Fork Suspension Upgrade/Rebuild 2001 M900 S

[diamonddog-2]

Sorry if this topic has been done to death. I looked around a little but didn't see a thread for this specific subject.

Now that I have a direction for the rear suspension, [thank you] I'm wondering about options for the front. I've read about the stock Showa and it's shortcomings and I can feel it's lacking. I can't afford a Ohlins and am not sure about the degree of difficulty surrounding swapping out different, "superior" forks off of a Honda, Kawasaki etc. sport bike, as well as the expense. However, with 31K miles on the bike, I think the forks need some work.  Any suggestions?
I believe I could rebuild the current ones.  It's affordable and doable for my skill set....with adult supervision.  I've done simple fork maintenance before but not on inverted. Anyway, is it worth it to do a rebuild or am I just putting lipstick on a pig?....[go back to above "different forks"?]
I've read about rebuild kits from Race Tech. I was wondering what is generally thought of them and the end result.  How complete is the kit?  Would I need to get new fork and dust seals as well?  New fork bushings or are they included in a kit?  What kind of fork springs are suggested to get?  I know Progressive and Race Tech have some available for my bike.  A while ago, somebody on the discussion board mentioned something about a linear spring [I may have that term wrong?] or something like that.    With a updated/upgraded fork kit, would I still use the same viscosity oil or something different?
Any special "must have" tools for the job?

Again, thanks to all.

[ducpainter]

Many will disagree, but for your riding, I think a rebuild along with a gold valve upgrade, and spring change for your weight, for your riding parameters, you'll think you're riding a different bike.

The upgrades you're planning for the rear won't be as effective if you ignore the other end.

[koko64]

+1
My old M900 I recently purchased came with a revalved/resprung front end (non adjustable Showa) and an Ohlins DU440 out back. It handles great, very poised, taut and planted, yet supple enough for our crappy canyon roads.

[diamonddog-2]

Thank you ducpainter and koko64.      Does anybody have any idea how complete the Race Tech rebuild kits are?  [I've not seen any other kit brands for sale]   I don't know if they come with new fork and dust seals or do I need to get them?, as well as new bushings, separately?

Any thoughts on either Progressive or Race Tech springs? .... or something else?     Stay with Ducati suggested OEM oil weight for the fork?

Ya know, I figured this is THE bike I'll have for kickin' ass on the twisty roads or sweeping curves ... and for gettin off the line! .... and I'll have for as long as I can. It's worth putting time and a few bucks into trying to bring out the best handling characteristics that it can have on my budget.     New tires are coming next.

Blessings upon you all 

[koko64]

Cheers.
It's  worth taking off the forks and shock and taking them (or sending them) to a pro suspension guy. If an aftermarket shock is out of your budget you can get it custom revalved and re-sprung to your needs and weight. It's important to communicate well with the suspension guy about your needs.
The change is night and day.

[Howie]

Cheers.
It's  worth taking off the forks and shock and taking them (or sending them) to a pro suspension guy. If an aftermarket shock is out of your budget you can get it custom revalved and re-sprung to your needs and weight. It's important to communicate well with the suspension guy about your needs.
The change is night and day.

Yep, the magic is in the shim stack.  The specialist should interview you and take a peak at your tires.  Plus Race Tech's recommendations are a bit off the wall.  You are paying mostly for the knowledge.  Nobody near you, well he can't look at your tires, but he will make you happy.

http://www.ducatimonsterforum.org/index.php?topic=18933.0

[MonsterHPD]

Well,
the topic may have been done to death, but everyone has to start somewhere.
 
Basically, it all depends on how much money one wants to spend, and how much work one is prepared to do.

With 31K miles in the forks, I would definitely change seals, dust scrapers and bushings, and give the fork a thorough clean-up, inside and outside. Personally; I would also pull the cartridge apart and clean everything up, but since you need to drill the dimples locking the lock ring in place, this is a little bit more involved. At least clean it out with thin damper oil or something.
I use SKF fork seals and dust scrapers for any fork I do, seems to be working really well.

As far as modifications go, the springs are definitely the right place to start, the 2-stage stock springs are ridiculously soft initially, then getting pretty stiff late on.
Acc. to the Duc owners handbook, the 2001 M900 has 43 mm stanchions, meaning there are a lot of springs that will fit (the 41 mm forks are much worse for springs). I use 240 mm long Öhlins springs which are available in  0.5 N/mm steps from 7 to 11 or so N/mm. To compensate for the difference in length, I make some spacer tubes from 2mm wall thickness alu tubing which I put at the bottom of the fork, same system as the SBK forks use; you also need the SBK fork washer between the spring and spacer for the spring to rest on.

Modifying hydraulics are a bit more complicated, in my opinion (and experience) putting in a shim-and-piston kit will bring nothing unless you modify the rebound circuit. However, I think Brad Black concluded in one of his blog posts that using very thin oil, allowing the rebound adjuster to be in a more closed position, does improve compression incrementally, but I have not tried that.

Modifying the rebound circuit (to get the compression circuit to work properly) is possible, but not quite cheap, and requires some workshop facilities.

Dropping in a cartridge from a GSXR Showa is also a possibility:
http://bradthebikeboy.blogspot.se/2014/07/gsxr-fork-cartridges-in-41mm-showa.html

.... as is a complete GSXR fork swap (several threads about that on this forum).

Oil level, BTW; I usually start at 120 mm (forks compressed, no spring or spacers).    

I think that doing the servicing with new seals, bushings and oil, and proper springs will be a huge improvment. Any more that that is quite a bit of work and expense, and something you can decide on after testing the "Stage 1" service / upgrade.

       

[ducpainter]

I'm no expert.

I have an expert do my suspension work.

You should too.

I can recommend one if you're willing to ship.

[diamonddog-2]

Thanks everybody. It sounds as if the Race Tech kit to rebuild the front suspension is best left to experts?    I've done service on traditional upright forks [oil, spacers, springs, seals] and think I could handle that level of service, including new bushings, on these Ducati inverted forks.  Of course, I didn't have to remove the forks on other bikes so this will be a bit of an ed-u-ma-cation.

So... if YOU guys are saying that you'd leave anything more than the oil, springs, seals, etc. to a suspension expert, well, so be it!  I don't need to get in over my head and lay awake at night AND end up with sh*tty suspension.

Just to be clear:  the consensus is that changing the springs, seals, oil, bushings is still going to greatly [or at least noticeably]  improve the suspension without the rebuild kit?....and is well worth the effort without the kit?  .... or for sure have them rebuilt with a kit, new gold valves, etc?   I would be willing to remove them and ship to a guy who knows how to do it right IF that's the way to do it.   Any idea what somebody might charge to do a thorough rebuild?   I did get the contact info on Eric @ Clubhouse Sports, thank you!

...as I tell people around me: "explain it like you're talking to a 10 year old and we'll be fine"

[Howie]

No doubt you can handle the work yourself.  Like I said, it is in the tuning.  This is where Eric comes in.  He will get those forks best as possible without going for high bucks upgrades like the K5 valves, Ohlins RTs or a Superbike fork upgrade.  Hmmm...GXSR cartidges.

[ducpainter]

Call Eric...be prepared to spend some time on the phone. He'll give you accurate information, and recommendations.

My opinion is that stock forks are undersprung and over damped for the average person. Go for the gold valves and straight rate springs, or a gsxr conversion. The bike is plenty powerful. The most effective upgrades are suspension.

[diamonddog-2]

Thanks again guys. I sent Eric an email inquiry and also sent one to a local Ducati guy who's known for dyno tuning. Maybe he's a suspension guy too?

So NOW I think I get it. Eric [or somebody else] has a conversation with me about my specific needs, possibly builds the correct kit based on that information [NOT a Race Tech off-the-shelf kit?] and then I purchase the kit from him and install it.... or send him the forks if I'm not comfortable with the project?   or he points me in the right direction for a kit?

I agree with you ducpainter, other than dialing it in, the engine is just fine for me.  If I wanted THAT much more power I'd get a different bike.  For me, expensive engine work isn't on the list of things to do to this beautiful monster.

[koko64]

 

Sending the forks can save a great deal of time tuning and testing them. An expert will return them 99% correct rather than having to remove them, work on them, reinstall them and test them again a few times until its what you want. If you want to get into this stuff and have the time then go for it. I have tried it and had the forks off and on 3-4 times before I got it right-ish. I figured it would be more cost/time effective to pick up an extra shift or two at work and just pay the man.
If the main components arrive all set up and all you have to do is complete assembly, set oil level/air gap and install and test then maybe its worth it. Depends how much money you save, how much time you want to save or how much you want to learn.

[diamonddog-2]

koko64, I gotta admit I'm a little on the fence about doing the job myself.

It sounds like, in order for the suspension to be set up as well as possible, somebody with a sh*tload of experience should be involved, either just turning the forks over to them or somebody pulling together a rebuild kit - specific to my riding and weight?

New springs, seals, bushings and oil just wouldn't be enough?

[koko64]

That's correct. Having the forks set up and tuned to you the rider is all the difference. When the bike is set up right it's amazing how fast and how safely you can go through corners. The gain in confidence and feel of what the tyres are doing is huge. Emergency moves in traffic become safer too.