Big Bores again, problems.
 

Getting tired of shocks, lol.

My problem is this, bearing in mind big bores have no bleed hole etc.

I fill body with oil, so it just creates a 'dome'

My aim is to set with minimal/zero rebound. I put the cap on only 1 turn or so & slowly push the shaft so almost fully compressed, do up the cap, what happens is i get 100% rebound, not good.
So i repeat, still 100% rebound, basically, the only way i'm able to reduce the amount of rebound is to remove oil.
For example, to get zero rebound i have to do the cap up with the oil 3-4mm below full but i then end up with lots of air inside & i can feel the air too ie, a few mm's of loose play with no damping.

I know the thread seals well even with the cap almost undone so i have to almost have the cap off in order to release oil.

I can't see how i can set these up without a) introducing air or b) having way too much rebound.

Any ideas appreciated :thumbsup:

At first Dandare I'am not an expert, been away for 15years:bored:

I saw a video about shocks during the Ifmar 2011 in Finland. Some guy's cut away the middle section from the rubber topcap, so there's only left a rubberring left to seal the shock topcap. I don't know this will help you, but the guy's from the video are enthousiastic about this!
Hope this will help:)

Im using the 22 bladder in my teamC Bigbore. I drilled a small #57 hole the side of the cap and removed to o-ring. They are now so easy to build.

Ok watch this
http://www.rccaraction.com/blog/2011...om-mike-truhe/

or/and
http://www.youtube.com/watch?v=pwtIRndovDI


I have no problems getting zero rebound or 2-3 mm (which is what I like) the 22 shocks are very similar to ours. we don't have bleed hole but you can see in the thread that there is a groove, well thats it.

Have the shaft pulled all the way out and oil level with the top.
Do the cap up until you feel it touch the Oring and back off just slightly the oil will start to bleed as you get close to the bottom.
Push in the shockshaft slowly to the desired rebound point and let it bleed.
Keep the shaft at that point and slowly screw the cap on tight.
Done.

here a video of a teamc bigbore build.
http://www.youtube.com/watch?v=LnY-p...e_gdata_player

Just watched this whilst building my own big bore shocks, i'm following what he's doing to the tee but.. when he's bled the air by compressing the shaft/piston with the cap still loose he then almost fully compresses the shaft then does up the cap, job done. When i do EXACTLY the same thing ie, i start doing the cap up fully the shaft starts to come back out so that when the cap is fully tight i end up with 100% rebound when i only want 0-20% rebound.

I simply cannot get these set up to give the desired rebound without emptying out enough oil to prevent the shaft rebounding but this is when i end up with air in the shock & a resulting nasty feeling action ie, the feeling that there is an air pocket.

The problem seems to be the thread is so precise, almost self sealing that the when i start to do up the cap the air isn't able to escape from the thread thus causing the shaft to rebound as i do it up, i'm just unsure how to overcome it..

Did you try getting no rebound by doing it with the shock horizontal?, works ok for me.:yawn:

at the movie you can see at 7.03 min a litle vertical opening in the treads of the shock body wear the top cap goes on. thats for bleeding. i know there were some versions that didnd have that. without it is hard to get zero rebound. i always hold the shock shaft when i close the top cap.

There is certainly no groove of any description in the thread for bleeding, & if i try to hold the shock shaft i can feel it just wants to come out as i tighten the cap, when i let go i just opens to 100% rebound.

If i drilled a tiny bleed hole in the side of the cap would this help or just bugger up my shocks, lol ?

Try pressing the cap down a bit while slowly screwing it tight so that the cap does not compress tightly to the threads and lets the air bleed through. Helps with bleeding, at least for me.

dont drill a hole in the side of the cap. cos the o ring has no efect anymore.
try to dremmel a groove in the shock body but carful not to damage the spot were the o ring closes the cap on the shock boddy.
hope you can folow my terible english:D

http://eazyrc.com/Shock-body-and-caps-big-bore-front
on this foto you can see on the left shock body the groof on top

Well, had another go tonight. Your method seems to have worked a treat, seems almost too simple to have not tried it already :lol:

Cheers bud :thumbsup:

marcel: appreciate the suggestions you've given, interesting to see those bodies in the linky have the bleed grooves, i think maybe this may have been my next step. Cheers.

Done all 4 now, feel lovely :D

nice. have fun racing;)