The work on little smurfs bike continues…(Scott Spark 20 Junior) and I need to call on the advice of STW once again.

I’ve got 2 questions:

– On a frame that has v brake bosses, is it normally possible to remove them? The ones on the Spark look like you should be able to unscrew them – there are 2 flat sides on the boss itself (i.e. the bit the brake hardware slides onto) and if you flip the upper swingarm piece round it looks like the bosses have been screwed into a thread hole. Of course, I can’t the bosses out and I don’t want to potentially damage the frame by trying too hard if they aren’t meant to come out.

– I need to get the lower swing arm off the main triangle so I can check / replace the bearings and get the frame off to the powder coaters but I can’t work out how to get the pivot hardware out of the frame.

Removing a thin plastic dust cover on the pivot reveals (on each side of the bike) what looks like two round tubes of metal that have been pressed into the swingarm / main frame connection point. There is a 6mm allen bolt on one side…and this seems to tie these 2 bits of round metal together. Removing this bolt reveals a 10mm allen key style “hole” on the opposite side. Putting an allen key in this and turning either way results in nothing visibly happening.

There doesn’t seem to be much of a gap between these metal pieces to allow you to tap them out from opposite sides and I’m a bit stumped.

I can’t use photo hosting websites at work but I’ve taken some photos on my phone that I can email to anyone who would like to take a look and offer some advice.

Scott UK aren’t being any help at all.

Thanks all

The brake bosses indeed do unscrew, but may have threadlock on them. Unscrew away!

The pivot bolt will quite often be a large ‘sleeve’ that is the diameter of the pivot/bearing hole with a smaller bolt the other side which screws into it. If after you’ve removed the smaller bolt, and are turning the larger one and it’s turning but doing nothing, it’s likely that it’s just the sleeve turning and it needs a little persuasion to come out. While you wiggle it back and forth, see if you can tap it out from the other side with a socket or, leave the other bolt in but sticking out slightly and give it a light tap to dislodge the main sleeve.

Can you get an allen key into both sides at the same time and unscrew?

Sounds like you are turning on one side but not stopping the other from turning.

Alternatively, the pivot may be a tube which has a smaller thread running through it, and each side a bolt is driven into it. You’d need to have a tool in either side for this too…

Thanks kayak23 – I’ll try unscrewing the 6mm bolt a little so I can get an allen key into the 10mm hole and then try unscrewing both together.

Quick update on this in case anyone else needs the info in the future.

The lower swingarm pivot bushings came out fairly easily in the end. I tried unscrewing the connecting bolt a bit and gave it a tap, and it pushed the opposite side enough to realise it just pushed out. A minute later I’d pushed out both sides and it allowed the lower swingarm to be removed.

I still can’t get the brake bosses off, and I’ve given them some heft. I’ll try soaking them in penetrating fluid a bit but I might need to resort to some friends help to have them drilled out.

I’d like to use one of the frame lugs to mount a guide for the rear brake hose, otherwise I’d be tempted to cut them down a bit and leave them.

In case it helps anyone else – I read that heating the brake bosses helps as it breaks down the thread lock. So, a quick go with the heat gun and they came out quite easily.