The 1098S race bike

The 1098S race bike
A Ducati 1098S street bike converted to a race and track bike.

onsdag 18 februari 2015

200/60 tire conversion

The 1098 comes with 190/55 spec rear tire. This tire hasn’t been updated for years by Pirelli and I was recommended by my suspension guru friend,Jocke at FJJ Racing to modify the bike to fit a more modern 200/60 tire. Reason being this tire profile provides more rubber to the road at any lean angle.

Easier said than done, no one I talked to could provide good instruction and most US communities was full of posts with people who had opinions but no knowledge. Anyways, I dug deep into my engineering skills not used for a long time and came up with the below:

  1. 15/40 gearing. With taller 200/60 tire this provide exactly the same rubber to road gearing as 15/38 on a190/55 tire. Since I ride some pretty long straights like Motorland Aragon I need that ratio anyways. You need a 520 race spec chain with 2 more links. 100 links instead of stock 98 links to get clerance to the swing arm.
  2.  Machine the rear brake caliper to be able to move the rear wheel further back. You need 13.5 mm (27/2), if you use Pirelli since the Pirelli 200/60 is 27 mm higher than a 190/55 on a std 1098S rim. The tire would otherwise touch the swing arm as mentioned above. No 1 in the drawing is the item you need to modify and sen in picture below. My new swing arm lengt is approx 505 mm.
  3. Longer rear wheel height adjuster. My starting ride height is 204 mm and for that I ran out of threads on my rod. I had some damaged threads and didn’t want to push my luck. I bought a Corse Dynamics rod from NF Racing in bad taste gold.

Added benefit is longer swing arm “ by 15 mm which I am told improves handling.
No 2 I the drawing, the spacer was stuck. I had to use heat from the outside, and cool spray from the inside and then a determined whack with my rubber hammer to get it off. Make sure to grease these things properly. Not done by previous owner on my bike.

Tire measurements fitted on std Ducati rim
190 tire 635 mm height, 193 mm width
200 tire 662 mm height, 200 mm width (3.5 mm closer to chain, but converting to 520 chain solves that issue)

Inga kommentarer:

Skicka en kommentar