[MoeRon]

Pre-LCI E91 325i SE. Finally got round to replacing the OEM 17" style 158s and horrible runflats with some lovely 19" alloys and Good Year F1s.

Driving out of the tyre place, it felt better than I could've imagined. Smoother, quieter, much less crashy, and the car finally went in a straight line. However, on the open road I found a wobble. I can feel it at anything over 35mph. The feeling is not so much like unbalanced wheels; more like the tyres aren't round. It feels 'lumpy'.

Now. at first I thought I was being paranoid - with the low profile tyres I can feel the texture of the road like I was running my hand over it so I assumed it was just the road, but now not convinced. Took it back to the tyre place and had the wheels rebalanced and the alignment done (both were out) , but it doesn't feel much better .

Google tells me that I need 'Road Force Balancing', which I'd never heard of before. Unfortunately, no-one near me does it. Has anyone ever experienced this? Are these cars so sensitive that the standard tyre-fitters balancing machines aren't good enough?

Is road force balancing a real thing? Or am I missing something much more fundamental? All advice and experience appreciated!

[rufnekfatboy]

Hi mate, just a thought but are your new wheels hub centric(I think that is the right term) Ie centre bore of wheel is the same diameter as the hubs on the discs?
I assume if they are OEM wheels they probably are but if they are reps then they would poss need spigot rings.

As I say this is just a thought.....

[bazz780]

+1 on above, i had same issue which was resolved with spigot rings

[MoeRon]

They're not OEMs and I wasn't aware I needed any special fittings, but thanks I will check

[acerboo]

id rule out the F1s being responsible, brilliant tyres!

[MoeRon]

Nope, apparently they are the correct fit so must be some kind of balance issue...

[KM79]

At that kind of speed very very unlikely balance issue.You wheels may not be sitting correctly on hubs ie there corroded/dirty or as said spigot rings required.Have a check of you're tyres too,one May be out of shape.
Also you're road force balancing is where the wheel/ tyre is balanced on the car,something that was done in the 80's and you'll very unlikely get it done these days.

[Drrncour]

I also reacon incorrect hub fitment. What is the centre bore of the wheels?

also are these brand new wheels or just new to you (bought of someone else)

[MoeRon]

Wheels are new; Quantum 44 S1 19" with 72.6mm bore. Tyres also brand new.

Confused now. I agree, I've had badly-balanced wheels before and it didn't feel like this. It's quite a subtle wobble, but just feels so wrong I'm reluctant to drive it.

Will take them off when I get a chance and see what I can find. Thanks all for the advice.

[Corradokid]

Road force balance machines have a roller on them similar to what you see on a rolling road and will measure the pressure applied by the wheel assembly. Say for instance there is a flat spot on the tyre from poor storage this will show it up, and if the tyre is out of shape you can measure the rim and try to align the wheel and tyre together to minimise road force. It's worth having it done but I'd try and eliminate a wheel fitment issue first, also if there are flat spots they may well come out with normal driving. You should be able to get it done fairly easily but you might have to ring around to find a garage with the right machine for the job.

[MoeRon]

OK, checked the front wheels yesterday and they fit fine.

However, one wheel felt lumpy even just rolling it along the ground by hand. It appears that the tyre isn't round, or at least not round across the whole face. Anyone had this before? Can it be fixed?

[KM79]

Tyres could have been badly stacked at the tyre depot.The carcass will be deformed and unfortunately is scrap.

[M4rius]

Could be sticky brake caliper .