Hi,

I am embarking on a rebuild of my son's Montesa Cato 247: Engine & Frame number 21M22865,making it manufactured between October 1976 & March 1977.

I have a question about the swing arm. The bike is fitted with a standard swing arm but I'd prefer to fit a longer one for trials use. My question is where could I source one or alternaticvely how much longer is a trial SA so I could consider lengthening the standard one.

Thanks

From distant memory I seem to think that the Montesa suffered from being a bit long in the wheelbase, could be wrong.  It would be a case of balancing the extra suspension suppleness with turning capability.   

More expert opinion will no doubt follow.

I can't be sure of the question. Maybe "trials" and "trial" have been used instead of "trail"

Thanks for the reply but I really did mean for Trials. 

 

The "standard" arm is the trials one.  Have you found the handling deficient?

I cannot answer your questions sorry, especially about "Uk" version. All I know is I took over the restoration fom my son who's too busy doing track days and trialising on his Gas Gas bike to finish it! When he handed it over he said he was trying to source a Trials Swng Arm but could only find one in the US which would cost a fortune to import.

It now seems to me that I should leave well enough alone and concentrate on the rebuild as it is.

Thanks for all your help.

.. 

This photo shows a 21M17--- frame with swing arm , standard size.

You could lengthen by manufacturing copies of the rear spindle location plates with longer length from where it looks like the flat plate is welded into the tubular arm.

I would agree with other opinions though, that lengthening wheelbase would be detrimental to handling