Motobene
Well-known member
WYBDR - MY TECH LEARNING EXPERIENCES - PART 2
LYNDON POSKITT WIDE RATIO GEARBOX
Fitting a Rekluse auto clutch reduces the justification for the very expensive part and install labor costs of the complete Lyndon Poskitt wide ratio gearset by reducing the 'in your faceness' of the tall 1st. The problem of the low 6th is still there, however.
I already bought the $3,400 gearset (may it work as good as it looks!), so it will go in anyway. I didn't have time to risk putting it in before the WYBDR, and it was better to learn the stock box deeply before making the swap anyway.
I was thinking about the differences when riding, concluding that yes, the expensive cluster should make the bike better. The lower 1st will enable more precise technical creeping work. The taller wider spread and taller 6th will reduce shifting frequency and overall intensity. It will 'add length to the unicorn horn' by making super slab work at high speed (think: cruising at 80 to 90 MPH) more of a natural thing to do, widening the scope of use.
What the other gearbox will feel like I can estimate based on experience. Helpful is a practical analysis by the numbers, such as the following two from my Excel gearing calculator, where I look at travel rate at six RPMs. Most won't notice or care about the narrower-ratio-spread tranny. The latest LC4 with two counter balancers shakes less that the previous version, being pretty smooth on the highway even when running at higher rpm in a lower-geared 6th. What impacts riders more is the tall 1st gear, making slow work harder and requiring a lot of clutching skill to maintain smoothness, esp0ecially when the rider is tired.
Stock gears, stock final drive:
The stock tranny does have pretty even step-ups between gears.
Poskitt gearset, stock final drive:
Pick any RPM and compare between the two. A lower 1st is a positive, resulting in less clutch slip when creeping. The 2nd gear ratio via the same tooth counts for the drive and driven gears with both trannies for a 2nd gear well positioned for hauling ass in tight, rough terrain. The Poskitt has a general wider spacing between gears. That's not as good for stoplight-to-stoplight racing, but I'm no longer a pimple-faced kid so that's OK. I think the big LC4's wide torque curve, plus the elasticity of the Rekluse will reduce the perception of gaps.
Very appreciated will be the wider spread in general, leading to I think a more relaxed and practical ride. Having experimented a lot with gearing for unicorn bikes, I can tell you by experience that the feel difference is greater than the above numbers differences would suggest.
REVISED CONTROL SCHEME
Hand brakes only and no foot brake or clutch lever proved once again to provide me a significant advantage. I found the Rekluse clutch does a better job in the slip zone than I can, especially when fatigued. Raise the throttle slightly above idle and simply hold it there to creep along. The natural travel rate for 1st gear, especially geared stock on the final drive, is quite fast. I can cut that travel in third with very little throttle. I observed some 'whiskey clutch' by the manual clutch majority and once when swapping bikes I did that myself.
When swapping bikes I had guys get eyes wide during the preamble when I'd describe the controls. "There's no foot brake and that's not the clutch, it's the rear brake. Yeah you'll stomp air a few times on the non existing foot brake and brake hard using the 'clutch', but you'll get used to it pretty fast." And they would. My brakes are so immediate and responsive and that took them some getting used to. Once disappointment was in the ergonomics. I'd see primarily sit-down riders not standing very much. Such habits are hard to brake! But transition to standing and standing is where the more open trials ergonomics really shines.
LYNDON POSKITT WIDE RATIO GEARBOX
Fitting a Rekluse auto clutch reduces the justification for the very expensive part and install labor costs of the complete Lyndon Poskitt wide ratio gearset by reducing the 'in your faceness' of the tall 1st. The problem of the low 6th is still there, however.
I already bought the $3,400 gearset (may it work as good as it looks!), so it will go in anyway. I didn't have time to risk putting it in before the WYBDR, and it was better to learn the stock box deeply before making the swap anyway.
I was thinking about the differences when riding, concluding that yes, the expensive cluster should make the bike better. The lower 1st will enable more precise technical creeping work. The taller wider spread and taller 6th will reduce shifting frequency and overall intensity. It will 'add length to the unicorn horn' by making super slab work at high speed (think: cruising at 80 to 90 MPH) more of a natural thing to do, widening the scope of use.
What the other gearbox will feel like I can estimate based on experience. Helpful is a practical analysis by the numbers, such as the following two from my Excel gearing calculator, where I look at travel rate at six RPMs. Most won't notice or care about the narrower-ratio-spread tranny. The latest LC4 with two counter balancers shakes less that the previous version, being pretty smooth on the highway even when running at higher rpm in a lower-geared 6th. What impacts riders more is the tall 1st gear, making slow work harder and requiring a lot of clutching skill to maintain smoothness, esp0ecially when the rider is tired.
Stock gears, stock final drive:
The stock tranny does have pretty even step-ups between gears.
Poskitt gearset, stock final drive:
Pick any RPM and compare between the two. A lower 1st is a positive, resulting in less clutch slip when creeping. The 2nd gear ratio via the same tooth counts for the drive and driven gears with both trannies for a 2nd gear well positioned for hauling ass in tight, rough terrain. The Poskitt has a general wider spacing between gears. That's not as good for stoplight-to-stoplight racing, but I'm no longer a pimple-faced kid so that's OK. I think the big LC4's wide torque curve, plus the elasticity of the Rekluse will reduce the perception of gaps.
Very appreciated will be the wider spread in general, leading to I think a more relaxed and practical ride. Having experimented a lot with gearing for unicorn bikes, I can tell you by experience that the feel difference is greater than the above numbers differences would suggest.
REVISED CONTROL SCHEME
Hand brakes only and no foot brake or clutch lever proved once again to provide me a significant advantage. I found the Rekluse clutch does a better job in the slip zone than I can, especially when fatigued. Raise the throttle slightly above idle and simply hold it there to creep along. The natural travel rate for 1st gear, especially geared stock on the final drive, is quite fast. I can cut that travel in third with very little throttle. I observed some 'whiskey clutch' by the manual clutch majority and once when swapping bikes I did that myself.
When swapping bikes I had guys get eyes wide during the preamble when I'd describe the controls. "There's no foot brake and that's not the clutch, it's the rear brake. Yeah you'll stomp air a few times on the non existing foot brake and brake hard using the 'clutch', but you'll get used to it pretty fast." And they would. My brakes are so immediate and responsive and that took them some getting used to. Once disappointment was in the ergonomics. I'd see primarily sit-down riders not standing very much. Such habits are hard to brake! But transition to standing and standing is where the more open trials ergonomics really shines.
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