top_dog
Likes Dirt
This is a post I whipped up with links and all sorts of stuff to help you understand your suspension and what you can do to it to make it better. I will add more as time goes on. At the moment it is just a couple of DH forks, but it will grow considerably. If you have suggestions as to what to include in this thread don’t hesitate to ask. I would also be very pleased to put up some of the better DIY mods like Rik's U-Turn Shermans. Enjoy.
Marzocchi Forks
All Marzocchi Forks
The Marzocchi Oil level tables are located here:
http://www.marzocchi.com/spa/mtb/products/oillevel.asp?LN=UK&Y=2005&Sito=mtb
And the Manuals are Here:
http://www.marzocchi.com/template/listSPAManuals.asp?IDFolder=126&IDA=28182&LN=UK&Sito=usa-mtb
04/05 888R/888RC
Go-Ride Article
There is a very good tuning guide over on Go-Ride.com which goes into some details about setting up and tuning your fork.
http://www.go-ride.com/article_888_tuning.html
Spring Weights - Cave Dweller
spring length is 300mm
Soft = 2.7 kg/cm = 15lbs/in
Stock = 3.1 kg/cm = 17lbs/in
Stiff = 3.4 kg/cm = 19lbs/in
Mojo Cartridges
Mojo, the makers of the famous Boxxcart have recently released a cartridge and spring kit for the 888. Apparently it has far better speed sensitivity than the standard damper.
http://www.mojo.co.uk/888_Cart.html
BOS Cartridges
Oliver Bossard’s company BOS has also recently released a pair of cartridges for the 888. These are extremely expensive and are apparently very very good, but so dear.
BOS Engineering Cartridges (Translated from French)
uDi's Low Speed Compression Sleeve
How To
Thought this might interest other 888 owners out there.
This mod works for the 04 888R, 05 888RC, and the 05 66RC, which all run an adjustable HSCV cartridge for compression damping.
Now the problem was, the cartridge only offered damping in the last 2-3 inches of travel, leaving very little compression damping in the earlier part of the stroke. Not enough low speed compression damping meant the otherwise excellent fork would dive excessively during hard cornering and hard braking.
The culprit for this was the set of 5 holes on the compression cartridge that allowed oil to escape earlier in the stroke rather than forcing it through the actual damper (the shim stack).
The first two images that I have attached at the bottom of this post are full size pictures of the compression cartridge if you want more of an idea of where these holes are located.
Now those of you who have read the go-ride article on the 888, will know that marzocchi makes an adjuster that allows you to cover combinations of these holes - but after pricing it up it came to about au$80-90. Stuff that!
So I decided to make my own.
I started with a 55mm length of 20mm OD PVC piping (actual OD was 19.5mm) and the ID was roughly 15mm. Now the 888 cartridge has an OD of approximately 17mm, so it took some filing to get the inside of the PVC down to the right size - the trick here is to get it so it will slide on fairly tightly and not loose, as that is how it will stay on. I put my round file in an electric drill to get most of it shaved out and then did the rest by hand, checking for fit on the cartridge often. The finished product was 44mm long, but start with 55 so you have more to play with later.
I drilled 3 different sets of holes in the sleeve to give me 3 different settings (better pictures of the sleeve alone are attached at the bottom of the post). I found covering only the small lower holes just made the fork ramp up quicker (ie: not much use), so covering the two large upper holes is the way to go. My advice would be to use that (Setting 1) as a starting point and go from there.
The diagram shows which holes are covered on the compression cartridge for each setting, and the photos below them show the real thing.
Left Cartridge
Right Cartridge
Sleeve
Set Up
I ran it in "Setting 1" for about a month, and it was definitely an improvement over stock but not a huge difference. My fork setup then was Motul Factory-Line 7.5wt, 220ml per leg, and the compression knob wound pretty much all the way in. The fork wasnt blowing through it's travel too much but there was still a bit much dive when cornering hard. An important side effect to note when using a compression sleeve is that it will affect the bottom out resistance. I found I was only using 180mm of travel, so the plan was to drop the oil level next time.
I've just changed it to "Setting 3" today, which closes 4 of the 5 holes, and dropped the oil level to 205ml per leg. Just pushing on it on the driveway the difference isn't huge, but once you start moving and cornering at speed you start noticing a big difference. The fork stays higher in its travel and doesn't blow through nearly as many inches. I'm yet to hammer some DH runs with it but this seems to be the ticket. I'm still running the compression knob wound all the way in but if I feel there is too much damping i'll back it off a bit.
I believe treggs is running 10wt in the compression side instead of 7.5wt, and he is running the equivalent of "Setting 2" (2 large holes and 1 small hole covered) - apparently it works quite well. I think 7.5wt is fine for my weight (~60kg) but for a heavier rider the 10wt in the compression side would give you more damping again.
That's it for now.
Feel free to PM uDi if anyone wants more details.
A big thanks goes out to treggs on here - he was the first one on here to do the mod to my knowledge, and a bit of inspiration goes a long way.
--Udi
Monster T
Monster T exploded diagram - Cave Dweller
IS here: http://forums.farkin.net/attachment.php?attachmentid=25190
Spring Rates - Cave Dweller
Spring length is 320mm
Green = stock springs in 99-02 monsters = progressively wound springs, start at 2.5 kg/cm and ramp up to 3.5 kg/cm (14lbs/inch to 19.6lbs/inch)
Yellow = Soft = 2.5 kg/cm (14 lbs/inch)
White = Medium = 3 kg/cm (16.8 lbs/inch)
Blue = Firm = 3.5 kg/cm (19.6 lbs/inch)
Red = heavy = 4 kg/cm (22.4 lbs/inch)
Cave Dweller's Air Sprung Monster Mod
I have been toying with the idea for a while to air spring my monster to shave some weight. There is various ways to do this, drilling in air valves into the cap of each leg is one (like zedros shiver), making some volume reducers like in 888's is another, and the other mod is to completely remove one cartridge of the fork and air spring it. The later is what i have done here.
NOTE:- If you do this i accept no responsibility for your actions, infact, don't do this, it will probably wreck your fork.
First step is to remove the entire cartridge, spring and spacers from one leg. This leaves a hole at the bottom. Get a bolt, stick it in there and put the foot nut back on the bottom. The bottom of the fork leg is now plugged and won't allow oil out.
Next, go to your local tire shop and ask for a tubeless car valve, they cost $5. Stick it into the hole in the valve cap that used to let the cartridge/preload/rebound adjsuters through. Fill the leg with 50-70ml's of oil to allow for lubrication.
NOTE:- there will now be nothing holding this leg together as you have removed the cartridge, it will be held together by the other leg and crowns. So, remeber that you need to release the air pressure from the fork before you undo the tripple clamps otherwise you will end up with a stachion rocket
Open up the other leg and drain the oil out. You will need to put a heavier spring in to compensate as you will only be running one spring, not two. You will also need to put heavier oil in to help slow down the rebound, stock it is 7.5wt, i mixxed up some 12wt oil and put it in, i set the oil level 10-15mm higher the the marzocchi recommendation to help with bottom out resistance. Put it back together and bobs your uncle, air sprung monster
Not sure of the air pressure, i am putting in between 15-20 pumps of my bike pump. Seals are holding the air fine, minimal leakage over the week just gone by.
The fork rides almost the same, slightly more harsh over small bumps due to the air pressure, but it doesn't bottom at all, and the rebound is fine, no nasty top out clunks. Biggest difference is the reduced weight, this has saved around 1.5lbs from the fork making it around 8.5lbs, the fork also feels alot more responsive, probably from the reduction in unpsrung mass.
Picture of modded top cap.
Shivers
Spring Weights - Cave Dweller
Spring length is 334mm
Soft = 2.7 kg/cm (15 lbs/inch)
Medium = 3.2 kg/cm (18 lbs/inch)
Firm = 3.7 kg/cm (21 lbs/inch)
Exploded Diagram
02 Shiver DC dia. attached below
Marzocchi Forks
All Marzocchi Forks
The Marzocchi Oil level tables are located here:
http://www.marzocchi.com/spa/mtb/products/oillevel.asp?LN=UK&Y=2005&Sito=mtb
And the Manuals are Here:
http://www.marzocchi.com/template/listSPAManuals.asp?IDFolder=126&IDA=28182&LN=UK&Sito=usa-mtb
04/05 888R/888RC
Go-Ride Article
There is a very good tuning guide over on Go-Ride.com which goes into some details about setting up and tuning your fork.
http://www.go-ride.com/article_888_tuning.html
Spring Weights - Cave Dweller
spring length is 300mm
Soft = 2.7 kg/cm = 15lbs/in
Stock = 3.1 kg/cm = 17lbs/in
Stiff = 3.4 kg/cm = 19lbs/in
Mojo Cartridges
Mojo, the makers of the famous Boxxcart have recently released a cartridge and spring kit for the 888. Apparently it has far better speed sensitivity than the standard damper.
http://www.mojo.co.uk/888_Cart.html
BOS Cartridges
Oliver Bossard’s company BOS has also recently released a pair of cartridges for the 888. These are extremely expensive and are apparently very very good, but so dear.
BOS Engineering Cartridges (Translated from French)
uDi's Low Speed Compression Sleeve
How To
Thought this might interest other 888 owners out there.
This mod works for the 04 888R, 05 888RC, and the 05 66RC, which all run an adjustable HSCV cartridge for compression damping.
Now the problem was, the cartridge only offered damping in the last 2-3 inches of travel, leaving very little compression damping in the earlier part of the stroke. Not enough low speed compression damping meant the otherwise excellent fork would dive excessively during hard cornering and hard braking.
The culprit for this was the set of 5 holes on the compression cartridge that allowed oil to escape earlier in the stroke rather than forcing it through the actual damper (the shim stack).
The first two images that I have attached at the bottom of this post are full size pictures of the compression cartridge if you want more of an idea of where these holes are located.
Now those of you who have read the go-ride article on the 888, will know that marzocchi makes an adjuster that allows you to cover combinations of these holes - but after pricing it up it came to about au$80-90. Stuff that!
So I decided to make my own.
I started with a 55mm length of 20mm OD PVC piping (actual OD was 19.5mm) and the ID was roughly 15mm. Now the 888 cartridge has an OD of approximately 17mm, so it took some filing to get the inside of the PVC down to the right size - the trick here is to get it so it will slide on fairly tightly and not loose, as that is how it will stay on. I put my round file in an electric drill to get most of it shaved out and then did the rest by hand, checking for fit on the cartridge often. The finished product was 44mm long, but start with 55 so you have more to play with later.
I drilled 3 different sets of holes in the sleeve to give me 3 different settings (better pictures of the sleeve alone are attached at the bottom of the post). I found covering only the small lower holes just made the fork ramp up quicker (ie: not much use), so covering the two large upper holes is the way to go. My advice would be to use that (Setting 1) as a starting point and go from there.
The diagram shows which holes are covered on the compression cartridge for each setting, and the photos below them show the real thing.
Left Cartridge
Right Cartridge
Sleeve
Set Up
I ran it in "Setting 1" for about a month, and it was definitely an improvement over stock but not a huge difference. My fork setup then was Motul Factory-Line 7.5wt, 220ml per leg, and the compression knob wound pretty much all the way in. The fork wasnt blowing through it's travel too much but there was still a bit much dive when cornering hard. An important side effect to note when using a compression sleeve is that it will affect the bottom out resistance. I found I was only using 180mm of travel, so the plan was to drop the oil level next time.
I've just changed it to "Setting 3" today, which closes 4 of the 5 holes, and dropped the oil level to 205ml per leg. Just pushing on it on the driveway the difference isn't huge, but once you start moving and cornering at speed you start noticing a big difference. The fork stays higher in its travel and doesn't blow through nearly as many inches. I'm yet to hammer some DH runs with it but this seems to be the ticket. I'm still running the compression knob wound all the way in but if I feel there is too much damping i'll back it off a bit.
I believe treggs is running 10wt in the compression side instead of 7.5wt, and he is running the equivalent of "Setting 2" (2 large holes and 1 small hole covered) - apparently it works quite well. I think 7.5wt is fine for my weight (~60kg) but for a heavier rider the 10wt in the compression side would give you more damping again.
That's it for now.
Feel free to PM uDi if anyone wants more details.
A big thanks goes out to treggs on here - he was the first one on here to do the mod to my knowledge, and a bit of inspiration goes a long way.
--Udi
Monster T
Monster T exploded diagram - Cave Dweller
IS here: http://forums.farkin.net/attachment.php?attachmentid=25190
Spring Rates - Cave Dweller
Spring length is 320mm
Green = stock springs in 99-02 monsters = progressively wound springs, start at 2.5 kg/cm and ramp up to 3.5 kg/cm (14lbs/inch to 19.6lbs/inch)
Yellow = Soft = 2.5 kg/cm (14 lbs/inch)
White = Medium = 3 kg/cm (16.8 lbs/inch)
Blue = Firm = 3.5 kg/cm (19.6 lbs/inch)
Red = heavy = 4 kg/cm (22.4 lbs/inch)
Cave Dweller's Air Sprung Monster Mod
I have been toying with the idea for a while to air spring my monster to shave some weight. There is various ways to do this, drilling in air valves into the cap of each leg is one (like zedros shiver), making some volume reducers like in 888's is another, and the other mod is to completely remove one cartridge of the fork and air spring it. The later is what i have done here.
NOTE:- If you do this i accept no responsibility for your actions, infact, don't do this, it will probably wreck your fork.
First step is to remove the entire cartridge, spring and spacers from one leg. This leaves a hole at the bottom. Get a bolt, stick it in there and put the foot nut back on the bottom. The bottom of the fork leg is now plugged and won't allow oil out.
Next, go to your local tire shop and ask for a tubeless car valve, they cost $5. Stick it into the hole in the valve cap that used to let the cartridge/preload/rebound adjsuters through. Fill the leg with 50-70ml's of oil to allow for lubrication.
NOTE:- there will now be nothing holding this leg together as you have removed the cartridge, it will be held together by the other leg and crowns. So, remeber that you need to release the air pressure from the fork before you undo the tripple clamps otherwise you will end up with a stachion rocket
Open up the other leg and drain the oil out. You will need to put a heavier spring in to compensate as you will only be running one spring, not two. You will also need to put heavier oil in to help slow down the rebound, stock it is 7.5wt, i mixxed up some 12wt oil and put it in, i set the oil level 10-15mm higher the the marzocchi recommendation to help with bottom out resistance. Put it back together and bobs your uncle, air sprung monster
Not sure of the air pressure, i am putting in between 15-20 pumps of my bike pump. Seals are holding the air fine, minimal leakage over the week just gone by.
The fork rides almost the same, slightly more harsh over small bumps due to the air pressure, but it doesn't bottom at all, and the rebound is fine, no nasty top out clunks. Biggest difference is the reduced weight, this has saved around 1.5lbs from the fork making it around 8.5lbs, the fork also feels alot more responsive, probably from the reduction in unpsrung mass.
Picture of modded top cap.
Shivers
Spring Weights - Cave Dweller
Spring length is 334mm
Soft = 2.7 kg/cm (15 lbs/inch)
Medium = 3.2 kg/cm (18 lbs/inch)
Firm = 3.7 kg/cm (21 lbs/inch)
Exploded Diagram
02 Shiver DC dia. attached below
Attachments
Last edited:
