swinging arm bushes

andyp · Post by **andyp** » 05 Oct 2008 16:52

is there an easy way to fit new swinging arm bushes ? put the bushes in the freezer and warmed the swinging arm up, then tried fitting the bushes using a vice, finished up breaking the vice. any tips ?

EVguru · Post by **EVguru** » 06 Oct 2008 09:00

Must have been a really weak vice! If you have to use excessive force to fit the bushes, then you'll most likely distort them.

Where did you get your bushes from?

The factory bushes appear to have been fitted into painted bores in the swingarm, but I wouldn't recommend that approach. I clean the bores with an abrasive (a flap wheel on a die grinder works very well) and make my own bushes to be a light press. The bushes end up undersize after fitting (if they weren't already) and are reamed in situ to match the spindle.

I'm leaning towards plastic bushes in future. Acetyl has been recommended to me by a classic racer and I've made a set in PTFE for someone else. Normally PTFE wouldn't be suitable, its very soft and can 'cold flow' but the Morini bush is very wide and seems to be holding up so far. If it does start to distort it's an easy job to convert to a re-inforced PTFE or Acetyl.

andyp · Post by **andyp** » 06 Oct 2008 11:54

thanks paul, got the bushes from nlm, thought i'd cleaned the bores out ok. The old ones were a bit tight getting them out, the bike had been standing in a garden for years but its been blasted and powder coated. do the bush sizes vary between models ? thinking about sending the swinging arm down to nlm and getting them to fit them. cheers, Andy.

EVguru · Post by **EVguru** » 06 Oct 2008 13:01

Go down to Aldi and get yourself a Digital caliper, they've got them for less than Â£10 at the moment.

As I recall, the outside diameter of the bushes should be 24mm. The bores should be a little smaller, 0.05 to 0.1mm (about 0.002 to 0.004 inch). If the bores are just a little small, clean them out with a flapwheel on a drill.