Effect of rebound dampening on jumping vehicle ?

[Rat5]

Hello,

What effect does rebound damping have on a vehicule taking a jump ? (MotoX or trophy truck for example )

In my opinion, little rebound damping (faster rebound) causes the vehicle rear to ride high, because the action of the wheel going down will equally push the vehicle up, correct ? (Newton's 3rd)

Now i came across this video which has a whole different answer to this. And im not sure which explaination is correct ?


At 13:00

https://youtu.be/G8ILm3AVtlw

 

[BrianPetersen]

Video explains what happens. Your explanation is overly simplistic and doesn't consider what happens over a repeated series of bumps. The video addresses this, although it's still simplistic. (This topic can get too complex for mere mortals to understand, very quickly, so this situation is understandable...)

My hobby is motorcycle roadracing on pavement, not dirt, but on the typically bumpy tracks here in Canada, we still have to deal with this.

Do you understand what's meant by the suspension "packing down" over repeated bumps?

 

[Rat5]

Hello Brian, thanks gor the reply. Yes i do understand the concept of packing, but i was more interested in the single big jump situation.

 

[BrianPetersen]

The rebound damping has no effect on the first landing. It'll affect what happens on the rebound from that landing.

 

[GregLocock]

Single big jumps can be modelled quite well using a simple spreadsheet model, that's what the off road guys use to get to a rough tune for their complicated shock absorbers. Front axle, rear axle, sprung body mass and pitch inertia, 10 ms time steps.

https://www.youtube.com/watch?v=uXZlNwXEZI4

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?