|
|
|
|
PLEASE HELP SUPPORT E90POST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS! |
|
BMW Garage | BMW Meets | Register | Search | Today's Posts | Mark Forums Read |
|
BMW 3-Series (E90 E92) Forum
>
run flat in the front but not the rear?
|
|
Wheels and Tires forum Sponsored by The Tire Rack
Please help to directly support e90post by doing your tirerack shopping from the above link. For every sale made through the link, e90post gets sponsor support to keep the site alive. Disclaimer |
|
Thread Tools | Search this Thread |
11-10-2012, 05:29 PM | #1 |
Lieutenant
109
Rep 590
Posts |
run flat in the front but not the rear?
Hey guys
so i have a e92 rear wheel drive my rear tires are basically bald and my front tires are perfectly fine for a while longer. my question is do i put non run flats in the rear while i still have run flats in the front. or do i just put run flats in the rear again? does it really matter if i have run flats in the front and regular in the rear? My plan was to put a wider tire on my rear wheels but the run flats dont come wider than a 255 so i would have to do non run flats if i wanted to make them wider. give me your feedback thank you John
__________________
Current:F80 M3 SB/SO Full leather, Black Wheels, Executive Package, Adaptive Suspension, Manual
Sold: LeMans Blue 335i e92 Sold: JB 325xi e90 |
11-10-2012, 05:59 PM | #2 |
Lieutenant Colonel
176
Rep 1,843
Posts |
personally I wouldn't do it. Either get RFTs for the rear and make the switch when they wear out, or buy four matching non-RFTs now.
|
Appreciate
0
|
11-10-2012, 07:01 PM | #4 |
Lieutenant Colonel
102
Rep 1,597
Posts |
It is highly recommended not mix different kind of tires! This can lead to unsafe handling and to a possible collision!
DO NOT DO IT! Can't even imagine how the ride is with mixed RFT and non-RFT tires...
__________________
BEFORE: 130i N52 (2006-2011)
NOW: 335xi N55 (2011- ) |
Appreciate
0
|
11-10-2012, 07:10 PM | #5 |
I cut grass
5
Rep 23
Posts |
I did it. I had non run flats in front and run flats in rear. It was fine, no problems at all. I did it because I didn't want to spent 800 on tires that keep getting nails in them. So I got 2 non run flats for the front for about 250.00 total.
|
Appreciate
0
|
11-10-2012, 07:20 PM | #6 | |
Lieutenant Colonel
102
Rep 1,597
Posts |
Quote:
You, sir, are plain stupid endangering other people with that decision...
__________________
BEFORE: 130i N52 (2006-2011)
NOW: 335xi N55 (2011- ) |
|
Appreciate
0
|
11-10-2012, 07:59 PM | #8 | |
Banned
79
Rep 2,287
Posts |
Quote:
A non rft/ rft mixture is safer than having bald tires. The sidewall stiffness of an aux rft system is comparable to that of a regular tire. Self supporting tires such as bmw's system have the equivalent stiffness of a regular tire but just with some support patches built into the tires sidewall OUTSIDE of the inner wire and the beading is a bit more tough/stronger to hold the flat tire against the rim. I'd say, go with a tire that is non rft with a stiffer sidewall than say a 'nexen' tire. i.e. nitto neo gens, etc. then when the fronts wear out replace those. Get a spare and toss it in your trunk. I'm going with the above solution when my rft's are gone. |
|
Appreciate
0
|
11-10-2012, 08:27 PM | #9 |
New Member
6
Rep 26
Posts |
I am pretty sure it is safe if done in pairs on the same axle. I personally am going to upgrade to a non run flat tire and a small 12V compressor along with AAA for a spare tire. I just dont like the ridgedness of the RFT.
|
Appreciate
0
|
11-10-2012, 08:30 PM | #10 | ||
Lieutenant Colonel
104
Rep 1,555
Posts |
Quote:
__________________
|
||
Appreciate
0
|
11-10-2012, 09:07 PM | #11 | |
Lieutenant
20
Rep 512
Posts |
Quote:
It is not "dangerous" to run rft in front and non-rft in rears. Its dangerous to run different sized tires on the same axle or tires with different amounts of tread remaining on the same axle. Or drive around with bald tires or have deflated tires or have a sidewall bubble or one of a million other things. The composition of the sidewall of a tire does not determine its ability to be mated with various tires on different axles. |
|
Appreciate
0
|
11-10-2012, 09:35 PM | #12 |
Banned
50
Rep 1,556
Posts |
Search the forums, there are plenty of threads on these boards about people doing this an it introducing strange ocillations in transient maneuvers and overall "spooky" handling characteristics.
Generally, this is not a board for people that are so broke that they want to mess up their handling for a few dollars. Not worth it... |
Appreciate
0
|
11-10-2012, 09:45 PM | #13 |
Second Lieutenant
12
Rep 290
Posts |
running pirelli's RFT's in the front and continental extremecontact's in the back. No problems at all. Just make sure when they rotate the tires they don't mix them up.
|
Appreciate
0
|
11-11-2012, 07:24 AM | #14 |
Captain
38
Rep 715
Posts |
I've read threads on this topic in the Tires forum and the overwhelming response was don't do it.
I'm not an expert, but it seems like a bad idea because: - RFT have stiffer sidewalls. That's why they provide great steering response and can support the weight of the car with no air pressure. Having RFT's in front and non-RFT in the rear will cause oversteer. - There are usually significant differences in the ways different tires respond to various driving conditions, including dry traction, wet traction, turning, braking, etc. If the front and rear tires respond differently to different conditions, you might not notice much in normal driving, but there might be a huge difference in emergency conditions or when you intentionally push your car. The traction and stability control systems were developed and tested assuming you have the same type of tires on both axles. I've noticed differences when I replaced the rear tires with the exact same type of tires on the front because the new tires have more tread (10/32 instead of 3/32). But don't take my word for it. This thread will be moved to the Tires forum and you'll hear the same thing from the experts. The OP states that he wants to put wider tires in the rear than stock. Going wider causes understeer. It's possible that the oversteer caused by the RFT/non-RFT combination will be cancelled out by the understeer of the wider tires, but it's more likely that making these changes will upset the handling balance and who knows what will happen in emergency and edge conditions. |
Appreciate
0
|
11-11-2012, 09:26 AM | #15 |
Lieutenant Colonel
102
Rep 1,597
Posts |
Whatever...
http://www.e90post.com/forums/showthread.php?t=726185 http://www.e90post.com/forums/showth...Different+tire http://www.e90post.com/forums/showth...Different+tire And it goes on and on... @Driverman
__________________
BEFORE: 130i N52 (2006-2011)
NOW: 335xi N55 (2011- ) |
Appreciate
0
|
11-11-2012, 11:00 AM | #16 | |
New Member
6
Rep 26
Posts |
Quote:
RFT do come larger than 255, I have 18" Wheels Staggered Front and Rear ( Factory option from BMW ) 245 REAR and 235 FRONT ,and yes they are RFT's. IMO Run Flat Tires are not necessarly an ideal performace tire. I think the engineers at BMW were looking for a way to eliminate the spare tire in the trunk to make room for a battery thus providing a better weight distribution. Since the military adopted Run Flat technology the BMW egineers looked there. Just my opinion. There are many benefits too not use the Run Flat tire There is only one benefit to running the RFT |
|
Appreciate
0
|
11-11-2012, 12:53 PM | #17 | |
Major General
124
Rep 5,626
Posts |
Quote:
Years ago this same debate arose re mixing radials & bias ply tires and the folks who were to cheap to spring for 4 radials caused quite a few accidents. Tom |
|
Appreciate
0
|
11-11-2012, 01:15 PM | #18 |
Captain
38
Rep 715
Posts |
From Gary at Tirerack on one of threads posted by BMW_Belgier:
"Avoid mixing tires, especially run flats with non run flats. Search and find many members reporting problems when mixing the two." |
Appreciate
0
|
11-11-2012, 01:31 PM | #19 |
New Member
2
Rep 23
Posts |
I mixed and I have not had any problems..
I'm not a fan of the RFT but 2 were brand new. Decided I'd replace the 2 worn out ones and see how I got on. Never had any issues.. so I left it. I would have just replaced them if I felt I had needed to. I will ditch the other RFT's when they need replacing. |
Appreciate
0
|
11-11-2012, 02:28 PM | #20 |
Major General
124
Rep 5,626
Posts |
|
Appreciate
0
|
11-11-2012, 03:24 PM | #21 |
Stay Classy
74
Rep 1,021
Posts |
I don't see how it would be an issue if you invested in a ultra high performance tire like a star spec, rs3, or RE-11 that are designed for autox and light track days. These have super stiff sidewalls for top handling under heavy point loads. These may not be as stiff as a RFT but they are certainly more stiff than most performance tires.
Personally I'm investing in Dunlop Star Specs once my RFTs are out. I've had track and autox experience with these and they perform like crazy and have great tread life. With that being said; I do agree that running regular summer tires would be unsafe because they will roll over before the rears in a turn causing a violent oversteer Last edited by GOTMH8N; 11-11-2012 at 03:29 PM.. |
Appreciate
0
|
11-11-2012, 06:22 PM | #22 | |
Major
133
Rep 1,363
Posts |
Quote:
|
|
Appreciate
0
|
Bookmarks |
Thread Tools | Search this Thread |
|
|