What Is This? Minibike Secondary Clutch

Kartman01

Active Member
#1
Does anyone know who manufactured the secondary clutch in the photos? There are no manufacturing logos or markings that I can find.

The clutch is on a 1970 Terra Trail Topper minibike. What research I have been able to do indicates Terra’s used Comet clutches, however neither the primary or secondary look like Comets.

Thanks for any insight!
 

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I74

Well-Known Member
#2
Does anyone know who manufactured the secondary clutch in the photos? There are no manufacturing logos or markings that I can find.

The clutch is on a 1970 Terra Trail Topper minibike. What research I have been able to do indicates Terra’s used Comet clutches, however neither the primary or secondary look like Comets.

Thanks for any insight!
Could be wrong, but,, I think that it's really a torque - ''compensator'' dampener, not really a clutch,, even though it might be generally ''worded'' like ones that sort of resemble it.

Added,,

Looks like it pretty much works like a ''compensator''/ ''crank'' sprocket on an old Harley ect.
 
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mustangfrank

Well-Known Member
#4
Does anyone know who manufactured the secondary clutch in the photos? There are no manufacturing logos or markings that I can find.

The clutch is on a 1970 Terra Trail Topper minibike. What research I have been able to do indicates Terra’s used Comet clutches, however neither the primary or secondary look like Comets.

Thanks for any insight!
The Comet TC88 and CAT99 (symmetrical or asymmetrical) used a spider design like that, didn't they? Clutch buttons look like they were replaced fairly recently but the rest is pretty crusty.
 

Kartman01

Active Member
#5
Does anyone know who manufactured the secondary clutch in the photos? There are no manufacturing logos or markings that I can find.

The clutch is on a 1970 Terra Trail Topper minibike. What research I have been able to do indicates Terra’s used Comet clutches, however neither the primary or secondary look like Comets.

Thanks for any insight!


Folks, a quick update: I have been able to get the secondary off the bike and after a couple of days in Evaporust, I have been able to confirm
my secondary was made by Horstman.

My new challenge will be to A) figuring how to take the secondary apart and attempt to repair it and B) if I cannot repair it, find another Horstman secondary to replace this one.

I will move my post over to 'Wanted' and see if I can find a replacement unit. If anyone knows how to disassemble a secondary, please let me know.

Thanks!
 

mustangfrank

Well-Known Member
#6
Folks, a quick update: I have been able to get the secondary off the bike and after a couple of days in Evaporust, I have been able to confirm
my secondary was made by Horstman.

My new challenge will be to A) figuring how to take the secondary apart and attempt to repair it and B) if I cannot repair it, find another Horstman secondary to replace this one.

I will move my post over to 'Wanted' and see if I can find a replacement unit. If anyone knows how to disassemble a secondary, please let me know.

Thanks!
Best way to ID stuff, nice job...I went and pulled one of my old Comet driven clutches off, they are very similar to the eye, just subtle differences, the spring leg not going through the spider hole like the Comet was what kept me looking.

Honestly I'd let that piece of originality go and replace with a modern clutch set. The lack of repair parts, prices and performance issues mixing with newer drive clutches due to belt size width changes will be obstacles.

If you're dead set on using it, make sure you get the same type, assuming your sheaves are symmetrical based on the spider mounting inboard but I'm not familiar with Horstman driven clutches, (obviously).

IMG_20211118_152724.jpg IMG_20211118_152709.jpg IMG_20211118_152701.jpg
 

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Kartman01

Active Member
#7
Best way to ID stuff, nice job...I went and pulled one of my old Comet driven clutches off, they are very similar to the eye, just subtle differences, the spring leg not going through the spider hole like the Comet was what kept me looking.

Honestly I'd let that piece of originality go and replace with a modern clutch set. The lack of repair parts, prices and performance issues mixing with newer drive clutches due to belt size width changes will be obstacles.

If you're dead set on using it, make sure you get the same type, assuming your sheaves are symmetrical based on the spider mounting inboard but I'm not familiar with Horstman driven clutches, (obviously).

View attachment 284187 View attachment 284188 View attachment 284189
Thanks Frank, I really appreciate your insights and help. I would like to see if I can get the secondary apart, repair it and use it. If not, I will definitely need to go down the path you suggest...
 

copyman

Well-Known Member
#8
That looks similar to Comet Cat99 torque converter setup that's used on the Hilltopper. Believe they call that the driven part. The driver part is more like the clutch and mounted on the crank.
 

Kartman01

Active Member
#9
That looks similar to Comet Cat99 torque converter setup that's used on the Hilltopper. Believe they call that the driven part. The driver part is more like the clutch and mounted on the crank.


Thanks copyman, I will do some research and see if I can find anything on the Comet Cat99.
 
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