Some Basic Wheel Questions

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Mar 27, 2007 | 10:38 PM

Robin Casady

Thread Starter

6th Gear

Joined: Mar 2007

Posts: 7,578

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From: Paradise

Some Basic Wheel Questions

Is there a FAQ for wheels somewhere? I have some very basic questions.

1. Is there a downside to light weight wheels? Are they more fragile? I assume that light weight is good, but most things in life a require balance between different forces. Would a bad pothole be likely to break a very light wheel? For example, the Kosei K-1 TS is only 14.1 lbs. while few other wheels drop below 16 lbs. and many are 20 lbs or more. Any disadvantage to the Kosei?

2. What is the offset, and should I care?

3. My R56 MCS is currently in Oxford in the last stages of production. I've ordered the Sports Package which includes 17" Crown Spoke wheels. Anyone know the weight of these wheels?

4. What does one gain with more expensive wheels? Is there more to it than brand name and style? For instance, there is the BBS RGR for $544 that weighs 16.3 lbs. Then there is the O.Z. Ultraleggera for $265 that only weigh 16 lbs. Or, the SPORT Edition D4 at 18.5 lbs for $109, vs. the much heavier (20.3 lbs), but similar looking BBS RD at $241. Are there different alloys, and/or better mfg. processes that really make a difference?

Thanks.

Mar 28, 2007 | 10:20 AM

sandtoast500

5th Gear

Joined: Nov 2004

Posts: 980

Likes: 1

From: Downtown Denver

This is the FAQ for wheels!

1. You're right, there should be a balance if these are going to be all around wheels. For just autocross, super light wheels would be good. For just show cruising, heavy wheels are OK. I think a good rule is to be within 1-2 lbs of a pund per inch for all around wheels. So 17" wheels from 15-19 will be pretty good all around. Koseis are great wheels for the price, even Randy Webb runs them on his Mule.

2. Offset is very impoortant, but may be pushed with slight modifications. Offset is how many millimeters off the exact center of the wheels that the bolts sit. It ends up determining how far the wheels stick out or are tucked in. Our cars will work with anything from et+35 to et+48 or so. Here are a few examples:

Konig rewind 15x7 with an offset of et40, which is good for our cars.

Konig Rewind 15x7 offset et0, which is right in the center of the wheel.
See how deep the lip is comparrred to the et40? This would stick out crazy far on our car and would cause all kinds of fender interference and rubbing.

3. I don't know about that exact wheel, but I would guess it will be around 21-24 lbs each. OEM wheels tend to err on the side of safety and reliability, hence the weight.

4. If you go with a BBS wheels, the fit, finish and trueness, or how even the wheel is, will all be better. Casting and forging processes can be far superior, allowing for a stronger, lighter wheel, then offering different spoke configurations. But ultimately, your budget will dictate which wheels you CAN get, so buy a wheel from a trusted manufacturer that's affordable, like Rota or Konig. These companies are proven and reputable. However you go, the tires will ultimately be the most important part of the combo. $800 BBS wheels on crappy tires will never outperform good tires on $80 wheels.