05 M1000S fork rebuild

[chris1044]

After two years of just riding it I'm finally getting back to working on it....I've got springs for my weight and plan to swap them in.  While I've got them apart though, I'm debating on doing the oil and new valves/shim stack.

1) Stock weight oil - any clue on what it is?
2) Oil height - any recommendations?  I'm roughly 190 dressed
3) Seal/valve/stack work - how difficult is this?  Special tools needed?  Race tech parts the way to go?

If I can rebuild an auto trans without issue, I should be able to do forks without much issue.  I know the sag/compression/rebound adjustment routine, just looking for some input on mainly special tools and the difficulty.

[Ddan]

The valve replacement is pretty simple, setting the stack is a different story.  IMO you'd be far better off getting the valves done by someone familiar with the valve system you're going to use.  You might as well change the oil even if you're only doing the spring.  I'd guess it's  10 weight, but no idea on the level.  A seal driver is nice  but not necessary

[MonsterHPD]

if you can do the tranny work, you certainly can do the forks without problems.

If you want to improve the action of the forks, you need to go all the way and modify your forks as per my "Showa Blues" thread in the tutorials. I checked the Duc spare parts catalogue, and the 2005 Monster has the same part number forks as my 2002 900, so it has the same design problem. 

Oil weight for cartridge forks is usually around SAE5, SAE7.5 would be an absolute maximum. Cartridge forks are meant to have the damping set with the correct shim stacks, not by using different weight oil.

The oil level is more a matter of how much progression you want than what your weight is, and the Monster has progressive springs as well. I use 120 mm from the top with the fork leg compressed and no springs etc. in them. 

[chris1044]

if you can do the tranny work, you certainly can do the forks without problems.

If you want to improve the action of the forks, you need to go all the way and modify your forks as per my "Showa Blues" thread in the tutorials. I checked the Duc spare parts catalogue, and the 2005 Monster has the same part number forks as my 2002 900, so it has the same design problem. 

Oil weight for cartridge forks is usually around SAE5, SAE7.5 would be an absolute maximum. Cartridge forks are meant to have the damping set with the correct shim stacks, not by using different weight oil.

The oil level is more a matter of how much progression you want than what your weight is, and the Monster has progressive springs as well. I use 120 mm from the top with the fork leg compressed and no springs etc. in them. 

Thank you for the reply.  Your "showa blues" thread is most excellent.  I read it once, plan to read it multiple times more, and then perform the mods as I have access to all the equipment needed.

Between that and the race-tech book I've got, I think I should be good....we'll see in a month or so.

[MonsterHPD]

Thanks, glad you liked the "Blues", hope you'll find it accurate and helpful in the event.

I also have the Race-tech book; not the thing you can't put down but the best book on the subject of suspension I've seen and an absolute recommendation for anyone interested in learning about suspension.