BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Phil C on 02 Mar, 2020, 16:13

Title: Mystery object (1965 B40F)
Post by: Phil C on 02 Mar, 2020, 16:13
Well, it's a mystery to me. Hopefully not to you.

Just behind the top of the main stand there is a piece of channel-section (extrusion?) about an inch wide, and very roughly, say, six inches long, which spans the frame. The front bottom of the rear mudguard is fixed there by a small nut and bolt.

But that nut and bolt also holds in place this (see pics.)   Could you enlighten me please: what is it?

Phil.
Title: Re: Mystery object (1965 B40F)
Post by: DAVE BRADY on 02 Mar, 2020, 17:31
Hi Phil,

It looks like a bracket from a kitchen unit rather than something that BSA would use.

Dave.
Title: Re: Mystery object (1965 B40F)
Post by: chaz on 02 Mar, 2020, 17:45
same as I thought, they used the pressed dents in the corners for rigidity as a normal bend can flex easier
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 02 Mar, 2020, 17:49
But why would someone have fixed it under their bike?
Title: Re: Mystery object (1965 B40F)
Post by: chaz on 02 Mar, 2020, 17:56
hold the mudguard in place or centre stand up? Heath Robinson may know.
Title: Re: Mystery object (1965 B40F)
Post by: DAVE BRADY on 02 Mar, 2020, 17:58
Phil,

Do you have a picture of it attached to the bike?

Dave.
Title: Re: Mystery object (1965 B40F)
Post by: berniej on 02 Mar, 2020, 18:05
Has someone bodged a replacement for the bracket shown in the pic below (taken from Drags web site)?

Cheers,
Bernie
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 02 Mar, 2020, 18:44
I don't have a photo of it attached to the bike, but tomorrow I'll put it in position and take a pic.

What is that, Bernie?

Phil.
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 02 Mar, 2020, 18:56
I'm wondering if it might be a scrap bit of metal someone has stuck on there to keep oil off the back tyre.
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 02 Mar, 2020, 19:54
By the way, the bolt you see on the bracket is not the one that holds it in place on the bike. I don't know what the one on the bracket does.
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 03 Mar, 2020, 16:22
Afternoon all,

In the garage just now, I had to stop and think for a moment: what was my objective in taking off my rear wheel, chainguard, mudguard and mystery object? Oh yes, I remember, it was to try to see the source of a slight leak (which I can't.)

Anyway, I've just stuck the mystery object back on to take a snap of it (not a very good pic, but the least bad of four efforts.)

Anyway, there it is, with the bolt threads pointing forwards.  Any ideas?

Phil
Title: Re: Mystery object (1965 B40F)
Post by: TTJOHN on 04 Mar, 2020, 11:17
To me, it looks like a bodge to hold the chain guard in place.

TTJohn
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 04 Mar, 2020, 11:41
No, it doesn't hold the chainguard. It doesn't appear to hold anything. It is held in place, on the underside of the bike, by the same screw that secures the front bottom of the rear mudguard.  I can't think what it could be for, unless it's to shield the back tyre from oil. (If that's the case then I think I personally would have tried to produce something a bit neater.)
Unless Bernie is onto something, but I don't know what the item Bernie shows is.  Phil
Title: Re: Mystery object (1965 B40F)
Post by: DAVE BRADY on 04 Mar, 2020, 12:42
Thinking about the oil idea, it may have had mud flap attached to keep oil off the back tyre and road dirt off the underside of the bike.  However, surely any thing hanging down at this position would be hit when the centre stand came up.
If the stand was up would it be near the bracket?  Perhaps temporarily fitted to hold the stand up if the spring had failed!

Dave
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 04 Mar, 2020, 13:36
Well yes I too wondered if there might at some stage have been a rubber flap on it, but if so then I guess there might be a bit of rubber remaining under the head of the bolt, but there isn't. Maybe just the mystery object itself is the flap, that's what I'm thinking. But it's so weird - odd shape, nut and bolt, etc.
Regarding the proximity of the main stand, when it's up, I'll see. I suspect the stand might straddle the object.  Phil
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 28 Apr, 2022, 17:32
This discussion was a couple of years ago. In the absence of any other explanation, I just kind of assumed it might be to prevent any oil from blowing onto the back tyre if there happened to be a leak under the engine or gear box. Today, by chance, I think I've come across the real reason for it. When refitting my centre stand, I noticed the little bolt, which sticks out at the front of the mystery object, acts as a stop for the centre stand when the stand springs back into its retracted position. I guess it was put there because of wear in the centre stand stop. I guess the reason I didn't realise it two years ago was that the centre stand was deployed at the time. Should have realised though. Obvious when you know!

Phil
Title: Re: Mystery object (1965 B40F)
Post by: Phil C on 29 Apr, 2022, 08:13
I said wear in the centre stand stop. Could be elongation of the pivot hole. Other thread discusses (at length!)