Martin Bromage's Hybrid
This is my BSA C15/B25 Hybrid. It is registered as a 1967 model C15 and
is powered by a C15G/B25 hybrid motor. The B25 top end was crafted onto
standard C15G crankcases by machining out the crankcase mouth and fitting
an alloy spacer. It has a twin plug head with 8.25:1 compression. Within
the motor the rocker arms and valve train are lightened and the gearbox is
close ratio. You can see in the photo the drilled camshaft gear. The
bottom end of my bike is pure C15 and uses a G crankshaft and crank cases
with the twin ball main bearings and roller bearing big end. This is
practically unbreakable in a C15 being designed for the larger competition
350cc B44. I had a spare C15G engine to hand and the B25 has a doubtful
reputation for breaking con-rods [I concede the latest B25SS alloy rods
are reliable if set up properly and you filter the oil correctly] so I
went with what I had. The engine was built and tuned by Dave Hopwood, the
London based BSA singles expert.
It uses Boyer Bransden 12v electronic ignition with a Dynacoil dual
output coil. The carburettor is a 28 mm 928 Concentric. The cycle parts were also beefed up with steering head taper roller
bearings together with a modified D & C Classic M/C silent block swinging
arm bush kit.
It is extremely quick and can reach 70 mph easily. Unfortunately the
standard C15 front brake is too poor to use the performance regularly but Iím
working on a TLS conversion.
To be honest I think some or all of this conversion has been done
before. I know B25 barrels have been used on C15s to save weight for
trials work but they use the original C15 head. I wanted to use the B25
head as the C15 head doesnít have the greatest valve geometry & breathing
Click on photo's to enlarge
Click on photo's to enlarge
I found your excellent C15 site whilst researching the bike I have just
purchased. I thought that you might be interested in the attached photos
as I've seen no other C15 like mine, although I am sure there must be.
My C15 was bought from a friend who wanted to thin his collection; he
had owned it since 2004 and being such a pretty bike I could'nt resist it.
The engine is 1964, it has a glass-fibre tail/seat unit and what looks
like a 'Spitfire' style glass-fibre tank, rear-set folding footrests,
clip-ons, alloy wheels with stainless spokes, alloy mudguards and a goldie
type silencer (silencer!!!!...hardly). The first registration date on the
V5 shows as 1979 but the year of manufacture was 1964. Looking at all of
the history that came along with it whoever owned it in 1990 spent a few
quid on it. I don't know if it had the Cafť Racer treatment then or prior
to that but I think it's a very pretty bike. It's been to the festival of
1000 bikes at Mallory park a couple of times and also paraded at the
Goodwood revival meet. It was also at the BSA centenary run in 2001 as it
was seen and admired by many.
There seems to be very little on this bike that's standard C15 but I
love the way it looks and thanks to a 'Goldie' silencer it sounds
fabulous, not sure my neighbours agree though.
I decided not to strip and rebuild the bike as I like the patina of age
and history that it's currently wearing; the battle scars add to its
character; rather I'll just tidy a few bits up and enjoy the bike. I'd
wheel it into the living room if Mrs P would let me as it is so nice! My
first task after the initial inspection, clean and polish was to line the
glass-fibre tank, I'd read the horror stories regarding the effects of the
ethanol in modern fuel so decided to waste no time in doing so as I can't
track down where it or the seat unit came from.. Next task was to re-mount
the speedo centrally on a more suitable bracket as it originally had a
huge chrome affair which had provided a home for a dummy rev-counter as
well! After the addition of new brake and clutch levers and a bit more
fettling, cleaning and polishing I felt that we were ready for our first
classic vehicle meet. I was impressed that we were awarded 'Best
Motorcycle', as was the only other entrant, a Sunbeam pilot, a nice chap
(and fellow West Ham fan) who was bored of being the only bike year on
That was all in the Spring of 2011 and since then I've had a lot of fun
with and on the bike, to such an extent that often the Triumph's been left
sulking in the garage (my other mount is a 2007 Triumph Speedmaster) when
given the choice of which bike to ride. I'm enjoying my first foray into
classic motorcycling and excepting and embracing the wet-sumping, sticky
carb float, wooden brakes, and non existent tickover as all part of the
I plan to keep it clean and on the road; enjoy putting a few more miles
photograph shows the bike resplendent under the Girling Tower at the
Goodwood motor circuit breakfast club back in September 2011 showing off
its cheeky pretend race number plates. Having had the carb in bits the
night before I was praying that the float wouldn't stick whilst tickling
it during the start up in front of an audience, what I wasn't prepared for
was the kick-start snapping which resulted in an authentic 'racing'
bump-start alongside the pitlane. Once again all part of the ownership
Hope you can include this on your great website.
Jones 1959 Green Machine
I brought this bike approx 3 years ago
(2008)as a retirement present to my self the wife got a Porsche (only
joking). Since having the bike I have had good use from it showing it at
rally's and at local meet ups; I have made 101 new friends with it. About
the bike its self I have replaced many parts and this year I have had the
colour changed to green. It started it's life as maroon in 1959 and was
changed in 2004 to bright red, but I always wanted it as a green one. I
have had a love a love for the BSA C15 since I had one 1962/63 and the
bike I had was a maroon one; I could not get a green one so this is why I
now have this one done in green. Back in the 1960s it was a pleasure to
ride this type of bike as the pace of life was much slower and you could
go everywhere without hold ups. At the time I lived not far from the Ace
Cafe in London just outside of Harrow on the Hill and a day out to
Southend on Sea or Margate; at least the bike has not changed over time.
Pearson's C15 Rigid
is a 1964 model, but is quite unique as it has been converted to a rigid
rear end. The main frame looks standard but the rear swinging arm assembly
has been professionally modified to bolt onto the sub-frame mounting lugs
and the swinging arm pivot point. The lower swinging arm has no bolt eyes
for the rear damper units or passenger footrests, just the holes for the
chain guard. Originally painted red and owned by the post office, this has
morphed into a pretty looking bike at some point in the past. The current
owner is trying to trace it's history, so if you know of it, please
Ledger's 1965 ex-Police Bike
Here are a photo of my 1965 c15,
originally a police spec model from the Carlise/ Northumberland force. Both
engine and frame numbers are as should be at the date of registration
! I've spent two years doing a full rebuild. I have fitted a larger
7" in headlight and speedo, also the sweptback exhaust and
"mini" Goldie silencer! It sounds quite nice too! Bought it from
Armours. Hope you like it.
Your website was invaluable in many aspects of the rebuild and was used
many times !
Excellent and very informative........
I have 2 C15S's. 1 a 1963 C15T and the other 1962 C15S most
likely from the USA which I have
converted for trials use, both have different electrical systems. The C15T has coil ignition and 12 volt lights as per your
other has 2 primary coils for ignition and 4 primary coils for direct lighting. The ignition appears to be factory
standard with the 2 primary
coils as a separate circuit with different voltage and resistance to the other lighting coils, (this is a 5 wire system 3 for the lighting which
can give you 6 volt or reconfigured for 12 volt and 2 wires for the ignition circuit.) The ignition is wired to a secondary coil though the
breaker points to complete the circuit, just like a magneto ignition. I use the lighting coils to run cooling fans on the engine in summer. The
engine number for my bike is C15S 4209 with frame number C15C 471 1963 I think. I have sent some photo's of them, the blue T model and the black
Brian - Phoenix, Arizona
I am the 2nd owner of this 1964 C15 Single. I acquired it from the original owner who was a friend
of the family. As a kid I remember him riding it around the neighborhood....after many years passed, one day I asked whatever happened to it
that old bike. I didn't even remember what it was (I was too young). But I wanted a project and new he had it somewhere. It was sitting outside
UPSIDE DOWN through 13+ Wisconsin winters! I graciously asked to rebuild it - he agreed and said "have fun it's been good to me". I
have had the bike for two years now....every thing is original except a few cosmetic things - badges, tail light lens, mirrors etc. I don't
think I plan to fully restore it for awhile, its a (almost ) daily rider. right now I'm enjoying it too much. plus I like the original
condition. Maybe when I move on to the next bike ( Norton atlas ) I will do a full and correct restore. Maybe. It starts first kick and purrs
nicely. Brian Breider.
sending you some photo's to add to your website. As you can see its a C15 of 1967 vintage and here is a "potted history". The bike was
first registered on the 29th of March 1967, I bought it from a relation down in Milton Keynes in 1997, he had
got it from a friend who had had it stored in small boxes under a bench for a few years, it had been put back together quite well and during our
first summer together we covered a few hundred pleasant miles, then disaster ---- the big end and main bearings rattled, seems like its long
period of rest had rusted the bearings so it was out with the spanners and a full overhaul ensued, I had a C15 in the early 1960's so seeing the
engine in bits was like meeting old friends once more, it was the following summer before we were one the open road again and enjoying the
fruits of my labours, then disaster struck again, the engine stopped and I was stranded miles from home but was saved by the wife and got towed
home by hanging onto the nearside doorframe of the car, which is not advised so now invested in a trailer, the problem, top of piston sheared clean
off, but after a visit to Don Laws in Hull and a new second-hand piston found we were back in business, not bad for £4.
Things now seem quite uneventful after those incidents, it starts first kick and apart from the usual ceefer noises runs like a dream.
As a youth I always wanted a C15 since my friend next door owned one. Unfortunately I couldn't afford a new bike
so I was stuck with my Francis Barnet. Although it was reliable it didn't sound like a C15! After passing my bike test I didn't want a small
bike anymore and like most of my mates I was into something bigger.
I have just started to restore a 1960 C15 standard model (my first project).
you please tell me what colour red it should be I have a parts book 1959 to 1962. The 61 colour is Devon Red
but nothing is mentioned about the 60 model. I have eventually got my C15 registered and I am now riding it. I converted it to 12V as per your
drawing, when I turn the ignition on it shows a discharge on the ammeter before the engine is running is this normal? I would like to travel
with my dipped headlight on, if I do the ammeter shows a constant discharge do you think my alternator is weak, the heat sink with the Zener
never seems to get hot even after 20 miles at 45 mph. This petrol debate confuses me even more than the electric's, I filled it with a gallon of
Unleaded to get it mot'd I then filled up with LRP and noticed a drop in power, so I drained that off and filled up with unleaded and added
Millers Petrol additive based on Manganese, the bike went better but seems to lose a bit of power once it is hot (I read that unleaded burn's
hotter than leaded) do you think the tappets need a bigger gap. What are your thoughts on the petrol debate. Hopefully next year my Brother and
me (He bought a 250 AJS CSR in beautiful condition) will see you at one or two events but living in North West Lincs we have a long way to
travel, we normally go to Newark Auto-jumble being the nearest venue. Thank you for your e-mail how to test my alternator I will try that. Here
is a picture of my bike.
Sorry itís taken me so long to reply to your email, been so busy at work .Your
photos were very helpful, things seem to click into place as soon as I saw them. I have managed to get hold of a new steel rim from Burton Bike
Bits, who were very helpful. Itís all back together now and looking quite good. Iíve sent you a photo so
you can see what Iíve been up to . Just got it started for the fist time, sounded great. Still got a problem with the fuel mixture being too
rich, Iíve lowered needle as far as it can go, It's made a bit leaner but could be better. Checked all the jets and have all the right sizes
for an SS80. Any Ideas? Came home from work, started it, put it in gear and we were off down the road. FANTASTIC. Thanks for the help.
R. Gough II's C15 Scrambles & Trials (USA)
I am currently restoring a 1960 C15 scrambles model. Thought you might
like to have some of the first photos. This particular one came with
direct AC lighting. I believe it is a US only model (not sure). Motor #
C15S 685 .The project has taken the better part of a year. The original
frame was badly twisted. I managed to find a new 'old stock' frame
that had never been used. I am very pleased with the performance. Happy
This is a photo of my BSA C-15T. Thanks for using my bike as an example
of what one is supposed to look like. John R. Gough II in sunny St Pete, Florida
Hello! Just want to thank you for your informative website, that helped
me restore my C15S from 1962 (even though somewhat "trialified",
but user friendly:-))
The bike was imported from USA in 1994, apparently picked up from a
backyard in California where it has been since the late sixties. The
camshaft was replaced with a slightly hotter and the ignition rotor was
180deg off.... Obviously something went wrong in the reassembly and the
bike was left to rot. Most parts are just tidied up from surface rust, but
fenders are replaced and a new seat fitted.
I just found your great C15 web site---great job. It brings
back a lot of great memories. I had a 1960 & a 1964 C15S Starfire
scrambler. These models were very popular at the race track in the early
60's. About 4 years ago I purchased a 1965 Starfire Scrambler. I bought it
from the original owner and it is nearly 100% original. I have attached a
picture of the bike.
I am also in the process of building a C15S Short Tracker.
This type of racer was used on the ľ & Ĺ mile dirt track ovals.
was given this BSA when I was a 12 years old by my dad and I have been
working on it since with a little help from my dad. After 3 years I have
now got it to the stage you can see in the photo, but it is still 'work in
progress'. The next stage is to convert it to electronic ignition and to
replace the Jap shocks with British ones.
I also own a standard C15 which is not a 100% built. I hope that when I
am on the road I will be able to do some long distant touring, like the
guy on your website, as at present I am not old enough being only a 15
year old school boy.
This is my other C15. I was originally going to put it
into a road bike but I loved my C15T that much I thought I would build
another. As you can see it is not a trials it has 6/1 piston and a small
valve head and also trials gearing. This bike was not built to be serious
as I am only using it for fun and to practice on, so I do not damage my
C15T which. I will send more photos as I am still in the middle of
If you would like to add some photographs of your bike
and a bit of a write up about it, please email me.