Similar to my S750 bike, the Superbike has had a full season of racing so far this year. I have been able to make some much needed changes to the bike to get it handle more like like it should and that has resulted in a number of podiums for this year, including a couple 2nd place finishes!!
Rewind to Barber last year and I made the switch to Continental race rubber from the Metzelers, which did seem to help with handling to some degree, at least with less wallowing in the corners. I wasn't able to get my Race Tech shocks in time so they would have to wait until Daytona to make their debut.
Daytona had me set up on Race Tech shocks and the 18" Conti's on my Astralite wheels. Good suspension added to my confidence as well as getting more seat time every trip out on track. I was finally able to push hard enough to find the next issue, that being that any throttle in a corner stood the bike upright and pushed it wide, leaving me with very slow cornering and corner exits. Once I was upright, the power was great, but no handling in the corner.
After Daytona, I bought a digital angle finder and plumb bob and started measuring everything on both bikes, comparing and contrasting every angle and distance, recording all of it. The offending measurement was my trail, with over 110mm! Without major surgery of cutting and tucking the steering neck, the fork length was the next logical choice. I ended up lowering the forks through the trees to change the neck angle to get my trail into the 95mm range. Once I had that information, I pulled the forks down and internally lowered them with spacers under the damper rods, ending up 1.5" shorter overall.
As it turns out, the S750 bike was even worse from a trail standpoint, but the handling was very different, in that I was pushed forward with the clip on bars and the overall wheelbase was already over 1" shorter due to the steering neck position difference between the K frame and the superbike's F2 frame. I still proceeded to lower them 1.5" internally to bring the front end of the bike down and level it out more, especially given that the GL1000 forks are already so long. I didn't notice as much difference as I did with the Superbike, but I am still quite happy with the result.
The last piece of the puzzle on the Superbike was tire selection via the wheels I was running. With 18" wheels, I have 2 viable options for race rubber and one (Metzeler) had already been taken off the list. With AHRMA approving slicks for Superbike, I decided to make the jump. I chose SV650 wheels in 3.5"F and 4.5"R for that task. They are a hollow 3-spoke design, very strong and noticeably lighter than my Astralites. It took a lot of modification to the sprocket drive and an offset front sprocket, but I did get the wheel centered and the sprockets aligned. I chose Dunlop for slicks, since they have the rear I needed readily available and are a top-quality race tire. Slicks inspire confidence you simply cannot get even from the best 18" race tire and while a big change, it was the right one and should really lead to better lap times and better finishes. Despite these teething issues, I am still 4th overall in the Vintage Superbike Heavyweight class and have 3 more rounds of racing this year, all at tracks that I like and am pretty familiar with, including my home track, Gingerman!
More to come as I continue the new engine build and prep for next season.
