Rear chain guard removal

[Phil C]

On my 1965 B40F, the rear chain guard is held in place by a bolt which fixes a little bracket to the swinging arm, below the bottom front of the rear mudguard. That bolt is very difficult to get at and turn. Turning it a tiny amount and then taking off the spanner to turn it another tiny amount would take ages. And I imagine getting it back in again would be very awkward. Can anybody recommend a best way to undo (and replace) the bolt please?   Phil.

[A10 JWO]

I have the same problem on my 5TA. I took the back wheel out and gave it a birthday whilst doing the chainguard. Fettling 

[Pete A10]

I think when BSA were building the B40 they started with the chainguard and then assembled the rest of the bike around it!! When I rebuilt mine I found it impossible to get at the bolt and nut. Solved it by drilling a 13mm hole in the chainguard opposite the bolt head which allowed me to get a socket and extension in to tighten it. Painted up afterwards and it looks fine though perhaps not for the purist.

[Phil C]

Thanks for this, Pete. At least I'm not the only one who's had difficulty with this.

I don't see quite how you sorted it. You say you drilled a 13mm hole in the guard, opposite the bolt head, which then allowed you to get a socket and extension in to tighten it. Two things I don't get about that:

1. Looking at mine, if I tried to drill opposite the bolt head I'd be trying to drill through the bracket as well.

2. Also I'd have thought a 13mm hole would not be anywhere near big enough?

Obviously you did what you say, but I wonder if mine is different from yours.     Phil.

[Phil C]

Anyone else know a good way?   Phil

[Pete A10]

I think the difference is that I was putting the chain guard on not trying to remove it. I've sold the bike on now so can't look at exactly what I did but from memory the bolt passes through the inner face of the chainguard and is secured by the nut on the inside of the bracket. The problem I had was that I had great difficulty getting at both the head of the bolt and the nut. Drilled through the outer face of the chainguard gave access to the head of the bolt. Magnetically held the nut in place and passed the bolt through the large hole in the outer face, through the standard hole in the inner face and tightened it up with a socket - cheap sockets have thin walls!!!
Not sure if this would be defined as bodgery or clever engineering!!
For removal by this method you would have to accurately mark where you need to drill the hole in the outer face. Maybe remove it by your slow method and then drill the hole when it's off. I seem to recall you can't get the chainguard off without removing the back wheel.
Picture of the bike when I'd finished it attached for interest

[Phil C]

Can't get the chainguard off without removing the back wheel?  Not the other way round?  Phil

PS Nice looking bike, Pete.

[Phil C]

Is it really true that you can't get the chainguard off without taking the back wheel off?  Phil.

[berniej]

Phil, if you can wait a few days I might be able to tell you! My bike was missing the chainguard and I've just found one so will be fitting when I've cleaned it up and painted it.
I'm hoping that I can to it using a long 1/4" drive socket with a flexi piece in if necessary to get square on to the bolt hole. That's the theory - I'll let you know the result!

Cheers,
Bernie

[Phil C]

Thanks very much, Bernie. I'm in no hurry. I bought a flexi drive for a socket but I don't think it's flexi enough. Phil.

[Phil C]

By the way, Bernie, this is what mine looks like. See the little right-angle bracket? The bolt I'm trying to undo is the one at the bottom of it. I wonder if yours is the same.  Phil

[chaz]

Thanks very much, Bernie. I'm in no hurry. I bought a flexi drive for a socket but I don't think it's flexi enough. Phil.

on some difficult parts Ive doubled up on the flexible joints, there is the spring style shaft but not strong enough for really tight fastners and you loose some control and can come off, or the universal joint type , a couple of them keep a good fit.

[Phil C]

It's not very tight, just difficult to turn more than a smidgen each time, because of it being awkward to access. The spanner handle bumps into other things so I can't turn it more than a little bit before I need to take the spanner off the bolt, and reposition it to turn another little bit. At that rate, it would take ages to get it out (and same to get it back in later.) The flexi drive I've got doesn't help - it doesn't flex enough to make access/turning room any better.   Phil.

[chaz]

In that case a socket a couple of Uj's and extensions from the other side of the bike

[SIE7RA]

If you undo the bolt above it , It has a captive nut, you just have to have a long extension .you will probably have to undo the mudguard bolts as well ,because the captive nut will stop you pulling the chain guard out