Wheel options for Australian Sonics

[Turbo]

Hi

Just to explain the threads title. The standard Sonic, if there is such a thing, specifies the use of wheel spacers. In Australia, if you want to register for road use, you are not permitted to use spacers.

The Manual has a recommendation of a 205/40/17 tyre, necessitating a 7” wide wheel (although other widths would work with that tyre). The offset recommendations are 15 mm with a 25 mm spacer, or a 40 mm offset and a 50 mm spacer. So both of these are effectively a -10 mm offset.

I have been playing with the standard Focus wheels to see what the problem is. Clearly it’s contact with the upper arm at the rear. The LR Focus has a 195/60/15 tyre on a 6” wide 15” wheel with a 50 mm offset.

This wheel needs about 25 mm of packing to clear the suspension.

Therefore a 15” wheel 6” wide would need an offset of 25 mm or less to work.

If you go to larger diameter wheels the clearance issue diminishes given the angle of the suspension arm at full droop, even allowing for the likely greater width of the wheel. This seems different to the Manuals recommendation of an offset of -10 mm.

I was wondering which 16” or 17” wheels you have used that do not need spacers.

thanks in advance 

[kiwicanfly]

Out od interest are you allowed to use adaptors instead of spacers?

[Turbo]

I’m guessing an adapter is bolted to the hub and the wheel then bolts to it, while a spacer has the hub studs pass through and allow the wheel nuts to attach directly. Is that right?

I don’t think either are allowed.

I believe the only car in the country with legal spacers is one of the Porsches because that is how they made them. So an ICV (individually constructed vehicle) doesn’t count.

[kiwicanfly]

You are correct.

Reason I asked is that I have a set of good adaptors which are no longer of use to me.

I originally used 16" on my rocket, 15" can be tight for clearance on everything at the rear, 16" are a lot more forgiving.

Rocket didn't need spacers (I bought the adaptors for a different reason), I thought the arms were the same on the rocket and sonic.

[Turbo]

Thanks, I’ll talk to my engineer and get an official answer.

Any comment on the -10 mm effective offset in the manual, it seems a long way from my measurements and calculations?

[buildityourself]

I can hopefully have a look in the next couple of weeks, as I have a set of 15x6 and 15x7 wheels with slightly different offsets which I can't remember off hand. Both of these clear the uprights, which is a reported issue with 15" wheels, but not sure about the wishbones.

[Turbo]

Thanks, that would help

Also, those mudguard or wing support brackets are very close to the side panel. I guess shifting the wheel out would allow these to be modified as well.

[buildityourself]

Mar 10, 2021 0:01:25 GMT Turbo said:

Thanks, that would help

Also, those mudguard or wing support brackets are very close to the side panel. I guess shifting the wheel out would allow these to be modified as well.

Shifting the wheel out doesn't change the position of the cycle wing brackets as they are bolted to the hubs. I have about 10mm clearance to the body on the rear. More can be obtained by rotating them.

[Turbo]

OK thanks, I guess I was thinking that they could be modified - cut and shut - to move them away from the side panel. But I'll have a look at rotating them before I start drilling!

[buildityourself]

I tried my 15x6.5 ET38 wheels on the hub without any spacers. The top wishbone just catches, so Et35 would probably clear ok (caveat I didnt have brake calipers fitted so they may catch still). However this is still not an option as the inside of the wheel is so close to the body, that the wheel arch stays would not fit and the tyre would hit the body on suspension compression.





To get the wheels in the right place you basically need a wheel that has a 80mm inset (measurement from the hub face to the inside edge of the wheel. The way to work this out for different wheel sizes/offset is to play around with this wheel calculator for different width wheels.

Wheel calculator

The link above shows my original wheels and the desired offset to get the new inset of 80mm. This corresponds to a bolt on wheel spacer of 50mm which I've just ordered and arrived. They are beasts. If I could have found a wheel 15x6.5 ET-02 then the spacers would not be needed however my understanding is that wheels with zero or negative ET are very rare.

If you are not allowed spacers you might have to go for a skinny 5.5" wheel like this in ET10. 

www.comp.co.uk/products/product.asp?item=ml1555-24-126

or these 6" in ET4

www.comp.co.uk/products/product.asp?item=ml1560-24-127

HTH.