Developing a Track Wheel Specifically Designed for the M2

Article | 05/16/2017 by Tom Maloney

Updated on 08/06/2024

Article updated on: 4/14/2023

NOTE: Since this article was first written, we have launched these fitments in our Flow Formed FL-5 and EC-7 designs alongside our Fully Forged VS-5RS wheels based on feedback from the community. A huge thanks goes out to everyone that participated. Choose your next set of M2 wheels on this configurator.

Since its launch, we’ve been receiving inquiries from M2 owners searching for the ideal wheel fitment to use at the track. It quickly became clear that the right fitment was not available unless you commissioned custom wheels. We’re trying to gather enough demand to make the production of an M2-specific fitment possible.

Although the M2 shares many components with the M3/M4, fender clearances are very different. Unique offsets are required to get an ideal fitment. There are a number of wheels intended for other BMW applications that are promoted by vendors, but those fitments present a compromise. They’re too conservative or aggressive in either width or offset. If they’re too aggressive then wide tires won’t clear, forcing a downsize in tire width or substantial rubbing. If they’re too conservative then space is squandered, limiting grip, track width, or require spacers for strut clearance.

At launch, we were hoping our 18×11″ ET44 wheel intended for the F8X M3/M4 would fit the rear of the M2. Unfortunately, the M2 has less inner clearance to work with, and it didn’t fit well. Since then we’ve been working with multiple partners who’ve helped us test a wide range of wheels and tires on the track.

Our Ideal M2 Fitment

An 18×10.5″ ET40 wheel for the rear that can properly support 285,295 or even 305 tires, and an 18×9.5″ ET28 wheel for the front that can properly support 265 or 275 tires. The two wheels allow for either a staggered 9.5″/10.5″ or 9.5″ square fitment depending on the driver’s preferences.

With the recent launch of two new stronger/lighter designs, we’ve modeled out both the SM-10 and FL-5 to see what they’d look like installed. Weights would range from 20-21 pounds depending on size/design.

Since the M2 is a limited production model we could only make this unique fitment available in one of the two designs. We need your feedback and help to pick the design, and confirming if this is a project we should commit to.

FL-5 Specifications

Size	Offset	Approx. Weight	Face Profile
18×9.0″	ET30	~20.2 lbs	Medium Lip
18×9.5″	ET28	~20.9 lbs	Medium Lip
18×10.5″	ET40	~21.2 lbs	Deep Lip

SM-10 Specifications

Width	Offset	Weight	Face Profile
9.0″	ET30	~19.6 lbs	Profile 2
9.5″	ET28	~20.3 lbs	Profile 3
10.5″	ET40	~21.2 lbs	Profile 3

Why 9.5” ET28?

We already offer 18×9.5” wheels in 22, 35, 43, and 58mm variants, yet we still wanted to add a 5th. Current M2 owners use our 35mm offset wheel but they sit too close to the suspension to be considered a perfect fitment for the front. When paired with 265 or 275 tires, especially track-oriented compounds which have a tendency to run wide, owners are forced to run spacers up front for proper inner strut clearance. By reducing the offset to ET28, our proposed wheel gains 7mm extra inner clearance, avoiding the need for 5mm spacers that aren’t hub centric. Yes, running these wheels up front will still require dialing in negative camber, but negative camber is needed for 265 and 275 tires anyway. Negative camber is extremely desirable for any track day enthusiast and is a key ingredient in any properly setup track car.

Why 10.5” ET40?

Enthusiasts attempting to put power down coming out of a corner need a wider tire and a wheel to support it. A 10.5” wheel with the appropriate offset can properly fit a 285, 295 and even 305 tires within the M2’s rear arches without the rubbing issues caused by 3 series offsets. The extra ½” of width this 10.5” wheel provides over the stock M2 rear wheel is evenly dispersed, extending the wheel 6mm both inward and outward. For those looking to maintain the car’s factory balance, the 1” stagger is restored when paired with the 9.5” front wheels.

Square or Staggered. Which is the right fitment for me?

For those of you racking your brains on this popular debate, let me start off by saying there is no right answer. Both fitments provide drivers with pros and cons. Factors like how you use your car, desired tire specifications, driving styles, budget, and power output help define which route is best for your personal needs.

In short, a square fitment will help mitigate understeer as well as dramatically reduce the seasonal tire budget through the ability to rotate any corner. Square fitments promote a very balanced handling experience where enthusiasts can channel their M2’s inner go-kart. If you like a car that turns in on command, and respect that a 275 r-compound is already great at this car’s power level then square is the way to go.

By going with a staggered fitment, you can maximize both wheel and tire width all around. This ultimately creates the largest contact patch we can, with the goal of putting as much power to the ground as possible. A staggered fitment costs more to own because the wheels and tires initially cost more, and most-of-all you can’t rotate anything. You can only dismount tires and flip them on the wheel which is also costly. If drivers are not consumed by the consumable costs of tires (you see what I did there?), and they upped the power on their N55 through tuning etc., then running more tire out back may be the key to quicker lap times.

Recommended Staggered Fitment

Wheel Specifications: Front Wheel Size: 18×9.5” ET28 Rear Wheel Size: 18×10.5” ET40 Note: The front will require negative camber to fit

Tire Configuration 1: Front Tire Size: 265/35-18 Rear Tire Size: 285/35-18

Tire Configuration 2: Front Tire Size: 275/35-18 Rear Tire Size: 295/35-18

Tire Configuration 3: Front Tire Size: 275/35-18 Rear Tire Size: 305/35-18

Staggered FL-5 & SM-10 Images