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View Full Version : O2+ REAR wheel wanted - plus advice on "offsets"



Chris W
13-10-2016, 02:55 PM
Looking for an O2+ rear alloy to replace fractured OEM rear alloy. In Silver (obviously?).

In case I need to replace whe whole set from aftermarket, does anyone know what the "Offset" is that I need. Read in some place it is "ET 30" and in others that it is "ET 60".

And what is an "offset"? Current wheels are 17x9J rear (255R17) and 17x7J front (215R17) OEMs.

Any tips on reliable place to buy replacements? Dont want to come away with 'drug-dealer' wheels !!

Chris.

goldnsx
13-10-2016, 03:11 PM
Offset is a measure of the center of the rim to the mounting plate (some might describe it better). OEM 02+ are 55 mm front and 56 mm rear (without spacers for sure!). A spacer reduces the resulting offset by its thickness. Going with a 45mm on the front moves the wheel 10 mm out of the fender. Conservative offsets are 35-50 mm on the front and the rear. I don't like those extreme offsets the US brothers run (<35 mm). Please remind any restrictions of your MOT.

Chris W
13-10-2016, 03:40 PM
Offset is a measure of the center of the rim to the mounting plate (some might describe it better). OEM 02+ are 55 mm front and 56 mm rear (without spacers for sure!). A spacer reduces the resulting offset by its thickness. Going with a 45mm on the front moves the wheel 10 mm out of the fender. Conservative offsets are 35-50 mm on the front and the rear. I don't like those extreme offsets the US brothers run (<35 mm). Please remind any restrictions of your MOT.

Great explainer.

That is exactly what I needed to learn. Now I can go shopping for a new set fully armed with what I need to know.

Thanks
Chris.

goldnsx
13-10-2016, 04:46 PM
Well, the info is not complete for now...

What tire sizes are you intending to run? Rim size? 17/17 or 17/18?

Chris W
13-10-2016, 05:49 PM
The plan would be to replicate the OEM dimensions (and keep my nearly new Bridgestones).

That means Fronts at 17 x 7J with 215/40R17 and Rears at 17 x 9J with 255/40R17. All onto the Honda 5 x 114.3 bolt pattern.

And -as you say - an Offset of around 55 all round and standard bore of answers over 70.3 mm.

As for design I am looking for similar clean and simple ~7 spoke design in silver (car is silver out, black seats, no mods).

Ideas and exerience much welcommed.

Chris.

goldnsx
13-10-2016, 06:21 PM
That is a very conservative approach. I had wider wheels with a low offset (43 and 38) on my car once but it didn't felt right. So I went 7.5/17 ET50 (45 mm would have been better as well) and 9/18 ET45 which is perfect for me with my focus mainly on driving than show. I thought about 9/17 but finally went with 9/18 which looked a little bit better but was not heavier. 9/17 is a little bit more comfortable but only by a slight amount. More tire choice in 255/35/18 than 255/40/17. Make sure you can get the right tires for your combo in the future as well. 215/40/17 is no problem but 255/40/17 was not easy a few years ago to get the exact same tire model of a top brand.

Be aware that with 7/17 you won't be able to mount wider tires like 225/35/17. I'd go for 7.5/17 at least. You can choose 8/17 but I would only if it offers better offsets than a 7.5/17. But the tire does look a little bit streched which I don't favor. Targeted offset would be between 40 and 50. Please remind that the shape of the rim matters if you go for ET50 as the rim needs to clear the front brake caliper.

In the rear I would choose 9-9.5/18. Is your car lowered with Bilsteins? Then you should choose the lower value of the targeted 45-50 mm of ET. A 9/18 can carry a 265/35/18 max. If you want the option to go wider in the future I'd choose 9.5 or wider.

I've no idea of your budget but if you can afford them get some lightweight rims and light tires as well. On this car you can feel the difference more than in another one and low weight is very rewarded in how the NSX drives then.

Ok, too much of inputs but I hope it helps. :)

Chris W
07-11-2016, 05:52 PM
That is great explanation of my options. And I agree my approach is very conservative!

Good news is that our latest efforts at welding the offending alloy seem to have now worked. It turned out there where two hairlines (around the spoke opposite the valve). Had to do a good bit of work on the leaking area and get hold of the right alloy to match. But looks to have held fine over a 200 mile road test.

Bad news therefore to those who were asking to harvest any spare front alloys from me.

Next project to sort out my terrible headlight performance - driving at night is now quite exhausting. Will send a separate post for ideas about that problem!

CW.