BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: MITCHELL on 13 July, 2017, 21:02:27

Title: A65 rebuild
Post by: MITCHELL on 13 July, 2017, 21:02:27
Evening all, more advice required I'm afraid, have built the front forks only to find one side has no circling grove, anyone throw any light on that? Also rear hub,cleaned everything up, wire brushed the sprocket back to bare metal and not quite sure of what Finnish would be best, open to suggestions....
Title: Re: A65 rebuild
Post by: Bess on 13 July, 2017, 21:42:39
Hi Mitchell,
                I normally fit new sprockets and they look like they have been galvanized. When in use the sprocket loses the protection due to chain rubbing and weathering. If I was going to use a used sprocket I would spray with a bright, galvanize rich spray paint.

I'm not sure what you mean by no circling groove, a photo would help unless others understand.

Good luck with the build...
             
Title: Re: A65 rebuild
Post by: JulianS on 13 July, 2017, 22:31:34
Do you mean no groove for the circlip which retains the top fork bush on pre 1966 models?
Title: Re: A65 rebuild
Post by: MITCHELL on 14 July, 2017, 07:53:57
Ah, predictive text, catches me out all the time,yes it's circlip grove. I did think about a new sprocket but the old one looks fine, the teeth are quite uniform with no curving or chips,but you've got me thinking again now!!!
Title: Re: A65 rebuild
Post by: Bess on 14 July, 2017, 08:47:58
Hi Mitchell,
                I have fitted new sprockets mainly because I have had to. To help me decide with a reasonable sound used sprocket I check as you did, but also fit a new chain completely around the sprocket and pull the chain to check its wear.

If possible a image of the forks would help.

Best wishes...
Title: Re: A65 rebuild
Post by: JulianS on 14 July, 2017, 08:54:09
Hello Mitchell

What year is your A65?
Title: Re: A65 rebuild
Post by: MITCHELL on 14 July, 2017, 10:45:40
It's a 1964 star
Title: Re: A65 rebuild
Post by: JulianS on 14 July, 2017, 13:06:03
The nearside fork leg was a part common to the A10 A65 and B40. During 1966 the B40 was the only bike being made using that part and it was modified to remove the circlip groove and use the top bush spacer introduced on the A65 of that year.

The offside leg was a slightly different part from B40 to A10/A65 - the spindle lug was narrower on the inside to accomodate the closer spacing of the B40 forks. This part does also fit A10/A65 (been there and done it). It was also modified in 1966 as above.

So I suspect that your fork bottom is actually a 1966 B40 one.

Dont panic because you can use the bearing spacer mentioned above, or it might already be there, and it does make things easier, not having to struggle with the circlip. It fits on the fork shaft under the oil seal holder and above the top bush narrow end to bush.

First photo shows Parts Service Bulletin G38 of January 1967 introducing the deletion of circlip groove.

Second photo shows the top bearing spacer. Part 68 5134.
Title: Re: A65 rebuild
Post by: MITCHELL on 14 July, 2017, 15:26:02
Hi Julian, brilliant,that also explains the part I have left over that I couldn't find anywhere in the workshop  manual  "the spacer" although mine is a bit mangled ( not by me I may add  it came in the basket like it).I'll have a bash over the week end and come back if I struggle, thanks again. Thanks Bess for your input as well, think I'm going to owe you fellows a beer when this thing is up and running.
Title: Re: A65 rebuild
Post by: Bess on 16 July, 2017, 23:17:23
Hi MITCHELL,
                    Thanks for the pint of beer offer, most welcome but I'm not really a beer drinker. Can I trade for a pint of Creme de Menthe?

Thanks.........
Title: Re: A65 rebuild
Post by: MITCHELL on 17 July, 2017, 19:14:37
By the look of that photo A R H positive would perhaps be apt   😊
Title: Re: A65 rebuild
Post by: Bess on 18 July, 2017, 21:10:01
 :) I,m not to good with selfies, it wasn't my best side on the day ;)...
Title: Re: A65 rebuild
Post by: MITCHELL on 19 July, 2017, 21:19:53
Ha,or should that be the modern LOL, anyway on a slightly more serious note  I got to compare the rear sprocket with a new one for a Norton, difference is to obvious not to go for a replacement,if that makes sense plus the new comes chemically blacked.
Title: Re: A65 rebuild
Post by: Bess on 20 July, 2017, 09:37:07
Hi,
    Not to sure if this will help in your decision.

 All the new sprockets I have fitted have been plated, not sure if this was the manufactures original specification.
 If you want the sprocket chemically blacked (I apologise now if you are aware) this can be done on the one you have by cleaning, polishing, heating and plunging in oil.

Best wishes...
Title: Re: A65 rebuild
Post by: MITCHELL on 20 July, 2017, 19:51:20
Hi Bess, no I was not aware of that process, another snippet to log in the grey matter,but I've made my mind up new it is,thanks again for the help so far, ill be back with more soon probably.