GermanLook Forums  

Go Back   GermanLook Forums > Technical Section > Suspension

Reply
 
Thread Tools Display Modes
  #1  
Old March 26th 2010, 07:28
Rob's Avatar
Rob Rob is offline
Registered User
 
Join Date: Jan 2003
Location: Dundas, Ontario, Canada
Posts: 786
Bumpsteer ?

I was driving my /70 Standard back from the shop yesterday and the car hit a dip in the road while turning right. It was not a real turn but a curve in the road, so I wasn't really slowing down.

As the car hit the dip, it 'jumped' to the left (steering wheel jerked to the left).
Is this what they call bumpsteer ?

The car isn't extremely lowered, I run an adjustable beam and lowered spindles with Koni adjustable shocks and 16" rims with spacers.

If this *is* bumpsteer, I'm pretty much screwed, right ? Isn't the only way to avoid this making sure the tierods are level ?

Thanks,

Rob.
__________________
EJ25 powered 1970 Standard Beetle
Subaru EJ25 in 1970 Beetle Project
Reply With Quote
  #2  
Old March 26th 2010, 10:12
evilC's Avatar
evilC evilC is offline
Registered User
 
Join Date: Jun 2008
Location: UK Where Leics is more
Posts: 644
I would imagine that what you experienced is bumpsteer but usually the effect is not so pronounced. The effect was probably magnified by the spacers on the wheels that have moved the contact patch of the tyre outside of the kingpin inclination/road patch point that will increase the leverage on the steering. What caster are you running? If you haven't corrected the caster then any loss will again magnify the effect because the steering doesn't want to correct. Also, is your steering damper working as it should? The damper will reduce the violence of the movement that you will naturally correct.
In conclusion I would first get the caster checked and adjusted as required, then check and replace the steering damper. If that fails get rid of the spacers and finally level the tie rods that will require some engineering. There are of course, bumpsteer bushes available that you might try.
Reply With Quote
  #3  
Old March 26th 2010, 11:16
Sandeep's Avatar
Sandeep Sandeep is offline
Administrator
 
Join Date: Aug 2002
Location: Brampton, Ontario, Canada
Posts: 1,795
Rob,

Good to hear the bug is on the road. Are you sure that the left tire is not rubbing on the back of the headlight bucket when turning on a dip ?

I had the same problem a while back, check the back of the headlight bucket for rubber ... One more thing to think about

Sandeep
Reply With Quote
  #4  
Old March 26th 2010, 16:57
Rob's Avatar
Rob Rob is offline
Registered User
 
Join Date: Jan 2003
Location: Dundas, Ontario, Canada
Posts: 786
Thanks for the tips guys, I'll check into that.
I have caster adjusters installed, I'll see if I can find a site that explains how to measure / check it.
The damper is pretty much new, so that one should be ok, although I'll check it as well.

I checked the headlight buckets, but it doesn't look like it's rubbing there.

Sandeep, you gonna be at Pete's tomorrow to Pillage that super ? I'll be there around 1 PM. I don't think I'm up to driving the bug all the way out there tho... gotta build a bit more confidence first

Rob.
__________________
EJ25 powered 1970 Standard Beetle
Subaru EJ25 in 1970 Beetle Project
Reply With Quote
  #5  
Old March 26th 2010, 17:41
petevw's Avatar
petevw petevw is offline
Moderator
 
Join Date: Jul 2002
Location: toronto, ontario, canada
Posts: 1,346
Rob,

I had the same issues with my '72 super when i slammed it. Installed the tie-rod flip kit, to get the tierods back straight. Bumpsteer went away.

Yeah, Sandeep will be at my place at 1 too.

Pete
__________________
'72 super
'65 bus
'52 split
Reply With Quote
  #6  
Old June 20th 2010, 10:15
Rob's Avatar
Rob Rob is offline
Registered User
 
Join Date: Jan 2003
Location: Dundas, Ontario, Canada
Posts: 786
Well I found out what the problem was. Sandeep was closest

It turns out that the fenderlip is hitting the tire when the suspension is fully compressed.
My tires are sticking out from under the fenders a bit, and under full compression the fenderlip hits the outside of the tire.
I didn't think I'd have that much suspension travel left

Sooo, I took out the spacers, but that didn't help much, so I guess I'm gonna need to get me some wider fenders....
Anybody ever cut and 'rolled' Beetle fenders ?
I'm guessing they'd be pretty flimsy once you cut out the 'folded' section ?

Rob.
__________________
EJ25 powered 1970 Standard Beetle
Subaru EJ25 in 1970 Beetle Project
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:12.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
© www.GermanLook.net 2002-2017. All Rights Reserved