Alpina Clutch Plates

[cdubb]

I'm putting together the clutch basket on a '75 Alpina 350 (model 138). I am cross referencing two documents. The Hugh's Bultaco 5 Speed Bultaco Service Manual and the factory Bultaco Parts List Catalogue. None indicate the amount of plates I am supposed to install in the clutch basket (tabbed on OD and non-tabbed).

I currently have 6 tabbed plates and 7 non-tabbed plates. Is that too many? What is indicating this concern is the Hugh's Service Manual. The manual shoes 4 tabbed and 4 non tabbed. *help*

There are also two conflicting diagrams which show two different assemblies. One shows that the first plate to go in the basket is a non-tabbed and another schematic demonstrates a tabbed one to go in the basket first. Clarification needed!

Also which do I end with? Are there supposed to be the same amount of each plate type in the basket?

[feetupfun]

There are a few different clutches fitted to 5 speed Bultaco motors. Yours may not be the original clutch, and Bultaco are known for changing the design of things like clutches during a production run. Not a real issue though because while the clutch baskets and hubs may be of different types, the type of clutch plates you have described are common to all 5 speed motors from about 1969 onwards.

The important thing is that you fit as many plates as you can, to minimise the pressure plate loading needed to prevent slip (more plates = more torque for the same clamping pressure)

Limits to how many plates will fit are the length of the basket fingers, the length of the hub splines, and how far the spring retaining nuts stick out after you have adjusted the springs correctly. If they stick out too far they will rub on the clutch cover. If you have retaining pins on your clutch hub rather than studs and nuts, they are not adjustable so won't be a problem as far as sticking out goes.

.

By the sound of it, the Hugh's Bultaco manual may be referring to either the aftermarket type (Barnett) tabbed plates that have friction material on them (and so are thicker), or Hugh may be referring to the early 5 speed clutches (1965 to 1969) that also had friction material on the tabbed plates. By the time your Alpina was made, the standard plates should have been all steel with no friction material and should have "T" shaped holes in them.

If you think about how the clutch works you should be able to work out which plate goes in first, but if you have problems with that, if you post up a clear photo of your clutch basket with no plates in it, there are many people on this forum who are very familiar with Bultaco 5-speed clutches who should be able to help further.

[nigel dabster]

frontera plates are thinner not too sure about alpina, if they fit its fine.

Gives a better clutch in the sherpa, btw.