The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: PatM20 on 22.03. 2018 11:44

Title: Swinging Arm Query
Post by: PatM20 on 22.03. 2018 11:44
Hi,

I am not sure if my swinging arm is worn on the right hand side (offside in the UK) where the long wheel spindle bolts into the hub. If it is worn, then it seems to have worn very evenly and looks like it was manufactured that way.

The second shoulder of the spindle is 20mm (first shoulder into the hub, second shoulder to fit the spacer, third shoulder spacing for the chain tensioner/alignment bolt), whereas the slot in the swinging arm is more like 25mm. This doesn't seem correct to me, even if the spacer between brake plate and the inside of swinging arm trues it up to an extent.

If I do need to take it back up to around 20mm, my guess would be that I need to weld up the slot and dress it back to 20mm ish. The altenative would be to build up the spindle and make a washer to fit (the washer being on the outside of the swinging arm).

Your thoughts would be most welcome.

Regards

Pat

ps wish I had spotted this before as the paint work isn't too bad!
Title: Re: Swinging Arm Query
Post by: PatM20 on 22.03. 2018 11:59
Or make a spacer/bush (o/d 25mm, I/D 20mm, width equal to the width of that part of the swinging arm) that fitted inside the slot of the swinging arm and was sandwiched between the spacer (between brake plate and swinging arm) and the third shoulder of the spindle!

That's the no weld messing up the paintwork option!
Title: Re: Swinging Arm Query
Post by: muskrat on 22.03. 2018 18:32
G'day Pat.
Are you sure it's the right swingarm? The 56-57 (for the Ariel alloy hubs) has different size (one side to the other) axle holes.
Cheers
Title: Re: Swinging Arm Query
Post by: PatM20 on 23.03. 2018 07:11
Hi Musky

The answer is I don't know, but UK nearside is 11/16" and UK offside is 1".

I found a post showing A10 dimensions equal at 13/16" either side.

My swinging arm looks A10 with the lugs for an enclosed chain. The rest of the dimensions seem good.

I have an inner ring bearing (hardened rolling bearing steel) that fits perfectly on the spindle, so will probably use that. I can't see that causing any problems and seems a better solution than welding the slot and dressing to size or the expensive option of having a bespoke spindle made.

Regards

Pat