Fortwo Alloys On A Roadster

This is a bit of a divisive subject.

On 1 side you have people who don’t think about it and just fit them. On the other side you have people who staunchly oppose such things because it’s either dangerous or blasphemous to degrade your superior Roadster with wheels from a lower class car. Yes, the Roadster snobbery is real.

As per usual, the facts are varied so have a read and make your own mind on the subject.

Width

This is the reason that 9 out of 10 people will tell you not to fit fortwo alloys.

Claim

More narrow alloys = more narrow tyres = less grip.

We all know that grip is the “Top Trumps” winning statistic for Roadsters so affecting that negatively is bad right?

Facts

Not all fortwo alloys are more narrow than Roadster wheels. The steel wheels and Spinline alloys are 5″ front and 6″ rear. So as long as you don’t go more narrow, you should be alright….. right? Well, no.

Offset

This is where it gets tricky. Offset is the position of the mounting face of the wheel in relation to the centre line of the wheel.

Claim

Fortwo wheels have a different offset so the wheels sit further in the arches. Apart from looking shit, this decreases the wheel track width. A more narrow track will negatively affect handling.

450 wheels will sit nearly 1 inch further in at the front (combined) and nearly 2 inches further in at the rear (combined).
451 wheels will sit nearly 1 inch further in at the front (combined) and more than 4 inches further in at the rear (combined).

Don’t believe what your girlfriend says, every inch matters.

453 alloys wheels won’t fit as they have a different stud pattern.

Facts

Yes, fortwo alloys do sit further in and this will affect the track width and the handling, however…

Wheel spacers exist.

You could use spacers to bring the wheels out to the correct offset or even a bit further to increase the track width.

Spacers

Wheel spacers adjust the position of the wheel in the wheel arch. There are 2 types. Bolt-to and bolt-through.

Bolt-to spacers bolt to the wheel hub and the wheel bolts to the new spacer. These are limited to width as you need enough thickness for the bolt to actually bolt to.
Bolt-through spacers are sandwiched between the hub and the wheel and longer bolts are used. The wheel is bolted to the original hub. You are limited by bolt length.

Claim

Wheel spacers are dangerous, increase the unsprung weight and also damage the wheel bearings.

Facts

If you don’t fit them properly or don’t regularly check the torque of the wheel bolts, yes, they’ll be dangerous.
If you buy cheap bolt-to aluminium spacers with no steel threaded inserts, yes, they could be dangerous.
If you use excessively thick bolt-through spacers it can put a sheer load on the bolts. Again, possibly dangerous.

If you do buy spacers, make sure they are hubcentric. They have a centre bore lip that locates the wheel in the same way it does to the original hub. This takes all the weight off the wheel bolts.

The increase in unsprung weight is negligible when using spacers. Any affect in handling is unlikely to be noticeable.

If you use the right size spacers that create the same offset as the original wheels, there’ll be no extra wear to the bearings. Again, even a normal size spacer isn’t going to affect the longevity of the wheel bearing that much. Plus the bearings are easy to change.

Insurance

Here’s the problem that can be a bit tricky.

Claim

Fitting fortwo wheels to your Roadster will nullify your insurance. In the case of a crash, if the investigator alerts the insurance company that you have fortwo wheels on your Roadster, they’ll not honour the insurance.

Facts

If you don’t tell them, sure, they could not pay out and you could even be in legal trouble depending on the damage to other cars, people or property.
However, with all modifications, just tell them. Let them know you have non standard alloy wheels fitted. They won’t know the difference. Of course it’ll increase the price of your insurance but that’s better than being out of pocket or possibly having your ring piece stretched in prison.

So What Happens If…

…I fit narrow fortwo wheels that have the wrong offset and don’t fit any spacers?

Look how tucked in these wheels are. I’m sure that the rain, speed and probably crap tyres had something to do with it but it just made me laugh that this was the 1st photo I found when I searched for a smart Roadster with fortwo alloys. These aren’t OEM Smart Fortwo alloys but they are aftermarket fortwo alloys so the offset is still incorrect and you can tell they aren’t particularly wide.

Sorry to Filip L for using your car as an example.

If you have a photo of a Roadster with fortwo alloys, send it to me and I’ll add it.