Monday, 20 May 2019

Dry Build - Fitting the Swinging Arm

Next, it's time to fit the swinging arm and understand how the FERC fits around it.

At first, I struggled to get it in at all. It's difficult because the frame tubes behind the swinging arm mount are more narrow than the width of the swinging arm...


The secret is to lift the frame at the rear, drop the swinging arm and come at it from underneath, with the swinging arm cocked over so the offside is higher than the nearside. Once you get the nearside more or less adjacent to the nearside mount, the offside will rotate up into place. This works because there is more space in front of the offside swing arm mount - the gearbox interrupts the nearside.


I made a decision about the bushes - Steve Carter, marathon FH rider from the AOMCC changed his rubber bushes for a pair of oilite bushes and a much larger swinging arm spindle, and I am going to replicate that approach. Those bushes have a reputation for being a bit of a pig to remove. I thought I would try a hole saw, between the two metal tubes and sawing only through the rubber. It worked fine, with a bit of silicone grease to prevent burning but ultimately my saw was too short:


I resorted to the more traditional approach - a twist drill:


This works very well and of course if sufficiently long will cut all the way along the length of the bush:


The next job of course is to remove the outer sleeves from those 'SilentBloc' bushes. Easier said than done.

My first thought was to weld a plate across the sleeve and drive the whole lot out. I got a decent weld, and then proceed to drift it out - and tore the weld out with the plate attached. The sleeve stayed in the swinging arm.


The Dremel is a more traditional approach and works a treat. I cut a slot in one with a burr; the burr was ruined, but cut one slot before is passed away.


Once you have the slot cut, you can prise the sleeve out of contact and it will be loose enough to drift out.


First battle won.