Boxer Rear Wheels

I have 7 1/2 X 15 Cromodora's up front but my rears are a 8 X 15 aftermarket wheel. Has never bothered me that much. Have the correct Michelin tires.

I just came across two 9 X 15 Cromodora's that were formerly on a Daytona.

My knockoffs are octagonal.

If I put these correct 9 X 15 on my 1979 BB512 will I need to purchase a deeper knockoff or are my present knock offs correct. That is the same for front and rear.

So the question is are the knockoffs on the front and rear of your boxer running 7 1/2" front and 9" wide rears the same.

I read somewhere, but it may have been for the deeper Borranis, that you had to run a deeper knockoff with the wider rear wheel.

I tried looking aht the Ferrari's owner site for the parts description to see if they were the same but they seem to be having problems for the past couple of days.

Any help appreciated.

Drew Altemara

Hi Drew,

Eurospares UK has new replica 9x15 Cromodoras with hubs for around $1200 each also.

Their are 2 types of octagonal knock-offs one is the Boranni hand style the other the Cavallino style. They are all the same in depth, the threads are either right hand or left depending on the side of the car they are on.

The deeper knock-offs you are referencing are the true 3 ear KOs, the rear 9" wheels require a deep KO which the ears are angled out further for hammer contact, the fronts for the 7 1/2"s are regular 3 eared KOs.

Ok, this is helping. So the thread depth of the knockoff is the same. The only difference is that on 9 X 15, this knockoff should be with the ears angled out so you can get at it with a hammer.

Now how about this. My knockoffs are octagon which was not only mandated for the US but also for other countries in Europe (Belgium comes to mind). So my octagon knockoff will fit wider rear wheels however I may have a problem using the "octagon wrench" in the tool kit as the side of the deep wheels may interfere with the end of the wrench.

Does this seem correct?

I have the factory wrench for the KO octagonal nuts and its angled, so it clears the all the wheel rims easily.

Well maybe I'm in luck. I have the heavy black tool kit wrench that is correct for the car also. Are you saying that it also clears 9 X 15 rims?

Yes if its factory, which it probably is, clears no problem.The tool is angled at about 45'.

I put a cheeter bar on the handle and opened the lids or turn the front tire so no chance of hitting a panel when using it, if the nuts have been on the car for awhile I couldn't see getting enough leverage with the tool itself to loosen the nuts.

Yep, that's it. Thanks a bunch Jeff. This makes a lot of sense. The tool kit would have to include a wrench to remove the octagon hubs for both the front and rear.