Progress (1953 BSA golden flash)

[rowanbsa]

So engine is finally out. Gear box sprocket teeth were well rounded and curved so a replacement has been purchased.
With the engine out I thought it might be a good time to crack open the rest of it and make sure everything is as it should and a give everything a good clean, make oil reservoirs are clear etc.

It has been re-bored to 0.40 which I've been reading is the maximum for an A10? Without a sleeve or new barrel? Unless somebody knows otherwise.

One of the bolts on the gear box attachment to the crank case was missing because the holes didn't line up correctly. Has anyone ever come across this problem? I was thinking perhaps the gear box has been changed? Although looking at the parts manuals, all of the ratios and the gear box case for the B31,B33,A7 and A10 of the 50s are the same? Hopefully that is the case because the mechanism is so smooth, smoother than the modern bikes I learned to ride on.
Also, can anyone tell me a reliable and reasonable place to buy a good quality rear sprocket (42 tooth) in the UK?

Richard

[Greybeard]

I've been happy with spare parts from Draganfly, other folks have had issues with them.

[cotterpinkid]

Just (Friday) fitted a 42t, purchased from SRM, to my '57 plunger. All the bolts lined up nicely and the bearing fit was excellent.

[rowanbsa]

Thanks for the info.
Would you mind sending me the URL for the sprocket from SRM?
I can't for the life of me find a sprocket on their website, there isn't a search box either.
Thanks
Richard

[cotterpinkid]

There you go:

http://shop.srmclassicbikes.com/product/a10-plunger-rear-sprocket-brake-drum-42t-made-uk

Brian

[rowanbsa]

Thanks, I don't seem to be able to "add to cart" from my phone so I'll give it a go when I'm back home.
Have you any pictures of your A10? How long have you had it? I'm only really getting to grips with mine.

[Greybeard]

Have you any pictures of your A10? How long have you had it? I'm only really getting to grips with mine.

My machine is '55 Plunger. I've owned it since the early 1970's. For most of that time it languished in various garages as we brought up a family and moved house several times. This means that my bike really only has about 24 years of actual use in the last 62 years. When I retired a few years ago I restored the old girl and she looks and rides lovely. Video here: https://youtu.be/nrOfq1O-gV8

[cotterpinkid]

A picture for you Richard. I've owned it since my teenage years some 37 years ago (where did that go?). Whilst most of my mates were burning up X7's, RD's, LC's, 740 4's etc. I jumped ship and bought this off a mate who was going to use it as spares for his plunger outfit. I used it regularly as my daily hack until I got four wheels and a girlfriend. It then languished in the garage for a number of years before I rebuilt it and then has subsequently languished in the garage again. I've just regained a little interest in it and decided to put a solo rear sprocket on it and change the cracked oil lines. It may even get a run out this year!

[Topdad]

Go on do it ,can't you see the bikes straining there to get on the road 

[rowanbsa]

That's a beauty, exactly what mine is supposed to look like.
Some asbo teen between now and 1953 has sprayed over the chrome on the tank (I can tell because where some of the paint is coming off there is a nice layer of chrome beneath it) but I kind of like the oily rag look anyway.

[cotterpinkid]

I've been down the shed for a couple of hours yesterday and today, oil lines and oil changed and back wheel back in after sprocket change. I have a gallon of petrol ready to threaten it with........

[muskrat]

Great work cpk, she looks great.
Hope she doesn't have the huffs after staring at the Velo sign so long 
Cheers   

[Greybeard]

Lovely. Takes me back four years to when my one was completed 

[mikeb]

Richard:

re-bored to 0.40 which I've been reading is the maximum for an A10

A10's readily go to +080 (i'm running that size, tho JP's for my sins) and some (like RR) say +100 is feasible.
your next step is +060 which is readily available

btw - nice looking bike

[duTch]

 Sarted this a few hours ago and mikeb has rounded me up in the meantime, but for what it's worth....

 

It has been re-bored to 0.40 which I've been reading is the maximum for an A10? Without a sleeve or new barrel? Unless somebody knows otherwise.

  I think the + 0.040 is the max factory oversize. I can't see that small fin barrels would be any different, but I believe +0.60 or more is common and I have them in my B/F-T/F barrels on my ~'52/3 Plunger. There's lots of topics on this you can read. ...


 

One of the bolts on the gear box attachment to the crank case was missing because the holes didn't line up correctly. Has anyone ever come across this problem?......

 That's interesting- have you checked the other sets of the holes to see if any align better than the others ?

 The way i see it is important for the mountings to be correct to ensure that the crank and G-box mainshaft are parallel and not 'twisted', and also for the primary to align properly.