PDA

View Full Version : Clutch; between engine and gearbox or engine and output shaft?



Steam
8th December 2007, 13:38
Does the clutch come between the engine and the gearbox, or between the gearbox and the output shaft/chain.?
I mean, when you pull in the clutch, does it disengage the gearbox and everything after that, or does it just disengage the output shaft?

I feel like such a dummy! :2thumbsup

Later edit: Okay, I have just realized what an incredibly stupid question this is. Must... use... brain... in future.

Sully60
8th December 2007, 13:49
Does the clutch come between the engine and the gearbox, or between the gearbox and the output shaft/chain.?
I mean, when you pull in the clutch, does it disengage the gearbox and everything after that, or does it just disengage the output shaft?

I feel like such a dummy! :2thumbsup

MOST bikes have the clutch mounted on the geabox "drive shaft"(so yes it's betwwen the engine and gearbox) which is driven by the small primary drive gear on the end of the crank which turns the gear around the outside of the clutch basket. When the clutch is engaged the inner hub of the clutch drives the geabox "drive shaft" which is meshed with the gearbox "driven shaft" or as you've called it the output shaft. Disengage the clutch and apart from any drag the gearbox shafts do not turn.

There are some exceptions to this setup but thats another thread.

Steam
8th December 2007, 13:52
Excellent answer, I am now much enlightened. Thanks!

dino3310
8th December 2007, 13:52
i learn something new every day

Sully60
8th December 2007, 13:56
Excellent answer, I am now much enlightened. Thanks!

No worries!

Just don't ask me about the role of Helium in the process of nuclear fusion reactions. I'm a little rusty with those subjects at the moment :rolleyes:

xwhatsit
8th December 2007, 15:21
MOST bikes have the clutch mounted on the geabox "drive shaft"(so yes it's betwwen the engine and gearbox) which is driven by the small primary drive gear on the end of the crank which turns the gear around the outside of the clutch basket. When the clutch is engaged the inner hub of the clutch drives the geabox "drive shaft" which is meshed with the gearbox "driven shaft" or as you've called it the output shaft. Disengage the clutch and apart from any drag the gearbox shafts do not turn.

There are some exceptions to this setup but thats another thread.

If the clutch wasn't between the engine and the gearbox, how would you disengage the engine so as to shift gears in the normal method?

Steam
8th December 2007, 15:28
*Steam's mouth falls open, aghast at his own stupidity*
*Steam writes on hand "must use brain"*

MSTRS
8th December 2007, 15:54
Clutch between engine and gearbox....but be aware of which moving part drives the oil pump. There are some bikes, notably, the "T' series Suzuki 2 strokes that drive off the gearbox, which means that when the clutch lever is in the engine is not getting any oil.

Mom
8th December 2007, 16:04
*Steam's mouth falls open, aghast at his own stupidity*
*Steam writes on hand "must use brain"*

No mate, Steam wanted to know the answer and asked, he was not teased in any way, and was given the answer he sought.

Steam should not be feeling stupid (well maybe a little tiny bit) It was a good question, may others learn from it too!

Sully60
8th December 2007, 16:12
No mate, Steam wanted to know the answer and asked, he was not teased in any way, and was given the answer he sought.

Steam should not be feeling stupid (well maybe a little tiny bit) It was a good question, may others learn from it too!

Exactley!
xerxesdaphat does some it up quickly and it does make it pretty obvious when you break it down. But sometimes you just need a snap from someone else's viewpoint and then all becomes clear.
But as far as I'm concerned the only stupid question is one that's never asked.

Max Preload
8th December 2007, 19:56
If the clutch wasn't between the engine and the gearbox, how would you disengage the engine so as to shift gears in the normal method?

The gears themselves are in constant mesh - only the drive dogs move along the shafts and they're splined to the same shaft as the gear they engage (obviously, otherwise they'd transmit no power, so the gears already spin in sync). The graunching you hear if you cock up a shift is not teeth on teeth but dogs against carriers.

If you want to know whether the clutch is before of after the gearbox input, pull the clutch lever in with the engine running. If the 'whirring' gets quiet it's before as the gears and bearings stop turning (as long as the clutch is actually fully disengaging).

xwhatsit
9th December 2007, 00:20
Ah, very interesting! I look at the gearbox pictures in my manual and just think... wtf is that. Most other things I can grep, but gearboxes are way over my head. So it doesn't matter where the clutch is in the sequence -- just so long as it unloads gearbox.

@Steam: I wasn't posting a `look here, dummy' post, I was interested to what Sully was talking about. Seems nonsensical but I think I understand now.

Steam
9th December 2007, 08:41
@Steam: I wasn't posting a `look here, dummy' post, I was interested to what Sully was talking about. Seems nonsensical but I think I understand now.
Yeah, I knew, no worries dude!:sunny:

Motu
9th December 2007, 09:43
Unlike a car gearbox.

Just like a car gearbox - the sliding dogs are just more complicated with syncromesh units fitted......the graunching you hear is syncro dogs hitting.Sliding gear boxes went out before WWII.....although sliding gear 1st stayed until the '60's.....sliding gear reverse is still with us.

Max Preload
9th December 2007, 11:47
The gears themselves are in constant mesh - only the drive dogs move along the shafts and they're splined to the same shaft as the gear they engage (obviously, otherwise they'd transmit no power, so spin in sync. Unlike a car gearbox. The graunching you hear if you cock up a shift is not teeth on gears but dogs against carriers.

If you want to know whether the clutch is before of after the gearbox input, pull the clutch lever in with the engine running. If the 'whirring' gets quiet it's before as the gears and bearings stop turning (as long as the clutch fully disengages.


Just like a car gearbox - the sliding dogs are just more complicated with syncromesh units fitted......the graunching you hear is syncro dogs hitting.Sliding gear boxes went out before WWII.....although sliding gear 1st stayed until the '60's.....sliding gear reverse is still with us.

Sorry - a bit of left over debris from my initial thought on how to post that I missed removing. I'll tidy that post up. :yes: