John Laverty's Pace Notes: Sachsenring 2016 - On Body Position, and Engine Braking

John Laverty is a former professional motorcycle racer, who raced three seasons in BSB. He is currently manager and rider coach to his brother Eugene Laverty, racing for the Aspar Ducati team in MotoGP. John acts as a track spotter for Eugene, checking what he sees on track from Eugene and other riders, and providing feedback to help the Aspar Ducati rider go faster. John will be contributing his insights into the things he sees at each track on a regular basis.

The Sachsenring circuit presents unique challenges for riders. For Eugene Laverty, it was the final sector, and the section between the two final corners. That was where John Laverty took me to start our brief tour of the German circuit, to see where he could help Eugene to improve and go faster.

John was looking at the body position of the riders, and in particular, the gap between the rider's backside and the back of the seat. "If you look at Rossi, he's right forward," John said. "And this is what I'm telling Eugene, he's sitting much further back. I know he's doing the right thing to try to keep rear contact, but I feel he is doing a lot on track to try to correct faults in the engine braking and chassis set up, which need sorted off track by the crew. They can adjust the bike settings to cure the problems."

He produced a handheld video camera, to film Eugene and other riders from the side, to show to Eugene later. This is something a lot of rider coaches do, though they use it only sparingly, often using the official footage.

"The Ducati's front heavy so I just want to give him that camera footage," John said. He doesn't see it that way, because [the Dorna TV camera in Turn 13] doesn't pick it up. But what I'm saying is that it's definite, you're the only person that has full extension of the body, nearly locking the arms on braking. He lies flat across the tank, a bit like Márquez does, he gets his weight distributed well across it."

That is not what the rest of the riders are doing between Turns 12 and 13. "When you compare it to what the rest are doing, everyone else is sitting tall, Eugene's lying across, the chest is across the tank. Now Márquez does that, he's distributing the weight well, but yesterday he was burying the front and then trying to distribute his weight. I'm afraid of him trying to do too much with the bike, where he needs to brake and set the bike up. He's trying to do a lot with his body."

Part of the problem was the way that Eugene was slowing the bike into Turn 12 using the rear brake. "He is good in the way he uses his rear brake," John said. "Some people don't care when they're in a left hander and the right foot is pointing out. He always has his foot on the back brake, and that in turn pushes him back a bit." Eugene's braking technique is what is pushing him back on the bike, forcing the body towards the rear of the seat.

Using the rear brake forces the rider's body further back on the bike, which puts more strain on the shoulders and body. In a 30 lap race at a track where there are no rest points, that can be incredibly tiring in an already demanding race. "As soon as you slide forward, your foot wants to go out. So to pull it in is really physical." John's own solution when he was racing was simple. "I was a lazy bugger and used a thumb brake..."

We rode up the hill to the narrow section of service road which separates the front straight from Turn 11, and the drop down the Waterfall. Here, John was looking at braking for Turn 1. As an Avintia Ducati came by, he commented on the way the rear tail section was shaking and vibrating on corner entry. "See that the last time, bouncing there in the rear? Probably a bit too much engine braking," he said. If the engine braking is not smooth enough, it causes the rear of the bike to judder, and shake its tail.

The way the different bikes approached Turn 1 gave clues to their design philosophies, John pointed out. "The Yamaha never lost contact, it keeps rear contact," he said. "Honda, Ducati, they'll lift the rear." As Marc Márquez came by, he pointed to the Repsol Honda. "It's funny that, you see the back wheel off the ground, but he can still get it stopped when it's on its nose. When you do that with a Yamaha, because it's long, when it lands, it just fishtails and goes straight on. It doesn't like to have the rear dancing. But the Honda will stop if the back's up, it'll still stop." The Yamaha will not do the same thing. "You have to stay in line and the Yamaha has to stay straight. You can't back it in, it'll just go straight. It doesn't like it," John said.

Did he have a theory on why that was? "I actually don't know, I'm making an assumption, because I don't know the weights of the crankshafts, but a heavier crank is harder to stop. Maybe it's that." That matches the general paddock opinion of the different bikes. The Honda is believed to have a much lighter crank, which produces a lot of power but leads to an aggressive engine which wants to spin up too freely. That is what is helping it into the corners, however, the crank inertia not affecting the braking as much. The Yamaha is said to have a heavier crank, giving it a more docile engine character, and making it much easier to ride. The price Yamaha pay is to have the bike be a little harder to stop, forcing its riders to brake in a straight line before entering the corner.

Sachsenring is a track John has never ridden, of course, so it means he has a slightly different approach to his job as rider coach. "It's mostly just comparison to others," John explained. Comparing what he sees with Eugene to what he sees with other riders can provide useful insight into how Eugene's bike is behaving, and what Eugene is doing right and doing wrong.

That comparison had helped John spot a problem in 2015. Last year, Eugene's bike was so bad round here that I had to come back in during one of the sessions and tell him, which I usually don't do. But I was so nervous about him going into the last turn that we only found out afterwards that the top out spring at the rear wasn't actually working so he was really struggling. Nobody else's bike was doing that."


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Comments

Great contribution from JLav. Motomatters raises the game once again. Gets better and better. 

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David, Mr. Laverty - thanks for that excellent column.  

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Great addition to your site! More of this. Thank you! Now, add a lot more tech and it's perfect!

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