instantly), so I have it in my 1150gs' tyre's. The chaps demo involved hammering in nails and screwdriver into Inflated bike and Range Rover tyre's, rotating them and pulling said items out with no significant pressure loss. Well worth googling.

 

[starlightexpress]

I swapped from runflats to normal on a 535d. It's fine as long as:
- you notify your insurer;
- you comply with speed and load ratings required for the car;
- you swap all 4 tyres.

Non-runflat tyres will fit on BMW rims that originally held runflats. The converse is not necessarily true.

Don't mix runflat and non-runflat even if it's on different axles. They behave differently, especially in cold weather and/or over poor road surfaces.

I bought an official BMW tyre inflation/sealing kit from an M5, off ebay. More expensive than a can of tyreweld, but reassuring to the next owner of the car.

Any tyre pressure reading functionality will only be lost if you change the rims, as the sensors are clamped to the inside of the valves.

 

[starlightexpress]

Also.... I'm impressed with the Contiseal self-sealing tyres on our new Touran. Maybe worth seeing if those are available in the size you need, or similar tech on another manufacturer's tyre.

My impression is that the tyres are a little quieter than normal, probably due to the gunk layer damping some resonance in the tyre carcass.

 

[former member]

I swapped from runflats to normal on a 535d. It's fine as long as:
- you notify your insurer;
- you comply with speed and load ratings required for the car;
- you swap all 4 tyres.

Non-runflat tyres will fit on BMW rims that originally held runflats. The converse is not necessarily true.

Don't mix runflat and non-runflat even if it's on different axles. They behave differently, especially in cold weather and/or over poor road surfaces.

I bought an official BMW tyre inflation/sealing kit from an M5, off ebay. More expensive than a can of tyreweld, but reassuring to the next owner of the car.

Any tyre pressure reading functionality will only be lost if you change the rims, as the sensors are clamped to the inside of the valves.

You definitely can't fit RFTs to non RFT rims. You can do the other way around.
And the vast majority of tyre pressure sensors (except on really high end cars) use the ABS sensors to detect a change in wheel speed rather than actually measuring pressure.

My Golf R32, 335d and current M135i all has/have non RFTs with a factory tyre weld kit; only had one slow puncture in the current BM (a nail from the dealers it had just been to); TBH if I had a nasty flat I'd call BMW Assist. The Cali and Outback both have a full sized spare.

 

[starlightexpress]

You definitely can't fit RFTs to non RFT rims. You can do the other way around.

Yes, but that's not quite what I was saying. For example, the most basic spec 5 series comes from the factory with 17" rims and non-RFT tyres, but those rims are still designed to cope with RFT tyres as well (the German configurator allows you to choose tyres with "Notlaufeigenschaften" on the same rims for another 320 euros). Hence "not necessarily true" rather than "never true".

 

[former member]

But RFT rims are different to non RFT ones; different "lip."
Just like in MTB world you can fit tubed tyres to tubeless rims, you can't fit tubeless to tubed rims.

Ask any tyre fitter to fit RFTs to non RFT rims and he will refuse.

 

[starlightexpress]

Why don't you read what I've actually posted instead of charging in ?

 

[former member]

Why don't you read what I've actually posted instead of charging in ?

You've made several errors "informing" a member about RFTs. I have read what you've written. Very carefully.

I don't think you really know what you're talking about and I'd rather flag that up and avoid issues for other members than just let it lie for the sake of being "nice."

Basing your "facts" on a car configurator isn't quite the same as speaking to many tyre fitters, researching properly etc.

You can't fit RFT on non RFT rims.

The end.

 

[Caravellet6]

Why don't you read what I've actually posted instead of charging in ?

Calm down son

 

[RattyMcClelland]

You can put run flats on any type of wheel. It will fit and will drive fine.

However Tyre fitters don't usually do it because if anything was to go wrong they are held responsible and the Tyre might behave differently when flatt on a different wheel.

They will fit any wheel though.

 

[T6 Dave]

Except square!

 

[starlightexpress]

You've made several errors "informing" a member about RFTs. I have read what you've written. Very carefully.

I don't think you really know what you're talking about and I'd rather flag that up and avoid issues for other members than just let it lie for the sake of being "nice."

Basing your "facts" on a car configurator isn't quite the same as speaking to many tyre fitters, researching properly etc.

You can't fit RFT on non RFT rims.

The end.

We agree you can't fit RFTs on rims that aren't designed for them.

The point I was making is that just because a car comes with non-RFTs on a rim from the factory, doesn't mean that rim isn't suitable for RFTs. That is what the configurator demonstrates.

 

[Caravellet6]

We agree you can't fit RFTs on rims that aren't designed for them.

The point I was making is that just because a car comes with non-RFTs on a rim from the factory, doesn't mean that rim isn't suitable for RFTs. That is what the configurator demonstrates.

So, what errors have I made ?

You've made your point I don't think this is adding any value to this post......