Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Passenger vehicle Bumpy ride. 1

Status
Not open for further replies.
senjim

senjim

Mechanical
Joined
Oct 21, 2001
Messages
16
Location
AU
Hi all

When a vehicle ride is said to be bumpy in a very good road condition, can i say that shock absorber damping co-eff to be increased to reduce it? But the Damping of the Shock absorber theoretically matched to give a comfortable ride.
Wat else could cause this in general?

Thanx in advance

Cheers
Sen
 
Sort by date Sort by votes
Tyres or wheels being non concentric with axle.

Tyre walls having hard and soft spots.

Tyres or wheels being out of balance.

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
 
Upvote 0 Downvote
Many of the problems indicated by Pat can be the result of poor inflation. My 4Runner's tires got VERY lumpy after running underinflated for a while


TTFN
 
Upvote 0 Downvote
Sen:

Depends what you mean by 'bumpy'. What sort of vehicle is it, and might it have been 'modified' by some previous owner who thinks that rock hard suspension makes you go round corners quicker?

Harsh, jarring ride (even on a good surface) can be caused by seized dampers, or over-firm adjustment of dampers or hard springs. Low profile tyres increase harshness, too.

Could be any of the tyre problems Pat mentions but the bump will be very regular (every 2 metres or so, depending on the rolling circumference of the tyres).

Increasing damper forces will help if the 'bumps' are long, slow, high amplitude inputs from a wavy surface. Otherwise, in my opinion, it will make things worse.

Cheers - John
 
Upvote 0 Downvote
Thanx all..
Well, the vehicle is a minibus (7.5Ton GVW) brand new vehicle.
By bumpy ride i mean the vehicle oscillates up & down once it crosses a bump..
Should i increase the shock absorber damping.. if so is there any rule to relate suspension stiffness & damping?/ (Its a rigid axle suspension-Shackle ended)

Cheers
sen
 
Upvote 0 Downvote
That is not, typically, described as a bumpy ride.

Anyway, yes, you should look at the shock absorber tuning, but you might also find a mismatch between the front and rear axle spring rates as well.

Check out Olney's book on ride and handling for a description of the 'flat ridw' criterion and related subjects.

Cheers

Greg Locock
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

C6H5CH3
  • Locked
  • Question Question
Aluminum Monocoque for a production vehicle
Replies
4
Views
597
GregLocock
GregLocock
Rat5
  • Locked
  • Question Question
Effect of rebound dampening on jumping vehicle ?
Replies
4
Views
531
GregLocock
GregLocock
GEspo
  • Locked
  • Question Question
Flat Ride and Center of Percussion
Replies
3
Views
710
GEspo
GEspo
Viswa_K
  • Locked
  • Question Question
Variation in ride height with sprung mass, ADAMS Car
Replies
3
Views
480
GregLocock
GregLocock
jack brown
  • Locked
  • Question Question
vibration analysis of a co simulation controlled vehicle in adams/car
Replies
2
Views
307
jack brown
jack brown

Part and Inventory Search

Sponsor

Back
Top