Motor Races: Bonneville Vintage GP

Friday, October 30, 2015

Bonneville Vintage GP

The day after I got back from the Classic TT at the Isle of Man, I rode my CBR250R 250 miles up to Danvers, Ma. and back to to check out a new van. The next day, I flew to Salt Lake City for the Bonneville Vintage GP at Miller Motorsports Park. As in the last several years, I was racing Mike Bungay's 350 H-D Sprint and Gary Roper's '51 Velocette MAC. I had entered Class 'C' footshift on Velo and both 350GP and 500 Premiere on the Sprint. But, as the 500 Premiere race was scheduled before the 350GP, Mike asked me not to race the former in order to not jeopardize a result in the latter. So, I switched my Premiere entry to Classic 60's with the Velo.

Gary had made a few changes to the Velo, most notably rebuilding the magneto, which had failed at Sears Point, and moving the oil tank to make room for a longer intake tract, which Karl Engellener's dyno had shown made more power.

The latest iteration of Gary Roper's Velo MAC with relocated oil tank

The relocated oil tank allowed a longer intake tract.

Though it now has a 650 Triumph 70mm piston in it, it's still a 370cc motor in a 500 OHV/750 flathead class. The bike worked great right from the first practice.

Mike had Jim Belland check the frame (that Jim had made) after I crashed the bike in oil at Willow Springs and then it wanted to shake it's head at Sears Point. Sure enough, Jim found that the steering head was pushed back and to the side, but he was able to bring it back in spec and straight.

In the first practice, it steered better than at Sears, but the tach didn't work at all. Mike thought he found the problem with the tach, but in the second practice it still didn't work and when I came in, I noticed that the front brake was dragging. Inspection revealed that the lining was worn enough the the brake cams were starting to go over center. Mike got some aluminum sheet and cut strips of and appropriate length and width to to wrap around the brake cams and shim them up.

Karl working on the front brake of the H-D Sprint

My first race was the Class 'C' which was gridded in the second wave behind 200GP. I quickly got in the lead of Class 'C' and set about seeing how many of the 200GP bikes that I could catch. I got to about the middle of the 25 200GP entrants, but when I came in, it was immediately pointed out to me that I had forgotten to move my transponder from the Sprint to the MAC in the confusion over the brake. Therefore, I wasn't scored in the race. Oh well, it's not like I was in contention for the championship.

I was out again on the MAC for the Classic '60s race, again starting from the second wave. The other four starters in the race. all on 500s, pulled away. However, I closed up on Swiss Neiderberger on his 500 BSA Goldstar and was able to get by. He motored back by and I again got him in a corner. we repeated this pattern a couple more times until I stayed ahead of him for a couple of laps. I figured that I must be clear of him, but on the back straight on the last lap, Swiss motored by again and I finished 5th and last in class. It was fun dicing with Swiss, but a bit of a quixotic exercise.

Immediately following the Classic '60s race was the 350GP. In the earlier race#6, 500 Premiere had been in the first wave and 500 Sportsman in the second. Eirik Nielsen and Steve Hipp, on their CB350 Hondas had come through from the second wave to finish first and second overall. Now, in race #10, I would be on the pole in the first wave in 350GP and Eirik and Steve would be in the second wave in 350 Sportsman. So the challenge was not only to win the class, but to win overall. I pushed hard from the start and managed to lead flag to flag, though the tach still didn't work and the bike was starting to chatter some, and I noticed a change in the exhaust note during the race which turned out to be caused by a broken exhaust pipe.

On Sunday, we went back to the original plan with me riding the Velo only in Class 'C' and running the Sprint in both 500 Premiere and 350GP. In practice, Walt Fulton, who was riding Karl Engellener's sister bike to Mike's Sprint, and I decide to switch bike in practice. Karl prepares both motors and they are a close as possible to identical. The bikes have the same frames, bodywork, rear wheels and tires, but have different forks, front brakes and tachs. Walt and I agreed that Karl's bike had the better front brake, didn't have the chatter, and vibrated less than Mike's. Looking over Mike's bike after practice, we discovered that one of the engine mounting tabs on the frame was broken and another engine mounting bolt was loose. This certainly accounted for the vibration and maybe the chatter. Or, was that simply more worn tires. We decided that we didn't have the time to repair the frame as it would have meant removing the engine. We just made sure everything was tight.

This time I made sure the transponder was on the Velo for the Class 'C' race and I was able to pull away from all the bikes in the class and pass 12 of the 200GP bikes from the first wave and finish 9th overall.

Next up was the 500 Premiere/GP with 500 Sportsman and F-500 & F-250 in the second wave. Based on the previous lap times, if figured that I had a pretty good shot at winning the 500 Premiere, but the question was: could Eirik catch me from the second wave. I got into the overall lead on the first lap, kept pushing, and wasn't passed before the checker flag. The tach worked long enough for me to get my shift points down a little better. Eirik finished 2nd overall, just over 24 seconds behind which had to be largely the delay to the 2nd wave and having to plow through more traffic, as his fastest lap was 0.011 seconds faster than mine.

Eirik Nielsen's CB 350 Honda

While the chatter was getting a bit worse, the bike seemed fully capable of winning the 350GP and we didn't change anything. The 350GP was gridded in front of Vintage Superbike Lightweight in the first wave with 350 Sportsman, 250GP and F125 in the second wave. Again, I led flag to flag and again Eirik was 2nd overall, but this time just over 13 seconds behind. My fastest lap was just over 3/4 sec. slower than in the 500 Premiere race, but Eirik's fastest lap was 1.785 seconds faster. Walt Fulton was again 2nd in 350GP.