Haynes Forums  

Go Back   Haynes Forums > Haynes Roadster Forums > Running gear
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 8th September 2009, 12:05 PM
Rik178m Rik178m is offline
Senior Member
 
Join Date: Feb 2009
Posts: 121
Default 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?
Reply With Quote
  #2  
Old 8th September 2009, 12:54 PM
slimtater slimtater is offline
Senior Member
 
Join Date: May 2008
Location: Derbyshire
Posts: 250
Default

"May" be a problem:

http://www.driverstechnologyassociat...eel-offset.htm
Reply With Quote
  #3  
Old 8th September 2009, 01:14 PM
AshG's Avatar
AshG AshG is offline
Super Moderator
 
Join Date: Jul 2008
Location: Rochester
Posts: 1,882
Default

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
Reply With Quote
  #4  
Old 8th September 2009, 07:49 PM
RAYLEE29's Avatar
RAYLEE29 RAYLEE29 is offline
Senior Member
 
Join Date: Sep 2008
Location: POOLE DORSET
Posts: 520
Default

Bumpsteer!!
Reply With Quote
  #5  
Old 8th September 2009, 10:01 PM
Matthew Matthew is offline
Member
 
Join Date: Mar 2007
Location: Liphook, Hampshire
Posts: 95
Default

Quote:
Originally Posted by RAYLEE29 View Post
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
Reply With Quote
  #6  
Old 8th September 2009, 11:13 PM
Rik178m Rik178m is offline
Senior Member
 
Join Date: Feb 2009
Posts: 121
Default

What exactly is bumpsteer?

If they dont work I'll just put them back on ebay.
Reply With Quote
  #7  
Old 8th September 2009, 11:35 PM
alga's Avatar
alga alga is offline
Senior Member
 
Join Date: Feb 2009
Location: Vilnius, Lithuania
Posts: 1,249
Default

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.
Reply With Quote
  #8  
Old 9th September 2009, 07:48 AM
Matthew Matthew is offline
Member
 
Join Date: Mar 2007
Location: Liphook, Hampshire
Posts: 95
Default

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
Reply With Quote
  #9  
Old 9th September 2009, 01:06 PM
RAYLEE29's Avatar
RAYLEE29 RAYLEE29 is offline
Senior Member
 
Join Date: Sep 2008
Location: POOLE DORSET
Posts: 520
Default 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
Reply With Quote
  #10  
Old 9th September 2009, 01:19 PM
Bonzo's Avatar
Bonzo Bonzo is offline
Senior Member
 
Join Date: Jul 2007
Location: Cornwall
Posts: 3,321
Default

Quote:
Originally Posted by RAYLEE29 View Post
anyone remember the carlos fandango ad with the anglia with oversize wheels!!
Ray
That's a classic Ray.

Still makes me smile

Carlos Fandango
__________________
I am not a complete idiot...........Some of the parts are missing !!
Ronnie

www.roadster-builders.co.uk
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 11:54 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.