Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board BSA C15 Scrambler project .....

So, in preparation for playing in the woods and running Moto Giro events, I've got a 1961 C15 Scrambler. Two-owner, fairly complete, rolls, has some compression, brakes engage, shift through gears, all the switches and levers move. Needs a a complete going-through, of course. I'll have the appropriate manuals and parts lists for this year, and will search thoroughly through past posts on this and other sites before asking any potentially dumb questions.







Just straddling it and going "Vroom Vroom", it feels like it has plenty of room for me, so that part will work.

I'll be looking at photos to see what the "battery box" area should look like - it looks a bit "homemade" as it is. The numbers match on the frame and the engine at "C15S3692". The original title has a notarized date of 5/20/61 for when it was first titled for the road in Pennsylvania, so I'm going with it's a 1961 unless someone changes my mind by showing that 1962 BSAs were sold in the USA in May of 1961..

I don't know if the alternator or charging system works. I had thought I read that the Scramblers of this era had an Energy Transfer system and no battery, but this one has a "distributor", although what it could possibly be "distributing" to I don't know, since there's only one place to send a spark.

I'll be doing a compression and leak-down test before I take the top end apart, and assessing whether the bottom end needs to be replaced. There's quite a bit of "patina" on the wheels, so I'll be looking to see whether to wire-brush them and go on, or whether a nice set of period-correct aluminum rims would be good. I can see that the rear tire is too big, so I'll look up the modern equivalent of the old sizes, and find some 50/50 road/trail pattern tires.

I'm going to order a 500-pound hanging scale and work on getting this thing down as light as I can. Not for speed, since the best way to do that would be to get some of the lard from off the top of the seat, but for ease of handling and picking up off the ground.

I'll have to count teeth on the sprockets and figure out how to gear it - it has a manhole-cover-sized rear sprocket which looks like good fun on a trials bike, or a fire-road bike at 35 MPH, but I need it to go 50 - 55 MPH without throwing the rod to get me over the back roads from home to the state and national forests and game lands.

Looking at some of the wiring, I'll either buy a wiring harness for it, or make my own, it looks simple enough.

I don't want to take this apart and scatter it all over the shop ... I'll probably start at the front and the back and R&R the wheels, forks, brakes, Shocks, wheel bearings, etc a bit at a time, and finish up with the motor so as to have a minimum apart at a time ....

Lannis

Lannis......the "3692" shows it to be 62 like Steve already said. 61 would have been "2692" ( I think?)

You've got a pretty interesting bike there. Going to take more close up details but IME there aren't a lot of these over here in the States.

It could be even rarer if it happens to be one of the Scrambler Specials.

That tank is a hard find.

Yea.......this is going to be fun.

Gordon

Gordon

Oh no, and here I was just going to go with the "patina'ed" look, and you had to show me this!!!

All I can hear now is "ka - CHING!!" in my head, as I contemplate a speedometer, new kicker, a stock-looking seat, a new taillight, a proper front fender (although I may use the one I have), and possibly a chainguard which the BSA brochure shows, but the restored-bike picture does not and it looks OK.

Since I'll be riding it in the National Forest, I'll need to have a proper silencer on it, not the straight pipe in the brochure, and figure out an air-cleaner for the Monobloc ....

The fun begins soon .... Got to get the Firebird Scrambler off the lift ASAP!

Lannis

Lannis.......IMO it might be worth trying to get a copy of the dispatch records.

I "think" you have a fairly rare (for the US market) bike. Well........I just don't see as many of these as later unit singles. I have a soft spot for that look since my very first motorcycle was a 1965 B40ES (w/an odd frame????)

All those bits you mentioned should be obtainable. The proper ones are probably sitting on someone's swap table.......in the UK ( but you do have connections!!!)

Does the foot peg on the kicker side fold?

The photo of the "restored" bike is just someone's interpretation.....but it sure looks nice.

That rear sprocket looks like my 60s. Best choice for climbing trees!!!

Beauty is in the eye of the beholder.......your bike already looks beautiful to these eyes.

Gordon

I owned a C15S. The original kickstart bends under the footrest and back up. The rest doesn’t need to fold out of the way.

Yep......Gordon

I have some previous experience with one of these in a field, wonderful bike, it had ET ignition , liked a bump start, IIRC the bottom end has better bearings than the stock ceefers, scrambles cam, bumpy piston and big ish carb. A modern front end would shed a lot of weight, this model got the "heavy weight " forks. Get Rupert Ratios books they will be invaluable. Nice find.

It'll be interesting coming up with "the most likely" model of this bike. According to the BSAOC site, the "C15 Scrambler" numbers only go up to 3551 for 1962. So (according to them), this 3692 must be a 1962 "C15 Scrambler Special" model, because anything in 1962 from 3552 to 10001 was a "Scrambler Special".

I'm willing to believe that the "5/20/1961" date on the title is a typo. HOWEVER, title dates are usually well AFTER the model date, as bikes may have sat at the factory or on a dealer floor for years before they actually got titled. You don't see a title that is BEFORE the model year, any more than if I bought a Ford F-150 right now titled as a 2022, it would actually be a Ford 2023 Model Season truck.

I AM surprised to see matching frame and engine numbers. They didn't start out the C15 year with matching numbers ... but I don't know about the "Scrambler Special" models if that's what it is. BSA might have done anything in the way of restarting a sequence somewhere.

Luckily, my mind is not clouded with a desire that the bike be a "matching number" model for concours purposes, nor do I need Rare Bike status. I really need to know what to call it when I order parts, or when someone says "I may have one of those parts if it's a Special, they're different than the regular Scrambler."

Lannis

Lannis wrote...."Luckily, my mind is not clouded with a desire that the bike be a "matching number" model for concours purposes, nor do I need Rare Bike status. I really need to know what to call it when I order parts, or when someone says "I may have one of those parts if it's a Special, they're different than the regular Scrambler."

Rupert's "Lesser Known Models"

I understand you're not focused on numbers BUT........if in fact the frame and engine numbers do match that's a huge difference between that and your 1970 A65 having matching numbers. I have to stick with my "fairly rare" statement. (might have to bump that up to chicken lips) Something you should at least pass on to any future owners.....it would be a shame to just ignore it and somehow they get separated. ( that's the Unit Single fan coming out of me...I can't help it)

Gordon

This thread is going to bring back memories, some good, others not quite so warm and fuzzy. My first "real" bike was a 1961 C15S, frame #C15S3417, engine #C15S2540. It's amazing that I still remember those numbers. It was actually a pretty good bike and withstood most of the serious abuse I sent its way and when it didn't, it was simple enough that I could dive right in to the deep repairs when needed.
Bacon's singles book lists the 1961

Engine: C15S 2112 through C15S 3100 (1962 beginning production number minus 1)

Frame: C15S 2701 through C15S 3600 (1962 beginning production number minus 1)

So your 3692 frame number does appear to be 1962 number.
I think matching numbers would have been a coincidence in these years.

Rupert Ratio's Unit Single book will be a big help to you.

I currently have a 1965 side points C16FSR that I rode the crap out of for years. It's basically stock but with lightened and balanced flywheels and a 69mm Triumph T100 twin piston in it. This piston trick is super handy if you have a rusty or worn cylinder that would clean up at .080" over. I've even heard of using a 71mm T120 piston in these iron cylinders. Apparently they are thick enough though I haven't tried it myself.

So anyway, thanks for starting this thread. Best of luck with the old thing.

Yep, I think all the sources indicate that a serial number (starting with C15S) which begins with "3" is a 1962 model.

The question now is, since 3692 is more than 3100, 3551, or 3600 which is the upper limit number for the C15 Scrambler ... is this bike a "Scrambler Special" as the BSAOC data seems to indicate ... ?

Lannis

No guarantee that it's running its first distributor
but the distributor will have a month and year date stamp

I've been hoping that I can find the "month and year of manufacture" based on the engine number, but no luck so far.

I'll get out my flashlight and magnifying glass and have a look at the distributor.

Is it just called a distributor because it looks sort of like a real distributor? You'd think it would just be a "points housing" like the ones down on the end of the camshaft under the outer timing cover.

Lannis

Yes.

The dating info on this site states.

1962 C15 Scrambles, Engine numbers start at 3101 with frame numbers starting at 3558. (C15S prefix)

1962 C15 Scrambles Special, Engine numbers start at 3101 with frame numbers starting at 10001. (C15S prefix)


Approx 60,000 C15s were produced from 1959 to 1964? They weren't supposed to have matching frame and engine numbers.......could have been the luck of the draw......or a purposed numbering? Either way if they match......it's interesting.

Someone could have pulled the frame out of line and waited for the engine to catch up? It sounds like they were stamped at different times during production?

You gota love BSA......Gordon

Sez "6/60" on the distributor body...?

Answers everything.....

Gordon

Well, it is a distributor, but it only distributes to a single location.


It's good to see that you chose the BSA unit single approach in the end.
The Rupert Ratio books are definitely worth having. He ran a few sessions at Moreton in Marsh.

Where do you get these books for a reasonable price? They're like $100 each at the places I usually shop .... ?

Lannis

BSA UNIT SINGLES..............linked on this site. (for me it's a banner at the bottom of the page) "Archives for download" for downloadable manuals and such........ "BOOKS" for all the Ruperts books!!!!!

You'll find those links under "Resources" on the right side of UNIT SINGLES' home page.

IMO Rupert's "The Engine" is a must. "Everything Else Except the Engine" covers all the different bike parts. "Lesser Known Models" will have a short chapter on your scrambler. You should be able to get all three for around $100.

After looking closely Peter doesn't have much information on your bike at all. No specific Workshop or Parts manual.......just an owners manual. The parts manual he has for the C15 covers several models.

Gordon

PS........email Peter Quick if your looking for something you can't find listed on his site. He's gained a LOT of knowledge/connections since he first open up for business........and he's easy to talk with.

PSS.......he has the correct air filter for your bike listed, used.....and a beautiful new seat......ka - CHING$$$$$

Cover of Rupert's "Lesser Known Models"



and here's what it says about the bike pictured.




Gordon

Gordon - Thanks for the continuing research.

It certainly sounds funny that my bike has a "frame number" matching the engine number. Here's a photo of the frame number C15S.3692 just below the headstock on the near side. Experienced folks may be able to tell whether this is a factory stamping, or someone was satisfying an overly officious Motor Vehicles jobsworth by making the number match ... ?

Lannis, hope I'm not over doing it? I do tend to get carried away. Can you tell I like these bikes?

I've never owned a swan neck frame so I have nothing to compare it to but that frame number looks good to me. I also agree with you that is probably the factory paint.

SO.........maybe IF someone "re-numbered" something it might have been the engine?

Do you know how much it costs for dating info now a days.......or if they even do that anymore?

Looks like I had a complete C15S engine, 3333. Alex got it along with some other bits??? I remember him being here but that's about it. CRS. Most of my other C15 engine stuff is for road models.

It would be an oddity if your numbers left the factory together. If it were mine, I'd have to know....if there was a way.

I've got a couple of frames that I'm pretty sure are restamped or mis stamped. The numbers look good (to me) but don't match some of the stuff on the frame......like a VS number with SS center stand lugs.

I have a new project at work that starts tomorrow....maybe that'll slow me down a bit

BAD thing about having time on my hands and browsing through used and new motorcycle bits on Peter's site looking for stuff for your bike.........I ended up spending $200 to add to my horde.

Gordon

Both the UK BSA Club and the VMCC have a machine dating service. The VMCC will do 2 bikes/year free for members, otherwise 10 or 15 quid. I think the BSA Club is similar, but don't know if affiliated BSA clubs count.

They were all rather stretched over the last couple of years, but seem to be getting back to normal.

It's certainly worth checking up on rare and unusual machines, and I reckon this one counts.