Shock Rebound
 

Hi all

What does everybody run there shock rebound set at, for a smooth track, bumpy track, tight twisty track, open flowing tracks.

not a lot is said in car kit instructions and setup books about shock rebound, I run my son's at 75%, looking to see what others run.

Regards
Gary

Normally I aim for 2-3mm of rebound, in general.

Good Question
 

Gary

I also would like to know whats best on this subject.

Personaly I like to run 100% rebound on our track as it has some bumpy section, which i think the car rides alot better. I think the rebound holds the tyres down on the road instead of skipping over parts.

I'm going to see how this works at the Gold Coast track this weekend.

Cheers Todd

i agree with 100% rebound, but it should rebound very slowly, like 4 seconds to full stroke. If it rebounds fast like 1 or 2s, you will lose traction, thats what happened to me. And if if you just rebuilt your shocks with full rebound, you will lose rebound on the second pack, becuase some of the oil leaks out. Its not a bad thing and i find i have more traction with a reduced rebound.
Let me put it this way, for full fast rebounds, my car rolls and skates everywhere. for slow full rebound, it grips better, and traction gets even better as the shocks lose its full rebound over 1 or 2 packs.

i tend set my shocks with 0 rebound and let the springs and oil do the work. this way i get to set my shocks more consistently between rebuilds.

+1 :nod: On the "Zero" Rebound.

I have been in RC for a long time, and I truely think shock rebound is something you just "cannot" do "consistantly" on all 4 shocks.... With practice you may be able to come close, but it is like trying to make lightning strick twice in the same place, you just can't do it. Then if some oil leaks out of one shock..... you just lost your handling....

The shock "spring" is the shock rebound. That is the purpose of having the springs there, and being able to change springs. Build your shock with Zero rebound and let the spring do the work. You get consistant handling, and handling you can actually change by changing the springs.

And if you don't think your shocks are reacting quick enough on a rough track, increase the number of holes in your pistons, or go to a lower weight oil. For a rough track, I like 4 large holes in my pistons, with a mid to heavy weight oil. The shocks move quick enough to respond, but are Very Smooth because of the thicker oil.

I agree, completely. But the only reason I do run rebound is so I know if any of the shocks have blead. With 0 there is no knowing, until you feel the shock.

Hey All, great conversation. Just had one of my newer club members asking about rebound and shock movement in general. I didn't feel I answered his questions well so I need to ask just HOW you're setting your shocks for 0 rebound. Can somebody describe it by the numbers. You'll greatly help alot of newbies and some of us old farts too. Thanks.

When ever i set zero rebound i get negative rebound!!! I am sure i am doing it the wrong way or over doing something.

Hi you are not doing any thing wrong negative rebound is a trade off when running 0% it seems not to affect the handling if you can find a very soft blatter it will help with negative rebound.and all so if you are getting zero rebound with out a hole in the cap then put a hole in will help to.

Thank you

Setting the rebound must vary from car to car. I followed a schumacher video on it but trying to replicate on my tc5 didnt work at all. Needed to put 2mm clips on the shaft otherwise the rod would hit the diaphram when i tried to bleed it.
So aiming for 2-3 mm netted ne half the shock travel. Shocks seem very fiddly and after one race theynseem to leak and the settings are all off again.

youtube.com/watch?v=HNJy7kreK90&feature=youtube_gdata_player

Try this, I know he is building a 1:8 shock but it is the same theory

Btw: I can not post url's

When I build Schumacher shocks with 100% rebound, the cars seems very darty and unsettled. I've played with less rebound, but haven't done enough focused testing to be really confident of the results. The car does seem more settled, but it seems like they may pull air in and go flat after just a race or two.

On the advice of one of the local fast guys who swears by holes in the cap, I got myself a pin vise and some small drill bits, and got to work. It took some patience with the aluminum caps. The holes are something like 1.5-2mm, which is probably bigger than ideal, but I messed up the first one and felt like I should do them all the same. :blush:

With this set of shocks, I build them with "100%" rebound... i.e. I pull and hold the shaft all the way out, gently press the bladder in, and then put the cap on. Like this, the shocks are basically "dead". The shaft just stays where I left it. If I push it all the way in, it'll rebound a few mm very slowly. The car handles smooth and consistent, and they seem to stay that way for quite a while without needing a re-bleed.

-Mike

Also if you drill a hole in the shock cap the shock will feel more dead without the negative rebound feel

Jilles has a video showing how to build shocks with zero rebound

+ YouTube Video