Quantcast

Steve's TPC+ Rockitou Doroxxer

djivotno

Monkey
Oct 3, 2008
108
0
...
You only need one piston for rebound and one piston for compression (that'll be the best setup IMO) ...
I'm a fan of simple design too, and that's why i was considering the shimmed check-valve side of the rebound and... now having that idea scrapped i'm thinking more in the lines of trimming the second MoCo unit i have down to it's shimstack, and having it for LSC with oil level responsible for the ramp-up (more like your setup :) )

The rebound goes for sure, but i'll keep my MoCo unit just in case. :brow:
 
May 25, 2006
62
0
Yeah, I just finished making my externally (LSC) adjustable damper. Mostly kingpin and some rockshox bits. I might update my thread with some pics and details whenever I have some time.

You only need one piston for rebound and one piston for compression (that'll be the best setup IMO) which leaves you one spare in case you mess something up. You will need to source some shims though (for the compression assembly at least, maybe rebound) because the kingpin ones are quite thin and bend a little too easily (= too little damping in mid to HSR and mid to HSC).

Be creative though, come up with your own ideas based on whatever you have in your garage... seems to work best.
Nice, sounds good. I would love to see pics and details when you have a chance! Sounds like I might want to see if I can get a new MoCo cartridge to have as a spare and then maybe cannibalize my current (old) one that leaks a bit.

My big question is... whose is better, your setup, or Socket's setup? A mix of TPC+ and MoCo, or the full TPC+ conversion?

Yeah, I'll definitely be looking at getting some more shims. No clue what kind of sizes or thicknesses I will want... I've got an old SPV Sherman kicking around, would the shims from that be a decent start?
 

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
Nice, sounds good. I would love to see pics and details when you have a chance! Sounds like I might want to see if I can get a new MoCo cartridge to have as a spare and then maybe cannibalize my current (old) one that leaks a bit.

My big question is... whose is better, your setup, or Socket's setup? A mix of TPC+ and MoCo, or the full TPC+ conversion?

Yeah, I'll definitely be looking at getting some more shims. No clue what kind of sizes or thicknesses I will want... I've got an old SPV Sherman kicking around, would the shims from that be a decent start?
Finally got some real riding on the TPC+ damper on Sunday (til my mate broke his ankle), have to say that thing is pretty berserk. Tracks extremely well and feels like motorbike suspension. Keeps its ride height very well, doesn't allow the fork to blow through its travel, and keeps the bike super stable. The downside is that running it with so much compression damping makes the front end not kick at all off lips, which means the rear end tends to get kicked up a bit by comparison. Will have to adjust the setup a bit more (probably more comp in the rear end, maybe run a tad less up the front) to reduce that a bit. Right now it feels like the front end just plain outperforms the rear end. Sounds wanky I know, but the front end is more planted than anything else I've tried.

As for whether mine or udi's is better, who knows... mine works very well, his probably does too, unfortunately we live 2000km apart so can't easily test each other's!

If you're going to use the TPC+ pistons, I'd recommend using all 0.2mm thickness shims at the very least (I have some 0.3s in there too). 0.1s are just too thin and you end up with a stack like a centimetre thick which still doesn't provide much lsc but gives a fair bit of HSC.
 

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
so how did you come up with idea exactly?
Well I wanted all the best characteristics of a Boxxer and a Dorado, basically... The Boxxer is pretty good out of the box compression-wise (the rebound is a bit dodge though), but there isn't much tuning you can do other than what you can do with the external adjustments.

As it stands now, with what is pretty much my first attempt at reshimming the damper, the fork is a noticeable step up from what it used to be with the stock Boxxer gear. It has the potential to be better yet.
 

RedOne

Monkey
May 27, 2007
172
0
Nuremberg, Germany
After reading this and Udi's thread i disassembled my old '03 Sherman Slider. My Boxxer is a '05/'06 Bastard without Moco, doesn't even have a real compression damper, so it's more like a Junior T. :plthumbsdown:
I modified that sherman a few years ago, to get more travel than the stock 6" (6.7 to 7" were possible). Performed well but i scratched a stanchion pretty bad and i think the whole thing is slightly bent, so it's time for the butcher.

Socket, you mentioned that the TPC+ compression rod was 70mm shorter than the Moco assembly. The comp rod of my sherman is about 315mm (12.4"). How long is a Moco "cartridge"?
 

Attachments

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
After reading this and Udi's thread i disassembled my old '03 Sherman Slider. My Boxxer is a '05/'06 Bastard without Moco, doesn't even have a real compression damper, so it's more like a Junior T. :plthumbsdown:
I modified that sherman a few years ago, to get more travel than the stock 6" (6.7 to 7" were possible). Performed well but i scratched a stanchion pretty bad and i think the whole thing is slightly bent, so it's time for the butcher.

Socket, you mentioned that the TPC+ compression rod was 70mm shorter than the Moco assembly. The comp rod of my sherman is about 315mm (12.4"). How long is a Moco "cartridge"?
Wow, 315mm?! Moco comp cartridges are about 220-225mm from the underside of the top lip (ie the lip that sits against the top of the stanchion when you screw the cap in)... the TPC+ compression assembly I have is out of a singlecrown, 5" travel Sherman, so yours would no doubt be bigger - but that's a LOT bigger, you'd need to actually shorten that I reckon, otherwise it'd hit the rebound piston before full compression.
 
Last edited:

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
www.teknikmotorsport.com sell them direct over the net, but they're based here in Aus so the price would probably be ridiculous to ship to Chile.

Go and find a motorbike suspension tuner in your area - they should be able to either sell you some themselves, or tell you where you can buy them.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
Socket, you mentioned that the TPC+ compression rod was 70mm shorter than the Moco assembly. The comp rod of my sherman is about 315mm (12.4"). How long is a Moco "cartridge"?
That's the same as the TPC+ assy that comes out of the kingpin, it's quite long. What you can do is unthread the base floating piston assembly (IMO it's not necessary) and use the lower piston's nut on the upper piston - that way it's a nice conventional shimmed piston + needle valve damper. You're going to have to cut the main shaft either way though, to fit a topcap - socket probably has more details on that, you're going to need access to a lathe / machine shop though I think.

If you want to keep both pistons there, it'd just be a matter of cutting the main shaft shorter than you would have otherwise.
 

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
That's the same as the TPC+ assy that comes out of the kingpin, it's quite long. What you can do is unthread the base floating piston assembly (IMO it's not necessary) and use the lower piston's nut on the upper piston - that way it's a nice conventional shimmed piston + needle valve damper. You're going to have to cut the main shaft either way though, to fit a topcap - socket probably has more details on that, you're going to need access to a lathe / machine shop though I think.

If you want to keep both pistons there, it'd just be a matter of cutting the main shaft shorter than you would have otherwise.
Shortening the outer shaft is easy to do, the hard part is shortening and re-joining the adjuster rod that goes through the middle.
 

atb

Monkey
Jun 18, 2004
201
0
the north shore
how much travel can a sherman slider/kingpin damper have? there both 32mm so what if i just used that whole side of the fork.

me and a buddy are working on building a fork for his new bike, and we already got a 7" kingpin sitting around, its got updated internals too, no air cap. in fact it doesn’t even feel that bad. i haven’t taken it apart yet.

i'm running a 07 travis, with a tpc+ cart instead of intrish!t. its f-ing godly(i'v also had fox40rc2, and a boxxer team), now that i have the oil height set(i was having problems with cheep oil expanding). small bumps dont exist, doesn’t dive under braking, and it never bottoms harsh, it just stay stuck to the ground.

maybe even just make a new top cap for the travis tpc+ cart to match a boxxer?
 
Last edited:

scar4me

Chimp
Jul 26, 2012
8
3
Holy thread resurrection.....

Just thought I'd add in that I've just successfully converted a set of Rockshox Sektor's to use a TPC+ compression assembly.
So I've now got a set of Secktance's :)

I went for the easy option and used a non-externally adjustable Stance assembly.
Then stripped the Motion Control damper down till I just had the top-cap.
Fully compressed the fork to confirm the exact clearance to the rebound piston at bottom out.
Then used this as a guide for the TPC+ total damper length. (I wanted to maximize the damper length and not just go by the Motion Control length)
As it was their was only 8mm between the measurements, so I left a 3mm clearance on the TPC+ damper.

I had to set the TPC floating piston length to its shortest setting, and then cut off the excess below this.
Then I cut down the main compression mounting rod to the correct length, threaded the ID of it to an M6 thread, then got the correct size of Xring seal, and made up some spacers so that it sealed the topcap fully.

I also had to seal the thread to the bolt with some penetrating loctite 209, and then drill through some small holes into the rod.
This was needed to maximize the air volume available above the TPC pistons, and minimize the ramp up due to rebound shaft displacement.
If I was to do it next time, I'd use one of the Sektor Air topcaps, so that you would also get damper pressure adjustment.

Then I also had to lathe down the TPC pistons to fit the Sektor stantions. (leaving the glide rings off as the pistons are plastic anyway)
Once this was done I calculated the oil level so that it was just over the top TPC piston, and put it all together.

Been out for a ride on it today, and deffinately puts the fork into a different league for bump compliance!


For any of you out there that fancy trying it, the challenge is deffinately worth the result!


Scar