- Joined
- Jun 30, 2012
- Messages
- 13,892
I was thinking about the thread which relates to fitting a 2S cam. The way I ride, smooth power delivery is very important - probably more important than actual power delivered. To ride faster when on a lean, we become tyre dependent and that dependency is relative to the amount of lean. I got very tangled-up when I was trying to figure-out steering geometry. When I studied physics the resultant force was calculated by adding vectors. When you have a wheel spinning, the force vector direction is through the centre of the wheel, and I cannot remember in which direction it goes. When I was a kid, we all used to avidly read Phil Irvings book tuning for speed. It told us nothing about race bike construction and the way the type of power delivery is relevant.
With Manx Nortons, the power delivery was fairly gentle and the steering had a lot of trail, so the bike self-steered in the correct direction, if you gassed it when on a lean. Most bikes will do that, even if they have neutral handling. It is actually difficult to lean a Manx more that it wants to go due to it's set-up - a Triton is usually easier because the motor is back a bit. But cannot be ridden as fast.
A Commando must have less trail than a Manx or more guys would be crashing. So the amount of lean in corners should be greater. To my mind, a Commando engine should be fast enough with only minimal modification. The crank balance factor is a problem, but can be fixed. For speed work, the standard gearbox is useless.
Thev tyre thing is strange. With my bike, I have found that if gas it very early in corners, I can use it like a drag bike, and ride under and past most of the others. It is really silly stuff and potentially dangerous. You can meet the leader as they come down from the ripple strip.
When you need to counter-steer a Commando going into corners, that is understeer, and a symptom of insufficient steering trail. My bike simply gets flicked into corners and gassed. It over-steers both going in and coming out.
Less trail makes the bike more stable,and causes more lean in corners. Then you need better tyres.
With Manx Nortons, the power delivery was fairly gentle and the steering had a lot of trail, so the bike self-steered in the correct direction, if you gassed it when on a lean. Most bikes will do that, even if they have neutral handling. It is actually difficult to lean a Manx more that it wants to go due to it's set-up - a Triton is usually easier because the motor is back a bit. But cannot be ridden as fast.
A Commando must have less trail than a Manx or more guys would be crashing. So the amount of lean in corners should be greater. To my mind, a Commando engine should be fast enough with only minimal modification. The crank balance factor is a problem, but can be fixed. For speed work, the standard gearbox is useless.
Thev tyre thing is strange. With my bike, I have found that if gas it very early in corners, I can use it like a drag bike, and ride under and past most of the others. It is really silly stuff and potentially dangerous. You can meet the leader as they come down from the ripple strip.
When you need to counter-steer a Commando going into corners, that is understeer, and a symptom of insufficient steering trail. My bike simply gets flicked into corners and gassed. It over-steers both going in and coming out.
Less trail makes the bike more stable,and causes more lean in corners. Then you need better tyres.
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