M900 Forks - overfirm?

[Goofle]

The forks on my 1993 Monster seem very hard, almost jarringly so. As they need new seals anyhow prior to the mot is there an mod I can I do / fit to make them a little more comfortable? Or am I just used to the armchair ride that is my zzr and I need to zip up my man up suit??
Thanks!

[Stafford]

I thought the M900 had adjustable preload, rebound etc?

[Mr Gazza]

Somewhat predictably..! I would suggest that if the seals are due for replacement, then the internals of the forks could well be due for a service also.

I often find that a good clean of the internals and some new fork oil, works wonders.

Sometimes a change to a thinner damping oil helps things, but generally just new stuff will do the trick.

I think the '93 might not have adjustable settings..Not sure.. But if any of the little holes or valves inside are gummed up with sludge they will not work properly.

If they are adjustable, you may find a small cylinder at the top of the damper rod. This is the cartridge. Don't attempt to dismantle that. Everything else is just cleanable unless excesive wear is seen....have fun.

[DrD]

Early M900 are none adjustable other than springs, oil weight and oil level.
There are a few threads around on upgrades (not cheap)

[Goofle]

There's no adjustment on it...

[Goofle]

I was thinking along the lines of keeping the original forks rather than swapping for a adjustable set.
I sent a shock off and got it rebuilt. It wasn't particularly cheap (it was 20 years old and looked like the original) but I'm considering this may be way forward, although I don't think fork servicing is massively tricky?

[Kato]

I thought the M900 had adjustable preload, rebound etc?

Early M900 are none adjustable other than springs, oil weight and oil level.
There are a few threads around on upgrades (not cheap)

Both correct and both wrong;)

As with anything Ducati it depended on the day of the week, as the early bikes were using a lot of 888/851 parts bin leftovers some had adjustable forks and some did not it just depended on what came down the assembly line when being built, the only certainty is that only 900's came out of the factory with these forks even though 600's & 750's were built on the same line, the adjustable forks ran out circa 1998

[DrD]

I was thinking along the lines of keeping the original forks rather than swapping for a adjustable set.
I sent a shock off and got it rebuilt. It wasn't particularly cheap (it was 20 years old and looked like the original) but I'm considering this may be way forward, although I don't think fork servicing is massively tricky?

If you ask Maxton, they might tell you otherwise!
We convert your forks, but not by modifying the existing internals. We throw everything inside the fork away and start again with our internals.

The internals we supply is our own GP20 cartridge style damping system.
The cartridge system is the same type of internal as what you would find in any modern front fork. It has been manufactured and developed by our own engineers and has pistons and shim stacks for the rebound and compression damping. The Cartridge also has needle valves so you can adjust the damping. The damping adjusters are external, so you can change the damping without having to strip the forks down, but we hide the adjusters to keep the classic appearance. As part of the conversion we also machine new fork tops to take the new cartridges and damping adjusters. We also fit new springs.

Every Maxton GP20 cartridge is built to order, the reason for this is to valve and spring the cartridges to suit the fork, the bike, the riders weight and what they are using the bike for. Once the cartridge has been manufactured we then fit the cartridge to the fork to make sure it works correctly. In most conversions we have to modify the original bottom sliders and stanchions so our cartridge will fit and work properly. The forks are then returned to you fully serviced with new seals and the spring preload and damping set up.

The Maxton GP20 cartridge costs between £340.00 and £640.00 + V.A.T.
Depending on how adjustable you want the cartridge to be.

- For £340.00 + V.A.T the cartridge is adjustable for rebound damping.

- For £440.00 + V.A.T the cartridge is adjustable for rebound damping and preload.

- For £540.00 + V.A.T the cartridge is adjustable for rebound and compression damping.

- For £640.00 + V.A.T the cartridge is adjustable for rebound and compression damping and preload.

To service the forks with new seals and install the cartridges costs an extra £140.00 + V.A.T on top of the cartridge.

All adjustments can be made without having to strip the forks down.

[Pedro]

You can find Hyperpro progressive springs on eBay, I have them in my 93 900. It's not fabulous but much better than stock. I think I used lighter oil as well.

[Goofle]

I have to honest and say I can't see me spending £600 plus on a rebuild...
I'm not actually bothered about adjustability to be honest!

[Mr Gazza]

Sounds like a good clean out is the way forward then..?

Paraffin is said to be the best thing to clean the bits with...Never used it myself.

Try a slightly lighter oil than recommended as standard, but use the correct levels.

I saw multigrade fork oil for sale in Halfrauds recently...WTF is all that about? How can a fork oil be multigrade??

[Flip]

You also need to remember that they fitted both Showa and Marzocchi forks to the 900 and only springs etc. are available for the Showa units so if you have the latter then it is either a complete fork upgrade to some adjustable units (which apart from the 888 ones will be over sprung too) or giving them to someone like Maxton (who do amazing things with them if my little race bike is anything to go by) or Mark at MH Racing or one of the reputable suspension specialists around or go the K-Tech/Hyper-Pro route and replace the internals yourself.

[Wasta]

Performance Bike magazine have been doing a feature on Rupert Pauls 900ss. He is working with Gareth from Reactive Suspension near York.

The results are quiet shocking (ha ha) It appears that neither the Showa or Marzocci are much good. The shim stacks don't work the needle valve is all wrong etc etc.

Sadly I left the mags in Kuwait but I could scan the last issue if anyones interested.

[Dukedesmo]

Whilst researching rear shocks for mine I found the following info regarding M900 suspension from Maxton;

"DUCATI 900 MONSTER

FRONT

The forks feel very notchy and harsh and kick off small bumps, this is
because they have too much compression damping over small
movements, however when you brake very hard you may be able to feel
the forks bottom out, this is because there is not enough support in the
compression damping over large movements. The other problem with the
damping is there is not enough rebound damping which means when you
let go of the brake the forks spring back at you and the bike does not turn
into the corner as well as it should, this also causes the bike to run wide out
of a corner. The springs inside the forks are actually too hard and we fit
softer springs to suit your rider weight and also to suit what type of riding
you do. The biggest improvement we carry out is revalving the cartridges
of the forks increasing the rebound damping to control the forks
extension, reducing the compression damping over small bumps to stop
the forks kicking off small bumps and increasing it over large movements
giving more support with the spring. The conversion costs £300.00 plus
worn parts i.e. Seals - £24.00 and Bushes - £24.00. A service on the forks
would cost £100.00 plus worn parts. ALL PRICES EXCLUDE V.A.T.

REAR

We cannot modify the standard rear unit, it is a fairly cheap shock and the
spring is slightly too soft, but it is not worth changing as it will not make the
bike perform any better. The only thing we can offer is a replacement
Maxton high pressure gas shock cost £405 plus VAT and carriage."

[jerry]

I have seen factory M900 showa forks with 10nm springs much too hard and others with 8.5nm or 9nm much more compliant ,, 5w oil helps

[perkles]

Mine have adjusters on the top ,what type are they ?

[Flip]

I have seen factory M900 showa forks with 10nm springs much too hard and others with 8.5nm or 9nm much more compliant ,, 5w oil helps

That doesn't surprise me at all, as Kato says it really depended what day it was as to what parts came along in the trolley to build the things back then.


Perkles-
Men (I presume you mean 'mine') have adjusters on the top ,what type are they ?

It depends if they are kind of flat blue plastic thumb wheel type adjusters or if they are metal ones with a brass slotted screw adjuster?

[Martin C]

My 1994 M900 has the earliest type, non-adjustable Showa forks, which were always way too firm. They had recently started to leak (at 30K miles), so yesterday I replaced the seals & bushes and fitted a Hyperpro progressive spring & oil kit. The Hyperpro spring/oil kit was £118 from The Sports Bike Shop (highly efficient online service), and as I live near the very helpful & knowledgeable K-Tech Suspension I popped over and bought all the seals & bushes from them for £67. It's a bloody great improvement, the bike handles far better at higher cornering (& straight line) speeds on the bumpy lanes of South Derbyshire and feels much safer when braking hard - and i can even ride straight across speed-humps now! I mostly followed my Haynes Manual, which was almost entirely correct, but I used Hyperpro's specified oil level. Both of the (original factory?) oilseals had been installed by a ham-fisted bodger who damaged them, and I also had to drill out & salvage 3 of the 4 mudguard bolts which were seized solid. Total cost £185 plus a day of my own labour - all very well spent! My solo fortnight riding around central Portugal in a couple of weeks will be even more enjoyable than last time!

[Islander]

That doesn't surprise me at all, as Kato says it really depended what day it was as to what parts came along in the trolley to build the things back then.


Perkles-
Men (I presume you mean 'mine') have adjusters on the top ,what type are they ?

It depends if they are kind of flat blue plastic thumb wheel type adjusters or if they are metal ones with a brass slotted screw adjuster?

I'm also interested in this. Mine have the brass slotted screw adjuster - what type are they? I can't find a guide to this anywhere!

[Mr Gazza]

My 1994 M900 has the earliest type, non-adjustable Showa forks, which were always way too firm. They had recently started to leak (at 30K miles), so yesterday I replaced the seals & bushes and fitted a Hyperpro progressive spring & oil kit. The Hyperpro spring/oil kit was £118 from The Sports Bike Shop (highly efficient online service), and as I live near the very helpful & knowledgeable K-Tech Suspension I popped over and bought all the seals & bushes from them for £67. It's a bloody great improvement, the bike handles far better at higher cornering (& straight line) speeds on the bumpy lanes of South Derbyshire and feels much safer when braking hard - and i can even ride straight across speed-humps now! I mostly followed my Haynes Manual, which was almost entirely correct, but I used Hyperpro's specified oil level. Both of the (original factory?) oilseals had been installed by a ham-fisted bodger who damaged them, and I also had to drill out & salvage 3 of the 4 mudguard bolts which were seized solid. Total cost £185 plus a day of my own labour - all very well spent! My solo fortnight riding around central Portugal in a couple of weeks will be even more enjoyable than last time!

Blue Peter badge for this one Martin....Ace tip.

Sounds like a really good value for money tune up.

Perkles.. I think the man adjuster you are refering to is a Bra.?

[jerry]

Performance Bike magazine have been doing a feature on Rupert Pauls 900ss. He is working with Gareth from Reactive Suspension near York.

The results are quiet shocking (ha ha) It appears that neither the Showa or Marzocci are much good. The shim stacks don't work the needle valve is all wrong etc etc.

Sadly I left the mags in Kuwait but I could scan the last issue if anyones interested.

Standard M900 and S4 forks are crap ,the needle rebound circuit on the fork top is a dummy ,,,,,,, I replaced mine with 996 superbike showa forks with a real rebound circuit with Ktech valves and custom 7.5nm ktech springs ,, now the bike is brilliant

[perkles]

Blue adjuster on mine :)

[SteveG]

Blue adjuster on mine :)

Same with mine Perkles I believe the Blue adjusters are Rebound on the Right Leg, Compression on the left. The standard setting is 7 clicks out from full clockwise according to the manual I have. I've set them on standard. Not tried fiddling with them.

[Flip]

Same with mine Perkles I believe the Blue adjusters are Rebound on the Right Leg, Compression on the left. The standard setting is 7 clicks out from full clockwise according to the manual I have. I've set them on standard. Not tried fiddling with them.

Spot on Steve and you and Perkles have Marzocchi forks. To be honest fiddling with the adjusters will make very little (if any) difference to the feel, in addition to this there is no pre-load adjustment either and no spring kits available so apart from positioning in them differently to give you slower or faster steering response all you have to play with is oil weights.

The forks with brass slotted screws on the top (there should also be some other adjusters on the lower fork too) are Showa and depending on whether you have a hex adjuster too will mean whether you have pre-load adjustment also.

[Darren69]

Adjustable Showas. They're the same as on the 900ss 750 too as I recall.

http://www.ebay.co.uk/itm/DUCATI-900ss-FRONT-FORKS-PAIR-STRAIGHT-1994-BIKE-/271459353575?pt=UK_Motorcycle_Parts_13&hash=item3f343d03e7

[Flip]

Adjustable Showas. They're the same as on the 900ss 750 too as I recall.

Yes I think the Showa units were the same as those fitted to the SS's but as previously mentioned it is not always as easy as that as it depended on what was on the parts trolley when it came to suspension on early bikes meaning some Showa equipped bikes have the full adjustment on the top and others have plain caps and only the lower adjusters.

[Islander]

Thanks folks. Mine have both screw and hex adjustment. I'm happy with that.:spin:

[chris.p]

A full rebuild to suit your weight etc is not that cheap, but will transform the bikes handling, most of the above posts give you the details for getting them sorted, just your choice of who to use.

A cheaper option is to get the sags checked (see the attachment) as Jerry mentioned and I would recommend is to get 8.5nm or 9.0nm fork springs. Start with an 20mm air gap when you rebuild them. Put a tie wrap round one of the fork legs, take the bike out and do some heavy breaking, what you do next depends on what the gap is below the tie wrap, if it is more than 15mm increase the air gap in the forks and then repeat till you have a gap under the tie wrap 15mm ( you can go under this but a gap of no less than 10mm is recommended).

http://www.ducatisportingclub.com/attachment.php?attachmentid=10452&d=1237678306

[Flip]

take the bike out and do some heavy breaking

Please build up to this steadily on a quiet piece of well surfaced road as to adjust the air gap by this method takes a bit of doing. As Chris (rightly) says ' do some heavy braking' it needs to be on the 'bloody hard' side of heavy braking 'else when it comes to a time when you really need to brake hard and you have not gone hard enough to reach your setting you will run out of suspension travel and once the suspension is locked solid with no more travel there are only two outcomes- One: You've slowed down enough to have avoided the problem. Or Two: The front tyre's locked and you're looking at the sky wondering what happened.

[Drumnagorrach]

I recognize a few of the symptoms Maxton mention, the running wide out of some corners. I was going to ask about sliding the forks down 15 mm and raising the rear to get my m900 IE to turn in a bit sharper.
I have a concern that raising the rear will bring my chain into contact with the swinging arm wear strip .
I liked the handling of the Buell M2 I used to have,the Monster is similar but requires more effort to turn in on corners The Monster fork angle doesn't look as steep as the Buell hence wondering about lifting the back or lowering the front, Don't want to reinvent the wheel ,I'm sure someone knows ,ANY IDEAS ?

[Flip]

I have lifted the rear (ooo-errr) and dropped the front on my 900 to reach a point where I am happy- it gets a little frisky on very rough country roads but by then I should know better!

But it is a revelation to how it came from the factory.

Personally I would get the static and dynamic sags as close as you can on whatever suspension/spring rates etc. you have.

Then assuming your tyres are not less than half worn (the rear will be squared off too much otherwise) I would start by raising the rear (how you do this depends on the suspension you have- 'Hoop' or RR linkage) as this way you won't compromise any ground clearance which is already a little limited (take note anyone with scrapes on their exhausts) and should result in helping with the under steer you are experiencing by the bike wanting to push wide.

If after that you was faster steering still then drop the front by pulling the forks through the yokes 5mm at a time until you are happy.

Ideally ride the same piece of road in both directions with each adjustment. The first at a 'normal' speed and then a more 'enthusiastic' one.

[Dirty]

Even I noticed a difference when I jacked up the ass of mine (bigger ooooerrrrr :)) and I'm very much the novice when it comes to bike handling.

[chris.p]

I recognize a few of the symptoms Maxton mention, the running wide out of some corners. I was going to ask about sliding the forks down 15 mm and raising the rear to get my m900 IE to turn in a bit sharper.
I have a concern that raising the rear will bring my chain into contact with the swinging arm wear strip .
I liked the handling of the Buell M2 I used to have,the Monster is similar but requires more effort to turn in on corners The Monster fork angle doesn't look as steep as the Buell hence wondering about lifting the back or lowering the front, Don't want to reinvent the wheel ,I'm sure someone knows ,ANY IDEAS ?


Before you start altering the geometry of your bike, get the sags checked first to see that you have the right springs in, a bike that is too soft at the rear will make the bike run wide on exit, and visa versa one that is to hard at the front will also make a bike run wide on the exit of the corners.

Once your suspension is correct, then you can alter the geometry of your bike.

[Flip]

Before you start altering the geometry of your bike, get the sags checked first to see that you have the right springs in

Which takes us back to the subject of the thread...the fact that almost all Ducati's are over sprung (for most people).

But it still possible to get the bike to 'turn better' by altering the geometry on standard springs once the sags are as close as you can get them on what springs are fitted. it will then start to show up that you do need to delve deeper into the world of spring rates and oil weight to get it perfect for you and it's intended use.

[Drumnagorrach]

Which takes us back to the subject of the thread...the fact that almost all Ducati's are over sprung (for most people).

But it still possible to get the bike to 'turn better' by altering the geometry on standard springs once the sags are as close as you can get them on what springs are fitted. it will then start to show up that you do need to delve deeper into the world of spring rates and oil weight to get it perfect for you and it's intended use.

I had to soften off the rear spring to give my 70kg weight any static sag at all, when i got the bike it didn't budge when I sat on it and subsequently the ride was awfull on Aberdeenshire/Morays tarmac over cart track roads. My forks are too hard also ,but they will have to wait till winter when I will dismantle and fettle. i think my 2002 M900 ie has bargain basement suspension, correct me if I'm wrong ,only good bit (i think) is the swinging arm /shock set up same as S4.Having said that it handles well,I just want it a bit sharper at turning in ,don't want to work so hard at laying it down.
Thanks for the feedback.
Lee

[chris.p]

Which takes us back to the subject of the thread...the fact that almost all Ducati's are over sprung (for most people).

But it still possible to get the bike to 'turn better' by altering the geometry on standard springs once the sags are as close as you can get them on what springs are fitted. it will then start to show up that you do need to delve deeper into the world of spring rates and oil weight to get it perfect for you and it's intended use.



altering the geometry with the wrong springs may improve the handling, but all it will be doing is masking the problem and could ultimately lead to a smaller window of safety.

[Drumnagorrach]

So this lifting of the rear,it looks like just lengthening the rod that connects the top bell crank to the shock top,ees correct yes ?I don't suppose it's engineered with left and right threads as in a turnbuckle , that would be too easy ?
Lee

[Dirty]

You can lift it a bit via the rose joints.

[chris.p]

Two rose joints at the bottom, also you can get two extenders for those rose joints, this is what the riders Desmo Due race series do.

[Langy]

Just take it to MCT. He transformed my suspension on an original yellow hoop. Stunning work

[Flip]

So this lifting of the rear,it looks like just lengthening the rod that connects the top bell crank to the shock top,ees correct yes ?I don't suppose it's engineered with left and right threads as in a turnbuckle , that would be too easy ?
Lee

Yes pretty sure they are but I think you can get a proper adjustable rod

You can lift it a bit via the rose joints.

Not sure by how much though- you'd have to take them out to check the length for safety and make sure there is a lock nut fitted.

Two rose joints at the bottom, also you can get two extenders for those rose joints, this is what the riders Desmo Due race series do.

That'll be the early hoop type that you can get the extenders for not for the later bikes with a single linkage rod

Just take it to MCT. He transformed my suspension on an original yellow hoop. Stunning work

Do you know exactly what he did?

I suspect he simply wound out the rose joints to raise the rear up which will improve the turn in and stop the horrible understeer feeling of the original full wound in position- unless of course you are also running a better rear shock?

[Darkness]

Which takes us back to the subject of the thread...the fact that almost all Ducati's are over sprung (for most people).

But what about the less svelte of us?

[Flip]

But what about the less svelte of us?

Well with the early bikes in particular it is worse as the suspension is so budget, meaning that even if the spring rate is right for you the damping is so rubbish it still won't feel good and then add to the mix that if a bike is still running the original set up it is all getting rather tired.

This of course is compounded if you happen to have Marzocchi forks up front (as my 900 has) which work in a rather odd way with one 'controlling' the compression and the other the rebound damping which is why Maxton rip out the internals and after machining the insides to suit, fit their own complete cartridge units.

This is what they have to say about what and why:

"The forks feel very notchy and harsh and kick off small bumps, this is because they have too much compression damping over small movements, however when you brake very hard you may be able to feel the forks bottom out, this is because there is not enough support in the compression damping over large movements.

The other problem with the damping is there is not enough rebound damping which means when you let go of the brake the forks spring back at you and the bike does not turn into the corner as well as it should, this also causes the bike to run wide out of a corner. The springs inside the forks are actually too hard and we fit softer springs to suit your rider weight and also to suit what type of riding you do.

The biggest improvement felt is from increasing the rebound damping to control the forks extension, reducing the compression damping over small bumps to stop the forks kicking off small bumps and increasing it over large movements giving more support with the spring".

Obviously if you have Showa forks there are other well documented options available to sort them out with various springs and tuneable shim stacks etc.

[Luddite]

Just take it to MCT. He transformed my suspension on an original yellow hoop. Stunning work

Hence the subtle 'MCT' stickers visible in the photos of your Monster in February's 'Bike' magazine!