AFM Round 1 - Buttonwillow

Tire choices...

I'll try to catch everyone up as quickly as possible. Keep in mind I'm putting together a full 2006 season close report, but for the interim I'll provide a synopsis.

Making a long story short, the frame of my SV was cracked in three places in round 7 last year. Over the winter I completely rebuilt the bike around a new chassis. Tons of work.

The first chance I had to ride it was at Sears Point (Infineon Raceway) on March 12 of this year. Unfortunately, either the master cylinder or the calipers were faulty as I was getting huge brake fade after 4 laps or so. I never really got a chance to get the bike up to speed for fear of never being able to stop. :)

David Ben-Jamin helped me set up the bike with a new master cylinder (Brembo radial) and rebuilt calipers. The brakes ROCK!! With this fixed I thought the bike was sorted out. Boy was I wrong.

For the first AFM round of the year, I went down to Buttonwillow on Friday for their extra practice. It was apparent immediately on my first session that there was something wrong with the bike. The most indicative problem was that there were bumps in the high speed left hander before the bus-stop that would bounce the bike like the frame was made of jelly. I could only go through there at ~50-75% because the bike was very close to going into a tank slapper.

I asked David to take it out for a session to make sure it wasn't just in my head. He came in after barely a lap. He didn't even have his helmet off before he yelled to make sure that the front wheel was on tight. It was that bad.  (Of course, the wheel was on tight.)  ChrisV and DaveK took a look at the suspension and suggested some adjustments here and there. I took it out for a session after every change but it made no difference.

I was hoping Phil from Aftershocks was going to be there, but unfortunately he was not. Dave Moss from Catalyst Suspension worked with me all afternoon on the track trying to tune this problem out. He was able to remove some of it, but for every little bit of high speed turning stability gained, it was lost on upright stability. Going down the front straightaway there were bumps 1/3 and 2/3 of the way that would send the bike into a near tank-slapper. Not even at full-throttle.

I was frustrated to say the least. The day was over and all I had to show for it was a bike that went from crap-my-pants-scary to just frightening. There were specific places on the track that I had to back off which completely sucked.

That night while chatting with some other racers over beers, I was talked into trying a set of non-Dunlop tires. They, too, had experienced head shake/wobble with the new Dunlops and going to Pirelli tires made the difference. (Oh, right, DavidB was trying to get me on Pirellis before I switched to Dunlops this year. Should have listened.) I was unconvinced. Frankly, changing to a set of take-offs for a Hail Mary fix was ridiculous. But, as luck would have it, a friend of ours had made the trip down in the RV with us. He's rides, knows motorcycles, and is mechanically inclined.  If he wasn't there to help swap out wheels, I wouldn't have done it.

...

First thing Saturday morning DavidG (I know, a lot of Davids) and I pull the wheels off and take them down to the Pirelli truck. We'd already talked to Josh at www.tigersharkracing.com and he was so sure that the tires would solve the problem that he set us up with a set of really good take-offs and free mounting/balancing. If it didn't solve the problem, he was going to put the Dunlops back on for free.

Well, it solved the problem immediately. No more head-shake ANYWHERE! It was totally gone! But that was just the first session. Better take two sessions to get up to speed.

The second session went even better! I've already far exceeded Friday's pace and I'm much more in control. Even better, I got to feel these tires when they've been pushed too hard. The rear was an SC0 qualifying take-off which isn't meant to last very long. They slide predictably. Two problems solved at once.

I immediately went back, pulled the wheels off and had a new set of SC1/2 front/rear put on. I'm back in the game.

From there, it was pretty uneventful. I broke in the tires and started working on my game, unfortunately, a day and a half later than I'd planned on. Suspension felt good, tires felt good, and the brakes felt phenomenal. (Thanks, Dave.)

In the Sunday races I didn't do as well as I'd hoped. I've got a lot of improvement to make happen. There were a couple of battles I was part of, and I'm proud to say that I won, but in the end, I place 3rd to last and 5th to last. Official results are posted yet. I'll update when they're available.

On the positive side, I think the bike is sorted out.  ;)

On to Infineon!