65 AV88: Missing Variator Keyway

Okay, decided to replace the old variator on my 1965 AV88. It's still in decent shape but don't trust it because of the age.

So after an hour battle trying to get the last cir-clip off the engine shaft without the correct tool, I succeed. The variator came off and out popped the key. I noted the keyway on the engine shaft.

The new variator is identical to the old one in every respect EXCEPT there is NO KEY SLOT in the variator hub! WTF?

My questions are:

1. Is friction/an interference fit enough to keep the variator hub from slipping on the engine shaft with no key? It would appear so as they keyway is eliminated in the new hub.....what do you all think?

2. How do I install/solidly seat the new variator hub on the engine shaft?

Any advice greatly appreciated.


Re: 65 AV88: Missing Variator Keyway

It will be fine.....it's only the clutch...

my '69 AV92 was like this, had a 3 shoe keyed clutch reverse-rotation, put it on a new bottom end with no keyway, just fine. (edited)

Re: 65 AV88: Missing Variator Keyway

The clutch is taper fit so it will grip, they stopped using the key in 1969 with Formule 8 variators. I do have a service letter in French from Motobecane that tells official service departments that the key is not required and may be omitted because they will no longer be producing covers with keyways.

Lots of engineering went into the variators from their first appearance with 38 balls... http://mabecanemobylette.freeforums.org/viewtopic.php?f=30&t=1730

Re: 65 AV88: Missing Variator Keyway

Thanks Gents,

I'm relieved to know that the key is not necessary. I just installed the thing and torqued the nut to 22 ft-lbs.

Interesting article Rebel Moby! Thx!


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