Suspension set up help.

[Lee76 638]

Very ‘noob’ question here,  when driving the monster beetle around, on flat short grass. High speed corners the inside front wheel (unloaded wheel) bounces off the ground. It’s in no way hampering me but just for academic fun... is this a case of stronger springs needed, or less viscous damper oil or something else? Need to recharge battery anyway so thought I’d put this out for opinion before experimenting with spacers. Thanks in advance.

[ALEXKYRIAK 1046]

not a noob question at all! It’s likely that the car chassis rolls into the turn, and lifts the inside wheel, depending on if you're still accelerating or not. If the chassis is rolled slightly, the inside wheels will go ‘light’, as it’s not loaded up with the weight of the car. If it’s still slightly in contact over the terrain it can then ‘bounce’ if it’s momentarily deflected as it travels over the ground. If there was weight over the wheel it’d be pushed into the ground more and the shock would hold the wheel down whilst absorbing the impacts of the terrain. 
 

[Saito2 6686]

Is this a re-release Monster Beetle? If so, I've found the front dampening to be too heavy as setup from Tamiya. The Monster Beetle's front end is fairly light and the body is lighter than that of its brother, the Blackfoot, making issues even more noticeable. When you corner hard, unloading the inner wheel takes even more weight off it. The front end, in general, seems to skate over small irregularities rather than absorbing them. Tamiya CVA dampers come in two varieties now, one with piston rods and removable plastic pistons for tuning and one with fixed steel heads/pistons The re-re front dampers unfortunately have steel, fixed piston heads (discs) rather than the removable/swap-able plastic ones of old. 

You have some options... Without making any changes, you can start with lighter oil. You can also modify the steel piston heads by filing notches in the outer edge or carefully drilling small holes in them to allow more oil flow past the piston. If you really want more tune-ability, you can pick up new piston rods that accept e-clips along with a selection of plastic pistons with varying sizes of holes. 

I wouldn't go with stronger springs, lighter if anything but not before addressing the dampening issue. The spring spacers only affect ride height, they do not affect actual spring stiffness on a linear rate springs. The Monster Beetle's front end is pretty archaic so its never going to be perfect but there is room for improvement if you like to tinker. Hope this helps.

[Lee76 638]

Thanks both, it’s a re-re.  @Saito2 I get what you’re saying about the spring stiffness not being affected by the spacers because of the linear rate, but it would increase the load, I guess this might just affect the bounce frequency? I’ll see about getting some lighter oil. What do you think about the weight of the wheels? I was surprised to find them hollow, perhaps a foam inner might add a little mass to the wheel which might also affect it’s bounce, change the damping? I’m not a speed hunter on this one, just want it to look a little more real... though that said.. I read the topic on classic 80’s monster trucks someone posted... they bounce all over the place!

[Lee76 638]

14 minutes ago, Saito2 said:

You have some options... Without making any changes, you can start with lighter oil. You can also modify the steel piston heads by filing notches in the outer edge or carefully drilling small holes in them to allow more oil flow past the piston. If you really want more tune-ability, you can pick up new piston rods that accept e-clips along with a selection of plastic pistons with varying sizes of holes

That’s a good idea.. I might later experiment with gouging down the inside of the cylinder.. I’ll probably look at getting some spare parts and do some back to backs.

[Lee76 638]

I was actually surprised about how stable it was in general, even snatching a 180 at top speed it didn’t roll.. My avante however has some battle damage...

[Saito2 6686]

46 minutes ago, Lee76 said:

What do you think about the weight of the wheels? I was surprised to find them hollow, perhaps a foam inner might add a little mass to the wheel which might also affect it’s bounce,

In general, adding weight to the wheels/tires in not advantageous. This increases unsprung weight which is hard to control. Monster Beetle tires are not particularly soft or absorbent. I wish they were a softer compound like Lunch Box tires. In the old days, Marui Big Bear tires were the hot ticket for Beetle/Blackfoots as they were softer and more stable. 

Most Tamiya trucks (even Lunch Boxes) tires are stiff enough that they don't require foams. Foams are usually used in truck tires that use rubber compounds that are so soft (which makes them more grippy) that the tires aren't self-supporting without them. 

46 minutes ago, Lee76 said:

I was actually surprised about how stable it was in general, even snatching a 180 at top speed it didn’t roll.

Yeah, they're not too bad depending on the surface. The Monster Beetle's lighter body helps in keeping it less top-heavy. On harder/dustier surfaces, the truck does spin out rather than roll. I usually only roll mine, on occasion, on high grip surfaces like grass. They are fun trucks to toss around.

[slimleeroy 241]

4 hours ago, Lee76 said:

Thanks both, it’s a re-re.  @Saito2 I get what you’re saying about the spring stiffness not being affected by the spacers because of the linear rate, but it would increase the load, I guess this might just affect the bounce frequency? I’ll see about getting some lighter oil. What do you think about the weight of the wheels? I was surprised to find them hollow, perhaps a foam inner might add a little mass to the wheel which might also affect it’s bounce, change the damping? I’m not a speed hunter on this one, just want it to look a little more real... though that said.. I read the topic on classic 80’s monster trucks someone posted... they bounce all over the place!

Increasing the wheel and tyre weight will just add unsprung weight to the chassis and won't affect suspension

[BattleTrak 61]

Back in the day..Trinity made a rear sway bar kit to combat this.  Maybe keep an eye out for one..I finally found one a few months ago for $40 on ebay.

Also mentioned here..