New tires go on tomorrow

[maxzander]

i ditched mine after the 1st week when i got my z4...coz the ride is pretty stiff with RTF......

[teagueAMX]

Originally Posted by Drjoeb

I'm intrigued with this post. Out of curiosity how many miles have you guys put on your RFT before ditching them. I've got less then 2k miles on mine. But if the difference is night and day then perhaps its worth ditching th RFT asap.

In addition to the ride quality issue, there's a suspicion the low profile RFT are contributing to wheel damage/cracks. Rolf-Dieter has a couple of threads on the issue.

Here's one and I think link another one on his sig.

http://www.bimmerfest.com/forums/sho...76#post5390176

.

[KrisNL]

I got the idea everyone with 19' RFT have or problems with cracked rims or other problems (vibrating mirrors...).
The 18' RFT seem fine to me. Probably anything over 18' is not made for RFT?

[teagueAMX]

Haven't heard of any 18" wheel crack complaints.

[KrisNL]

Originally Posted by teagueAMX

Haven't heard of any 18" wheel crack complaints.

I chose 18's because I already expected problems with 19 RFT. A lot of other sportscars with 19 RFT have similar problems. And I prefer RFT because I hate flat tires. Every single car I had surprised me with a flat one.

Could be all the junk on the dutch highways, ZOAB asphalt sucks. (especially after winter)

[teagueAMX]

How's the ride quality and handling?

[Silver-Bolt]

Originally Posted by Drjoeb

I'm intrigued with this post. Out of curiosity how many miles have you guys put on your RFT before ditching them. I've got less then 2k miles on mine. But if the difference is night and day then perhaps its worth ditching th RFT asap.

1067 miles on our RFT's before pulling them. Would have done it sooner had the tires been available.

[Mr. ///M3 RD]

Originally Posted by teagueAMX

Haven't heard of any 18" wheel crack complaints.

I agree, have not seen any myself. All the cracks in England as far as I know from reading on the UK Watchdog site was always on the 19"

as documented here on a TV show, quite interesting

and here a follow up

I further believe that due to the low and so stiff profile of the RFT the inside outer rim is exposed to undue or shall I say additional stress, thus the weaker inside edge of the wheel seams to be susceptible to cracking. I truly
believe BMW knows all about this they just don't want to admit to it.

Funny that if you try to purchase a new Z4 today the 19" wheel option is not part of the option list anymore ... Hmmmm I wonder why.

My RFT will be history in the spring, soon I will mount my winter wheel/tire package and very closely examine my new rear wheels, one having seen around 4,000 KM and the other around 1,000 KM.

[Mr. ///M3 RD]

yesterday I came across some posts in another forum regarding RFT ... quite interesting

Here are the posts on it, I normally don't refer to other sites however, this happens to be very much on topic and some of the information is good to know

Last week I went into a Mercedes showroom and was told we do not sell Run-Flat-Tires not now nor will we in the future.

[teagueAMX]

Originally Posted by KrisNL

I chose 18's because I already expected problems with 19 RFT. A lot of other sportscars with 19 RFT have similar problems. And I prefer RFT because I hate flat tires. Every single car I had surprised me with a flat one.

Could be all the junk on the dutch highways, ZOAB asphalt sucks. (especially after winter)

You were thinking ahead. You have to know your environment. There may be a place that has very nice roads, and putting aside handling and ride quality, the low profile tire may not be an issue in those environments. However, with governments being strapped for cash, road repair is not a top priority. I believe in many places that road quality will continue to decline over time.

[teagueAMX]

Originally Posted by Rolf-Dieter

yesterday I came across some posts in another forum regarding RFT ... quite interesting

Here are the posts on it, I normally don't refer to other sites however, this happens to be very much on topic and some of the information is good to know

Last week I went into a Mercedes showroom and was told we do not sell Run-Flat-Tires not now nor will we in the future.

Interesting thread.

[Mr. ///M3 RD]

Originally Posted by teagueAMX

You were thinking ahead. You have to know your environment. There may be a place that has very nice roads, and putting aside handling and ride quality, the low profile tire may not be an issue in those environments. However, with governments being strapped for cash, road repair is not a top priority. I believe in many places that road quality will continue to decline over time.

I so agree with you on the road issue. On my way back east from Idaho in August I came across miles and miles of road work one of the stretches must have been over 10 miles long driving on preliminary road surfaces (stripped) some even gravel. You can imagine how worried I was that my TPMS light would come on and I be stuck near a farmers field knowing I am driving with one wheel having 2 hairline cracks ... going over countless little bumps. Your post in mind where you explained .... 100 plus little bumps building up stresses then the 101 bump may cause the crack.

Well I already knew I had the 2 hairline cracks and driving along them roads under construction was like nothing I can describe in words. My thoughts at the time were .... This is no JOY at all. I was talking to myself at the time why ever did I sell my reliable M3 that had 19 inch wheels and normal Michelin tires gave me good service of over 50,000 miles ... anyway that went thru my mind at the time. Thank god I made it home alright.

[zEdP]

Originally Posted by Rolf-Dieter

Funny that if you try to purchase a new Z4 today the 19" wheel option is not part of the option list anymore ... Hmmmm I wonder why.

Interesting, this sounds like BMW has also found a reliability issue.

My 19" wheels are still ok. Even with the weekly torture of 40Km Belgium road's that you can put in the category pre world war II.

If my wheels survive the next 6 months, the RFT are also history. The Continatal contact sport or the Michelin Pilot sport will be the candidates to replace the RFT's.

[teagueAMX]

Originally Posted by Rolf-Dieter

I so agree with you on the road issue. On my way back east from Idaho in August I came across miles and miles of road work one of the stretches must have been over 10 miles long driving on preliminary road surfaces (stripped) some even gravel. You can imagine how worried I was that my TPMS light would come on and I be stuck near a farmers field knowing I am driving with one wheel having 2 hairline cracks ... going over countless little bumps. Your post in mind where you explained .... 100 plus little bumps building up stresses then the 101 bump may cause the crack.

Well I already knew I had the 2 hairline cracks and driving along them roads under construction was like nothing I can describe in words. My thoughts at the time were .... This is no JOY at all. I was talking to myself at the time why ever did I sell my reliable M3 that had 19 inch wheels and normal Michelin tires gave me good service of over 50,000 miles ... anyway that went thru my mind at the time. Thank god I made it home alright.

I apologize that my analysis contributed to your anxiety during that troublesome stretch of road. That certainly wasn't my intent. We're very glad that you made it back OK, Rolf-Dieter.

And, I believe there's something to be said for the normal tire and forged wheel combo. Of course the Michelin's are superior tires - they've improved every car I fitted them to. Although, forged wheels are very lightweight and have a very thin rim cross section, by the nature of forging (forming metal under extreme pressure and heat) a wheel with far more elasticity and durability is created than from the casting process.

Wiki - Forging:

Forging can produce a piece that is stronger than an equivalent cast or machined part. As the metal is shaped during the forging process, its internal grain deforms to follow the general shape of the part. As a result, the grain is continuous throughout the part, giving rise to a piece with improved strength characteristics

Wiki - Heat Treatment

[brisk3]

so if i were to get the non RFT's the only way for me to put in the correct PSI is by doing the chalk test?

also what about the TPMS? isn't that defaulted to the OEM psi? at i believe 42?

thanks.

[Mr. ///M3 RD]

Originally Posted by teagueAMX

I apologize that my analysis contributed to your anxiety during that troublesome stretch of road. That certainly wasn't my intent. We're very glad that you made it back OK, Rolf-Dieter.

No worries, and certainly no apologies are necessary to be sure, you did not contribute to my anxiety during my drive home ... it was a natural phenomenon caused by the facts at hand.

If anything, you and others have been quite supportive during my ordeal. And I am thankful for that support.

Cheers,

Rolf-Dieter

[Vintage]

just over 8,000 miles and should have ditched hem at 0 miles - what a waste

[marcw]

What are you talking about? The Style 296 19" wheels can still be had today as per bmwusa.com.

Originally Posted by Rolf-Dieter

Funny that if you try to purchase a new Z4 today the 19" wheel option is not part of the option list anymore ... Hmmmm I wonder why.

[rmorin49]

Originally Posted by Drjoeb

I'm intrigued with this post. Out of curiosity how many miles have you guys put on your RFT before ditching them. I've got less then 2k miles on mine. But if the difference is night and day then perhaps its worth ditching th RFT asap.

Mine came off at delivery, about 1.7 miles on the clock. Sold them to a guy with an E92. He got a great buy and I got enough to buy a set of real tires.

[Mr. ///M3 RD]

Originally Posted by marcw

What are you talking about? The Style 296 19" wheels can still be had today as per bmwusa.com.

What I meant is, if you go to one of our BMW sites and build a Z4 (any of the models) then you no longer have the option to have the 19 inch wheels.

I suppose you do if you are at the dealer?

[marcw]

Well maybe the Canadian version doesn't let you do that any more, but www.bmwusa.com let's you option the Style 296 wheels just fine.

Originally Posted by Rolf-Dieter

What I meant is, if you go to one of our BMW sites and build a Z4 (any of the models) then you no longer have the option to have the 19 inch wheels.

I suppose you do if you are at the dealer?

[Horsedoc67]

I am probably in the minority relative to this tire discussion, but I am very happy with the RFT's.(19") I drive on the lousy roads here in SoCal(101, PCH etc) and have hit potholes that made me cringe. I have 4500 mi on the car and at 4000 I had the oil changed and all the wheels inspected for cracks by BMW and none were found. I drive hard in the twistys and fast on the open road and I find the tires perform as well as any conventional tire. I have been driving high performance cars for over 50 yrs although this is my first experience with RFT. I had a conversation with two very bright BMW Service advisors that believe that the stiffer sidewalls of the RFT offers more protection for the wheels than conventional tires.
I have more concern about the HPFP problem as I am planning a 4000 mi road trip later this month with the route being sparsely populated by BMW dealers. It seems a shame not being comfortable taking a high dollar car like this out on the road without the fear of mechanical failure.