Project Ducati Superbike 998 Part 2: Suspension and Chassis Geometry
The aluminum piece carries the rear caliper. It is secured by the hub and must move back and forth when the hub position is changed. The little slot and pin on the right-hand side were milled out to allow the most rearward position of the hub to be attained.

Moving back to the front end, more work was needed to actually get the front wheel to fit between the fork tubes properly. First the 916-998 axle is slightly different than the 848/1098 axle and has a smaller ‘big end’. A used 848 axle and spacers were solved the issue. The right side spacer for the 848 must be used, but the left side does not work. The 998 comes with a cable-driven speedometer, which I’ve removed. To take up the space that the speedometer cable housing did, a new spacer is needed. Motowheels sells a nice little piece. Buy it, it fits. Podium Racing also sells an axle drift, it’s great too. It’s aluminum with a steel bolted insert that you can smack with a plastic hammer to remove and reinstall the front axle.

The 998 axle is too small to into the fork bottoms.

 

The 848 axle fits in forks that were intended for an 848. No surprise there.

 

Podium Racing axle drift tool makes removing the axle much easier. The bottom end is a steel piece secured with a bolt, the rest is aluminum.

6 comments

  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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