Who would buy one of these AMC gearbox clutch centers?

Joined
Aug 9, 2008
Messages
2,063
Country flag
Am I understanding correctly that there is very little or no engine braking by design with this type of clutch? I think I would miss that.
 
Joined
Jan 21, 2011
Messages
639
The engine braking works fine with this clutch, it is just the sort of extreme engine braking that would lock up a rear wheel, or downshifting into first going down a steep grade that will make it slip.

It never slipped on me just doing the normal fourth to third to second to first downshifting at legal speeds.
 
Joined
Apr 20, 2011
Messages
4,521
Country flag
Am I to understand that only the clutch inner has a spiral, and the outer clutch case have straight cut slots, as per normal? :?:
 
Joined
Jan 21, 2011
Messages
639
The only part you would be replacing is the clutch inner drum itself, that single part. All the rest of the parts would be stock Norton parts.

Ideally I suppose an angle could be put into both the inner and outer drums, but it has been shown to not be necessary and would just be more cost and more to manufacture.
 
Joined
Apr 15, 2009
Messages
10,388
Country flag
beng said:
The only part you would be replacing is the clutch inner drum itself, that single part. All the rest of the parts would be stock Norton parts.

Ideally I suppose an angle could be put into both the inner and outer drums, but it has been shown to not be necessary and would just be more cost and more to manufacture.
But there might be a benefit to angle the clutch plate tines?
 
Joined
Jan 21, 2011
Messages
639
Heinz Kegler, because an infinite number of factory servo clutch inner drums was not available and in fact limited to a handful, found it easy to take a regular clutch outer drum and grind an angle into it. In fact he offered this service along with his work on brakes, setting up clutches and manufacturing his swingarm collars.

Because the torque is not the same as it is at the outer drum far away from the center as it is closer to the center of the clutch, putting the same angle in would help but might not have as much servo effect.
Heinz said it took a lot of trial and error to get the exact right angle for the inner drum, too much and it would not release, too little and it would not clamp hard enough.

I talked to one 650ss rider who had installed one of Heinz' re-ground clutch outer drums and he said it did help him use less spring pressure to get satisfactory performance from it.

Of course opening up the slots to an angle means they will be wider at one end than the other, but they naturally line up against the side that drives them so it is not an issue, they are not rattling back and forth causing any trouble.

If someone is patient laying it out and altering it either with hand or machine tools, it might be a nice project for the bored Dominator enthusiast with an extra clutch laying around to play with.
 
Joined
Apr 20, 2011
Messages
4,521
Country flag
beng said:
Heinz Kegler, because an infinite number of factory servo clutch inner drums was not available and in fact limited to a handful, found it easy to take a regular clutch outer drum and grind an angle into it. In fact he offered this service along with his work on brakes, setting up clutches and manufacturing his swingarm collars.
Because the torque is not the same as it is at the outer drum far away from the center as it is closer to the center of the clutch, putting the same angle in would help but might not have as much servo effect.
Heinz said it took a lot of trial and error to get the exact right angle for the inner drum, too much and it would not release, too little and it would not clamp hard enough.
Of course opening up the slots to an angle means they will be wider at one end than the other, but they naturally line up against the side that drives them so it is not an issue, they are not rattling back and forth causing any trouble.
If someone is patient laying it out and altering it either with hand or machine tools, it might be a nice project for the bored Dominator enthusiast with an extra clutch laying around to play with.
Re;
"Of course opening up the slots to an angle means they will be wider at one end than the other, but they naturally line up against the side that drives them so it is not an issue, they are not rattling back and forth causing any trouble."

:?: :?:
Sorry, but I have to question this, as from the photo at the beginning of this page it is not a modified standard clutch centre, or the angle would break into the already straight cut groves/slots :?: :?:

Do you happened to know what the angle of this clutch centre is, as per picture :?: :D
 

bwolfie

VIP MEMBER
Joined
Sep 21, 2010
Messages
3,289
It os a new part, the angle is spelled out in the article I posted, something like 1 thread per 37".
 
Joined
Apr 20, 2011
Messages
4,521
Country flag
hobot said:
Count me in on one for under $100, kewl.
Some of you bikers obliviously still live in the 1960s :!: :D

those were the days, but they have ..........gone :!:
 
Top