The tale of two bikes. One, fettled and tuned for the last few seasons, fits like a great pair of gloves, gives (nearly) flawless performance, and is predictable. I know every piece and part of both bikes. The second, however, is new to me and the world, and while it shares so many things with my S750 bike, is its own unique creature in so many ways.
The fine tuning is yet to come but things have already come so far so quickly, and I couldn’t be more proud, despite the result. I left for Topeka over Memorial Day weekend, and the frame had just been painted, parts scattered around the shop and basement, a bike waiting to be born. I returned home from Topeka with issues to sort on the old warhorse, while also pushing to finish the new Superbike Heavyweight to debut at the Jersey round only a month later. And so it began, engine building, chassis assembly, the last little 5-minute bracket that takes half a day to get right, the whole deal. Many 16-18 hour days from early morning until well past 1am came to pass, every day inching closer to a very special machine, capable of competing with the best the air-cooled 4-cylinder era had to offer. It certainly took a toll on me and my family, but has proven to be a great adventure. Without a doubt it could not have been achieved without the support of my best friend, crew chief, and biggest fan, my wife Ashley.
The plan was to get it started and rings seated and head for a dyno session in northern New Jersey the Thursday of race weekend. Im thrilled to say that after some delay, the bike started and ran very nicely. I was able to make a few laps around the neighborhood at varying RPM to seat the rings and get a but a small feel for the bike. The upright riding position is something I am no longer used to, having only ridden my S750 bike over the last few years, with its low clip-ons and lay over the tank rider position, a mirror opposite of my new sit-up-and-beg superbike, with wide upright bars and cut down stock seat. Many nuances to adapt to are in my very near future. An extra 20+hp on tap, and only about 30lbs heavier, coupled with substantially better brakes (a single 12in rotor vs 2x 13in units), all in an effort to be competitive in a class of air-cooled monsters. Given all that, off to Jersey we went, old faithful and the new kid on the block.
The dyno session, as George mentioned, was quite the ordeal. This dyno had never taken advantage of its ability to start a bike, as it was nearly exclusively used for street bikes equipped with starters. After using my roller battery to hook up the never-been-used starting mechanism for the dyno, I thought we were in good shape. After some work the bike finally started and settled to a sweet idle. I get off the bike to look it over and see if there are any issues only to find fuel POURING out of the #2 carb overflow. The trusty wrap of a tool on the bowl as the bike is idling was not enough to right the issue with the float valve. At that point, it was quite a job to pull the carbs and assess the situation, with our dyno time already running out. The decision was made to try again at the track, and gently ease into running it, reading plugs as best we could and go from there.
We decided to start the bike again at the track without pulling the carbs on the off chance the valve had fixed itself on the last leg of the drive, and it had. A terrifying issue to be sure. Funny how things work, you load them up, then calamity ensues only to reverse itself again later. Old bikes man, that’s the game. Either way, it was time to get this thing out and finally get some actual track time. After a thorough warm up in the pits, its accelerated, turned and stopped as expected and it was my turn to practice. I head out on track, carefully easing into the feel of the bike, a bike I had never ridden in anger, on race tires I had never tried, on a track I had one session on so far, and a bike that had equal parts blood, sweat, and money poured into over the last year or so. As I gather enough speed after a few slow corners I gently throw it into the turn, and I feel it. The rear end starts wallowing, as if quickly finding and losing grip as I round the corner. Next corner, same result, and so on. I make it just under 2 laps and pull in to assess the issue. George notices as he stares at the rear ends of both bikes that the S750 wheel spins absolutely true rotation after rotation, nary a wobble to be detected. On the other hand, the Superbike wheel wobbles noticeably left and right and slightly up and down as well. While we likely had the wherewithal to swap the S750 wheel to the Superbike just to make sure that was the issue, we decided that it was time to throw in the towel and focus on what we could control, the S750 bike, which ran like a top all weekend. We also discovered the tiny oil leak from the copper base gasket had grown worse with my time on the track and more heat in the engine. It seems that its still trying to find its final home between case and cylinder and needs another round of torqueing to find that final home.
Back home after a successful weekend on the S750 bike (read about that in my other thread) I started to assess the rear wheel issue. I had just picked up another Astralite wheel complete with bearing hubs only a few weeks before, so I started mixing and matching hubs to wheels. The new wheel and its hubs spun true left/right and up/down as well as a true wire wheel so I had a baseline. I bolted my current hubs to the new wheel as they were already set up for the disc and sprocket, making the wheel swap a breeze, or so I thought. Just minutes before when the new wheel spun true on its hubs, it now spins like a drunken sailor on the hubs that came off the bike. Curious to say the least. I put the new hubs on my current wheel, and of course, the wobble all but disappears. It seems that I don’t have a wheel issue, I have a hub issue. I swap hubs and wheels back and forth and measure runout to see if it really is the hubs. The new hubs spun on both wheels substantially better then the old hubs did on either. Fortunately, despite being a quite different design, the spacing from hub face to sprocket mount was the same, and the disc carrier just so happened to be a perfect fit for the bolt pattern on my Ducati Monster rotor, what luck! With that, I have decided to use the new hubs (duh!) on the current 3.5” wheel, as the new 4.5” wheel would require a new tire, and I had just bought fresh race rubber for the 3.5. They both spun equally true, so that was a non-factor. I set about ordering fresh bearings and some of the long bolts required to bolt the hubs through the wheel, as well as a new custom sprocket, as the carriers are totally different in bolt circle and center hole diameter.
As for the leaky base gasket, the frame kit will allow me to pull the valve cover and with the help of the crow foot wrench I will be able to torque everything again, hopefully for the last time. There are a number of small things yet to finish on the bike, but without the crunch of getting ready for Jersey, I will have plenty of time to get things sorted. Remember, this year is for tuning and refining, and next year is for competing for points. Track time is a must this year so I can acquaint myself to my new machine and do as much tuning and fettling as possible before next season starts.
Gingerman is coming up at the end of July with a race the very next weekend at Blackhawk Farms so it should be a very eventful time of the season, hopefully with lots of good things to report about both bikes!
The glamour shots after final fitting of everything:
