Engine/gearbox mounting plates

[RichardL]

This post originally asked which side gets the bent engine mounting plates on a swing-arm frame. Embarrassingly, I lost track of how the mounting plates go together. I have since found a picture that shows this, a picture sorely missing from any of six books I have (Haynes, for example) and from my own earlier photos. Perhaps posting the picture will help someone else, or myself, when next I must rebuild (oh, please let that be a long time!).

Richard

[Rob_Roy]

i get your point with regards to Haynes manual.  Every question I have on the bike seems to be glossed over on the manual.
Rear brake brake light switch mounting, design, operation just for one!

Thanks for the photo

[G/F DAVE]

Hi, Rob best place for a haynes manual is in the bin (unless you need basic settings). You need to source BSA service sheets / Pitmans manuals. I recently found a manual  by D W MUNRO 1955 2ND edition 1960  titled bsa twin motorcycles which covers all models from 1946-1959. This manual covers everything  for BSA twins very informative & includes things like part numbers for gaskets for induction bias /colour schemes for different years etc etc. best regards G/F DAVE

[a10 gf]

Nice book, one on ebay uk right now. Looks like the 1st edition 1955, which mainly covers the early models and plungers.

http://cgi.ebay.co.uk/BSA-Twin-Motor-Cycles-from-1946-Practical-Guide_W0QQitemZ260260327415QQcmdZViewItem?hash=item260260327415

[RichardL]

Gents,

I am in no position to debate with Dave on issues "A10", as he (and others, of course) have provided me with much useful advice. Thank you for that. Flawed as it is, I have found the Haynes manual to be useful, in this, my second engine rebuild. However, now I always check with my other two books (Chilton Publishing and Roy Bacon) for additional information and/or confirmation. If one wanted, one could possibly blame the need for my current rebuild on the Haynes manual, having underemphasized the importance of sludge-trap cleanout and taking advantage of an A10 (can I say?) "virgin".  (I've decided to clarify that last statement. I meant, myself as a first-time A10 engine builder, not three other interpretations that I now think of.)

Richard

[tomkilde]

Regarding the bent mounting plates on the left (drive) side, they are meant to be bent in the front only, right?  Not also in the back, where they overlap and attach to the lower frame cross member?  I think I know the answer already, just want someone with more experience to confirm this before I destroy the freshly powder coated finish trying to straighten these plates.

The plates I have for the other (timing) side are dead flat.

[Swarfcut]

 TomK.     Right side are flat.  Left side are the ones with a bend  at the front  to fit around the crankcase. All are flat at the back end.
    Another example of the benefit of a dry build before investing in a final finish, and never accepting any part as Gospel. Good chance they can be straightened cold with wood packers to protect the finish and a handy press or big vice, rather than unrestrained violence.

    For those searching for a set, B series S/A  look the same as A Series, but the arms on the upper plates are an itsy bit longer. Lowers are harder to tell apart, but again are different.  Usually found when that ebay or swap meet/autojumble  purchase meets the frame, front mounts and engine for the first time.

 Swarfy.