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How to guide: Reshim your ABS+ HSC shim stack

203K views 740 replies 114 participants last post by  half_man_half_scab  
#1 · (Edited)
Seems like there has been a lot of talk on here about Manitous ABS+ damper and how good it is. I have been playing around with the HSC shim stack over the last few months and figured i would make a "how to" guide so others can do the same. It only takes 15-20 minutes and once you get a shim stack set up for your weight, The ABS+ damper is even better!

Use a 2.5mm allen wrench to take the top cap off. Take it off carefully!
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Be careful not to loose the little ball bearings and springs, They are very tiny and easy to loose track of.When you reassemble, it doesnt matter where they springs and bearings go as long as they are across from each other.
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Once the top cap is off, unscrew the damper from the leg and pull it out. Pull is out slowly and you wont loose very much oil. Keep a rag near by because you will loose a little no matter what.
Damper after being pulled out.
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At the very top of the damper, there is a place for a 10mm wrench to hold the damper while you use a 13mm socket to unscrew the nut on the bottom of the piston.

One shim that is used as a check valve and a spring are under the piston. This just allows oil to flow freely back into the leg after the fork is compressed and re-extended. When reassembling, The spring goes back with the wider end toward the piston and the skinnier end toward the nut.
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Close up of bottom of piston
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Close up of top of piston
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Shim stack installed
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My 2010 drake has 6 compression shims stock. 3 the same size, and 3 that get progressively smaller in a pyramid shape. Lighter rider can remove shims to allow the HSC to open with less force, while heavier riders will want to add shims. Endless possibilities for shim configurations, So if you try this, post your weight and shim stack.

Reassemble same way you take it apart. Make sure the LSC is all the way open(counter clockwise) when you put the damper back in the leg. Oil height should be 87mm from the crown when fully assembled. If your careful taking it apart you shouldn't loose a significant amount of oil, but always check to make sure.:thumbsup:

Key points from that this thread has turned up:

1. Thanks to Solitone, we have the Manitou ABS+ tuning guide which includes dyno charts and many different shim stack combinations. Its probably the single best find this thread has produced (thanks Solitone)

This link should work:
https://goo.gl/JaqWO

2. Spring rate needs to be set up correctly. I get PM's and hear of people trying to get their fork to feel right when it is way under/over sprung. Spring rate trumps damping and should always be set up correctly prior to trying different shim stack configurations.

3. A good place to order shims is MX tech.
MX-Tech Suspensions
 
#455 ·
Hi All. Ive got a 2012 Marvel Expert (120mm) that I bought new about 18 months ago. The rebound has always been super-fast even with the damping set at max. Im about 85kgs (187 pounds) if that makes a difference, and I ride trails with loads of rocks, small drops (1 ft) and small jumps.
Other than using 7.5w oil (instead of the 5w), is there anything I can do with the rebound shims? The new oil is the cheaper option, but it might also affect the compression??
Any advise would be awesome.
Thanks
 
#459 ·
Hi All. Ive got a 2012 Marvel Expert (120mm) that I bought new about 18 months ago. The rebound has always been super-fast even with the damping set at max. Im about 85kgs (187 pounds) if that makes a difference, and I ride trails with loads of rocks, small drops (1 ft) and small jumps.

Other than using 7.5w oil (instead of the 5w), is there anything I can do with the rebound shims? The new oil is the cheaper option, but it might also affect the compression??

Any advise would be awesome.

Thanks
First need to drop the lowers, I had a problem with my '14 marvel where the nut retaining the shim stack came loose. Messed up rebound and compression damping.

If your compression damping adjustments work fine and have full affect, then you'll need to tune the shim stack. But on mine im a Clyde and rebound damping was great stock till I got my air pressure up where I needed it.

If you change the oil weight you'll have to retune the compression damper as well.
 
#463 ·
I'm expecting a Manitou Marvel Comp 120 to arrive tomorrow or the next day for my single speed. It should have a MILO with it, but not installed. It sounds like the MILO evokes some pretty mixed feelings, so lets leave that completely out of the equation for a while. My questions are this:

Does anyone know which stack the Marvel Comp 120 comes with?

Does anyone have any notion where I might want to go from stock, given: I'm 220ish kitted up, ride technical XC style trails, small drops, occasional small jumps. Most trails are rooty or rocky.

If I understand what I've read in this thread correctly, I'll likely want a more stout spring (which determines sag?) at the very least. Can anyone confirm this, or provide other pointers? Thanks.
 
#465 ·
The Marvel Comp uses a regular air spring, not the air spring plus coil spring combo used in the Minute Pro. All you need to do with the Marvel Comp is set the air pressure, there is no coil spring to swap. As for the shim stack, the Marvel series uses the XC stack, hard to say how it'll work for you since I have no idea where you prefer to set the adjustment, which fork you were using before, and how you want the fork to feel. I'd say ride it and see how it feels, then go from there.
 
#469 ·
Getting educated already - thanks guys. I was worried I may have to change out a spring to even begin to get the ride right. The fork coming off the bike is a slightly shorter rigid steel fork, which has been great fun, but my upper body has been telling me I'm not as good a damper as I used to be, so I'm shooting for some unknown level of plushness out of this fork. It will be important that it locks out for climbs, and important that it unlocks and takes the edge off every where else. Can't have a soft suspension fork slowing a single speeder down on the climbs, right? Tracking info says the fork should arrive this afternoon, so it'll likely take a couple days for the LBS to install it and cut the steerer for me, etc, then we'll get a look at it.

Thanks for the answers so far, I'm sure I'll end up with more. This is an awesome thread, by the way. It's one of the reasons I decided to pull the trigger on this fork. Maybe you guys should be getting kickbacks from Manitou? :D
 
#470 ·
It took a while to get my bike back with the fork on it because the shop had to order a post mount adaptor (never thought about that) for the front brake since the old fork was ISO. I picked the bike up from the shop and went straight to the trail with it, and based on the tuning sticker on the fork, but 75 PSI in the fork (figuring for the low end of 220 since I'm about 215+hydration pack). I cranked the damper back to three clicks from locked out to get the brake dive under control, and it felt pretty good. I'm going to actually measure the sag at some point today and see if the air pressure is in the ball park.

Big question is this: I see the MILO looks like an on/off unit. I also see some indication that it doesn't provide the full range of adjustment. Can anyone comment on how much or how little adjustment it can give? For instance, if my sag is in the ball park with 75 PSI, can I make the MILO only run from closed to three clicks open?

I have to be honest, I'm super impressed with how good this fork felt for just throwing some air in it and hitting a trail with some rock gardens and real technical stuff.
 
#471 ·
Yes, MILO is on/off and it doesn't pull enough cable to spin LSC knob across its full range. Usually MILOs are set up so as to close off LSC completely when engaged.

However, it (the LSC knob, either with MILO attached or not) has no relation to the fork's air spring pressure, those are independent settings.

As to how much adjustment does MILO give, I'd say that with factory damper oil the MILO "open" position should be enough for a plush ride. However take it with a grain of salt form me as my idea of plush is anything that bobs when I pedal out of saddle. :) -- running a rigid fork currently and happy so far.
 
#472 ·
Right, I get the air pressure isn't affected but LSC, but I was able to tune out some brake dive by closing down on the LSC some. While they're independent settings, they do interact.

When I actually checked sag %, it looks like somewhere between 70 and 75 PSI is where the air should be, but brake dive is still an issue. I'm going to get it close and ride it through the break-in and see what happens at that point.

I put the MILO on (took about a half hour, including fishing one of the metal balls out of the bottom of one of the little holes the springs are supposed to sit in because I've got fat fingers) and rigged it up to lock out, and turn only the distance of three clicks back towards open by fiddling with where i put the spring that returns the knob.

I'm supposed to hit a pretty fun trail with a group on Saturday, so I'll have a much better picture of how all of this works together then, but so far, I'm liking the stock setup pretty well. I'm coming off a rigid fork, so the lock out is important to me for climbs (SS and all that) but yes, anything not rigid becomes plush when you kick the lockout off.
 
#479 ·
Is it possible that I feel less LSC damping just because I changed fork seals? Now I have installed Enduro seals, which appear smoother than stock Manitou's (pretty less stiction). Everything in the abs+ damper configuration has not changed. I checked oil level 2 times. Still, it seems there is less LSC damping. Even when abs+ is maxed, the fork is not completely locked out (previously it was, almost).
 
#491 ·
Can any lightweight (135lb here) share their setups? I am on a 27.5 120mm Marvel Pro and riding rough XC. Here are some of my notes:
-Got it used. Came with 3 x 19x2.0 XC shim kit. This was way to harsh

-Went to EK-12611-02 |60-65psi | Max-6 or 7 even to full open. This was better, but not able to get full travel .

-Tried a modified CV-11711-01 due to shim availability.
Clamp shim|19x0.15t | 10.5x0.25t | 17.5x0.2
-65psi, Max-6. Too soft and divvy.

-modified EK-12611-02 with 19x0.10 instead of the 19x0.15
60-65psi| Max-5 or 6

-repeating with the above with 60psi, max-1 or max-2 and faster rebound

I am finding that rebound is one of the hardest things for me to tune. There seems a point in turning the knob where it goes from damped to bouncy.

is there any information on how to tune the rebound damper?

-I got a tip from Mullen to try a linear stack. I'll post my results

-
 
#494 ·
Can any lightweight (135lb here) share their setups? I am on a 27.5 120mm Marvel Pro and riding rough XC. Here are some of my notes:
-Got it used. Came with 3 x 19x2.0 XC shim kit. This was way to harsh

-Went to EK-12611-02 |60-65psi | Max-6 or 7 even to full open. This was better, but not able to get full travel .

-Tried a modified CV-11711-01 due to shim availability.
Clamp shim|19x0.15t | 10.5x0.25t | 17.5x0.2
-65psi, Max-6. Too soft and divvy.

-modified EK-12611-02 with 19x0.10 instead of the 19x0.15
60-65psi| Max-5 or 6

-repeating with the above with 60psi, max-1 or max-2 and faster rebound

I am finding that rebound is one of the hardest things for me to tune. There seems a point in turning the knob where it goes from damped to bouncy.

is there any information on how to tune the rebound damper?

-I got a tip from Mullen to try a linear stack. I'll post my results

-
I've got my wife running the lightest linear tune (I think it's CV-11411-11, but haven't got records handy).
I tune it to about halfway on the LS dial and it appears to work very well. It's stable enough that people 20kg heavier can get on and ride and it still feels like it should.
 
#492 ·
Your first problem is running damper at max 6 and expecting it not to dive. That's almost full open low speed. Changing the shim stack does NOTHING for low speed setting. And low speed setting is the knob, knob adjusts nothing in the shim stack which is high speed.

Secondly weight matters little for the shim stack. Also what % sag are you running. Psi number is another "means nothing" do to pump differences.

You need to set the knob where you want it for lack of dive (I ride at max 3-4) then tune ur shim stack for high speed where you want it.

Also stop worrying about "getting full travel" on xc trails, especially on a 120mm fork. My trails are really rough "xc" and 80mm is plenty, I ride at 110 travel and never use it all unless I land hard. Be worried about control and feel, not how much travel you use.

As for rebound, no guide for tuning. But if you take a little bit of time to understand the fairly simple concept of how the shims work, you can tune it but its more difficult. And very easy to break the rebound system if you do t have the proper tools to be working on it. I did tune my rebound because of the higher pressures I have to run.
 
#493 ·
Ahh, finally some shim talk... it's been a while :)
Linear stacks are great for freeridey biking, but for XC purposes I prefer a preloaded stack, so that there is very little damping on the blowoff.
You can try to do a {clamp, 19x0.15} configuration. Very simple, but the increased preload should keep the brake dive at bay, while the extremely digressive profile of the lack of shims should make rocky sections use a lot of travel. If it still bottoms out, you can stack some light shims between the clamp and the other shims to increase preload+highspeed, or you can increase air pressure, or reduce air-chamber volume.

For the rebound, I tend to slowly roll around in the parking lot, and then suddenly jam my weight on the handlebars, trying to use as much travel as I can. I keep my arms stiff, and try to feel whether the rebound jumps beyond sag, and back down again. I aim for a slightly underdamped/critically damped feel:
 
#495 ·
Been messing with the shim stack on my 120 marvel which came with the XC stack (that had a solid platform) and running the trail stack now (which is a lot more plush) its on my single speed tho and I'm really missing the platform when I'm climbing out of the saddle. Any suggestions on what to try next?

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