Uphill Racers

Go Back   Uphill Racers > Technical > Engine & Chassis
Register FAQ Members List Calendar Downloads Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 15-03-18, 07:34
team knifedge's Avatar
team knifedge team knifedge is offline
Return of The Sith
 
Join Date: Jan 2007
Location: I can hear The World Famous
Posts: 1,123
team knifedge will become famous soon enough team knifedge will become famous soon enough
Suspension pre load - why/what

So, can anyone in the wide world of uphillracers explain the concept of pre load on suspension
How does it work influence the cars behaviour?
What are the + and -
I’ve read a few things on that there t’interweb but I’m mostly confused
Reply With Quote
  #2  
Old 15-03-18, 08:49
AlexChard AlexChard is offline
Senior Member
 
Join Date: Apr 2015
Location: Leamington Spa
Posts: 107
AlexChard is on a distinguished road
I can't help, but I can recommend someone who does.

They turned my car from undriveable in the dry to on rails in the wet. Yet to test in the dry, but I can't wait.
Reply With Quote
  #3  
Old 15-03-18, 08:57
Adam's Avatar
Adam Adam is offline
Senior Member
 
Join Date: Jan 2007
Location: Cirencester
Posts: 613
Adam is on a distinguished road
Quote:
Originally Posted by team knifedge View Post
So, can anyone in the wide world of uphillracers explain the concept of pre load on suspension
How does it work influence the cars behaviour?
What are the + and -
I’ve read a few things on that there t’interweb but I’m mostly confused
Preload on what would be the first question? The preload on a standard corner spring is just the weight of the car unless you run a 'zero droop' arrangement and preload the spring against the droop stop. Or are you referring to preload on the bellvilles on a monoshock arrangement?
Reply With Quote
  #4  
Old 15-03-18, 09:06
team knifedge's Avatar
team knifedge team knifedge is offline
Return of The Sith
 
Join Date: Jan 2007
Location: I can hear The World Famous
Posts: 1,123
team knifedge will become famous soon enough team knifedge will become famous soon enough
pre load on a front mono shock with zero droop for example.....
I understand bellville pre load
Reply With Quote
  #5  
Old 15-03-18, 09:12
wil_ker's Avatar
wil_ker wil_ker is offline
Senior Member
 
Join Date: Feb 2012
Location: Betwix Harrogate and York
Posts: 694
wil_ker will become famous soon enough
I've only ever heard preload used as a term for motorbikes. In this instance, the rear spring is preloaded to a setting that accommodates the weight of the rider (or if you have a pillion).

So, at rest with no rider, the bike sits a bit higher for a fatter rider.

I guess you could apply the same reasoning for a car, but the drivers weight is a lower percentage of the vehicle weight (unless you have a Saxon PCD!) and our cars are much more stiffly sprung than a motorbike.

Having said that, I set my car up with me in it, so it is accounted for.

EDIT: posted before above response!
Reply With Quote
  #6  
Old 15-03-18, 09:22
Adam's Avatar
Adam Adam is offline
Senior Member
 
Join Date: Jan 2007
Location: Cirencester
Posts: 613
Adam is on a distinguished road
In high aero / single seater specific speak, it will increase the speed at which the ride height transitions. Think of it as raising the front rideheight, but only during the mid speed phase (ie between zero-droop and bump rubber phases). A graph would be a good way to explain it, I'll have a go later.
Reply With Quote
  #7  
Old 15-03-18, 09:26
Rob Way Rob Way is offline
Senior Member
 
Join Date: Jan 2009
Posts: 167
Rob Way is on a distinguished road
Quote:
Originally Posted by team knifedge View Post
pre load on a front mono shock with zero droop for example.....
I understand bellville pre load
Has the affect of stiffening the initial spring reactions obviously depending how much pre-load.

Stiffer springs would have the same affect but in a more linear way.

With aero it gets really complicated.

What are you trying to achieve?
Reply With Quote
  #8  
Old 15-03-18, 09:58
No Imagination No Imagination is offline
Senior Member
 
Join Date: Jul 2007
Posts: 445
No Imagination will become famous soon enough
Quote:
Originally Posted by team knifedge View Post
So, can anyone in the wide world of uphillracers explain the concept of pre load on suspension
How does it work influence the cars behaviour?
What are the + and -
I’ve read a few things on that there t’interweb but I’m mostly confused
Chris, I can send you the page about pre load from the Gospel according to Inginere Gina Paolo Dallara - but it doesn't explain the theory!
Reply With Quote
  #9  
Old 15-03-18, 10:08
No Imagination No Imagination is offline
Senior Member
 
Join Date: Jul 2007
Posts: 445
No Imagination will become famous soon enough
Quote:
Originally Posted by No Imagination View Post
Chris, I can send you the page about pre load from the Gospel according to Inginere Gina Paolo Dallara - but it doesn't explain the theory!
I've just changed his sex - should have read Gian..................
Reply With Quote
  #10  
Old 15-03-18, 10:51
team knifedge's Avatar
team knifedge team knifedge is offline
Return of The Sith
 
Join Date: Jan 2007
Location: I can hear The World Famous
Posts: 1,123
team knifedge will become famous soon enough team knifedge will become famous soon enough
that would be great - I can pm e.mail
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

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

Forum Jump


All times are GMT. The time now is 14:40.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright© 2007-2018 Uphill Racers www.uphillracers.com