Some facts about Minute MRD, Absolute+, Mars Air

MRD Absolute+ shims have not been covered in this thread so far.

My Minute MRD, 100 mm travel, 20 mm thru-axle, came with the following shims, starting from shaft:

narrow clamp shim, 9 x 0.2(*) mm x (1)
wide clamp shim, 11 x 0.1 mm x (1)
blow-off shim, 14 x 0.15 mm x (4)
preload reducer shim, 9 x 0.1 mm x (3)

Which is a strange stack: a lot of equal height blof-off shims, reinforced by a wide clamp shim, and preload reduced by as much as 0.3 mm. The fork was impractical to ride with needle fully closed, too much platform and spiking. Running the needle in semi-open positions was a compromise between plushness and bob/dive.

I have installed a 0.2 mm M6 precision washer (technically it's not a dedicated damper shim) to use as the speed shim and only left 1 blow-off washer (now preload reduced by 0.2 mm) and the narrow clamp washer. I hope that this setup resembles tune EK-012611-02 from the Manitou document, which only mentions non-MRD dampers.

I am yet to test this setup in real use -- waiting for the current cold spell to end.

_____________________
(*) This number is taken from memory.

PS
I'm overhauling the fork completely anyway, and have changed the stock coil spring (color code red, which is medium I guess) for spring code 83-3172, which was sold to me as firm, although it has no color markings. It feels firmer by hand indeed. It's also 3.7 mm wire thickness and 87 mm long, as opposed to 3.4 mm and 77 mm respectively on stock spring.

I had to shorten the rubber top out bumper (the one on spring rod) by 10 mm to accomodate the longer spring.

Also, it's a known fact that there is no spring grease/semi-bath oil separating seal in Mars Air forks. Which results in oil penetrating coil spring chamber in use, where it attempts to dissolve the grease (even if you only leave enough grease to cover stahcnion wall from inside -- they put a huge amount of grease in during assembly) and gets thickened in the process. This thickened snot-like mixture has trouble reaching the upper bushing.

What I have done is cut a 4/2 mm heat shrink tube into several 1 cm pieces, piloted them on the spring wire, distributed them around and shrunk them until they are unable to move. I used no grease at all, relying instead on the tube and quality motor oil to protect the stanchion wall.

 

MRD Absolute+ shims have not been covered in this thread so far.

My Minute MRD, 100 mm travel, 20 mm thru-axle, came with the following shims, starting from shaft:

narrow clamp shim, 9 x 0.2(*) mm x (1)
wide clamp shim, 11 x 0.1 mm x (1)
blow-off shim, 14 x 0.15 mm x (4)
preload reducer shim, 9 x 0.1 mm x (3)

Which is a strange stack: a lot of equal height blof-off shims, reinforced by a wide clamp shim, and preload reduced by as much as 0.3 mm. The fork was impractical to ride with needle fully closed, too much platform and spiking. Running the needle in semi-open positions was a compromise between plushness and bob/dive.

I have installed a 0.2 mm M6 precision washer (technically it's not a dedicated damper shim) to use as the speed shim and only left 1 blow-off washer (now preload reduced by 0.2 mm) and the narrow clamp washer. I hope that this setup resembles tune EK-012611-02 from the Manitou document, which only mentions non-MRD dampers.

I am yet to test this setup in real use -- waiting for the current cold spell to end.

_____________________
(*) This number is taken from memory.

PS
I'm overhauling the fork completely anyway, and have changed the stock coil spring (color code red, which is medium I guess) for spring code 83-3172, which was sold to me as firm, although it has no color markings. It feels firmer by hand indeed. It's also 3.7 mm wire thickness and 87 mm long, as opposed to 3.4 mm and 77 mm respectively on stock spring.

I had to shorten the rubber top out bumper (the one on spring rod) by 10 mm to accomodate the longer spring.

Also, it's a known fact that there is no spring grease/semi-bath oil separating seal in Mars Air forks. Which results in oil penetrating coil spring chamber in use, where it attempts to dissolve the grease (even if you only leave enough grease to cover stahcnion wall from inside -- they put a huge amount of grease in during assembly) and gets thickened in the process. This thickened snot-like mixture has trouble reaching the upper bushing.

What I have done is cut a 4/2 mm heat shrink tube into several 1 cm pieces, piloted them on the spring wire, distributed them around and shrunk them until they are unable to move. I used no grease at all, relying instead on the tube and quality motor oil to protect the stanchion wall.

Instead of using the washer, You should get the results you are looking for by removing one(or maybe even two) of the blow off shims. It would allow the stack to blow off easier while still using damper shims. You can also add the shims you remove to top of the stack to give less platform, but keep a little more HSC overall

Let us know how it rides when you get a chance:thumbsup:

 

Well, here's how that 0.2 mm "speed shim" and 0.15 mm blow-off shim combination feels in room test with needle fully closed: no perceivable blow-off force on low-speed movement, and a suddenly appearing spike feel when I try to compress the fork faster.

Feels like 0.2 mm is way too thick of a speed shim for MRD. At least the improvised type. Since any blow-off force seems to be absent, I'm not even going to try this stack on a real ride.


Next stack to try, starting from shaft:

narrow clamp washer (it's 0.25 mm, I've just measured it)
wide clamp washer
2 x 0.15 mm blow-off shims
1 x 0.1 mm preload reducer
2x 0.1 mm "speed shims", hopefully for 4 times less stiffness than 1 x 0.2 mm (not gonna give up on that idea right away..)


PS
Results are weird. I expected the blow-off force to be about half of what there initially was with 4 blowoff shims and 0.3 mm total preload reduction (which was way too much). But there is still no detectable blow-off force. And the higher speed spike remains, it just requires me to push the fork faster to trigger it, than it was with 0.2 mm "speed shim".


Anyway.. next stack, starting from shaft:

narrow clamp washer
wide clamp washer
3 x 0.15 mm blow-off shims
2 x 0.1 mm preload reducer
1 x 0.1 mm "speed shim".


PPS
I'm using a very light oil, Stendec Crystal Fork Fluid 2.5W (stock oil that I dumped was definitely heavier). This must be why very low speed compression with needle closed feels like there's an orifice still open. Oil must be having very little trouble flexing whatever "speed shims" that I tried, and (what is mysterious) up to 3 x 0.15 mm blow-off shims, preload reduced by 0.3 mm.


PPPS
I went back to (almost) the first stack I was going to try, but with wide clamp washer added:

narrow clamp washer
wide clamp washer
1 x 0.15 mm blow-off shim
1 x 0.2 mm "speed shim",

and this time changed the oil to a 1:1 mix of Stendec 5W and 10W. Weeeeeeell... it feels better now (with needle sitll fully closed). Much more explainable. What was preceived as absence of blow-off and a sudden spike, is now a platform-like feeling that with reasonable force opens to what feels like heavily damped travel (real riding will tell whether it's too heavy or not).

I guess that the light oil was (in small quantities) bypassing the (defective?) check valve on the front side of piston. It would have had little effect when riding, but on manual room test even the small blow-off force kicking in at higher speeds was perceived as a spike (which it wasn't, it would open if I pressed harder, but in comparison to very low speed free travel it felt like hitting a wall). It's as if the needle was not fully closed, but instead 1-2 clicks from closed.

 

Marzocchi 55r 08'

Hi guys,

Im all the way from the Philippines and I read one of you forum posts. I own a Marzocchi 55r 08 model. It seems to lock out and I only get 2-3 inch travel and even less sometimes. This form is supposed to be 160mm travel.

I read that you can drill into it and make it work again.

Im am not really sure how to do it so I am researching for more info and photos as well.

It'll be a great deal of help if you can send me more specific details.

Thanks much!:thumbsup:

regards,

Nicolas

 

badburn666,
you may want to look here, for instance.

 

55r

yup, read that already. thanks though.

Still need more instructions and illustrations for it.

 

This isn't about reshimming, but I'm hoping some of the manitou experts might be able to help out.

I just serviced my 2011 r7 for the first time, and when I was putting it back together it seems like the threads at the bottom of the leftleg/compressionrod are stripped. The manual says to tighten to 45-55 in-lbs, but I can only get it a little more than fingertight and then it spins and spins. I don't think I stripped it, but the threads are just plastic so it seems like it would be an easy thing to do?

Anyway, I'm assuming that running it like this would be a bad thing and that I should try to track down a replacement compressionrod assembly? Or did I miss something during reassembly that's preventing me from tightening it up? Any advice from the experts?

 

newfangled,
yes, the plastic nut threads can be stripped. Examine them closely.

Also examine threads in the stanchion, just in case -- maybe there's something that fscked up the plastic thread.

 

The piston may be spinning in the stanchion. Take the lowers back off and put the bolt back in and tighten it. If the compression rod is spinning with the bolt then the piston is spinning in the stanchion. To fix this, hold the compression rod to stop it from spinning while tightening the bolt. This should clean out the threads and allow you to tighten it when the lowers are attached.

 

Thanks mullen, I'd considered taking it apart again and threading it in without the lowers, but I was feeling too lazy. I'll give that a shot, though.

 

Ah, that bolt. I thought it's about the plastic nut that you turn with 22 mm wrench. One came from factory with stripped threads recently.

 

^ sorry, yeah it's the metal bolt into plastic threads. I don't think I stripped it because I wasn't able to get any force into it, so either the piston is spinning (hopefully), or it came stripped and was never tight to begin with. We'll see after I take it apart again.

 

Well then, lowers on a R7 (TS Air sprung) fork are best removed and put on with some pressure in air chamber. This preloads the negative spring, which, in turn, presses down on the plastic rod thus preventing it from turning somewhat, together with the force that bolt creates pulling the rod into the bottom of the lower leg. You kind of compress the rod in between the negative spring and the bottom of lower leg.

 

This is good advice. But I was just thinking about it, and 45in/lbs is not more more then finger tight. Its not a bad idea to pick up a torque wrench if you dont have one already. My current fork( RS Lyrik) says 60in/lbs on the foot bolts and I was shocked at how little torque it was. After you put the bath oil in, Put the bolt in the get everything lined up, then take it out and clean it(bolt and lowers) with rubbing alcohol to get any oil off. Then use some blue locktite to keep it from coming loose. (oil and locktite do not mix very well)

If you dont have or cant get access to a torque wrench, 45/in/lbs will be just a hand tight when holding the short side of an allen wrench.(hope I worded that so it makes sense :lol

 

tagged for future reference

 

I have no problem running with the clickers closed. If you can acheive the ride you want with all the oil through the shims it's not a bad thing.

 

Can any that has used the minute with both absolute and ABS+ please tell me which of the systems is more plush in the open position?

 

They are both the same system. Absolute only had 5 detents from fully open to close while the ABS+ has 7 from fully open to close. They are the same when fully open or fully close.

 

So the only advantage is tuneability and detents range, right?
And if you use MILO remote (2 positions, full open and full close) they act exactly the same

now I know the update is not necesary for me, thanks

 

yes, I do not use the MILO remote for that exact reason. I use fully open, the third detent(where I usually ride) and fully lockout available to me.

 

I've used ABS and ABS+ ( in Drake ,but it doesn't matter I think) and IMO ABS+ is much more plush in fully open position. ABS+ made my fork more sensitive for small bumps and more linear than with ABS. Tuneability and detents range are additional bonus .

 

Absolute is a very different damper, it's nothing like Absolute+.

In Absolute, there are no compression shims, just constant sized oil port plugged with blunt-needle-shaped check valve. And it's the preload of that valve which you adjust with the knob, not port size directly.

 

Absolute + is better compared to the original TPC damper which was similar in design.

 

Anyone got the piston head dimensions - in particular the outside diameter?

 

It would depend on the fork. The Minutes/Towers would be different from the Match, which would be different from the R7. Would also depend on if it was MRD or not.

 

Same as any minute damper.. I dont want to pull my abs+ unit, but the SPV unit it replaced measured 28.62mm. The abs+ should be the same or very very close.

 

Awesome. Cheers.

 

On a semi related note, I went for a ride on my coil u-turn D) abs+ minute. Beautiful ride, I love this thing.

 

This sounds very interesting, please explain........

 

Its down on travel currently (as expected), so not 100% done. I used a tora coil u-turn spring. Just have to change the lower leg cap from a seal head to one for a coil. I used the drake lower cap, and a drake top spring cap. Removed the u-turn cap (its just a c-clip), drilled out the drake cap and installed a short rubber bumper and put the c-clip back on. Slips right in and you're on your way! If i had a pike spring, it would be perfect.

I intended on using all manitou parts for a coil conversion, but they just dont exist. Tried a drake coil pushrod, but its too narrow and falls through the lowers. nixon 145 coil, but its way too long and too fat. The RS u-turn parts end up working better.

Weight be damned, im faster on the coil and its so so much smoother!

 

Its down on travel currently (as expected), so not 100% done. I used a tora coil u-turn spring. Just have to change the lower leg cap from a seal head to one for a coil. I used the drake lower cap, and a drake top spring cap. Removed the u-turn cap (its just a c-clip), drilled out the drake cap and installed a short rubber bumper and put the c-clip back on. Slips right in and you're on your way! If i had a pike spring, it would be perfect.

I intended on using all manitou parts for a coil conversion, but they just dont exist. Tried a drake coil pushrod, but its too narrow and falls through the lowers. nixon 145 coil, but its way too long and too fat. The RS u-turn parts end up working better.

Weight be damned, im faster on the coil and its so so much smoother!

That is awesome. Post some pics when your done. I love franken forks. A straight coil Minute is very appealing.