suspension is set for RFTs ?

_dopehead_ · 03-21-2010, 01:55 PM

Hey Guys,

i just ordered new tires for my 135, and some ppl in another forum commented that the car would not act as well on non-rft's, and that it generally wasn't recommended, as the suspension is setup for RFT's....now i get the exact opposite idea when reading through pretty much all the threads here about tyre choice....should i just ignore them ?

ps:i got Toyo's in 225/40 and 255/35

BMW86 · 03-21-2010, 04:55 PM

Which forum is this? They are talking smack. The non-RFT are better in every way trust me

_dopehead_ · 03-21-2010, 04:58 PM

its a local forum, and i think he actually meant that it would handle very differently, which is what i am after..so no issue there anyways.

DBFIU · 03-21-2010, 05:09 PM

Leave that forum.

But he is right, it will handle differently, much much better.

_dopehead_ · 03-21-2010, 06:24 PM

I hope so :-) can't wait to get them mounted now that the sun seems to be peeking out a little bit.

WhiteOne · 03-21-2010, 06:26 PM

If you are "scared" , pay the big bucks for "safety" tires.
If you want the car to ride & handle better, ditch the runflats.
JMHO

_dopehead_ · 03-21-2010, 08:53 PM

I'm not scared, there is really no problem with getting a flat in my little country, there is no place where i drive that i wouldn't be able to get a tow truck or a friend to come get me, thats the good thing about living in a small country

new2the3 · 03-21-2010, 11:20 PM

The only downside is non runflat tires do not have as stiff sidewalls as RFTs. The suspension is designed with these stiff sidewalls in mind. With a non RFT you will have a much high quality tire with more grip and a huge improvement in ride comfort but.... the tire sidewall will definitly be softer. Maybe increased body roll?

Lester · 03-22-2010, 05:43 AM

Body roll would be affected by the suspension, not by the stiffness of the sidewalls. In any event, body roll doesn't impact normal driving much. If you track the car, chances are you have already upgraded the suspension.

JME · 03-22-2010, 07:06 AM

Quote:

Originally Posted by new2the3

The only downside is non runflat tires do not have as stiff sidewalls as RFTs. The suspension is designed with these stiff sidewalls in mind. With a non RFT you will have a much high quality tire with more grip and a huge improvement in ride comfort but.... the tire sidewall will definitly be softer. Maybe increased body roll?

Two problems with that. Number 1, the effective spring rate of inflated tires is much much higher than the effective wheel rates of our car. We're talking on the order of 1000 lb/in as compared to 110 lb/in for our suspension. Number 2, the majority of that effective spring rates comes from the tension of the tire carcass, not from the sidewall stiffness. Even in RFT that sidewall stiffness--while allowing us to run on a flat tire for a short amount of time--is nothing compared to the tension in the rubber from being pumped up to almost 3 atm. Why do you think we don't run lower tire pressure in a run-flat? The harshness from RFT comes from the resistance to deformation in the sidewall, caused by, but not wholly responsible due to the stiffer sidewall.

GaryS · 03-22-2010, 09:29 AM

A few people have said they felt some loss of steering sharpness with non-rft. But most people say the change was 100% positive. Obviously it depends on which non-rft you choose.

larryn · 03-22-2010, 09:38 AM

Quote:

Originally Posted by GaryS

A few people have said they felt some loss of steering sharpness with non-rft. But most people say the change was 100% positive. Obviously it depends on which non-rft you choose.

True.

Buying $80 all seasons will cause that.

RaceTime · 03-22-2010, 09:41 AM

It is 100% positive. I still have stock tires on stock rims to go back and forth to the track...once the stock run flats die, I will be putting on some non-run-craps

. You will not be disappointed with a good performace non-runflat tire!

arrutled · 03-22-2010, 09:42 AM

besides the harsh ride, the one thing I noticed when I put my runflats back on was the sharpness. but comparing them to winter tires isnt really fair.

SV Concepts III · 03-22-2010, 01:02 PM

This was my first mod, to get rid of the RFTs. The car will be a pleasure to drive with regular tires.

Gary@TireRack · 03-22-2010, 01:52 PM

^^ My first mod also. I've never regretted it.

ruffstik · 03-22-2010, 03:53 PM

I have some new star specs waiting to get mounted...cant wait!

_dopehead_ · 03-25-2010, 09:46 AM

I just received the new rubber, damn 255/35 is big tire :-) my old car was on 205/40-17's so this is quite a step up in size. Can't wait to get them mounted, hoping there is no rubbing on orig bmw 264 rims.

GaryS · 03-25-2010, 10:19 AM

Don't worry, it won't rub.

03-21-2010, 01:55 PM	#1
_dopehead_ Private 6 Rep 75 Posts Drives: BMW 135i AW 2008 Join Date: Aug 2009 Location: Denmark iTrader: (0)	suspension is set for RFTs ? Hey Guys, i just ordered new tires for my 135, and some ppl in another forum commented that the car would not act as well on non-rft's, and that it generally wasn't recommended, as the suspension is setup for RFT's....now i get the exact opposite idea when reading through pretty much all the threads here about tyre choice....should i just ignore them ? ps:i got Toyo's in 225/40 and 255/35
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03-21-2010, 04:55 PM	#2
BMW86 Major General 398 Rep 9,156 Posts Drives: RS3 Sedan / Macan S Join Date: Jul 2008 Location: Australia iTrader: (0)	Which forum is this? They are talking smack. The non-RFT are better in every way trust me
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03-21-2010, 04:58 PM	#3
_dopehead_ Private 6 Rep 75 Posts Drives: BMW 135i AW 2008 Join Date: Aug 2009 Location: Denmark iTrader: (0)	its a local forum, and i think he actually meant that it would handle very differently, which is what i am after..so no issue there anyways.
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03-21-2010, 05:09 PM	#4
DBFIU Crack Addict 84 Rep 759 Posts Drives: Fast Join Date: Nov 2008 Location: Hollywood, Florida iTrader: (0)	Leave that forum. But he is right, it will handle differently, much much better. __________________ 2009 - Titanium Silver - Steptronic - 135i - Nasty
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03-21-2010, 06:24 PM	#5
_dopehead_ Private 6 Rep 75 Posts Drives: BMW 135i AW 2008 Join Date: Aug 2009 Location: Denmark iTrader: (0)	I hope so :-) can't wait to get them mounted now that the sun seems to be peeking out a little bit.
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03-21-2010, 06:26 PM	#6
WhiteOne Major 28 Rep 1,000 Posts Drives: 2008 AW 135i Join Date: Dec 2007 Location: Alabama iTrader: (0)	If you are "scared" , pay the big bucks for "safety" tires. If you want the car to ride & handle better, ditch the runflats. JMHO
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03-21-2010, 08:53 PM	#7
_dopehead_ Private 6 Rep 75 Posts Drives: BMW 135i AW 2008 Join Date: Aug 2009 Location: Denmark iTrader: (0)	I'm not scared, there is really no problem with getting a flat in my little country, there is no place where i drive that i wouldn't be able to get a tow truck or a friend to come get me, thats the good thing about living in a small country
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03-21-2010, 11:20 PM	#8
new2the3 Colonel 378 Rep 2,067 Posts Drives: 2020 X3M Competition Join Date: Jun 2006 Location: San Diego iTrader: (0)	The only downside is non runflat tires do not have as stiff sidewalls as RFTs. The suspension is designed with these stiff sidewalls in mind. With a non RFT you will have a much high quality tire with more grip and a huge improvement in ride comfort but.... the tire sidewall will definitly be softer. Maybe increased body roll? __________________ 2020 X3MC 2009 135i: AW/CR Aluminum Trim, 6 speed, M-Sport, Premium, Heated Seats, Ipod, BMW Performance Pedals, BMW Performance SSK, BMW Performance Exhaust, BMW Performance Grills E93 M3 FSB
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03-22-2010, 05:43 AM	#9
Lester Brigadier General 295 Rep 3,350 Posts Drives: Join Date: Oct 2007 iTrader: (0)	Body roll would be affected by the suspension, not by the stiffness of the sidewalls. In any event, body roll doesn't impact normal driving much. If you track the car, chances are you have already upgraded the suspension.
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03-22-2010, 09:29 AM	#11
GaryS Colonel 37 Rep 2,084 Posts Drives: 2009 135i 6MT Join Date: Feb 2010 Location: Maryland iTrader: (0) Garage List 2009 135i [6.50]	A few people have said they felt some loss of steering sharpness with non-rft. But most people say the change was 100% positive. Obviously it depends on which non-rft you choose.
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03-22-2010, 09:41 AM	#13
RaceTime Auto X'er 3 Rep 157 Posts Drives: 2009 Space Gray 135i Join Date: Jul 2009 Location: Northern Colorado iTrader: (0)	It is 100% positive. I still have stock tires on stock rims to go back and forth to the track...once the stock run flats die, I will be putting on some non-run-craps . You will not be disappointed with a good performace non-runflat tire! __________________ 2009 135i SGM, Premium, Sports, Nav. Dinan Stage 2 software, Injen intake, RR Oil Catch Can, H&R Pro-coilovers and springs, H&R front sway bar, Vorshlag camber plates, Vorshlag comp studs, BMW strut brace, BMW performance pedals, G-Force harneses, BMP tow hooks, Breyton GTS-R wheels with 255-35R18 (square set up) and custom axel back exhaust with muffler delete.
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03-22-2010, 09:42 AM	#14
arrutled Colonel 104 Rep 2,474 Posts Drives: Olsa Join Date: Jun 2008 Location: Western Mass iTrader: (0)	besides the harsh ride, the one thing I noticed when I put my runflats back on was the sharpness. but comparing them to winter tires isnt really fair. __________________ AW 135i w/ blackette, performance short shift kit, BMW alarm, Performance rotors, APEX ARC-8 wheels, Direzza Star Spec 235/275, Dinan stage 3 suspension, M3 wishbones/tension rods/front sway/rear subframe bushings and thats all folks!
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03-22-2010, 01:02 PM	#15
SV Concepts III Lieutenant General 375 Rep 17,017 Posts Drives: BMW Duh Join Date: Apr 2005 Location: Santa Clara iTrader: (13)	This was my first mod, to get rid of the RFTs. The car will be a pleasure to drive with regular tires.
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03-22-2010, 01:52 PM	#16
Gary@TireRack Moderator 369 Rep 4,745 Posts Drives: Formerly 1995 M3 Join Date: Oct 2006 Location: South Bend, IN, Tire Rack HQ iTrader: (2)	^^ My first mod also. I've never regretted it. __________________ Gary. Tire and Wheel Forum Moderator. Tire Rack Sales Rep Gary@Tirerack.com http://www.tirerack.com/a.jsp?a=AH8&url=index.jsp Please refer to 'Gary/E90 Post' as your previous contact when you order online to help support this forum.
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03-22-2010, 03:53 PM	#17
ruffstik Pirate 56 Rep 692 Posts Drives: 2025 M2 G87 - on the list Join Date: Mar 2008 Location: Wisconsin iTrader: (0) Garage List 2008 135i [9.50]	I have some new star specs waiting to get mounted...cant wait!
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03-25-2010, 09:46 AM	#18
_dopehead_ Private 6 Rep 75 Posts Drives: BMW 135i AW 2008 Join Date: Aug 2009 Location: Denmark iTrader: (0)	I just received the new rubber, damn 255/35 is big tire :-) my old car was on 205/40-17's so this is quite a step up in size. Can't wait to get them mounted, hoping there is no rubbing on orig bmw 264 rims.
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03-25-2010, 10:19 AM	#19
GaryS Colonel 37 Rep 2,084 Posts Drives: 2009 135i 6MT Join Date: Feb 2010 Location: Maryland iTrader: (0) Garage List 2009 135i [6.50]	Don't worry, it won't rub.
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