Plunger service

[Greenfield]

This question covers many of the older bikes, not just singles. I've just bought a 1950 B33 with plunger suspension to keep busy over the winter. There's certainly lots to do. Can anyone tell me what the length of the plunger springs should be and is it possible to dismantle the plungers without tool 61-3222 as in service sheet 213?
Cheers

[martinh10]

I can't help you with spring length but regarding reinstallation without the special tool, I used 10mm threaded rod and two 3mm thick aluminium plates slotted for removal (similar to the picture in service sheet 213). It worked quite well with plenty of grease on rod/nuts and plates. As always when working with compressed springs care is needed especially when removing the plates. As it says in the service sheet, the springs go with quite a kick when released from the frame.

[martinh10]

I should have read your question more carefully! I managed to tap out the centre column quite easily without the special tool so I would say it is unlikely you would need it for complete dismantling.

[Ian C]

I should have read your question more carefully! I managed to tap out the centre column quite easily without the special tool so I would say it is unlikely you would need it for complete dismantling.

The tool definately recommended for re-installing though.. I made mine from M12 threaded rod and some scrap strip steel I had knocking around. If you have access to a Lathe and Pillar Drill this would be easy to make.. HTH

[Greenfield]

Thanks both. I'm quite used to cobbling together tools for the bikes. As long as I can get the plungers apart, I'll then know what's needed to reassemble. They're pretty awful externally but with so much grease around, we'll see what they're like inside. Draganfly shows the top spring length as 160mm long, so that'll give me a starting point to see if they've settled.

[DAVE BRADY]

Hi Greenfield,

Plenty of grease is a good sign.  I always pump the grease in until it come out from the cover and wipe off the excess.  During use some more grease will come out and after a while it will stop.  When it does stop do not wait too long before filling them up again.

Dave.