Shocks - Getting Technical....

[Nick Goodall]

Me and my Dad were talking about Motocross last week and how the suspension these days is so advanced the bikes literally let the riders get away with murder, landing on crests of jumps that a few years ago would have launched the rider off the bike and probably caused serious injury.

Does anyone know about the internals of modern shocks these guys run??

I've found some info on the KTM twin piston shock:
http://www.thumpertalk.com/forum/arc.../t-423056.html

This bike is awesome, the rear suspension has no link at all as all the technology is in the shock itself.

I would just love to see someone go to town on the R/C world and completely change the way our shocks work. It would be far more beneficial in 8th at the moment but would soon make its way to 10th should it work....

If you think about it our shock technology is still very basic and hasn't actually changed at all over the last few years.... The predator was the last off road buggy to have advanced technology when it comes to suspension as that system is fully progressive, but the shocks themselves were still relatively simple in design.

I think this could be the biggest step forward that could be made in off road R/C racing as i don't think there's a lot more to learn about layouts etc - especially in 4wd now just about everything has been changed...

[GRIFF55]

Shocks are still the same nick apert from the ktm which fixes direct to the swingarm. The reason more people can get away with casing jumps is that the level of fitness and rider ability has increased loads over the years. Also everybody is getting used to mahoosive jumps. Go club racing and you'll still see riders bouncing off left right and centre
One thing i have noticed is the ammount of people getting their suspension set for their weight at lower rider levels, this does make a world of difference.
Yam, honda and suzuki are all still using the linkages under the swingarm.

[Nick Goodall]

Haha i know what you mean about club racing, and even the fitness / ability of the top guys but the shocks have improved massively, i'm sure there are some new developments these guys are running now? I think the KTM shock definitely has something interesting in it to enable to run straight on the swingarm??

What about these:

http://www.ridemonkey.com/forums/sho...d.php?t=195126

[Nick Goodall]

This definitely makes some interesting reading, i'm sure some of these features could be scaled down by some very clever people

http://www.motocrossactionmag.com/ME...A11F6DB344982B

[Losi_110]

gotta say there's a guy i know of who works in formula 1 and he's designed his own version of a car and there were rumors of him making some multi piston shocks for this car. The thing goes as if it's on tarmac but couldn't say if it's true about the shocks because if wont even open his shocks to do his oil if anyone is any where near. But that in itself says something really doesn't it.

[craigosh]

Progressive Suspension made some shocks for 1/8th monster trucks that i think had high and low speed compression settings with a piggyback.

Personally I think it'd be more trouble than its worth having all of those adjustments, so much time worrying about the settings rather than just racing.
I remember spending a whole week setting up the shock on my old Orange, was madness, so many settings! rebound, HS comp, LS comp, bottom out, platform pressure. No need just stressed about it all the time!

When I got the SX Trail, i just set the rebound, and the propedal in the street and went riding, so much happier!

I'm not sure how effective those adjustments would be with an RC, with such small volumes, low weight and lower forces.

Would be interesting though to see some shocks made. Expensive but interesting.

As for internals, i think Fox Shox have some cutaways on the shocks with annotations on their site.

[Nick Goodall]

Originally Posted by craigosh

Progressive Suspension made some shocks for 1/8th monster trucks that i think had high and low speed compression settings with a piggyback.

Personally I think it'd be more trouble than its worth having all of those adjustments, so much time worrying about the settings rather than just racing.
I remember spending a whole week setting up the shock on my old Orange, was madness, so many settings! rebound, HS comp, LS comp, bottom out, platform pressure. No need just stressed about it all the time!

When I got the SX Trail, i just set the rebound, and the propedal in the street and went riding, so much happier!

I'm not sure how effective those adjustments would be with an RC, with such small volumes, low weight and lower forces.

Would be interesting though to see some shocks made. Expensive but interesting.

As for internals, i think Fox Shox have some cutaways on the shocks with annotations on their site.

Yeah i think 8th scale i could see it being more important, and i agree with you about over the top and time consuming but if there's an advantage to be had you know people would be happy to spend the time getting them right - even now they play around with it enough

[SHY]

There's the RPM 2-stage pistons... (search ebay)

Made for RC, been around for many years.

[sosidge]

The Thunder Tiger S3 buggy was originally released with dual-stage pistons, they had a few ball bearings inside them that would block holes on either bump or rebound (can't remember what was the suggested setting).

No surprise when all the team switched to standard pistons and Thunder Tiger released standard ones shortly after.

The RC cars and shocks are so small and lightweight that these multi-stage pistons just don't have the chance to work, or be truly adjustable. Adjusting low speed damping with oil weights and high-speed damping with piston holes seems the most usable compromise - and we rarely change those settings by more than about 10%!

[Nick Goodall]

It's all relative though, even though we're talking 1/10th scale it could still work if it was scaled down properly (or even 1/8th scale)....

Just something to think about anyway, when you go to bumpy tracks damping becomes so important i'm sure there is still a lot of room for development in the physical shock absorbers themselves as i haven't really seen any changes there in years.

[Alfonzo]

Scalar effects mean that it would be very difficult / impossible to re-create the fancy complicated shock designs seen on full size stuff. I'm sure there's still room for improvement in geometry and suspension though. Personally, I think larger volume shock absorbers would help.

[ryanlownie]

Has anyone ever seen Cannondale's (bike manufacturer) Electronic Shock Lockout system? Press of a button electrifies the oil in the shock and stiffens them up, press the button again and you have normal shock use again!

I remember test riding one of these bikes it must of been around 8 years ago now! The little circuit for the lockout was tiny and I think something could be made for an RC car. The downside is that it runs off 9V.

[sosidge]

Originally Posted by Alfonzo

Personally, I think larger volume shock absorbers would help.

Considering the Losi shocks have a fractionally larger diameter and everyone raves about them - whyever not!

I'm sure a little lathe time could shorten a few 1/8th shocks to 1/10th length.

[bigred5765]

losi and ae shocks have the basic same internal diameter,

[Nick Goodall]

Has anyone ever tried running Upside-down shocks? In theory moving the weight lower... but i guess outwards to the wheels too which may have a strange effect....

[Lee]

For some reason our shocks just dont work upside down, they leak like a biatch no matter how well built they are. I tried it a few years ago as i thought about other bikes etc that have the damper below the shaft but i could never get it to feel as good.

I know someone who managed to make gas filled shocks years ago, he never opened them up either to show mw how it was done.

[sosidge]

Originally Posted by bigred5765

losi and ae shocks have the basic same internal diameter,

Not according to Arno's measurements he posted on this site. OK, it's about 0.1mm, but people claim to be able to tell the difference between a piston hole that is 0.1mm bigger!

[sosidge]

Originally Posted by Lee

For some reason our shocks just dont work upside down, they leak like a biatch no matter how well built they are. I tried it a few years ago as i thought about other bikes etc that have the damper below the shaft but i could never get it to feel as good.

I know someone who managed to make gas filled shocks years ago, he never opened them up either to show mw how it was done.

Was the gas 80% nitrogen 20% oxygen?

Upside down shocks will also add significantly to unsprung weight which is not generally a desirable thing, will make the car a lot less responsive.

[bigred5765]

didn't mention the hole, i said internal measurement,i have losi pistons in my b4 right now,

[SHY]

Originally Posted by Lee

For some reason our shocks just dont work upside down, they leak like a biatch no matter how well built they are. I tried it a few years ago as i thought about other bikes etc that have the damper below the shaft but i could never get it to feel as good.

I know someone who managed to make gas filled shocks years ago, he never opened them up either to show mw how it was done.

Not true, the swiss SMP Slide had all four shocks upside down. Never any problems with leakages. I guess it's harder to do for OR though with all the dust & dirt...

RPM two-stage shocks for 1:10, see here: http://cgi.ebay.com/Two-Stage-Shock-...3%3A1|294%3A50