Hi,

I have recently rebuilt my montesa forks which are fitted to a Francis Barnett for trials, everything seemed fine when i rebuilt the forks with new oil seals.

The problem is one minute they are fine, compressing and returning in a smooth fashion then for no apparent reason they will only compress about half way with no return, I have studied the assembly drawing time and time again and I cannot understand what the problem is.

Anyone any ideas?

Nige

So sometimes they work normally and then randomly they will stick half way down and not return to top?

Can you lift it back up?

Pul the wheel, pull the caps and spring/springs and slide the forks through their travel range looking for a sticking point

hi try undoing wheel spindle nut then see if its any better your spacers might be not quite right or mudguard stays best of luck stan

ive had an alloy part inside the inner tube sticking ,had to sand it down , it must of swelled

Some Montesa forks use an anti-bottoming device which can swell/bell causing the forks to stick, but that is when they are fully compressed, not half-compressed.

It is also possible that one or both of the tubes is bent, and that when you reassembled them into the triple clamps, the bend/s might be causing a sticky spot. I would look for bends in the tubes. If they are both bent you may get away with aligning the orientation of the bends to be fore-aft and both the same way, so that the mudguard mount and axle fixing location holding the fork bottoms in the one position does not cause the bends to cause a sticky spot. Better still to have the tubes straightened.

Maybe there is a little dent in one of the fork bottoms that combined with a slight tube bend, is causing the jamming. In this case you should be able to get them to move freely by rotating one or both of the tubes in the triple clamps so that the bend moves the "high" point of the tube away from the dent.

It is worthwhile to note that on some older Montesa models the fork tubes bend easily. Take out the forks and roll them on a flat surface. Granite kitchen tops are great for this! (yes love, the forks are clean.....)

Mark the location of the bow "high spot" on the front edge of the fork leg with a little notch filed in at the top. Assemble the forks with the notches facing forward.

Works like a charm!

Regards

David

Edited November 8, 201312 yr by farmer58za