[Cave Dweller]

Hi,

I need some help from someone who knows a fair bit about tpc+, most probably from orven.

Cut a long story short im thinking about putting the guts of a dorado TPC+ damper into an old 2000 monster T chassis i have (the carts are not so good anyway and need replacing) for something to do as i like to tinker and make things better

I have a couple of issues, like making new top caps, bottom caps etc i can handle all that.

Problem is the complete damper is 30-40mm too long, and i need to shorten it.

On the dorado the leg is actually the outside of the closed damper, so i need to make a new outer casing as the dorado has that cnc'd axle clamp cryo fit on the stanchion.

If i make a new one, can i make it 30-40mm shorter without effecting anything? For example, the top and bottom pistons won't bash together?

I was looking at the sherman single crowns and the stanchion (outer damper casing) is alot shorter so i think it would be ok to do this.

Or would i shorten the rod??

Just want to know if this is doable before i pull apart the closed damper to take a look.

Thanks

 

[Cave Dweller]

So, basically i want to know if these internals pictured will work in a tube that is 40mm shorter. Pic is from orvens "dorado exposed" thread.

Or can i shorten the rod, or even remove that big white plastic spacer on the end???

 

[Rik]

Damn... I wish I wasn't so busy at work, this looks like a project I'd love to help tinker with. You know I like swapping parts between different forks already

 

[profro]

I've had my Dorado TPC+ apart, and the "cartridge" is nothing more than a tube (stanchion) sealed at both ends. One end has the compression shim stack and floating piston. Which in the above picture is the rod with the two red things. In the newer TPC+ systems there would a piston with another spring located on the other end of that rod assembly.

The other end of the "cartridge" has the rebound assembly, which is the lower rod in the above picture. That is the pumping rod so to speak.

Each of these rods is screwed into a tube at opposite ends. The volume in between the two rods at rest is filled with oil. When assembling you must get all the air out. Any air in the assembly will cause poor damping.

The white pieces in the above picture are part of the spring carrier assembly.

I think you can shorten the "cartridge" or tube, but make sure that the rebound and compression rods don't collide under full compression. I think you could do that by shortening the rebound pumping rod. All the damping is done at the bottom end (red thingy). So cutting the rebound pumping rod by 40mm will do nothing but limit the travel by 40mm. But cut the end opposite of the shim stack.

 

[Cave Dweller]

Damn... I wish I wasn't so busy at work, this looks like a project I'd love to help tinker with. You know I like swapping parts between different forks already

Don't you worry rik, this project will probably take a few months. If you feel like doing a little bit of machine work from detailed drawings let me know Shouldn't be much.

I think you can shorten the "cartridge" or tube, but make sure that the rebound and compression rods don't collide under full compression. I think you could do that by shortening the rebound pumping rod. All the damping is done at the bottom end (red thingy). So cutting the rebound pumping rod by 40mm will do nothing but limit the travel by 40mm. But cut the end opposite of the shim stack.

Yep, the manitou cart is basic and shortening the tube would make it fit and would be the easiest option.

That was the main question i was asking, will they collide, and if they won't does not having as much oil in the damper degrade the performance?

How does manitou get the 6inch single crown tpc dampers so short?

Guess i am going to have the pull it apart to find out.

Anybody else have any info on this?

What do you think i should call it. I was thinking "monstarado"? :devil:

 

[profro]

There's a ratio of "cartridge" length to pumping rod length. As you shorten one you have to shorten the other. The other player in the equation is the compression side. Since you won't be shortening that side it is taken out of the equation. The reason I pulled mine apart was that I was only getting 5" of travel. Once I got it apart there was a plastic spacer that had come loose and was binding the pumping rod at 5". The spacer was only used to set the rod depth to bleed the system. Since I can set the depth myself, I cut that spacer out and everything since has been great. I even preformed the same operation on a team mate's fork. The plastic spacer was press fit into the underside of the top cap and once loose it was binding around the c-clip above the rebound shim stack.

I bet that they will collide unless you shorten the cratridge and pumping rod together at the right ratio.

The amount of oil only needs to fill the cartridge. As long as you don't have any air in the system, the preformance will be the same.

 

[Cave Dweller]

There's a ratio of "cartridge" length to pumping rod length. As you shorten one you have to shorten the other. The other player in the equation is the compression side. Since you won't be shortening that side it is taken out of the equation. The reason I pulled mine apart was that I was only getting 5" of travel. Once I got it apart there was a plastic spacer that had come loose and was binding the pumping rod at 5". The spacer was only used to set the rod depth to bleed the system. Since I can set the depth myself, I cut that spacer out and everything since has been great. I even preformed the same operation on a team mate's fork. The plastic spacer was press fit into the underside of the top cap and once loose it was binding around the c-clip above the rebound shim stack.

I bet that they will collide unless you shorten the cratridge and pumping rod together at the right ratio.

The amount of oil only needs to fill the cartridge. As long as you don't have any air in the system, the preformance will be the same.

Cheers. Will pull it apart on the weekend and have a look and figure out what needs to be done.