Project Ducati Superbike 998 Part 2: Suspension and Chassis Geometry

On the speedometer side of the 998 wheel, there is a raised lip that centers the spacer and sits proud enough to center the disc as well. On the right side, there is no lip, the hub is actually beveled. This means the spacer is centered on the wheel hub but the disc is centered only by the bolts. This is far from ideal. It’s not worth losing sleep over, but it is a bummer and ensures that when I replace these discs, I’ll get proper offset 748R-998R ones to eliminate this potential problem. The new disc bolts also have a slightly taller head than the OEM ones. They appear to fit without issue, and all the aftermarket Allen key bolts have heads this height. Not sure why Ducati would use a nonstandard size.

The hub of the wheel protruding from the inside diameter of the spacer. This protrusion is what will center the brake disc.

When I bought this engine it had an EVR 48 tooth clutch installed but only a stock clutch drum and pressure plate. A used Bucci slipper clutch was found online and installed in the ‘race’ orientation. A slipper clutch decouples the rear wheel and gearbox to allow them to rotate at different speeds. This prevents the rear wheel from locking up and skidding under fast deceleration and quick downshifting. Slipper clutches are hugely beneficial for race track use, especially on a high compression engine with two big pistons.

Brake reservoir hose that is fifteen years old is junk, replace all of it. Everyone that sells this stuff online sells 12” sections at a time. This really is all that’s needed for just the brake master cylinder, but for $7 per foot, you can find better. McMaster-Carr also carried this, but for less than $2 per ft. I ordered 5ft of length. It’s really imperative to get the proper type of hose, otherwise, the hose could ‘sweat’ brake fluid through it. The pictured hose is what you’re looking for. Keep in mind if you buy it from amazon, it comes in 12” sections, even if you order 5ft. This tubing isn’t really advised on street bikes because UV rays break down brake fluid over time and degrade it. This is why OEM hose is black. Being that this bike will he race track only, it’s not a concern.

Bucci slipper clutch backed by an EVR 48 tooth clutch basket and plates.


Brake hose must have the right rating to insure super corrosive brake fluid doesn’t leak through it.


  1. Be careful substituting in stainless steel bolts in the place of carbon steel bolts. Austenitic stainless steels like 18-8/304 are typically very low strength with the amount of work hardening that goes into making a bolt. Additionally, the different methods of making a bolt, and how much the threads are rolled drastically affect the final tensile strength of the bolt, to the point that they typically aren’t even rated for tensile strength or hardness.

    Most low carbon bolts are going to have a tensile strength in the 115-145 ksi range, while most commercial CRES bolts will be in the ~70-85 ksi range.

  2. Great comment Def. McMasterCarr sells multiple types of stainless fasteners. For clarification, I used the ‘High Strength Stainless Steel Socket Head Screws’ specifically because they have a higher tensile strength of 110 ksi vs the regular stainless’s 70 ksi.

    I think either would work though; titanium bolts are readily available as replacements and have less tensile strength than either type of steel.

  3. A good point to make Rob, it might be good to note this in the article because I was thinking the same thing as Def.

      1. Had the exact same thought regarding 300 series stainless fasteners. Nice find with the high strength options. That being said, there are many titanium fasteners that are 110+ ksi. The ones on mcmaster that quote 50 ksi are probably grade 2 titanium for corrosion resistance. Grade 5 is much stronger and that’s what is more typical for performance oriented fasteners (pro-bolt, allied titanium, etc.)

        1. You’re right. Pro bolt lists grade 5 for their titanium fasteners with a ‘greater than 120ksi’ tensile strength. They also list shear modulus, ductility, Rockwell hardens etc. Really quite impressive that they have all of this information for the customer.

          They also DLC coat the fasteners for corrosion resistance. Shame their too expensive typically for a cheap ass like myself.

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