Custom 15x7.5 Rotas & 224/45-15 fitment

[Echo Leader]

No doubt that the 225/50-16 is a big'un. I'm just struggling to find a good ST* size for the Alfa that appears to have a future.

Yeah, I don't know how similar the rubbing issues are between the GTV6 and Milano, but I've never had issues with rubbing in roll. My issues are purely based of the front outer edge of the tire and the arc it makes when turning from lock to lock. Thus if I incease OD, but simultaneously increase positive offset, I might end up at a happy place were I can use a commonly available 225. If the Verde's rub issues are at the top of the fender or something, it might be a more difficult thing to fit a big OD.

There really doesn't seem to be a 'perfect' ST* tire size for the Alfas...

In other news: have fun at the autocross

[JoeCab]

Quote:

Originally Posted by Echo Leader If the rubbing issues on the Verde are similar to those of the GTV6, you may want to think about running 16" with a higher offset and a larger OD tire size.

[Echo Leader]

Joe,

Thanks, I didn't realize there was a dramatic difference. Where does the rubbing occur? And did the Milano run the same +45ET that the GTV6 did?

[Grant]

Some Verdes got 30ET wheels (Benzoni) versus the 45ET Speedline, even though the wheels look identical for the most part.

When I had 37ET 16x7.5 with 225/45/16, the rubbing was quite bad and required reducing the amount of caster (not good - especially for autoX as it reduces the amount of camber gained in hard cornering) and pulling/stretching the fenders.

Pic: Daniel's gtv6 in OZ with 3rd gen rx7 wheels.

[AlfaAutoCrosser]

Grant, getting back to one of your earlier posts, you mentioned the 16x7.5 45mm offset and your 20mm spacers. Do you feel that the 24" OD is more of the problem, or would you wish for a different offset than the effective 25mm you end up with?
I'll basically be running an inch less in diameter, and since I can choose offset, would 25mm still be the best number to use, or should I go with something different?
Thanks...

[Grant]

I think you'll be fine with 25mm offset and 15 inch wheels. My main problem was my rolling diameter. I had issues with et37 wheels, and now et25 has made problems much worse as the scrub radius has greatly increased, allowing the tires to swipe my fender splash guards with an even greater reach of the rubber. (I'm getting pretty severe kick back now too with the low offset combination when hitting expansion joints on the freeway!) Unless you greatly increase your spring rates (stiffer than 27mm torsion bars I think) you might have to remove the Verde flares and pull your fenders out - when the car rolls a lot, I think your 225 tires are going to become friends with the plastic fake flares.

If I had an extra inch of clearance, I don't think I would be having problems. My issue with rolling on 15 inch wheels is that my car is so low, I can't clear speed bumps with 15's on. I think I will be looking for 15 inch wheels for track use though, as the CG of the car will be lower without having to make the suspension geometry even worse to achieve that ride-height.

[91spiderNV]

I took the 15x6 campy wheels off a '83 GTV6 with 225/50/15 Kumho tires and put them on my old Milano Verde and they fit very well, no rubbing. Looked like an easy way to increase tire width. But my track times were no better than the 205/50/15 that I was originally using. But you never know until you try.

I do agree that 15" wheels are a thing of the past. I just tried to buy 15" wheels for a '98 328i BMW and Tire Rack along with everyone else I tried said that 15" wheel was not available. They did have 16" wheels. Tire Rack sales rep told me that the 15" wheels are going to be phased out. Man, if you can't get a 15" wheel for a BMW, think about an Alfa?

I know you can get 15" Team Dynamic wheels but 13lb wheels on the street look like easy benders to me.

[Grant]

Campys are +45 offset, and I think a 225 tire is best used with 7 inch wheels and up. The ballooning doesn't allow the tire contact patch to stay where you want it. Just putting that info out there.

I have never run slicks or R-comps, so I don't know if the sidewalls are strong enough to make up for that issue.

[Potenziato]

I just bought Falken Azenis in 215 45 16 on 16 X 7 SSR Type C and they fit pretty nice. My offset is 35 plus a 7mm spacer so that puts me at et 28mm.

The rear edge of the fender is always going to be really tight. My car has the front edge of the fender rolled and the bumper shaved and spaced a little. I think 225 is possible but will require a reshaping of some parts of the back fender to make it clear and wider arches like evo or cut out fenders with glued or riveted flares.

You also need enough offset to push the wheel out or it will hit aftermarket swaybars like RSR or Shankle because they don't contour at the ends. The stock swaybar is possible to use less offset without rubbing.

Going over 24 inches in diameter at the front is a recipe for severe rubbing. Also check the data sheets on tires from the manufacturers. The tire sizes vary widely even though they all use standard sizing like 205 50 15.

It's hard to say what fits because no one uses the same ride height, offset camber, caster, and of course car to car variations. Even the 215 width tires require a bit of work to fit on a Milano.

[Grant]

I think the rear fenders would be pretty easy to roll. Main concern is almost always the front end area.

[thesameguy]

FWIW, I got in on a group buy of Rotas about three years ago. It was a 4x108 fitment for Euro Fords, but same idea. We went through Cosmic Marketing, a Fremont, CA-based company and the West Coast distributor for Rota. They were easy to deal with, totally pleasant. We had to commit to 80 wheels of the same type/dimensions but colors were optional. Price was either $100ea or $125ea (can't remember) for the 17x7s we got.

Somewhat coincidentally, I'm trying to repeat the purchase on some Rota Grids... a very light (for cast) wheel in 15" or 16" size.

[AlfaAutoCrosser]

Well, after waiting about 5 months or so, 18Racing contacted me and said that Rota was not willing to create a new mold and they were going to cancel my order. They offered me a set of 15x7 Track R's that were done with 5x98 and 30mm offset for $500 shipped, and after thinking about it for a week, I decided to take them. It's certainly the cheapest way to go, and probably the lightest in weight, especially since I won't need to use adapters. Not as light as the Slipstreams though.
I probably won't bother with the 225's, and will instead get Azenis or the new Kumho XS in 205/50-15. Might as well go skinny since the rest of the car really isn't going to be that good anyway.

[thesameguy]

What color did you end up with? I'd love to see some pics when they're installed...

[AlfaAutoCrosser]

They are Bronze, which I'm not too happy with, but I can always re-spray them once they get here. I should have them in about a week.

[Grant]

The trackR's are available in 5x98 or they just drilled them especially for you?