Granite Chassis slap and plush shock setup

[FH-RC]

Hello everyone,

I would like to ask you guys on your shock setup and how plush you have set your Granites/Big Rocks suspension for big air?

Or in other words:
From what heigth can you drop your vehicles before you get chassis slap?

My own setup:
I run my Granite with the ZD Racing shocks (Link) with 6-hole pistons, the stock ZD springs, little to no preload and 1000cst (~75wt) on RPM arms at the outer, more stiff hole position. Normally, I can drop my Granite from about 30cm before the chassis slaps onto the ground. Hence, I would like to know, if for example the Kraton/Mojave/Typhoon shock combination would make it more plush, so I can drop from higher heights before the chassis slaps.

I know, chassis slap is normal and a must if you don't want to break the suspension (piston out the shock cap is no good), but I send the Granite up to 6m into the air at my local dirt park. So, this means that I basically drop this thing from 5,7m into the ground without damping

 

[stiles]

I drop mine from about 2 feet and it slaps. I have Typhon/kraton shocks and use 90 weight.I’ve added a lot of weight with tires/4s motor etc... I would like to upgrade my springs in the future and maybe lessen it a little. I got the m2c motor mount which is the only thing I worry about on a chassis slap.

 

[GRC]

I have a Granite with Tekno SCT410 shocks, very stiff Kraton/Mojave springs, and 80 weight oil. I still get chassis slap over 18 inches. With even stiffer Arrma pistons I was able to increase that to 2 feet, but then I broke a shock rod end and a shock shaft. (But that could also be because I didn't tighten the pistons properly.)

Quick ways to reduce chassis slap is use the inner hole of the RPM arms. You'll increase ride height. Definitely add some pre-load. Check out the pre-load of big air YouTubers, Most have the pre-load really cranked down (Duperdash is actually an exception to this). Stiffer springs will help. ZD shocks are considerably longer than stock so I wouldn't know the best springs to recommend.

 

[FH-RC]

Thanks for the input. Good to know, that there is still about a foot to go in terms of damping, but not miles more. I always thought my shock pistons are inclined and slipping or so, as it felt so soft.

Yes, I could add preload to optimize for jumping, but then the thing can’t do anything else than bouncing on the track when not jumping. I think it’s always a compromise.
The ZD are longer, but I limited its extension and they are also limited by the arms possible movement, so standard Granite length springs should work.

Does anyone have experience how high the Granite can be send, before you most certainly break stuff? ( and what would break first most commonly)

 

[RackwitzG]

Does anyone have experience how high the Granite can be send, before you most certainly break stuff? ( and what would break first most commonly)

Depends on what and how you land. You'll have to find that out, I'm afraid.

I can imagine your shock towers first to go if your shocks are too stiff. The impact energy must go somewhere.

 

[stiles]

I regularly go 20 feet and no problems. I seen duperbash take one out and get it up there. Turnbuckles, shocks, bulkheads, steering knuckle seem to be the most common

 

[razorrc]

Motor plate, servo, shock shafts, chassis, shock tower…. probably in that order.

Do people really break arms on the Granite? I don’t think I’ve ever broken one.

If you land it clean, 15-20 feet high is pretty safe.

 

[FH-RC]

Motor plate, servo, shock shafts, chassis, shock tower…. probably in that order.

Do people really break arms on the Granite? I don’t think I’ve ever broken one.

If you land it clean, 15-20 feet high is pretty safe.

Yep, unfortunately.
I also thought the Granite v3 is nearly indestructible. Hence my question on your damping and "safe" jump heights.

My list of disaster since January:

Broken parts after clean landings (prior damage might be possible, but unnoticed):
- Arm front (completely through)
- Arm rear (at one side of hinge pin)
- Steering knuckle
- Diff crown gear and input gear (landed on throttle, but still clean )
- ESC to battery cable (ripped at peakeater)
- Bend shocks shafts en masse
- Two rod ends


Broken parts from (very) bad landings:
- Bend motor plate (cost me a spur gear too)
- Chassis cracked through
- Rear diff tower cracked
- Body
- Two rear bumpers!

Servo still holds up though, thanks to your video on EPA setting and enough slop in the whole steering assembly

 

[stiles]

I’ve broke a rpm arm. It was cold but it happens

 

[GRC]

My list of disaster since January:

Well I've broken many of the same, but not quite as much. The surface you're landing on obviously makes a big difference. Soft dirt is best. Concrete is asking for a break even when landing on the wheels. RPM arms, more durable shocks are a good idea if you're jumping. That ESC wire is a common problem. I broke 3 ESC's there in no time after building a bigger ramp. Wrap the ESC wire with electrical tape to immobilize that joint,

 

[RackwitzG]

Yep, unfortunately.
I also thought the Granite v3 is nearly indestructible. Hence my question on your damping and "safe" jump heights.

My list of disaster since January:

Broken parts after clean landings (prior damage might be possible, but unnoticed):
- Arm front (completely through)
- Arm rear (at one side of hinge pin)
- Steering knuckle
- Diff crown gear and input gear (landed on throttle, but still clean )
- ESC to battery cable (ripped at peakeater)
- Bend shocks shafts en masse
- Two rod ends


Broken parts from (very) bad landings:
- Bend motor plate (cost me a spur gear too)
- Chassis cracked through
- Rear diff tower cracked
- Body
- Two rear bumpers!

Servo still holds up though, thanks to your video on EPA setting and enough slop in the whole steering assembly

Quite a collection you got there. Ironically your servo holds up.