[AngryInch]

I’m ordering Brixton forged wheels.. was thinking 20 because I want to keep the weight down as low as possible… but I see a ton of guys running 21s…

Thoughts?

[Evil Derboy]

I’ll currently eyeing up 21s. Surprised BMW don’t offer a 21 option from factory. The 20s look a bit too small for it IMHO. Especially when you consider you can spec the RS6 on 22s.

[M5 F90 (2018)]

21s look so much nicer and the difference in ride quality is negligible.

[AngryInch]

Hmmm can’t decide… trying to go light weight, but the 21s look nice…

[adeuel]

What’s the goal? Looks or performance?

[BayDriverSF]

I researched moving from 20" to 21". No doubt 21" looks better. From what I've heard, ride quality isn't bad either.

But the reason it's not offered by the factory is that 21" has a lot of structural problems. "Bent rims" is not something you see a lot with 20" wheels--with 21" wheels you do. Your wheel profile will be much thinner (like riding on tires that look like bubble gum), so it has less flexibility, will rupture more easily, and not protect the rim as much. If I'm just driving in the neighborhood maybe 21" is still ok. But I'd never take them on a road trip.

21" wins on looks hands down. It loses on everything else (safety, reliability, maintenance, headache).

[adeuel]

My father in law has 22” on his B7. Good thing he bought the rim insurance, he’s replaced 5 so far in a couple years.

[josec70]

I've had 21" wheels on 3 different M5's with no issues.

The roads you drive should be the primary factor to consider when deciding to go with 21" wheels. I live in Miami where the roads are great so I've never had an issue but this would be a very different story if the roads were in poor condition.

You have less protection with 30 profile tires against potholes which could result in a bent rim.

There is also less protection against curbs but they're much easier to avoid than potholes.

Aesthetically, 21"s look much better IMO but this is subjective at best.

Good luck.

[AngryInch]

Hmm, I think we have worst roads than a 3rd world country. Plus 30c in the summer to -30c in the winter.. lots of frost heaves and potholes.. think I’ll stick with the 20s.. they will be lighter too…

[Evil Derboy]

Originally Posted by BayDriverSF

I researched moving from 20" to 21". No doubt 21" looks better. From what I've heard, ride quality isn't bad either.

But the reason it's not offered by the factory is that 21" has a lot of structural problems. "Bent rims" is not something you see a lot with 20" wheels, with 21" wheels you do. Your wheel profile will be much thinner (like riding on tires that look like bubble gum), so it has less flexibility, will rupture more easily, and not protect the rim as much. If I'm just driving in the neighborhood maybe 21" is still ok. But I'd never take them on a road trip.

21" wins on looks hands down. It loses on everything else (safety, reliability, maintenance, headache).

This can’t be the reason it’s not offered by the factory.

Audi offers alloy wheel options of 22 inch on the RS6 and RS7 (both of which are heavier than the M5)

It’s simply a case that BMW and Mercedes offer 20s due to comfort as they feel it better suits the car.

The tyre profile required on a 21 inch wheel on the M5 is 30. Which is pretty much standard on many smaller cars running 20 inch wheels.

[euro*]

Originally Posted by AngryInch

Hmm, I think we have worst roads than a 3rd world country. Plus 30c in the summer to -30c in the winter.. lots of frost heaves and potholes.. think I’ll stick with the 20s.. they will be lighter too…

Where are you? Montreal?

[AngryInch]

Originally Posted by euro*

Where are you? Montreal?

Way worse. Prairies….