Early in the day, I ran into Bill Werner, who called me over to say that he'd seen a 'Blue Groove' post about the early evolution of the XR-750 motor. He pointed out one factual error in my account and clarified a possibly mistaken impression that post may have left.
Bill worked in the Harley-Davidson race shop during that KR-to-XR transition, around 1970, so he knows of what he speaks. I had cited Dick O'Brien as the principal architect of the XR, which was accurate, but I also credited 'an engineer' at Harley-Davidson named Peter Zylstra. Bill told me that Zylstra was a draftsman, not an engineer; he was involved, but didn't have significant design input.
The larger error, perhaps, in my story was that according to Bill, Harley-Davidson was not really taken by surprise by the failure of the first iron-head XRs. "We knew all along," he told me, "that they were just a stop-gap measure."
One of Bill's jobs in the race shop at that time was converting Sportster-based rear cylinder head castings, so that the exhaust valve was in the front. This was an unbelievably finicky operation involving a huge amount of welding up and reshaping, filling in the old spark plug hole and drilling and tapping a new one, and on and on. He told me that it was nothing to have dozens of hours of work in a head, and then it would just be sitting there cooling and 'ping!' a crack would form between a valve and spark plug. There was so much hand-work in a set of iron heads that the shop only managed to produce something like 18 sets in a year.
In the end, they devised a system where the heads, after all the welding up, were slowly cooled in -- brace yourself -- 45-gallon drums of asbestos dust! Back then, of course, asbestos was still a major component of clutchs and brake pads. It was also used by Harley-Davidson's maintenance department to insulate hot water pipes, etc. So they had lots of it around. Bill remembers going to the maintenance department and just picking up a drum of it.
He told me that they'd work on a head, then put it into the drum full of asbestos dust to let it slowly cool off, then days later they'd just blow it off with compressed air.
"My doctor asked me if I'd ever smoked," he recalled. "I told him no and he said that was a good thing because if I had smoked, I'd have about 800 times the likelihood of getting lung cancer."
As he mentioned the old asbestos clutches, he also told me something I'd forgotten, which is that the early XRs were intended to run with dry clutches. Those had problems with heat buildup, and soon they converted to wet ones.
While Harley was making do with the iron-head XRs, they were busy developing the next-generation aluminum head version. It even had a different bore and stroke. Some of that work was farmed out to well-known hot rodders; Jerry Branch worked on the aluminum head design, for example. Bill remembers that work beginning as early as 1970.
After being rained right out on Saturday afternoon, the TT race was run under hot, sunny, and breezy conditions on the holiday Monday. There were quite a few times that, as the water-truck circulated the track, I had to fight the urge to strip off my shirt and run through the spray like a kid playing in a lawn sprinkler. I have to admit that some time in the middle of the program I forgot about being a journalist and moved up into the shade of a big old tree on the grassy slope across from the grandstand, where the shade and breeze made the heat just tolerable. Up there, I watched the racing from a fan's perspective.
Early in the day, though, the story I was writing in my head was about Chris Carr, looking like a favorite to win his final appearance at the Springfield TT. (Henry Wiles was sidelined after surgery to repair a knee injured in a freak accident at Du Quoin. That left the TT field a little more open than it might usually be.) Carr was seriously quick in practice and blitzed the first qualifying session with a lap of 24.516 seconds. No one touched that lap time all day, as despite officials' best efforts, the track slicked up and slowed down with each passing session.
The slick track (and perhaps, fatigue after a tiring day at the mile, along with heat and hydration issues) caught out veterans and rookies alike, over and over again as the day wore on. One of the first victims was Carr, who started his heat from pole and opened up a gap right away before committing an unforced error in the right hander after the jump.
Carr rode like a maniac - aided by a restart - but came up just short of a transfer spot, which relegated him to a semi. In that race, he crashed hard in Turn 2, and spent a long minute lying winded on side of the jump. Watching from up on the hill, I wondered if Carr's day was going to end in the ambulance. But he got up, shook it off, and got back on his bike - which didn't seem to have sustained much damage. Again, he worked his way from last to sixth place, which was a lot of work for no reward.
Both Carr and Bryan Smith, who had also had a luckless heat and semi, wanted to use their provisional start to get into the Main. Carr got the referee's nod, because the rule gives it to the rider with the highest points total.
That put Chris in the Main, though he was starting from the next county over. To my eye, Chris came out swinging. Maybe he was remembering the Pro race, which had about five restarts, and thinking that if he could pass a few guys between red flags, he could work his way up in stages.
That strategy could have worked, and indeed there was an early red flag in the Expert Main, but as the laps wore down and Jake, Jared Mees and J.R. Schnabel strung together a long run, Carr found himself in an unusual position - looking over his shoulder to make sure he wasn't going to be in the way as the leaders came through to lap him. At the end of the day, four points was a pretty disappointing haul in exchange for his provisional start and after such a promising morning.
Chris' Farewell To Flat Track Tour is bringing a lot of fans down to his autograph table in the pits, and the crowds are really pulling for him. A win would be hugely popular, and it would have been deserved on Memorial Day, when he was the fastest man on the track.