Cooter
Well-known member
...and I'm not sure how to use it:black_eyed:
I get this question a lot. So it seems a good idea to lay out the basics here. Just the basics. I'll keep it relevant, because there are WAY too many power transmission types to discuss.
The modern motorcycle transmission is designed to not use a clutch between forward gears.
Originally designed by Keppel LeTourneau Inc. March, 1947. The constant mesh transmission was originally meant for heavy equipment. The whole point of it's design was to afford the ability to not disengage power while shifting and lose traction. The "hydraulic clutches" talked about in the patent are only for shifting of the gears, not for disengaging power through the transmission.
https://patents.google.com/patent/US2553376A/en
Using that same patent, motorcyclists get the benefit of fast clutchless power-applied shifting. The misconception that the clutch needs to be dis-engaged between up shifts is a hold-over from peoples experience with a manual transmission (patented 1894!) that would be commonly found in a car or truck. They are NOT the same.
While you CAN also shift any "manual transmission" without the clutch, you cannot have power flow through it at the instant of gear change because the gears are not in mesh for that instant, unlike the constant mesh trans in your motorcycle, that are in uh... constant mesh.
A manual transmission equipped with "synchro-mesh" (Patented 1919 by Earl Avery Thompson) is still a normal manual transmission with the addition of cones to accelerate or decelerate the mating gears and tooth guides for smoother shifts, but because it is a manual transmission design, it is still incapable of having power flow through it while shifting gears.
This is a 5 speed thats very similar to a Buell trans and the VAST majority of motorcycles use the same style of constant mesh transmission.
Thomas Schwenke did this sweet animation. At 3:00 for the ADD among us:
https://www.youtube.com/watch?v=E2CybLSrN5Q
Even though you can shift your motorcycle transmission without the clutch, it's not 'wrong' to do so. With the clutch engaged your engine is directly coupled to the rear wheel. *"Cush drive" and clutch basket springs are a cushion, not a slipping or disconnection point. So a big, instant, ratio change between the crankshaft RPM and rear wheel RPM with no slip between the two, can be a jerky affair.
Allowing that '*solid' connection between the engine and rear wheel slip by using the clutch will provide smoother, non-jerky shifts, less effort, and less noise at almost any RPM/Speed point.
I get this question a lot. So it seems a good idea to lay out the basics here. Just the basics. I'll keep it relevant, because there are WAY too many power transmission types to discuss.
The modern motorcycle transmission is designed to not use a clutch between forward gears.
Originally designed by Keppel LeTourneau Inc. March, 1947. The constant mesh transmission was originally meant for heavy equipment. The whole point of it's design was to afford the ability to not disengage power while shifting and lose traction. The "hydraulic clutches" talked about in the patent are only for shifting of the gears, not for disengaging power through the transmission.
https://patents.google.com/patent/US2553376A/en
Using that same patent, motorcyclists get the benefit of fast clutchless power-applied shifting. The misconception that the clutch needs to be dis-engaged between up shifts is a hold-over from peoples experience with a manual transmission (patented 1894!) that would be commonly found in a car or truck. They are NOT the same.
While you CAN also shift any "manual transmission" without the clutch, you cannot have power flow through it at the instant of gear change because the gears are not in mesh for that instant, unlike the constant mesh trans in your motorcycle, that are in uh... constant mesh.
A manual transmission equipped with "synchro-mesh" (Patented 1919 by Earl Avery Thompson) is still a normal manual transmission with the addition of cones to accelerate or decelerate the mating gears and tooth guides for smoother shifts, but because it is a manual transmission design, it is still incapable of having power flow through it while shifting gears.
This is a 5 speed thats very similar to a Buell trans and the VAST majority of motorcycles use the same style of constant mesh transmission.
Thomas Schwenke did this sweet animation. At 3:00 for the ADD among us:
https://www.youtube.com/watch?v=E2CybLSrN5Q
Even though you can shift your motorcycle transmission without the clutch, it's not 'wrong' to do so. With the clutch engaged your engine is directly coupled to the rear wheel. *"Cush drive" and clutch basket springs are a cushion, not a slipping or disconnection point. So a big, instant, ratio change between the crankshaft RPM and rear wheel RPM with no slip between the two, can be a jerky affair.
Allowing that '*solid' connection between the engine and rear wheel slip by using the clutch will provide smoother, non-jerky shifts, less effort, and less noise at almost any RPM/Speed point.