Ducati 998 basket case project

This shit is a million times better than game of thrones...

Can't wait for the next episode!

 

Fail to prepare and you prepare to fail.

I arrived at the track when it opens at 7a. I do this knowing we won’t hit the track till 20 past 9. It gives time to set up properly, stretch, hydrate more, and give the bike a last once over, or in this case, both bikes.

65*F and sunny, this never happens here. Setting out for the first session the Ducati feels great. Power is wonderfully linear, clicking up through gearbox hearing the thunderous sound of the Termignoni exhaust chase me as I enter the straight.

The brakes feel equally as amazing, although there’s a slight shudder from the discs under hard use from high speed. I’ll need to either replace the buttons or look into new discs. Turning left into turn two I’m amazed how light this thing feels for a nearly 20yr old machine. It doesn’t feel any heavier than the Triumph, just....longer. The slipper clutch surprisingly doesn’t need any adjustment, it’s perfect. Lucky.

Having a little difficulty figuring out gearing on the track because it’s so different than the 675 I usually ride. I may have also undergeared the Ducati for this track. My current setup is 15/40 and I see 10k rpm in 6th before my braking marker into T1. It also makes 2nd gear extremely short for the tight stuff. I’m thinking a 38T would be ideal.

Diving into the fast esses I notice a propensity to headshake while transitioning. The front feels a little ‘wallowy’. I’m having to keep too tight a grip on the bars. I need some tank grips. They’ve been on the 675 for 10yrs and I never realized how much I rely on them. I’ll add some rebound damping next session to see if it helps.

After 2 sessions handlebar and footpeg position are sorted. A little extra rebound damping moves the suspension feel in the right direction. I’m beginning to feel more confident, the track temp is rising and grip is good. Coolant temps never go above 190*F, all is well with my hideously rigged 999 radiator setup.

For session 3 I thumb the starter and suddenly the bike won’t start. Cranks over without issue, but won’t fire. This has been the best starting Ducati I’ve ever witnessed up until this very moment. Start with the easy stuff. Fuel in the tank, coils plugged in. Hmm. Open the fuel cap and prime the pump. Crap. There’s 45psi or so of fuel spraying around in my tank.

I remove the tank and fuel pump flange to see the hose has slipped off the pump despite my use of high quality Oetiker clamps. I grab a generic hose clamp and zip it tight with an impact driver. That oughta do it. The rubber fuel flange O-Ring though has now ballooned up from sitting in fuel. It’s never going back in. I have 20 of them at home. I tried getting it back together but failed and split the O-ring. Looks like I’ll be on the 675 the remainder of the day. Next time I’ll bring more damn O-Rings.


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Thanks for documenting this build. Its a fun read minus your struggles today. Good luck getting it sorted.

 

Cool read. Thanks for posting.
Keep the updates coming.

 

Going over my notes to prepare changes for the next event. I mentioned the gearing feeling too short as I was seeing 10k rpm in 6th well before my brake marker going into T1. Using an online gearing calculator (and double checking longhand) my current setup of 15/41T should result in a 10k rpm 6th gear speed of 163mph. There's NO way I'm reaching that speed a few seconds before my normal braking marker. I'm now actually second guessing that I was in 6th gear. Is it possible I goofed the 6th gear shift and was in 5th and just presumed from that point on that I was geared too short and never tried again to get 6th?

My Triumph for example is currently geared with a top speed (13k rpm in 6th) of 151mph. I get right up to that point on a fast lap. I absolutely brake earlier on the Ducati, even though it does seem to have a little more pull. I can't imagine the Duc is putting 10-12mph on the Triumph while braking earlier too. For reference the last 'fast' bike I rode here was an 1199 Panigale about 6 years ago which saw roughly 170+mph on the instrument cluster. The 998 probably makes 10-15hp more than the Triumph, but 50 less than the 1199.

Unsure if I want to bother changing the gearing before next event. I’d hate to go out and be so short geared again but I’d also hate to buy another rear sprocket for nothing as this is the longest track I’ll frequent.



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You know you are allowed to change the rear sprocket at the track, right?

 

I know I know. I have a 39T in the parts bin. It’s more about purchasing ANOTHER one that I don’t think I’ll at all need now. I’ll bring the 39T next time and see what’s what.


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For how much you've really done, I'd say that's a damn good first outing. I'd almost be superstitious if I did that much work and took that much time getting things up to speed to NOT have anything go wrong.

 

I completely expected some type of failure, but honestly was not thinking it'd be something so stupid as a hose clamp not being sufficient and then not having the proper O-ring to reseal the damn thing. But I'll have extras next time.

 

Back in the garage, the new o-ring went in without a hitch to reseal the fuel pump flange. I’ll need to remember to bring spares to the track just in case.

To solve my braking shudder, let’s first determine the problem. The stock discs are semi-floating as almost all OEM units are. This means the rotor is held to the hats by button just like the fancy race discs, only the buttons are riveted into place instead of just clipped. This greatly limits their freedom of motion and over time the buttons can seize from dirt, debris etc and cause vibrations. In the past I’ve cleaned the hell out of these and knocked them loose with rubber mallets with some success, but there are better options for a race machine. First, get some super nice Brembo HPK discs for around $700 and bolt them on. With little baby no.2 due in 90days, I’m trying to lie low on this. Never gonna get fly.

Option 2 is to replace the buttons with full floating units by Brembo as used on their HPK discs. I bought them from Kurvey Girl for $36ea. They come 10/pack because HPK discs have 10 buttons per disc. OEM discs have 9 because they’re less cool, you’ll need two packs of buttons.

The buttons are made for 5.5mm HPK discs and come with .3mm shims that are to be fitted to one side of each button. OEM discs are only 4.5mm thick because they’re designed to have lower thermal capacity than the race units. Because of lack of thickness the buttons won’t work with .3mm shims, you need something to take up the additional .7mm of your thinner disc. The HPK style buttons are also aluminum, so I don’t have to feel as bad weighing 230lbs because I saved probably .5lb of unsprung and rotating mass.

I measured the shims and ordered some .5mm shims from McMasterCarr to use 2 per button (1 per side of each button) to get the proper clearance. I’m not certain that the as shipped .3mm shims would cause a problem, but they left the discs with an uncomfortable amount of play with the carriers for me. The .5mm shims were $9/pack of 25. You need 2 packs.

To drill out the stock buttons you’ll need a shar 3/8ths still but and a pair of vise grips. If you don’t grip them the rivets will begin to turn with the drill but and you’ll get frustrated and throw things.


Once you drill out each of the rivets they fall right out. Clean off the disc and carrier. If you’re going to hone the discs, now is the time. I use this flex hone on the end of a drill. It really should be done anytime you replace the brake pads as this will knock off the embedded pad material and give the new pads some new steel to bite into.
After honing, place the new buttons in place with a shin on each side of the disc. The new buttons use E clips to secure them so they’re easily removable in the future.

I’ll admit this is the first time I’ve done this and I’m astonished at the results. The amount of friction reduction spinning the front wheel while on the stand is amazing. The pads used to drag the wheel to a stop in 360* or so. Now the wheel will make several rotations. Can’t wait to see the improvement on track. The 675 may get this same treatment instead of buying fancy discs.

I also added StompGrips as mentioned previously. I’d forgotten how much of a difference these little things made until I jumped from the 998 to the 675 last day out.


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Regarding wheel rotation resistance, have you closely examined the wheel bearings?

 

I'm a fan of ducati and euro motorcycles. Had an 848 now a triumph 675. Kind of strange that I know the r6 is the best bike with no problems, but love a bike with character, a 998 is in my future

 

Heh, I should make a video of my old school EBC Prolites if you're worried about excess disc movement. Freaking tambourines.

I wonder if that button kit works with OEM R6 rotors?

 

I've checked them for freeplay and smoothness which both feel fine. With the calipers removed and only the wheel on the axle the resistance is very little. Maybe one day I'll do ceramic bearings. But for now this will do.

 

I'll admit I enjoy working on/building them nearly as much as riding them. The Triumph is far less fun to tinker with than the Ducati. The Ducatis are almost like legos from the early 90s till 2011 model year. Makes it fun to mix and match and make your 'favorite' type of machine. The sound and feel is also something much different than anything else I've ridden. One of my favorite bikes ever was an 848 w/1040kit FGRT suspension and lightweight wheels, all dialed in. It was amazing, if expensive.

 

If you can get the diameter dimension of the R6 discs, I can tell you if these will work. You'll just have to workout which shims you need for proper free play. If R6 discs are 4.5mm then you'd need the same .5mm shim per side as I used.

 

Spent the last 2 evenings getting the bodywork fitted. Paintwork is excellent, the fairings are of good quality. They’re very flexible, but thick. Less rigid than the Armour Bodies on my Triumph. Fitment however was...interesting. I must take at least part of the blame though. Some of the fitment issues stemmed from using non-998 spec oil cooler and radiator setup. These are things you have no way of knowing before
You try to hang the fairings on. I still need to fit the tail section and trim to make room for the shift pedal, but otherwise ready for the next event.

The horizontal header has almost zero airgap between itself and the bellypan. Hopefully the heat wrap and reflective tape hold up.




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I really hope you found a spot to rub some dirt on the lower to appease the pavement Gods. That is way too pretty.

 

Not sure why I didn't think of this. Definitely going to do this. I may try to to something similar at the front where the exhaust is extremely close as well.