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January 24, 2009

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They work in an interesting world. For bike skeleton design, especially, about front alignment, it is a very deep matter. We have an accepted theory in Japan. I will show you some.(700c) 1) Trail--- Trail is born by caster angle of bike, of course. A) In slow speed, the trail is 20 – 30mm. Good handling. And Max is 60mm. Over 60mm--- It is not possible to control. B) In high speed, if the road is in a good condition, 20 – 30mm. In rough condition, around 50mm is good. These are a capacity. And then, for a suitable fork rake, we can get it by “wheel radius x tan (90-head angle) / 2 “. And then, Precession effect (Weight effect), Tire effect, Connection with position and air resistance… We have to consider about many things. I have also had a test about a relation between trail and fork rake in Japan. That was, first, we tried to ride with rake(0)--- it was not possible (of course). Then, + 5,10, 15, 20 (It got better) and –5,-10,-15,-20. When we had 0 to –15, Not good, but around rake(-17), it got better… I cannot say all of them here, just a part of them, sometimes we had to calculate with some formulas (small wheels and tricycle and so on). This matter is quite complicated and deep, as you know. But it is a very interesting and so I like this job.

They work in an interesting world. For bike skeleton design, especially, about front alignment, it is a very deep matter. We have an accepted theory in Japan. I will show you some.(700c) 1) Trail--- Trail is born by caster angle of bike, of course. A) In slow speed, the trail is 20 – 30mm. Good handling. And Max is 60mm. Over 60mm--- It is not possible to control. B) In high speed, if the road is in a good condition, 20 – 30mm. In rough condition, around 50mm is good. These are a capacity. And then, for a suitable fork rake, we can get it by “wheel radius x tan (90-head angle) / 2 “. And then, Precession effect (Weight effect), Tire effect, Connection with position and air resistance… We have to consider about many things. I have also had a test about a relation between trail and fork rake in Japan. That was, first, we tried to ride with rake(0)--- it was not possible (of course). Then, + 5,10, 15, 20 (It got better) and –5,-10,-15,-20. When we had 0 to –15, Not good, but around rake(-17), it got better… I cannot say all of them here, just a part of them, sometimes we had to calculate with some formulas (small wheels and tricycle and so on). This matter is quite complicated and deep, as you know. But it is a very interesting and so I like this job.

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