The BSA A7-A10 Forum
Bikes, Pictures, Stories & more => Introductions, Stories, Meetings & Pictures => Topic started by: Superflash on 20.01. 2020 10:54
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Hi guys. New to the forum here as I've recently started the slow, laborious and somewhat expensive project of building a 53 A10 Superflash out of a couple of boxes of sad parts. Have been reading through a number of threads here which have been extremely useful in answering my questions. History has mainly been Triumphs and Harley's, but I saw this odd looking BSA motor on ebay, so thought I'd give it a crack. Be prepared for lots of questions as I progress through the rebuild. Cheers
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Welcome SF, ask away we're a freindly tolerent group, good luck with the project
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SF,
Welcome to the forum. We look forward to the story, the questions and lots of photos.
Richard L.
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*welcome*
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*welcome*
You’re in the right place !
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Hi SF, welcome to the forum. I am getting near to completing my Superflash and was lucky to have started with an almost complete bike as a project. My avatar is the bike as I got it. Any help I can give you please ask.
You mentioned in another listing about part numbers. Do you have the BSA A7 / A10 1949 to 53 parts book with the supplement at the back showing Superflash parts? I also have a copy of bulletin given to US dealers with the clutch parts listed that were not in the main book (attached).
You also mentioned you had a standard head that came with the project and a re looking for a correct one. Are you sure yours is incorrect? A correct one would have a casting number of 67-251 (same as a standard A10 head) and a small 966 stamped under the left hand side of the inlet branch.
Cheers, John
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Welcome aboard! Good luck with that interesting project.
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Hi John. Thanks for the offer of assistance....I certainly think I'm gonna need it. After your comment about the Head part number, I went back to the parts list that I have, and you're probably right. I was looking at 67-0965 which is for a complete head. The number I have matches what you suggested, so all good there. All the valve gear part numbers match the SF list, and are all new. So far I have replaced the following with new parts - Valve gear, push rods, cam and cam followers, pistons and 1 x con rod, mains and big ends, (got crank ground to .020 under. New piston set (.040 over) and cylinders bored, SRM oil pump (because why not???), new timing side bush, all the others look ok. New engine breather oil pressure relief valve and the little spring and ball inside the timing case. All new nuts, bolts, washers and studs throughout.
When I bought the motor on EBAY, he reckoned it was only missing 1 valve.....yeh right. What I've done/bought here is just to replace what really wasn't there.
So, once I get all this together, then I'll worry about such exciting things like electronic ignition, converting an old 2nd hand dynamo to 12v, and look at using a 376/80 carby that I picked up along the way as well. Have got a fairly decent gearbox with 6 spring clutch set-up that I will refurbish with new parts. It only has the duplex primary drive, but I'm ok with that. Not getting too carried away with "must be original". The original idea was to build a bobber, but if I can keep the over-all appearance similar to original, then that will just be a bonus. Regards
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Hi Tony, glad to be of help and great that the head was correct. Have you got the correct frame and any of the correct tin ware as well? Cheers, John
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Sounds like a great project and you have the advantage of having Mike Reilly parts and expertise not far away!
look forward to seeing pictures and hearing progress.
The super flashes are pretty rare beasts and a bit more than the humble plungers can handle. Quite a few unique bits on them I recall.
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Hey John. At this stage I don't have any chassis parts other than a set of 2nd hand plungers. There's a guy down on the Gold Coast called Britcycles. He has a fairly wide range of early BSA parts. Most are used, but look to be in pretty good nick. Nothing a bit of sandblasting and powder coating wouldn't fix anyway. Once I've finished the motor and gearbox, then I'll start looking at a frame. I guess by buying the plungers, I've more or less committed to that path. I had originally been toying with the idea of trying to cram her into a A7 rigid frame that is for sale here. Have bought quite a few bits and pieces from Mike at Mikes Classic Spares. Am fairly lucky to have a couple of good local suppliers, although I have bought a few of the more hard to find parts from Draganfly. Once I've set up a folder for all the photo's, I'll start putting a few up. Cheers
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Hi SF. welcome from the SE side or brisbane. I’m currently restoring a 1953 A10 Golden Flash. Without ready all the threads, are you firmiliar with Mike Riley in Brisbane. He is a true SF man.
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Gidday Dave. If he's the bloke that owns'/runs Mikes Classic Spares, then yes I've bought a few bits and pieces off him, however have yet to have a chat. I'm also thinking that I should probably have a look at joining the local BSA Owners Club. Sounds like they meet monthly down Beenleigh way. Cheers
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Hey guys, just done a dry run to see what little honey traps I'd fall into. Putting the front engine mounts on before the dynamo is a goody...only took 3 attempts... *conf*
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Super Flash......Next trap for the unwary.
The engine plates pictured are from a S/A frame, and won't fit the earlier plunger/rigid type.
As experience tells us, squeezing a fully loaded engine unit into a newly refinished frame is a nightmare, and it is far easier to build the motor into the frame. Crankcases and attached gearbox are quite manageable, the web above the camshaft makes a good lifting handle.
Swarfy.
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Hi Mate, once you have the correct front engine mounts for your frame, the best way i have been told (and used very sucessfully on my 3rd plunger frame) is to lay the engine on its side on a well prepared (Padded) benchtop.
Then overlay the the frame on its side and bolt it up loosely. When done, simply lift the frame back upright, and you have managed to keep all the paint (powedercoating) on the frame !!!
Unless you manage to get the essentials back to front, but also living down under, I assume you can sort that !!!
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As experience tells us, squeezing a fully loaded engine unit into a newly refinished frame is a nightmare, and it is far easier to build the motor into the frame. Crankcases and attached gearbox are quite manageable, the web above the camshaft makes a good lifting handle.
I agree.
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Oh goodie *sad2* I did wonder why they seemed a bit sloppy...thanks for the info.
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Alrighty then. Have managed to get a pair of plunger mounts for 40 bucks each. Will consign the SA ones into the box of interesting but bloody useless parts... Just need to get the spacer thingy that goes in the middle. Still waiting for the piston set to arrive then I can send the cylinders off for the big rebore. Think I shall have to get a decent set of whitworth spanners before too much longer.
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Think I shall have to get a decent set of whitworth spanners before too much longer.
G'day SF.
Get two sets, both ring and ring/open end as well as sockets of good quality. At least 1/4 5/16 and 3/8. Throw in 2BA and ignition spanners. You'll be set for life.
Cheers
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While you flash the cash, a few cheap Cycle and Whitworth Thread taps and dies are worth having, to clean up rusted and gummed up threads. Carbon steel will be fine, 1/4, 5/16, 3/8 sizes cover most fixings. Threads into alloy are Whitworth, Cycle thread on the common nuts and bolts.
Swarfy.
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Ok, stupid question time.... do these "cycle" threaded nuts and bolts go under any other name? The nice lady at the local nuts and bolts shop here could almost get her head around whitworth, but when I asked about cycle threads, she kinda when into a blank stare... *eek*. I'm guessing these are pretty much a Brit Bike exclusive thing yes? I suspect there is a definite difference back in old Blighty compared to the colonies here where everything in any auto shop you care to name is almost entirely metric. Cheers
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BSC, (British Standard Cycle thread). Also known as '26tpi' (though that pitch is not right for all the sizes).
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Ok, stupid question time.... do these "cycle" threaded nuts and bolts go under any other name? The nice lady at the local nuts and bolts shop here could almost get her head around whitworth, but when I asked about cycle threads, she kinda when into a blank stare... *eek*. I'm guessing these are pretty much a Brit Bike exclusive thing yes? I suspect there is a definite difference back in old Blighty compared to the colonies here where everything in any auto shop you care to name is almost entirely metric. Cheers
Most everyday outlets, (Halfords, DIY stores etc.) here would have no idea about Whitworth or Cycle threads.
You have a local nut and bolt store!? I need to use the Internet to buy, well, most things actually.
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G'day SF.
As Jools said most cycle threads are 26tpi for all sizes (1/4, 5/16, 3/8 etc) but can come in other tpi's and be called CEI threads. Brass thread is also 26tpi but has a different thread angle (55 for brass, 60 for BSC/CEI/BSCY).
If you need a 5/16 or 3/8 nut or bolt in a hurry your local pushbike shop has axles (to male a stud or bolt) & nuts in bsc/cei.
https://www.motalia.com/Html/Charts/cycle_chart.html
For nuts bolts and taps & dies. https://www.classicfasteners.com.au/british-threads/
Cheers
ps: another trap are the head bolts in BSF.
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think I'm right in that 7/16 can be 26 or 20 tpi above that it 20 tpi
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Superflash... It all goes back to BSA'S origins, diversifying from gun manufacture to bicycles, hence CEI (Cycle Engineers' Institute). The fine threads were found to be better at resisting vibration, handy to stop thing falling off on unpaved roads. This system was carried over as production got under way with motorcycles. BSCy and CEI are different notations for the same thread system. Thanks to Napoleon we have the metric system, which by all accounts can also have its variants. Being a world wide standard, this is what your local parts store stocks.
Specialist or internet suppliers are your best bet. eBay search should bring up plenty of choice.
Have a look at the literature section of the forum. There is a handy listing of fastener part numbers and their threaded specs. Plus a list of suppliers for most things you will need.
Bill...Cycle thread has a 60 degree thread form. 7/32" to 3/8" are 26TPI. 7/16" and above maintain the thread angle but are available as 26 or 20 TPI, up to 3/4". That's the end of my chart.
Smaller diameters also change the TPI. 1/8" is 40 TPI. 5/32 & 3/16" are both 32TPI, then we are off to 26 TPI at 7/32" and upwards until 7/16" and larger offers 20 and 26 TPI.
Swarfy.
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ill...Cycle thread has a 60 degree thread form. 7/32" to 3/8" are 26TPI. 7/16" and above maintain the thread angle but are available as 26 or 20 TPI
Thanks, Swarfy (76 and still learning or maybe 76 and being reminded) *conf*
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Too true. At 58 it's a pleasure to be able to still live and learn. Thank you all for all the words of wisdom. It's been a privilege. Tony
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Bill,
Generally speaking cycle thread on most bikes is 20 tpi from 7/16" but Royal Enfield liked 26 tpi so much that they used it on almost every thread on their bikes, even over 1".