V-Twin-Innovator- News page 11


Return to Index page: V-TWIN OBSESSION

Previous page: V-TWIN NEWS PAGE 10

Next page: V-TWIN NEWS PAGE 12

Posts dated in red start chronologically from the bottom upwards on this page






fitz3 fitz6 fitz9 s-l1600

The project was started in 1976 and completed in 1978. "Engine-designer" Gerald Fitzpatrick designed and built this 1000cc special using two BSA B50 top ends with a 10:1 compression ratio (accortding to the following article), on home-cast crankcases that he designed himself. It was a 60-degree vee. The crankwheels and crankpin were made by Gerald in his shed and he used Matchless "knife and fork" con-rods (presumably from a model X). Here is a PDF of the magazine article from Mororcycle Mechanics April 1978: MM April 1978

According to the following article (source for following pictures), http://www.b50.org/vtwin.htm Fitzpatrick offered it to Triumph, who considered producing the engine, but then decided not to, due to tooling costs. It was ridden for 2 years and clocked up 2000 miles, then went into dry storage. After 10 years, it looked like this:

vtwin1  vtwin3 vtwin2 vtwin4



heemskerk1c heemskerkfront heemskerk3 heemskerk1


Also started in 1976, Jan Heemskerk, an agricultural machinery test manager in the Netherlands, who owned an AJS 7R racer and used to own a Vincent, decided to design and build a modern v-twin that he considered BSA could have produced. The project was completed in 1982 .It was a 50-degree vee, like the Vincent, with Vincent-type big end bearings. It has chain-driven SOHC (single overhead camshaft) heads and chain tensioners similar to those on the AJS 7R. You can read about it in Alan Cathcart's article in Classic Bike from May 1984... read it below - (click on picture)... and articles translated into English from two Dutch articles. The originals are in: Motor Sport Nieuws jrg.17 #195 1982 and Weekblad Motor (date unknown):

heemakerk56 s-l1600-3  heemskekarticle Heemskerkarticle1 heemskerkarticle2 heemskerkarticle3 $_12

From the three articles, we can summarise the technical specs as follows:

1065cc* 50-degree v-twin *84mm bore x 96mm stroke * 2 valves per cylinder * Horizontally divided crankcase * Wet sump lubrication * Chain-driven overhead camshaft * Unit construction * BSA B50 cylinders, heads and pistons (modified) * Home-designed and cast crankcases, timing cover, camshaft, cam-chain tunnels, cam-follower housing and covers * side-by side Vincent con-rods* Camshaft adjuster coped from AJS 7R racer * Norton Commando alternator * Eccentric groove instead of holes for crank-balance * Triple-row roller big end bearings on EN36 crankpin * 2 x 30mm Amal carburettors * Air filters from BSA A65 * gearbox exterior from Norton/AMC * 4 gears from Norton Commando* Home-designed and built frame (single-tube backbone and twin-loop cradle) * Triumph handlebars, fuel tank, wheels, forks and brakes * Isolastic engine mounts inspired by Norton Commando * crankshaft and camshafts homemade * Cam grinding by Piper, UK * Cam-chain tensioners: “Weller” like AJS 7R* Cam-chain: Norton * Norton Commando clutch * Commando Triplex primary chain * Chain-case: Norton Commando * Oil filter from a car * Crankshaft gears (timing side and drive side) : Norton * Intermediate timing gear wheel: BSA * Camshaft drive gears: Norton * Home-made oil pump * Exhausts made by “London” in Hilversum, Netherlands * Manifolds: home-made * Silencers: 750 Commando * Marzocchi shocks * Saddle: home-made * paint by GL Paints * Avon tyres



In 1984, an engineer called Owen Evans wanted a British v-twin, but the price of Vincents and Broughs led him to design and build his own. Evans went to visit Gerald Fitzpatrick and then designed his own version of the idea. Like the Fitzpatrick, it was a 60-degree vee of 1000cc using two BSA B50 top ends on his own crankcases, but he reduced the compression ratio to 9.5:1 and used Harley 883 Sportster con-rods. The work on the engine started in 1984 and was completed in 1988, when an article appeared in issue 4 (January 1988) of British Bike Mechanics (later changed its name to British Bike Magazine). You can read the whole article here: http://b50.org/mags/bbmjan88.PDF

evansb50 evans5 evans9 evans7 evans2 evans1 ervans3 bbm-jan88


After 8 years work, the bike was running by October 1992, but there were some teething problems. After 300 miles, the front cylinder liner cracked and the piston was damaged. The CCM pistons were replaced with B50 ones, the CCM oil pump was modified to an increased capacity and oil jets were added to the base of the cylinders. By 1995, 700 miles were ridden on the bike, with no problems. You can read an article all about it in British Bike Magazine issue 91, from April 1995. Here are some pics from the article:

v60g v60f v60e v60d v60c v60b v60 s-l1600-1



The bike was spotted a bit later, with a disc brake. In order to fit this Norton Disc, Commando fork sliders were fitted.

The bike has now come into my possession, having been in a garage under a tarpaulin, near Portsmouth for 18 years. This is how it looks (March 2017) before being renovated:

100_5985 100_5986 100_6002 100_6004 100_5993 100_5987

Watch this site for the progress. Hopefully on thje road by Summer 2017!

IMAG2559 IMAG2593

...Ok... Autumn 2018 and NOW the Evans is on the road!

IMG-20181113-00753 IMG-20181113-00754 48053367_10156575812786885_4622904666278068224_o



weslakeowen weslakeowenb s-l1600-2

Owen Evans followed up his first v-twin with another set of his own crankcases, designed especially for the a pair of 4-valve Antig Weslake heads that topped it off. It is an 1100cc 60-degree v-twin bike that produces 76 bhp while weighing only 376 lbs. It hits 140 mph and does the standing quarter in 12.6 seconds at 105mph. It is in a modified Rob North duplex cradle frame and pulls wheelies in the lower gears - in fact he has a job keeping the front down. It has Cosworth pistons and Carillo con-rod and a Quaife-Hemming 5-speed gearbox. No expense spared. You can read all about the bike in Classic Bike Magazine of October 1999.



bsa-thompson-vtwin-2 bsa-thompson-vtwin thompsonbsav2


Built in 1991-1992, this was one of 5 B100 v-twins built by Pete Thompson. It has BSA B50 top ends and a BSA A10 frame and gearbox. The timing covers are Triumph Bonneville. It is a 50 degree vee and displaces 1100 cc. It was put up for sale on ebay in 2012.

Here is an article about it on the Kneeslider: http://thekneeslider.com/archives/2012/09/20/bsa-thompson-1100cc-v-twin/

1  2 3 0

The bike is currently for sale (March 2017) ... here is the website: http://motos.autos-markt.com/BSA-Thompson-V2-301625260823/lot59227



$(KGrHqNHJEwE-uwKHetMBPsytPS2+Q~~60_12 $(KGrHqFHJBEE-byTWv-yBPsytDhtW!~~60_12 $(KGrHqNHJFYE-k9SlcRuBPsytIVkKw~~60_12 $(KGrHqZHJDQE-nw!Fjy(BPsysd7vsw~~60_12-1 $(KGrHqZHJFcE-mMl)4y!BPsys5JpDw~~60_12

...and here is another of Pete Thompson's five v-twins with B50 top ends in an A10 frame -50 degrees and presumably also 1100cc.



29090782_792941734234718_2984832331748999168_n 29088211_420186008439724_3516006051235233792_n 56899629_387690358489041_5880631232697466880_n

Pete Thompson is the resident "genius engineer" at Attitude Cycles in Southampton, UK https://www.attitudecycles.uk Thanks to Ralph Southerton for the long-stroke bike pic, takem at Kent Custom Bike Show

This one (below) has just been "rebuilt after spending 15 years outside". Posted by Simon Harris of Attitude Cycles: https://www.imgrumweb.com/post/Bq0M5X9Ae-T

bsavtwin 46382030_2204396036502078_2307136973131979376_n

Before resto...............................................................................................................After resto (Nov 30 2018)

Chaincase side:

  43543358_188942195326040_8037933337495447951_n 43434566_349431889147479_7868653901388536223_n


This appears to be a sixth version of Pete Thompson's 'Thompson V2'. Pic: thanks to Ian Gittins photogrqaphed as Cassington or the Banbury Run 'a few years back'




Another picture found.



battlewagon ABW-Battlewagon-2 PC080162

ABW - "Australian Battle Wagon". The bike is on display in the Australian National Motorcycle Museum ,(Nabiac, NSW) which claims "Alternator by Magna, automotive carburettor, narrow-angle V-Twin home built." However, the first thing we notice is that there are 2 carburettors and they are Amal concentrics - motorcycle carburettors, not car ones! Next we notice that this bears an uncanny resemblance to the water-cooled version of the Howard "Twelve" rotary hoe engine, (1340cc) as made in Australia..see picture above. the crankcases say "Heavy Weight Power Cruiser"... and since the crankcases are cast iron, it will indeed be heavy!








Vincent in an Indian frame... from this unloadable page: https://egli-vincent.net/2014/01/01/the-american-corner/



AJW-996cc-V-TWIN-1927-VINTAGE-MOTORCYCLE-ARTICLE AJW-996cc-V-TWIN-1927-VINTAGE-MOTORCYCLE-ARTICLE-_57 996cc-ajw-anzani 7302347566_3bba813e76

This is an article in The Classic Motorcycle, from January 1987. Advanced features like an all-welded duplex cradle frame made it unique. It was fitted with a 996cc British Anzani (= British Vulpine = Summit) engine; a 4-speed Jardine gearbox; Royal Enfield wheewls with 8 inch drum brakes - then 9-inch ones - very advanced for 1927. This is the single-port head version, but they also offered the bike with the eight valve engine and 4 exhaust pipes and interconnected brakes (AJW were based in Exeter). The bike is on display in the National Motorcycle Museum.



Previous page: V-TWIN NEWS PAGE 10

Next page: V-TWIN NEWS PAGE 12

Return to Index page: V-TWIN OBSESSION