[BigBlack]

Thinking about this recall and knowing how things can break; a tranny failure (lockup) would be devastating on a motorcycle. I mean although rare it could happen to any bike. My solution would be a one-way ratchet type pulley gear. This way if a tranny locks up the bike will freely roll forward to a safe stop. Think of a bicycle pedal configuration. The bicycle will free wheel forward when you hold the pedals in one place.

Such a pulley if it were available could be installed on our bikes and relieve the lockup threat and let us ride without tearing our bikes apart.

Just deep thoughts here since I cannot ride anyway.

Come-On engineers this should not be hard to develop. Remember they once said we could not fly to the moon too.

BigBlack

 

[Kajo]

Hey, maybe toss this post in the tech section to get some more responses.

 

[liquid_bullet]

BigBlack: Your concept is sound, but could not be done in volume for less than several hundred dollars, and would likely require machining modifications. My company makes a needle bearing 'roller clutch' which only rotates in one direction, and locks when reversed. This could be mounted in the drive sprocket hub to achieve the desired effect. I will check if this is made to the proper shaft size, and if it can handle the torque. I'll get back.

 

[Dice]

sounds like an idea, but then couldn't engine break while downshifting.

 

[liquid_bullet]

OK, based on the drive sprocket speed at 140mph, (approx. 4500rpm), and the requirement to handle 180 ft-lb of torque (stage 4 120 ft-lb x 1.5 safety factor), this won't work. Unfortunately, the 4500 rpm top speed makes oil bath lubrication necessary (grease won't work), and the torque ratings of the applicable sizes are way low (around 50 ft-lb max.). You also have to deal with the splined connection between the transmission output shaft and the drive sprocket.

I am not aware of any other low profile, low cost solutions to the problem, but I think it deserves some consideration as a standard safety feature. It could be implemented in the design phase, but then I couldn't park my bike on an incline and leave it in gear. You'd have to come up with a parking brake as well.

 

[RickPullins]

A one way device wouldn't make a difference. You are talking about stopping rotation not reversing it. You would need a slipper clutch that would let go if the pressure exceeds a certain point. Of course then we would all be crying about not having full throttle take offs.

 

[Bunker]

A Slipper clutch limits back-torque, so as Dice said, you get minimal engine braking, which is the whole idea of a slipper clutch on race bikes. It allows full drive torque. It would reduce the affects of a lock-up, but fixing the **** tranny is the right way to do it.