20's and RFT's ride rough. Recommendations?

KingAventus · 05-02-2019, 07:46 PM

I just purchased my first BMW, and they have the staggered 624M's on them, in 20", fitted with Pirelli PZero RFT's.

They RIDE LIKE HELL! I gotta swerve around every pothole, and it's annoying.

Currently looking into getting new tires, non-RFT's. My dilemma is this; Which tire size should I get, not compromising performance , and a more comfortable - smoother ride?

TIA!

alohasurftoad · 05-02-2019, 11:56 PM

Quote:

Originally Posted by KingAventus

I just purchased my first BMW, and they have the staggered 624M's on them, in 20", fitted with Pirelli PZero RFT's. They RIDE LIKE HELL! I gotta swerve around every pothole, and it's annoying. Currently looking into getting new tires, non-RFT's. My dilemma is this; Which tire size should I get, not compromising performance , and a more comfortable - smoother ride? TIA!

generally i don't recommend tire diameters greater than 26.5" and approaching F34(GT) tire diameters, however if you want the most sidewall on your 624M, do 235/35/20, 245/35/20, 26.5"/26.8".

michelin pilot sport 4s or AS 3+ if you need an all-season. continental extremecontact sport if you don't want to pay MPS4S price and falken azenis fk510 for most bang for the buck.

the only other size combo that fits good on the oem widths is oem size combo, 225/35/20, 255/30/20. MPS4S or Falken

floydarogers · 05-03-2019, 01:22 AM

Go down to 18" rims, and the OEM size for those wheels.

Solidjake · 05-03-2019, 09:08 AM

You put 20 inch wheels on the car, what did you expect? 18" is the best size for performance, comfort, economy

Styx · 05-03-2019, 10:16 AM

I just went from 18's with pirelli runflats to 20's with Conti DSW06's. Even with far less sidewall the ride is significantly better. Run flats suck. I have wider rims but I went with 275-30-20 and 245-35-20.

Jeff_335 · 05-03-2019, 11:11 AM

I swap mine for ps4s in 235/35/20 & 265/30/20, the different is day and night.

cfm56d7b · 05-03-2019, 12:20 PM

Changing to non run flat tires will produce immediate and noticeable reduction in harshness. It's difficult to make a mistake by considering Michelin PS4S tires.

Changing to non run flat tires may not be enough as 20" wheels simply have less sidewall to absorb road imperfections. But - 20" wheels do look good if aesthetics are important.

To further improve comfortable ride without degrading suspension performance, few thoughts:

- More suspension travel is needed to provide comfortable ride
- More responsive compression and rebound behavior (ideally configurable) is needed to provide more controlled, performance oriented ride

Coilovers with adjustable compression and rebound controls (independent or linked) set at near OEM height will be the optimum option.

Even 20" wheels can feel reasonably comfortable on poor roads with coilovers which are configured with proper compression and rebound settings and set at OEM or near OEM height.

Caveat: encountering a pothole from the moon surface can blow any tire however whether 17" or 20".

05-02-2019, 07:46 PM	#1
KingAventus New Member 1 Rep 10 Posts Drives: BMW 328i Join Date: Mar 2019 Location: Atlanta,Ga iTrader: (0)	20's and RFT's ride rough. Recommendations? I just purchased my first BMW, and they have the staggered 624M's on them, in 20", fitted with Pirelli PZero RFT's. They RIDE LIKE HELL! I gotta swerve around every pothole, and it's annoying. Currently looking into getting new tires, non-RFT's. My dilemma is this; Which tire size should I get, not compromising performance , and a more comfortable - smoother ride? TIA! __________________ 2015 BMW 335i MSport
	Appreciate 0 Tweet Quote

05-03-2019, 01:22 AM	#3
floydarogers Curmudgeon and Pedant 690 Rep 3,489 Posts Drives: 2010 335d, 2014 328d Join Date: Nov 2012 Location: Bellevue, WA iTrader: (0)	Go down to 18" rims, and the OEM size for those wheels.
	Appreciate 1 alohasurftoad3078.00 Quote

05-03-2019, 09:08 AM	#4
Solidjake ¯\_(ツ)_/¯ 945 Rep 1,762 Posts Drives: '13 328i Msport 6MT Join Date: Jun 2009 Location: NYC/SNJ iTrader: (2)	You put 20 inch wheels on the car, what did you expect? 18" is the best size for performance, comfort, economy __________________ Tensioner/belt DIY \| Side skirt extension DIY Apex SM-10/DWS06+ \| 400m/X-ice Xi3 \| Injen Exhaust \| Stoptech SS Lines \| 335 Front Brakes Hawk HPS 5.0 \| RBF600 \| ER Charge Pipes \| Wagner Evo Comp 2 FMIC
	Appreciate 0 Quote

05-03-2019, 10:16 AM	#5
Styx Private 58 Rep 84 Posts Drives: 2014 435i Convertible Join Date: Oct 2017 Location: Fredericksburg, VA iTrader: (0)	I just went from 18's with pirelli runflats to 20's with Conti DSW06's. Even with far less sidewall the ride is significantly better. Run flats suck. I have wider rims but I went with 275-30-20 and 245-35-20.
	Appreciate 0 Quote

05-03-2019, 11:11 AM	#6
Jeff_335 Private First Class 102 Rep 116 Posts Drives: 2014 335i Join Date: Oct 2016 Location: Quebec iTrader: (2)	I swap mine for ps4s in 235/35/20 & 265/30/20, the different is day and night.
	Appreciate 0 Quote

05-03-2019, 12:20 PM	#7
cfm56d7b Lieutenant General 5886 Rep 10,256 Posts Drives: 2017 440i Gran Coupe & 2015 X5 Join Date: Nov 2012 Location: Orange County, CA iTrader: (2)	Changing to non run flat tires will produce immediate and noticeable reduction in harshness. It's difficult to make a mistake by considering Michelin PS4S tires. Changing to non run flat tires may not be enough as 20" wheels simply have less sidewall to absorb road imperfections. But - 20" wheels do look good if aesthetics are important. To further improve comfortable ride without degrading suspension performance, few thoughts: - More suspension travel is needed to provide comfortable ride - More responsive compression and rebound behavior (ideally configurable) is needed to provide more controlled, performance oriented ride Coilovers with adjustable compression and rebound controls (independent or linked) set at near OEM height will be the optimum option. Even 20" wheels can feel reasonably comfortable on poor roads with coilovers which are configured with proper compression and rebound settings and set at OEM or near OEM height. Caveat: encountering a pothole from the moon surface can blow any tire however whether 17" or 20".
	Appreciate 0 Quote