Motorcycle transmission theory

[Narcoleptic_Snowman]

can anyone explain how the clutch and transmission work in a motorcycle? I don't quite understand the whole clutch basket thing... car transmissions seem so much simpler... Or if anyone knows where some good reading is on these transmissions. I like to learn new stuff all the time, and this is just one thing that boggles my noggin.

[seuadr]

well, a sequential shift car manual and a motorcycle manual is pretty much the same thing. i like pictures, so here:

http://auto.howstuffworks.com/motorcycle2.htm

fun little aside.. i've got a lancer with the CVT transmission they mention and it's a hoot. you punch it and the transmission hits about 6k and stays there for as long as you hold the pedal down. on an on ramp i often go from 30'ish to 80'ish with the transmission never straying from the 6k rev point

[Narcoleptic_Snowman]

ahhh howstuffworks.com I totally forgot about that. the article on manual transmissions and sequential transmissions were very cool, however... I didn't ever find anything on how the clutch basket works. how does it engage/disengage from the engine? that's one part I really don't get... it would probably make sense if I tore it apart but I don't see a reason to pull apart a perfectly good transmission...

[seuadr]

oh..The clutch has several plates in it. Usually about 6 friction and 6 steel. The clutch plates sit in a basket and grabs and turns with the flywheel.Then you move, when you grab the clutch lever it releases the tension on the plates so you stop the transfer of engine power. basically like the second picture, only not two solid wheels, but a set of wheels all sitting there waiting to be engaged.

[76FJ55]

I'm assuming since you say it is easier to understand a car that you do understand the car clutch setup. Basically in a car you have the flywheel with the pressure plate bolted to it with pressure applied by springs, and a clutch disc sandwitched between them. the flywheel is attached to the crank (positive attachment) the disk is attached to the input shaft of the trany. in a bike the basker serves the same purpose as the flywheel (we're talking clutch function not rotating mass function). again there is a pressure plate at the opposite end of the clutch assemply bolted to the basket with pressure applied by springs. there is a ring gear at the back side of the basket that interfaces with the crank (positive coupling but with a gear ratio multiplier). inside the basket there are alternating plates drive and driventhe drive plates are splined into the basket (designed to increase serface area of the basket friction sueface, and alternating between the prive plates are driven plates which are splined to the clutch hub the hub is attached to the input shaft of the trany. again the multi plate system is to increase surface area. this entire stack is placed under pressure by the pressure plate driven by the clutch springs. when you qsueeze the clutch lever you phisiacly cdrive the pressude plate away from the clutch basket relieving the pressure between the drive and driven plates decreasing the friction and allwing the drive and driven plates to slit relative to one another disengaging the clutch.

[Narcoleptic_Snowman]

ahhhh ok. That makes sense. thanks for explaining that to me, my brain can stop melting in confusion now. It also makes sense now why they used a basket. More surface area, more friction, more reliable clutch. I love learning new stuff.

[Baatfam]

... it would probably make sense if I tore it apart but I don't see a reason to pull apart a perfectly good transmission...

Actually, you don't have to pull apart the trans to take a look at the clutch....
Pop the cover off, open up the clutch and it's pretty obvious how it works...
Or head over to your local drag strip when they are running a bike class and look around...somebody will have his clutch apart...trust me.

I can swap out a set of discs in mine in about 1/2 hour...

[Smokinapankake]

Hey Narcoleptic,

We should get together sometime. I live up in N. Ogden. Grew up in West Valley but never spent much time in Sandy.....
In fact, my good buddy with a V-Max and I are planning a little get together ride on the 23rd o' Aug. You're welcome to join as is 80GS1000.... I think he lives in Sandy, too.