rims for semi's - to 16'' or to 17''

[sambb]

I've narrowed down to 2 sets of rims that i'll set aside for when I do hillclimbs. 17 x 7 ET41 (10.6kg) OR 16 x 6.5 ET43.
After opinions on what will be more suitable.
I'm leaning more towards the 16's. Ideally I'd wanted 7in wide but I think 205's should be plenty and they will be much lighter and are the offset I was after. But then will the wider stance and contact patch of the 17's negate the weight issue??

help

[seangti]

If they fit over the brakes, probably best going a 16". Lighter, less rotational mass. Would just make sure that the tyres you're keen to run now and in the future come in the desired size/width and at a reasonable price point. My semi's are a 215/45/17 (Kumho don't import the 215/40/17 they run on the coopers in England), which I found out on the drive home will require raising the car marginally at the front as it touched the guards on a heavy compression. A 215/40 never touched.

[sambb]

Are you running V70A's?

[sambb]

sorry another question. If I was to source 15 x 7's, is there a limitation to how much negative offset can be run in terms of clearing standard calipers? ie would an ET43-38 clear?

[kaanage]

Won't the caliper tilt with the hub?

The GTi calipers have no problems clearing my 15x7 et38 Team Dynamics Pro Race 1.2s. I do wish they were et43

Low profile semi-slicks seem to cost a LOT more so I'm staying with 15s

[sambb]

sorry Greg I confused things then - I meant how much positive rim offset is possible before caliper fouling happens. Good to know ET38 clears. Thats the ballpark or more that I want with 7in.
Yeah 15's really are what I want but for the money I have I can't find nada. Plenty of 15 x 6J though. The 16's will do, and the 17's were just a really good deal but not really what I'm after.

thanks all

[seangti]

Are you running V70A's?

Yup, just got them put on this week. May not get to the track till October

[Stuwey]

how much positive rim offset is possible before caliper fouling happens.

This is two entirely different questions.

Wheel profile (spoke shape) will allow for big brakes, not the final offset. Work Meisters are a great example of this.

Offset of the wheel will affect scrub radius. The answer to which any more than none is bad if you're really talking performance.

[sambb]

yeah without anyone actually measuring/drafting the front end geometry, I can only assume that something in and around the factory ET43 - ET38 range of positive offset for rims produces a good scrub radius. I'm not going to second guess the VW engineers on that. I thought that generally FWD performance cars are designed with negative scrub radius aren't they. Then around that more rim offset will give more kick back/feedback in the steering and less rim offset will dull steering response down a bit. I wonder if that's why the factory moved from ET43 in the 06' cars to ET38 afterwards to try to engineer out the wriggling and torque steer etc in the wheel for the average buyer who just wants 'planted' steering.
I was just using rim offset as a vague guide for knowing roughly how far I can go re strut/brake clearance because generally anything set well inboard is at more risk. But yep seen plenty of spoke collisions when a rim seems to fit until you turn it.

[sambb]

Sean i'll be interested to hear how those V70A's go. They are just about the only R specs I've found that come in 205/45/16 but I was quoted $330 in that size. Ouch!