CC-01 suspension

[Wetman 417]

Has anyone else had a problem with a very soft front suspension with no rebound? The front of the Land rover goes down under virtually no pressure then stays down and doesnt rebound back to normal ride height, almost as if theres no spring assistance. The rears are fine. Is this a common fault and is there a fix for it. I havent checked the fluid levels in the dampers yet but theres no signs of leakage and I know they were filled to the brim when I assembled it.

[Nicadraus 6201]

The front suspension of the CC-01 is actually a design flaw as well as the lousy steering. The suspension arms Tamiya used for the CC-01 is too short. Same length as for the TA-01/02, FF-01. The only way to improve it is to replace the stock CVA with an 80mm shocks with medium springs. Although there are far better ways to improve it if you're daring enough to punch holes in the chassis to allow longer dampers 90-110mm.

[ChrisRx718 4470]

It's normal, unfortunately. As above, it's too soft and the design doesn't lend itself to the right geometry.

I have 4 CC01s here, 2 still have stock suspension and thus have 'saggy' front ends. On another one I have fitted Tamiya Barrel springs, but I had to fit the hardest one to the front to prevent the sagging! I'm not sure whether thicker oil would help, likely not, since it's not the damping which is a problem, but rather the weight vs the spring strength.

The official aluminium CC01 dampers work great and are nice and smooth, but they don't come with springs and require you to use the originals. So guess what? They sag too 

The front springs off of a DT02 / DF02 / TT02B are around the correct length and a bit stiffer, if you have any of those going spare.

[Mad Ax 9325]

The front suspension tends to be fairly soft on the CC01 (especially compared to most other Tamiyas which are too hard), but there should be at least some springing action.  However I've just pulled a CC01 off my shelf to check and the front doesn't sag that much under weight (King Blackfoot hardbody and full electrics but no battery), and if I compress the bumper and let go, it springs back normally.

First I'd make sure the suspension is moving smoothly.  Detach the shocks, remove the spring and make sure the piston moves freely in the cylinder.  Associated Green Slime is brilliant for freeing up sticky shafts.  Did you assemble with the supplied oil, or have you used stiffer aftermarket shocks / oil / pistons?  Too much damping will stop the spring from moving effectively.

Check you have the right springs installed and that they aren't binding on the cylinder.

Move the suspension without the shock attached, and make sure everything moves smoothly.  If the car has been run in the wet, make sure the hinge pins haven't rusted.  They can be very hard to remove if they have.

Once you're sure the suspension is fine, try adding spring collars to increase the preload, until you get the desired amount of sag.

Another thing to be aware of: as you compress the suspension, the tyres will need to move laterally as the suspension arms describe their arc.  If you have sticky rubber on a grippy surface, this may stop the suspension from rebounding.  This isn't noticeable when running because the wheels roll over the ground and re-centre.  This is one reason why we replace the wheels with acrylic plates when setting up cars on setup decks - they slide smoothly over the deck surface.  Consider fitting some tireless wheels to test the suspension and see if it makes a difference.

[Mokei Kagaku 2706]

1 hour ago, Nicadraus said:

The front suspension of the CC-01 is actually design flaw as well as the lousy steering. 

The issues addressed in this thread are of course fully legitimate, but I don't think it's quite appropriate to call the CC-01 front suspension a design flaw. At the time the CC-01 was designed, the RC-segments "crawler", "scale crawler" or "trail off-roader" didn't exist.  So, Tamiya can't possibly have had any clear expectations in the market to fulfill. The CC-01 hit the market as what would now probably be considered a scale SUV, a model for onroad and offroad with a relatively authentic chassis (for being a Pajero).

Admittedly, the included parts for locking the diff can be considered proof that Tamiya actually did have some ambitions for the CC-01's off-road capability, but it took quite some years before the CC-01 got popular and people started to use it as an off-roader, modify it for trial racing and so on. 

So, for its intended purpose, I don't think the front suspension is a design flaw. It's pretty robust, turning radius is OK for its original purpose, the geometry is fairly constant and the dampers and springs work acceptably, if however not great. I'd say that it is a good design for being almost 30 years old. The steering mechanism is a major design flaw though, even in my most tolerant opinion! 

Talking about the steering mechanism, I have wondered for many years why Tamiya hasn't released a hop-up for it. Tamiya has released quite many hop-ups specifically for the CC-01, of which most are a lot less needed than a better steering mechanism! I think that's pretty weird.

[Nicadraus 6201]

41 minutes ago, Mokei Kagaku said:

The issues addressed in this thread are of course fully legitimate, but I don't think it's quite appropriate to call the CC-01 front suspension a design flaw. At the time the CC-01 was designed, the RC-segments "crawler", "scale crawler" or "trail off-roader" didn't exist.  So, Tamiya can't possibly have had any clear expectations in the market to fulfill. The CC-01 hit the market as what would now probably be considered a scale SUV, a model for onroad and offroad with a relatively authentic chassis (for being a Pajero).

Admittedly, the included parts for locking the diff can be considered proof that Tamiya actually did have some ambitions for the CC-01's off-road capability, but it took quite some years before the CC-01 got popular and people started to use it as an off-roader, modify it for trial racing and so on. 

So, for its intended purpose, I don't think the front suspension is a design flaw. It's pretty robust, turning radius is OK for its original purpose, the geometry is fairly constant and the dampers and springs work acceptably, if however not great. I'd say that it is a good design for being almost 30 years old. The steering mechanism is a major design flaw though, even in my most tolerant opinion! 

Talking about the steering mechanism, I for many years wondered why Tamiya hasn't released a hop-up for it. Tamiya has released quite many hop-ups specifically for the CC-01, of which most are a lot less needed than a better steering mechanism! I think that's pretty weird.

Ok I stand corrected in the lower suspension but the steering is just horrible. Tamiya didn't even bother to come up with their own solution to this issue. Good this HR made the best steering set for this chassis that's bolt-on without the need of modifying anything.