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-   -   Just won some alloys, will they fit? (http://www.haynes.co.uk/forums/showthread.php?t=2708)

Rik178m 8th September 2009 11:05 AM

Just won some alloys, will they fit?
 
Cant get my head around the offset issue today. Just won some alloys on ebay pcd 108 offset 15. I know the offset needs to be 35-40ish. So my question is how do I get these alloys to fit or won't they?

slimtater 8th September 2009 11:54 AM

"May" be a problem:

http://www.driverstechnologyassociat...eel-offset.htm

AshG 8th September 2009 12:14 PM

they will stick out about 20mm further than a wheel that is the correct ofset. if you have wide arches on the rear it shouldnt be a problem

RAYLEE29 8th September 2009 06:49 PM

Bumpsteer!!

Matthew 8th September 2009 09:01 PM

Quote:

Originally Posted by RAYLEE29 (Post 21453)
Bumpsteer!!

I don't think that's right. Bumpsteer is caused when the steering rack isn't correctly aligned (or the right length), and doesn't have anything to do with the wheel offset. IF you ever measure it then you don't usually have the wheels attached anyway.

I think it does have some other effects though - something to do with how well the steering self centres I think.

Matt

Rik178m 8th September 2009 10:13 PM

What exactly is bumpsteer?

If they dont work I'll just put them back on ebay.

alga 8th September 2009 10:35 PM

Bumpsteer is the change of the effective length of tie rods due to the suspension travel. Nothing to do with wheel offset.
A wheel offset too low will shift the contact patch out of correct alignment with regard to the kingpin axis, thus increasing the scrub radius. The effect will be unsettled steering, exaggerated reaction to unevenness of the road, especially when braking.

Matthew 9th September 2009 06:48 AM

If you want a more detailed explanation then this site http://www.longacreracing.com/articles/art.asp?ARTID=13 has a good explanation together with instructions on how to measure and correct it.

Matt

RAYLEE29 9th September 2009 12:06 PM

Bumpsteer
 
Hi,
I believe there is more than one way of causing bumpsteer but i may be wrong, ive been modding cars for nearly 30 years and have experience of people fitting wheels with too much offset.
if you move the contact patch too far away from the middle of the point where the kingpin inclination hits the floor you will adversly effect the handling
when you go over a bump the car will try to steer into the bump if thats not bumpsteer what is it??
anyone remember the carlos fandango ad with the anglia with oversize wheels!!
Ray:)

Bonzo 9th September 2009 12:19 PM

Quote:

Originally Posted by RAYLEE29 (Post 21490)
anyone remember the carlos fandango ad with the anglia with oversize wheels!!
Ray:)

That's a classic Ray.

Still makes me smile:D :D

Carlos Fandango


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