17" Tyre Probs

Anonymous · February 17, 2006, 12:45

Hi Folks,

Been talking to lots of you about problems running 205's all around and decided I have to change. Its only when checking I realised I really have the wrong wheels on. They look fantastic but the sises and offset is wrong ( I think, I stll don't understand what offset is). There 17" with a 7" diameter 35mm offset and a PCD of 4/100 -108mm and a center bore of 72.6mm (whats a PCD?).They do however look great! and there Black

So went checking looking for 205/40 and 225/35's DISASTER checked a lot of dirrent companies and all the spec sheets say that 225/35's won't fit a 7" wheel. What does everyone else have? Is 7" a particullary narrow rim?

Failing to get a 225/35 could I change to 195/40 front and 215/35 Hankook do a tyre in this size (although it dosn't show specs for it on its main site). Would these be ok?

Please Advise

Also can anybody please explain what offset is, how spacers work, what the hell a pcd is, what are wheels.............Aaarrgh
Really really Confused. Please help if you can.

Tem · February 17, 2006, 13:14

Quote from: "kj"Is 7" a particullary narrow rim?

7"=177.8mm...so yes, there would be better choices for 225mm wide tyres, especially if they have small profile, which can't be stretched that much.

rmowbray · February 17, 2006, 13:17

Have a look at this: Clicky

<Edit>
If you fit wider wheels with the same offset as standard or more then the wheel will protude more into the wheelarch and potentially give rubbing problems. So in theory to keep the inside edge of the wheel in the same location you need to subtract offset equal to the additional wheel width.

6.5" wheel with +45 offset will have the same inside edge position as 7" wheel with +33 offset (12mm less +ve offset).
</Edit>

spit · February 17, 2006, 13:20

oops, meant to PM - ignore this....

philster_d · February 17, 2006, 14:21

Mine have spacers to bring the wheels back out to the right position and make sure its all centred too I guess.

Anonymous · February 17, 2006, 17:08

Quote6.5" wheel with +45 offset will have the same inside edge position as 7" wheel with +33 offset (12mm less +ve offset).

so my 7" with with 35 offset arnt bad 179+35=214 as aginst 165+45=210 at least at the rear but what about the front?

Anonymous · February 17, 2006, 17:41

Quote from: "rmowbray"6.5" wheel with +45 offset will have the same inside edge position as 7" wheel with +33 offset (12mm less +ve offset).

Err... but isn't the offset measured from the centreline of the wheel? Doesn't this mean that the offset adjustment should be half of the change in width? So, in the above example the new offset should be +39, to keep the inside edge position the same.

rmowbray · February 17, 2006, 19:50

Quote from: "peterb"
Quote from: "rmowbray"6.5" wheel with +45 offset will have the same inside edge position as 7" wheel with +33 offset (12mm less +ve offset).
Err... but isn't the offset measured from the centreline of the wheel? Doesn't this mean that the offset adjustment should be half of the change in width? So, in the above example the new offset should be +39, to keep the inside edge position the same.

You're absolutely right. My mistake s:oops: :oops: s:oops:

Anonymous · February 19, 2006, 15:08

Should I then use 4mm spacers on the rear? What sizes are spacers available in and from where. What about the fronts 6"=152 + 45 offset = 197 new sizes 7" 179 - 13.5 (- 1/2 dirrence from 6")+35 Offset =200.5 only a 3mm difference is this correct? If so is it worth worrying about?

Also has anybody thought about the tyres are 195/40 front and 215/35 rear going to be ok?