I have a astra 1.8 sri 2003 model, i have recently updated my standard alloys for a set of 18" alloys and noticed a slight knocking noise coming from the rear alloys, and if i have as little as 1 person sitting in the back my tyres start to scrape. can any 1 help??

craig dodd, January 2010

There is a rule of thumb calculation. Remove a wheel and put a bolt through one of the holes. A certain length should stick out the back of the wheel, but you willl have to search for the info or ask a tyre fitter or alloy sales shop as I cant remember.
There are also different bolt head shapes, rounded, tapered, flat.

http://www.priracing.com/section.php/73/1/wheel-nuts--bolts--locks

I'd also say the wheels are too big for the car if they are scraping

picker, January 2010

haha maybe i should picker all new to me. i just used the bolts that came with the wheels haha thanks very much mate ill try the bolts from old rims. thanks again

craig dodd, January 2010

Are you aware that different wheels often need different length bolts?
If the bolts you used are too long they will catch on the handbrake internals.
Perhaps you should sell your spanners before you kill someone.

picker, January 2010

The wheels are to big for the car,simple.

anon, January 2010