Ducati Monster Forum

I just got a set of 996 SBK forks off of eBay for a great price.  The forks came in today and look amazing.  Super clean, no scratches, etc.

According to the seller, they were setup by GP Suspension for a 160 lb rider.  I weigh 175 and plan on putting these on my 04 620.  Any ideas what a 160 lb 996 spring rate is?  Could I just slap these on the Monster and see what happens with sag?  Should I just suck it up and send it out to GP Suspension for a clean up and new springs?  Thanks guys. 

From what I know.. the SBK forks are all stronger front spring and weaker back springs than monsters.

so a 160lb spring rate on the monster would be too weak on a sbk for a 160lb rider.
vice versa a 160lb spring rate on a sbk would be too strong for a 160lb rider on a monster...

since you are 15lb heavier (is that 160lb with gear or just rider).. it might not be a bad setup.

I'd say get new springs. I was planning on doing something similar but the spring rates are REALLY different.. much stiffer on the SBK forks.

Getting new springs was the original plan.  These forks are just in such good shape.  According to the seller, the seals and oil have zero miles on them.  From the looks of it, I'm inclined to believe him.  If this is the case, and the bike was setup for a 996 with a 160lb rider, I'm wondering if it's in the ballpark for my Monster plus 175lb me.

Traxxion had recommended a .90 kg spring when we spoke about respringing the stock forks.  If these 996 springs are close, I might just try slapping them on the bike as is.

I'd run 'em.

Check sag and adjust as necessary.

Are spring rates affecting sag more than anything?  In other words, if correct sag can be reached within the pre-load settings, are the springs good to go?

No.


If you can get acceptable free sag and rider sag, then at least they're in the ballpark.

I'm with ducpainter on this, run 'em and see what you think.

On the subject of SBK fork swaps, what should I expect to pay for machining the stock triples?  Cost of having shims made?

That varies a lot depending on location.

Lots of people out there getting smart and doing this mod. Beats the hell out of spending a ton of money on useless carbon ;D   Before you attack me for being old & cheap I have no qualms about spending for useful carbon i.e BST wheels. 

csorin, I have some half a millimeter aluminum shim stock somewhere, you're welcome to some. Cost of getting a triple bored out varies depending on who you know & whether you have any machinist friends. I don't, but I got lucky and scored a stock triple from an S2R1000(removeable risers) already bored out from another member for $35 shipped.

On a 2004 620 you must remember that the handlebar risers are cast into the triple. You can't really use the stock bars because the forks will stick up ~35mm and interfere with the bars. This means clipons. If you get some stock triples from an S2R the risers are a tad bit taller and you might get away with using bars, however you'll need the S2R bars as well because they're different(thicker) at the risers on that model. You could just remove the risers and go to clipons, but that's more money.

I'd suggest boring your stockers out, milling or cutting the risers off, a nice powdercoat or paint job and clipons. Don't forget you might need some new steering head bearings.

Berg,

Thanks for the suggestions.  The plan was to bore the stock triples and cut the risers off.  In the threads that mention this mod, no one talks about costs.  I don't even know what the ballpark is.

I would really like to get something like this done:

(http://farm3.static.flickr.com/2394/2260142824_cca96a9706_o.jpg)

Really like the look of the cut down stock triple.  If cost is prohibitive (I've no metal working tools), I might just bore the triples and hook everything up.

Once the triples are bored, does the surface need to be coated/protected?  I'd hate for rust stains to start dripping down my new (to me) forks.  Can I just spray a clear protectant over the metal if there is such a thing?   

Racetech says the ideal spring rate (street) for a 175lb rider on a 403lb Monster is 0.835 kg/mm and for racing it's 0.885 kg/mm

Racetech says the ideal spring rate (street) for a 160lb rider on a 418lb 998 is 0.910 kg/mm.

Given that springs basically come in .05 increments (i.e. .85kg or .90kg) you probably have .90kg springs on there now.

You're in the ballpark.

http://old.racetech.com/evalving/menu/searchstreet.asp (http://old.racetech.com/evalving/menu/searchstreet.asp)

csorin, the upper triple is aluminum.  No need to coat it after boring, it won't rust.

That's the example that stuck in my mind. Nice craftmanship and I like the little Corse logo encapsulated in clearcoat.

Just take it off your bike, go to a machine shop and consult. Try to find one that focuses mainly on motos, but machinists are machinists. I cannot imagine it being ridiculously expensive to get done. The important thing is to ensure it's done accurately. If you need to save money, after it's bored out & milled down just prep well and rattlecan it to the best of your ability. Should look great. 

Ah, good news.  The more I can incrementally absorb costs, the better.


This too is good news.  Traxxion had recommended a .90 kg spring for spirited back country, occasional track, and occasional 2-up for my Monster.  Glad this is coming together better than expected.

In addition to what I said before....

I'd call GP and ask 'em what they think.

Heard back from GP Suspension.  Dave offered the same advice as here, which is to just mount them and give them a go.  He also stated that they were running a .95 spring.  So If .90 is ideal according to Traxxion, I think I might be alright with the slightly stiffer ride.

I'm in a little bit of a conundrum at the moment as far as triples go.  It's either pay $70 to get them bored, or save up a couple hundred and just get a Speedymoto triple.  I'm starting to sway towards the later.  Seems like less of a hassle, and the result will look great.

I've been able to scrounge up some Speedymoto clip-on mounts for $75, and just ordered replacement bars for $50.  So the clip-ons are taken care of at about half the price of new.  Stoked that this project is costing much less than anticipated.  The triple is going to be the major purchase in all this.

YMMV but be forewarned. I just installed a pair of monster S4 springs onto my S2R 800 and they were a lower spring rate than what you have. I weight 175 / 180 and have what should be a heavier bike. I had to back the preload out to all but one line visible on the preload adjuster just to get the proper sag values.

I think you're going to be unplesantly surprised at the stiffness. Mine was spec'd at .86. Just remember to budget some extra money for some springs in case you need em.

.90 is on the stifferside of right for a monster. i was 160lbs no gear when i got my mosnter springs swapped for .85 and agan on my end it is the stiffer side of things.

lots of room for personal taste on this one.

stiffer is better than weak when it comes to springs.

Stiffer would be a welcome change.  The wallowing over bumpy turns, while sometimes exhilarating, is getting old.  I look forward to feeling the difference these springs will bring.

I recently put 2000 or so 748 SBK forks on my 06 800 S2R. Backed out the preload about 4 rings, compression and rebound a couple for good measure and fork are still on the stiff side, a little out of balance with the mushy rear stocker. That said still a huge improvement, gone are the wallowy turns and bottoming in chuck holes. Well worth the effort. Have also noticed a glut of SBK forks on ebay @ $200 or less. I was charged $30 (gave $40) for the the triple bore and found SS .5mm stock in hopper at work so way too cheap for a great mod. I'm 170 lbs gearless but always ride with about 20 lbs in my backpack. Will probably go a little lighter in front but definetly heavier in rear.  bill

The rear is going to have to wait.  The Penske sport shock has my eye.

My only remaining concern is the install.  Do I need to lower my headlight and gauges to make this work?  I'm worried that I'll get the triple bored, the clip-ons placed, and then not be able to run the brake lines with the stock headlight placement.  I'm using Speedymoto clip-ons (not the tall boys).  Any experience with this is much appreciated. 

I ended up flopping the custer out of the way and removing the headlight bucket assembly to get the job done.  bill

Are you running the clip-one above or below the tripple?  I have Woodcraft 3" rise clip-ons mounted below a speedy moto tripple. The speedy moto has a few more inches space below than the stock.  I was able to keep the stock lines with just reclocking the lines with the stock headlight & gauge mounting.

I'll be running the clip-ons below the triple.  For now, I plan on using the stock triple. 

If the Speedymoto triple gives me more room and saves me the need to lower the headlamp, I'd rather get the aftermarket triple ($287) than spend money on lowering the headlamp and gauges ($70 for boring the stock triple, $87 for modifying bracket). 

On my S2R I'm still running my stock bars.  I set the ammount of tube above the triple based on the overall length difference between the SBK and OEM forks, about an inch. With  the preload out 4 rings the compression adjuster is just about touching the underside of the bars.

Thanks Cobra, but a big part of this project is moving to clip-ons. 

Has anyone run ~1 inch rise clip-ons below a Speedymoto Triple with stock headlight placement and stock coffin reservoirs?

Hey guys,

Was told part of my answer from another forum member, B.  It looks like I need the following part to get the reservoirs to clear the clip-on collars:

http://www.monsterparts.com/pc/ADAP/Clutch-Brakes/ADAP.html (http://www.monsterparts.com/pc/ADAP/Clutch-Brakes/ADAP.html)

Now my only concern is the headlight bracket ears at their stock height interfering with the brake lines.

+1 on those spacers, you need 'em.

when I work around that area I remove the headlight (2 screws and a connector) since it makes it easier for me to move stuff around.

there are easy (and cheap!) ways of lowering the headlamp and gauges. I ordered these clamps (http://www.aircraftspruce.com/catalog/appages/ms21919clamps.php), set them at the height I prefer and bolted the headlight on.

Can you expound a bit on the need for the spacers -I can't picture what they do. I'm planning Tall Boys installed, stock coffins (forever maybe) and stock triple (temporarily at least)

The spacers are needed because the coffin resevour on the master cylinder will contact the clip-on were the bar mounts.

Whelp, rather than spending the $40 on spacers for the coffins, I decided to upgrade my masters to some S4R units courtesy of another forum member here.  This project keeps getting more expensive, but hopefully the result will prove to be worth it.  I've managed to keep costs in line with a mix of ebay and forum purchases.  Still stoked.