Ducati Monster Forum

Over the last couple of weeks I've been learning all sorts of new things about front end dynamics, love this forum for that reason  [beer]

My 98 M900 has the adjustable Showas, however they're severely undersprung for my 210 pound self. I'd really like to get this sorted out one way or another and I'm seeking opinions on which way you guys would go. I should also say that I'm having difficulties getting my OEM calipers to work correctly, seems no matter what I do I can't get all the pistons to move at the same rate and it's causing "pulsating" when braking as well as decreased braking power.

Option 1: Purchase racetech springs that are sprung for my weight and just keep working on the calipers, withe the confidence that they'll eventually come around. Racetech springs are $114.99 I believe.

Option 2: Fit my bike with GSXR forks/calipers from around 2005-2008. To make this happen I figure:
  forks - $200
  calipers - $50
  rotor spacers - $13
  caliper spacers - $15
  brake line kit - $70
  pads - $50
  TOTAL - $398

Can anyone come up with a good argument to justify a $400 investment into option 2 over option 1? I'm worried I would still have undersprung forks with the GSXR's, however I've heard that the valving is much better, so that's a plus, and I would assume the calipers would be better.

Anyway, just brainstorming right now and I appreciate the help guys.

I also just looked and realized that racetech gold valves would be $169.99. So combined with the springs I'd still be far less than a conversion to a GSXR setup.

I should also add that I definitely do not have a money tree in my backyard.  ;D

you could upgrade your front calipers to sbk calipers as well

As in calipers from a 999 or something?

do you have the goldline 4 pot calipers? do you have the coffin master? if not mistaken, don't believe me, yoyodine has a rebuilt kit for these calipers but, on the master side, I would recommend an upgrade to a radial one, either accossato, brembo or why not, magura . . . and replace your lines, all of them . ..  

or as raux said, upgrade to 4/4 calipers, that is, 4 pot/4 pad . . ..

Yes I have the goldline 4-pots. I recently upgraded to a Nissin radial master.

Also, I've looked into the rebuild kit and they were like $60 per caliper I believe, IF they have them anymore.

then maybe, it would be time for either a rebuild or upgrade . . .

are you using your original rotors? are they clean?

is this happening after the accident?

if they have them, get 'em if you want to go this way

imho, is worth it

Woah, nvm, just the seal kit is $50 per caliper. If you find a kit with the pistons it's much more expensive, over $100 per caliper.

just get a very fine sandpaper, like 1200 and clean brake fluid to use to wet sand the pistons to clean them, this is how we 'refurbish' the pistons in the 3rd world . . . and no complaints up to now from no vehicle owner

Is it okay to remove pistons and then place them back in the original seals? I'm assuming yes.

take them out, replace seals . . . clean cylinders where pistons move . . .

Ugh, $50 per caliper for seals hurts...

beats new calipers ???

I suppose, yeah.

Can anyone give an opinion on if this is the route to go over a GSXR setup?

The Gen-1 Monster chassis' do not like larger forks than 41mm inverted units.  I've done some SBK fork swaps on customers Gen-1 bikes and the handling changes a good bit with the stiffer front end (as in the flex which used to be absorbed by the forks in now transferred to the frame and therefore felt by the rider).  Some of the customers didn't feel it, some did.

If you've got the adjustable 41mm Showas and they're in good shape, then my vote is to rebuild the forks first and then look into the brakes.  Upgraded rotors help and there are a LOT of different pad compounds out there for the Brembo 30/34 calipers.  Stainless braided lines are a MUST if you haven't done them...

Okay thank you.

Yeah it seems like I don't give enough credit to updated brake lines over the OEM ones, didn't realize they can make that much difference. Regardless of the lines though I still need to get my calipers moving the way they're supposed to. Also, I imagine severely undersprung forks can make braking power feel very limited, is this true? As in, the front end dips very hard under hard braking and so it doesn't feel as solid as it should.

don't forget to change out your steering bearings as well

I inspected those and re-greased them when I had it all apart. Did these things come stock with tapered bearings? If not, some previous owner had some put in.

Crappy fork springs/damping for your weight really upset the bike under braking. All the unsettled front end feedback can be confusing re your brake issues.

Having your forks set up with correct springs and damping for your weight is one of the best investments you can put into your bike. With that sorted you might better feel what the brake issues are.
That said, +1 on braided lines and good pads being important upgrades. I also got 999/S4RS radial master cylinders and that made a big difference to feel. I run the older 4 pot  2 pad Brembo calipers and I am very happy with the combination. Your 4 pad calipers should give more bite than mine, but mushy brake lines, unsuitable or contaminated pad material and issues with your master cylinder could undermine that.

FWIW, I have a K4/5 Gixxer 750 track bike. The Previous owner had soft fork springs, bad brake fluid (probably badly bled) and the wrong pads in it. The brakes and front end felt like crap. Had correct springs and valving for my 210 riding weight fitted by a good suspension guy and I changed the fluid (with careful bleeding) and selected appropriate pads and they're great.

Very interesting comment on the 41 Vs 43 mm forks issue re feel and feedback. My brother and I both have noticed a big difference in chassis/front end feel and feedback between his 2001 M900 and my 1995 M900.

I agree getting the correct internals for my forks will make a world of difference. That said, I KNOW that my calipers are causing my "pulsating" feeling while braking. I go through the process of cleaning the pistons, getting them behaving the best I can, and there is definitely less pulsating effect afterward.

I have the same 2 pad calipers as you, with Nissin radial masters.

Cool, according to your track bike account it seems I would have to respring GSXR forks if I were to go that route anyway. I believe the K4/5 series forks are the "vintage" I've been researching as possible replacements for mine, so that's very good to know.

Where is fork diameter measured? The upper triple area?

My apologies, I misread (it's 5am), and thought you had upgraded to 4 pad calipers. Of course you would need adaptor plates (or later forks) to mount 65mm 4 pad calipers off a 999.
You will love braided lines with a radial m/c.
What shape are your discs in?

At the hardchromed part. As a 98 model yours are 41s oem.

My discs appear to be fine. I don't have any real experience with telling if they're wore out. I seem to remember reading that 4mm is the minimum for material width on these rotors? Well they're thicker than that. Never feel a wobble or shudder or anything so I don't think they're warped.

It's a finer point, but the '01 was the only frame with the larger tubes, 12mm engine bolts, 43mm forks AND the hoop rear suspension. 

After riding (and owning) many 2002 & up Monsters, an 848 and now a '99 framed SS1000 I can notice a HUGE amount of frame 'wiggle' on a friends '97 when I take that for a toodle.  Not that it's a bad handling bike, just that I will NOT push that chassis like I used to when I had my '99 M750.  But, that's just me.  YMMV...

Just got the Racetech springs installed, correct for my weight. Just from the short ride I took on them tonight I can already tell this was probably the best mod I've done to my bike. Braking confidence is through the roof in comparison to the old springs.