BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      09-07-2010, 07:27 PM   #1
Cuz5150
Major
 
Cuz5150's Avatar
 
Drives: 06-M3ZHP/04-M3 Vert/02Duc998
Join Date: May 2008
Location: NJ

Posts: 1,237
iTrader: (0)

check this out: RFT

Flipping the pages on Oct issue Automobile Mag i come across.......
The Q&A section(page 66)
They asked 5 questions to Chassis development engineer Heinz Krusche.

The last question:
Why does BMW favor run-flat tires?

Answer:
They provide several advantages, including [b]more precise steering[b]andhandling
__________________
-Diplomacy is saying, "nice doggie while trying to find a rock"-

04-M3 vert-Black/Imolla/6MT/Cold/Xenon/HK/
06-M3 Cp-Mystic/Black/6MT/Comp/Xenon/HK/
09-135i- AW/Bk-Lette/6MT/M-pac/Nav/Hi-Fi/Usb-Ipod/SOLD
Cuz5150 is offline  
0
Reply With Quote
      09-07-2010, 08:25 PM   #2
gnat
Second Lieutenant
 
Drives: Wishing for an e30iX
Join Date: Feb 2009
Location: NoVA

Posts: 246
iTrader: (0)

Quote:
Why does BMW favor run-flat tires?

Answer:
They provide several advantages, including significant financial considerations for BMW.
There. Fixed that for him
gnat is offline  
0
Reply With Quote
      09-07-2010, 08:27 PM   #3
akak1997
Major
 
Drives: BMW 135 @ 135mph
Join Date: Aug 2008
Location: Los Angeles

Posts: 1,161
iTrader: (2)

Garage List
2008 135i  [0.00]
I thought stiffer sidewall does provide more precise steering. Just that the compound used on run crap is too hard to provide descent traction.
akak1997 is offline  
0
Reply With Quote
      09-07-2010, 08:38 PM   #4
JB135MDCT
I'm just a cook
 
JB135MDCT's Avatar
 
Drives: 2011 135i DCT
Join Date: May 2010
Location: MD

Posts: 958
iTrader: (0)

Achtung, Achtung, Heinz Krusche, You know nothing, you see nothing.
JB135MDCT is online now   United_States
0
Reply With Quote
      09-08-2010, 12:01 AM   #5
joeo
Second Lieutenant
 
Drives: 2009 Crimson Red 135i
Join Date: Mar 2008
Location: Sterling, Va

Posts: 288
iTrader: (0)

Garage List
2009 BMM 135i  [4.75]
I guess I'm in the minority, but I really do believe the RFT's had much better steering feel and response. After I switched the the Hankook's, it lost some of the instant response that the RFT's had. There is better overall grip, but the steering response is much more delayed.
Just my opinion!

-Joe
joeo is offline  
0
Reply With Quote
      09-08-2010, 12:54 AM   #6
MOCKBA
Captain
 
MOCKBA's Avatar
 
Drives: 135 convertible
Join Date: Nov 2006
Location: SFBA

Posts: 867
iTrader: (0)

Interesting, the topic pops up again and again. Over two years ago when I owned Z4 people were ready to kill each other arguing why RFT good or bad. My opinion that RFT are good, comfortable ride (same or even better than regular tires), precise handling, great grip for acceleration, but what is most important outstanding safety. Yes, here is some financial drawback for owners, like these tires not reparable, so you got nail, you got $500 out of your pocket.
__________________

135i/cabrio/p/s/c
MediaChest is iTunesLess way of iPod managing
MOCKBA is offline   United_States
0
Reply With Quote
      09-08-2010, 01:14 AM   #7
MarkR171
Lieutenant Colonel
 
MarkR171's Avatar
 
Drives: SLK55 AMG
Join Date: Dec 2009
Location: Honolulu, HI

Posts: 1,532
iTrader: (0)

Garage List
Quote:
Originally Posted by akak1997 View Post
I thought stiffer sidewall does provide more precise steering. Just that the compound used on run crap is too hard to provide descent traction.
This, and the compound on the 3rd gen Bridgestone RFTs are now supposedly the same as the non-RFT variants. I love my RFTs, both on the road and for competition. They've treated me well so far.

I've read quite a few threads now where people are disappointed after making the switch to non-RFTs because of the "sluggish" feeling of the tires, even though grip is possibly improved. That's why I haven't bothered to swap out the RFTs for autocross even though everyone there is saying "those are run flats? Man, I feel sorry for you" when talking in grid waiting for our runs. At the end of the day though, they always end up saying "Man, you're fast on those run flats!"

I ran faster than several experienced drivers in modified cars with supposedly stickier tires, including a very seasoned driver in an RX-8 with Hoosiers and all STU class cars last event and I've only done 7 events total, 3 with the 135, so I don't consider myself a great driver either. I even left the day thinking I could have gone faster, I even knocked 1 full second off my time on my last run.

The Bridgestone RFTs on the 2011s (possibly 2010s too) are great tires. Maybe on a track day with extended periods at high speeds/temperatures, the RFTs may not be so great... but for the majority, the RFTs are great.
__________________
2007 SLK55 AMG - Black on Gray/Black - AMG 030 Performance Package

2011 135i - Traded
///M-Sport - Dual Clutch - Harman Kardon - Bluetooth - iPod - Shadowline Kidney Grill - 225/255 Star Specs - Hotchkis Front Sway

Last edited by MarkR171; 09-08-2010 at 01:25 AM.
MarkR171 is offline  
0
Reply With Quote
      09-08-2010, 07:02 AM   #8
imported_mega
Colonel
 
Drives: various bmw's
Join Date: Jul 2007
Location: neverland

Posts: 2,011
iTrader: (0)

Quote:
Originally Posted by MOCKBA View Post
Yes, here is some financial drawback for owners, like these tires not reparable, so you got nail, you got $500 out of your pocket.
run flats are repairable
__________________
You only need two tools in life - WD-40 and Duct Tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.
Gone but not forgotten..
1974 2002, 1987 325ic, 1987 325is
1995 M3, 2001 X5, 2007 MCS R56
imported_mega is offline   No_Country
0
Reply With Quote
      09-08-2010, 07:11 AM   #9
Taymaishu
Banned
 
Drives: I love massive black cocks
Join Date: Jul 2009
Location: in my ass and around my mouth

Posts: 3,020
iTrader: (0)

Garage List
2009 125i  [2.75]
Quote:
Originally Posted by joeo View Post
I guess I'm in the minority, but I really do believe the RFT's had much better steering feel and response. After I switched the the Hankook's, it lost some of the instant response that the RFT's had. There is better overall grip, but the steering response is much more delayed.
Just my opinion!

-Joe
Agree - drastically reduced tram-lining with stiffer sidewalls is one of the biggest advantages I have seen with RFTs.
Taymaishu is offline   Australia
0
Reply With Quote
      09-08-2010, 07:12 AM   #10
imported_mega
Colonel
 
Drives: various bmw's
Join Date: Jul 2007
Location: neverland

Posts: 2,011
iTrader: (0)

Quote:
Originally Posted by Taymaishu View Post
Agree - drastically reduced tram-lining with stiffer sidewalls is one of the biggest advantages I have seen with RFTs.
I disagree with this, I drive the same road every day, on day one with star spec's I noticed how much less tram lining i had to deal with

the grip/handling on star specs vs stock runflats is an amazing improvement
__________________
You only need two tools in life - WD-40 and Duct Tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.
Gone but not forgotten..
1974 2002, 1987 325ic, 1987 325is
1995 M3, 2001 X5, 2007 MCS R56
imported_mega is offline   No_Country
0
Reply With Quote
      09-08-2010, 07:31 AM   #11
JB135MDCT
I'm just a cook
 
JB135MDCT's Avatar
 
Drives: 2011 135i DCT
Join Date: May 2010
Location: MD

Posts: 958
iTrader: (0)

Quote:
Originally Posted by MOCKBA View Post
Interesting, the topic pops up again and again. Over two years ago when I owned Z4 people were ready to kill each other arguing why RFT good or bad. My opinion that RFT are good, comfortable ride (same or even better than regular tires), precise handling, great grip for acceleration, but what is most important outstanding safety. Yes, here is some financial drawback for owners, like these tires not reparable, so you got nail, you got $500 out of your pocket.
Can you dig a bigger hole?
JB135MDCT is online now   United_States
0
Reply With Quote
      09-08-2010, 07:42 AM   #12
JB135MDCT
I'm just a cook
 
JB135MDCT's Avatar
 
Drives: 2011 135i DCT
Join Date: May 2010
Location: MD

Posts: 958
iTrader: (0)

Quote:
Originally Posted by MarkR171 View Post
This, and the compound on the 3rd gen Bridgestone RFTs are now supposedly the same as the non-RFT variants. I love my RFTs, both on the road and for competition. They've treated me well so far.

I've read quite a few threads now where people are disappointed after making the switch to non-RFTs because of the "sluggish" feeling of the tires, even though grip is possibly improved. That's why I haven't bothered to swap out the RFTs for autocross even though everyone there is saying "those are run flats? Man, I feel sorry for you" when talking in grid waiting for our runs. At the end of the day though, they always end up saying "Man, you're fast on those run flats!"

I ran faster than several experienced drivers in modified cars with supposedly stickier tires, including a very seasoned driver in an RX-8 with Hoosiers and all STU class cars last event and I've only done 7 events total, 3 with the 135, so I don't consider myself a great driver either. I even left the day thinking I could have gone faster, I even knocked 1 full second off my time on my last run.

The Bridgestone RFTs on the 2011s (possibly 2010s too) are great tires. Maybe on a track day with extended periods at high speeds/temperatures, the RFTs may not be so great... but for the majority, the RFTs are great.
They should be asking if you have DCT. RFT compliance can't deal with a bumpy road surface and have tendency to skip off the road and unsettle the car.
JB135MDCT is online now   United_States
0
Reply With Quote
      09-08-2010, 10:10 AM   #13
Red Bread
Brigadier General
 
Drives: My wife's car
Join Date: Oct 2008
Location: Dallas, TX

Posts: 4,215
iTrader: (0)

Garage List
Quote:
Originally Posted by maxnix View Post
Once again, one would have to run the same tire in RFT and non RFT back to back to obtain a valid inference.
I need new tires, and don't care what anyone says about RFT, I will not be replacing them with more RFT's (I also don't believe that anyone has 3rd Gen RFT's either). I have briefly considered trying the RE-050a non RFT, but don't really find them to be very good tires for any purpose, so will likely change to something else, but it's still tempting just to see what the change to the same tire, just non RFT would be. Unfortunately, they only make the RE-050a in 335i sizes (and non XL load rating), not the OE 135i sizes, so this idea seems dead in the water.
Red Bread is online now   United_States
0
Reply With Quote
      09-08-2010, 10:26 AM   #14
gnat
Second Lieutenant
 
Drives: Wishing for an e30iX
Join Date: Feb 2009
Location: NoVA

Posts: 246
iTrader: (0)

Quote:
Originally Posted by MOCKBA View Post
comfortable ride (same or even better than regular tires)
I hated the ride in my wife's e90 from day 1 (and if it wasn't for the e30 we picked up I would still hate BMW to this day) as it was just way too jarring and uncomfortable, yet it didn't have the crisp feel of a performance car to make up for it. Originally I thought the ride issues were the sport seats, but when she had a sidewall blow out she replaced them with PS1s and everything changed for the better. It now has a better steering feel and a much more comfortable ride (though still uncomfortable for trips over an hour or so for me).

Her's is an Xi, so she doesn't have the sport suspension and I could believe that there is a feel difference between the all weather and performance variant.

I have been hearing good reports on the 3rd gen RFTs so I will give them a chance as I drive all over Europe, but I'm still going to be prepared to re-shoe it after it gets home.
gnat is offline  
0
Reply With Quote
      09-08-2010, 10:49 AM   #15
vanbmw
Captain
 
vanbmw's Avatar
 
Drives: Black 135
Join Date: Feb 2008
Location: Vancouver

Posts: 768
iTrader: (0)

One funny thing I found about the BMW chassis engineers comments. If indeed BMW feels the RFT are the better choice for handling and steering then why do they fit non RFT on the M3? I believe it comes with Michelin non RFT. Seeing as that is their top car for steering/handling I would say they believe the non-RFT are the choice for the best handling/steering...wouldn't you say???
vanbmw is offline   Canada
0
Reply With Quote
      09-08-2010, 12:27 PM   #16
GaryS
Colonel
 
Drives: 2009 135i 6MT
Join Date: Feb 2010
Location: Maryland

Posts: 2,089
iTrader: (0)

Garage List
2009 135i  [3.25]
^^ Yes. M3 and 1M have non-RFTs.

As for advantages, RFTs are excellent when terrorists try to shoot out your tires.
GaryS is offline  
0
Reply With Quote
      09-08-2010, 12:29 PM   #17
Red Bread
Brigadier General
 
Drives: My wife's car
Join Date: Oct 2008
Location: Dallas, TX

Posts: 4,215
iTrader: (0)

Garage List
Quote:
Originally Posted by GaryS View Post
^^ Yes. M3 and 1M have non-RFTs.

As for advantages, RFTs are excellent when terrorists try to shoot out your tires.
Provided those terrorists are driving a Tesla, a Leaf or a Mini-E and only have a 49 mile range.
Red Bread is online now   United_States
0
Reply With Quote
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 08:44 AM.




1addicts
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST