Friday, July 12, 2013
VELOCETTE VENOM THRUXTON BEATER SPECIAL...This is a genuine Clubman RS frame but otherwise standard. Forks are double damped thruxton type, upgraded from the single damped unit, all fully rebuilt. New Akront flanged alloy rims WM2 front and WM3 rear with fresh Avon Roadriders. Rear hub is cotton reel type as per MSS (lighter), new drum\sprocket at the back + shoes. Brand new front hub and original TLS brake. Alloy centrestand, custom rearsets but mounted in conventional way on standard triangulal plates. New wiring loom, everything rewired 12V, gel battery. New RK Leighton 1.5 Sports seat, Tomaselli adjustable Ace bars, Tomaselli quick action throttle and alloy levers. Thruxton tinware, all freshly painted. Proper Thruxton oil and fuel tank (genuine not repro), Thruxton strengthened engine+box plates.
Gearbox - standard 12 type, fully rebuilt, including new layshaft and new mainshaft, the rest in good condition. New bearing including the large new bearing and shims. upgraded linkages(best velo box ive used if I may say so). Kevin Thurston complete belt drive with crankshaft seal and custom "chaincase" made from the standard screw up type.
Engine - Alan Walker strengthened crankcases, lightened beveled flywheels (as per works mods), genuine Carillo conrod, Cosworth Manx Norton piston. All valve gear lightened and polished and running Thruxton pushrods. Alfin barell. Genuine works Thruxton squish head with 1 3/8" inlet. Breather and oilpump mods as per works bikes. Timing gear all running roller needle bearings, cam is a custom profile but based on 17/8. Runnin on 1000 series Mk1 Concentric on a Thruxton manifold but also suitable for a GP. Manual K1F magneto. Dyno result with standard exhaust 37 BHP at the real wheel 39 with Megaphone and 43 with megaphone and GP.A REAL THRUXTON BEATER !...
Comfortably over £22k of receipts all together.
Saturday, July 6, 2013
Friday, July 5, 2013
Tuesday, July 2, 2013
Advertised as "By Black Lightning out of Comet" this 500cc single racer is very rare as only 31 were produced.
Vincents had a close association with motorcycle racing and the Phil Irving designed Vincent Comet provided the basis for the Series C 499cc Grey Flash racer. Tuned and stripped down to 330 lb (150 kg) as a 500 cc version of the 1,000 cc Vincent Black Lightning, the new 'Flash' was capable of 115 mph with a power output of 35 bhp 6,200 rpm.
Prototypes were raced in late 1949 and the last model was produced in 1952. The small numbers produced mean that there was plenty of variation of the specification. Earlier models were finished with chrome on the fuel tank and lower fork link but towards the end of production in 1952 this was replaced by grey paint. As well as the Burman BAR gearbox, Vincent also experimented with AJS 7R gearboxes but used Albion gearboxes for most of the machines produced.
Monday, July 1, 2013
The Mighty Mouse story is a classic tale of drag racing ingenuity. A skilled rider and engineer who took an idea and gradually developed and improved upon it until he had done everything he could to wring every last ounce of horsepower and performance from it.
From the mid to late seventies a bike with, in some cases, a fraction of the capacity of its competitors, showed allcomers the way to the finish line with alarming regularity. Like all Drag Racers Brian Chapman was never quite satisfied with his achievements, always looking for the next increase in performance. Over the years the bike evolved, the nitro content increased and by the time he retired the Mouse in 1980, to make way for his new project, he had shaved nearly seven seconds off its original times.
Brian built the first incarnation of Mighty Mouse in the mid-sixties having spent two years competing in various speed trials and sprints on his road going Vincent Black Shadow, complete with sidecar! Like many he was inspired by the success of the Dragfests and the growing popularity of Drag Racing in the UK and decided that it was the direction he was going to move in next.
Being a big fan of the Vincent he decided to use a 1951 Comet engine as the powerplant for his purpose-built Drag Racer. The Comet was a 500cc single cylinder engine that was effectively half a vee-twin. It was not known for being a high performance engine but Brian had big plans for the inoffensive unit and set about constructing his machine in his garden workshop. He decided that he had to keep the bike as low as possible and fabricated his own tubular frame which allowed him to tilt the motor forwards by 15 degrees. The motor itself was used as a stressed member. The new angle of the powerplant meant that modifications had to be carried out to the oil pick up and rocker gear drainage.
The frame was in two parts with the front section being easily removable to allow easier access to the engine. Initially forks from a 98cc Moto Guzzi were used. Weight was kept down by dispensing with the need for an external oil tank. Instead two pints of mineral oil were carried in the timing chest and in a small extension attached to it where the original magneto would have been. A dual ignition system was used featuring two rotating magnet magnetos which were shortened at their contact breaker ends and coupled back to back. The contact breaker points were mounted on an external plate and driven from the remote end of the second magneto. A single carb fed the methanol from the three pint fuel tank mounted above the clip-on handlebars and an open pipe provided an outlet for the exhaust gases. The carb was later replaced by a Wal Phillips injector.
The drive was transmitted to the 18 inch rear wheel via a single row primary chain, a strengthened AMC clutch and an AMC Norton gearbox with the first gear pinions removed. This left three standard ratio gears which were all used on the bikes run up the quarter mile. Final drive was via a secondary chain to CMA cast alloy rear wheel with single Vincent drum brake.
To start with the machine had more than its fair share of teething troubles and Brian recalls that he did more pushing than riding at some meetings. When the motor did choose to run the bike turned in times in the region of fourteen seconds. Transport to meetings initially was achieved by mounting the Mouse in the sidecar of the Black Shadow outfit! Over the next two years the times gradually improved until early in 1969 when, running with 25% nitro in the tank, Brian got down to 12.3 seconds. Feeling that he had done as much as he could with a normally aspirated motor Brian added a Rootes blower in mid '69 and experienced problems almost immediately as it frequently cooked the vee-shaped drive belts. A toothed belt was found to be the answer to this problem. The blower was driven at engine speed and took the fuel mixture from a single ex-Jaguar 1 3/4inch SU carb. A fuel cut-off valve was fitted which could be operated directly or from a trigger on the left handlebar. The motor retained standard sized valves with the exhaust being made from Nimonic 80 material.
The original front forks were replaced by shortened Godden Engineering grass track items and a hydraulic steering damper was added.
He had some success with individual final round wins and by the end of 1970 the bike was winning more regularly and had run a best of 11.10/120.
In August of 1971 Brian took the bike to the NDRC meeting at Blackbushe. There he put in a run of 10.77 seconds making Mighty Mouse the quickest single-cylinder dragbike in the world. After that momentous occasion sub-eleven second runs started to come more frequently and Brian began to stick the ten second time slips on the wall of his small workshop.
In March 1973 Brian arrived at a Santa Pod practice day and stunned everyone present by putting in a 10.35 off the trailer. When asked about what modifications he had carried out on the bike over the winter he replied that winter had been spent decorating his house and all he had done to the Mouse was run a feather duster over it! Next month at the Season Opener he ran the quickest bike time of the day at 10.48. In April at the Springnationals his luck ran out as the motor blew itself to pieces. Undeterred Brian took it back to his workshop and began the rebuild. He had been using a lightened crankshaft, so light, it is reported, that lead had to be added to balance the flywheel. With a return to the track as soon as possible on his mind he rebuilt using a standard crank. A move that turned out to be for the better as the bike instantly ran quicker than ever! The addition of a twin lobe Marshall supercharger and an increase in the fuel mixture to 75% nitro with 25% methanol meant that the bike was now producing an estimated 125bhp at 9000rpm and returning a fuel consumption of four miles per gallon. The tradition of putting the ten second timeslips on the workshop wall was getting out of hand!
Chapman was now running in the Top Bike class and at Santa Pods August Nationals he amazed everybody by taking the bike into the nines with a 9.92/139 which was good enough for number two qualifier just behind Norman Hyde. He backed the nine up with a 9.98/141 in the first round, more than enough consolation for not making it to the final.
By the end of 1975 Brian had secured the Top Bike Championship honours for the first time. He continued to run against, and regularly beat, the quickest bikes in the Country through '76 when he ran a seasons best of 9.07 in September. A year later at Santa Pods September International he finally managed to get it into the eights with an 8.96. He was awarded the BDR&HRA Motorcyclist Of The Year trophy in recognition of this feat. He also won the ACU Championship outright in 1977 and the following year recorded the bikes best ever figures of 8.81/157. In 1979 despite still being competitive Brian was getting beaten more regularly by the multi-motored Superbikes of John Hobbs, Henk Vink, John Clift and Jeff Byne who were now knocking on the door of the sevens.
He decided that he had taken the machine to the limits of its performance and set about creating a Vee Twin version, with twin superchargers, to be known as "Super Mouse".....
Mighty Mouse is still in existence today, in exactly the same guise as when it was retired. Brian has taken it out a couple of times since then for a quick blast, notably on the Isle Of Man at the Vincent Owners Club Golden Jubilee celebrations in 1999. The bike can be seen on display at the Enfield And District Veteran Vehicle Trusts museum in Whitewebbs Lane, Enfield, Middlesex.
Super Mouse Vincent V-Twin
The Velocette KTT is a racing British motorcycle made by Velocette. The most significant of the K series (the K rather curiously stood for Camshaft) the TT designation indicated that it was a TT production racing replica. The Velocette KTT was notable for having the first positive-stop foot gear change on a motorcycle. As well as being significant improvement for racing, this quickly replaced the difficult hand gear change lever and became the standard for almost all motorcycles to this day.
Based on the Velocette KSS, the KTT was developed as a production racer specifically for the challenging Isle of Man TT course, which was the main road race in the world at the time. The prototype was built by Percy and Eugene Goodman, sons of the Velocette founder in 1924 and after twelve months of development secured Velocette their first TT win in 1926. Alec Bennett was the winner with Gus Kuhn and Fred Povey finishing in the first nine to give the factory the team prize. Further work on KTT led to the first positive-stop foot gear change on a motorcycle in 1928. Other makers had modified the hand change for foot operation but none had achieved a mechanism which could change up or down gears with a single click. As well as being significant improvement for racing, this quickly replaced the difficult hand gear change lever and became the standard for almost all motorcycles to this day.
The Velocette KTT continued in development to sort out reliability problems after a number of retirements and went on to become the first Junior competitor to lap the island course at over 70mph and won several TT's and Grands Prix (the amateur version of the TT). The KTT also set a new 350cc world record of 100.39mph at Brooklands.
Another innovation on the 1929 model was the strengthened front fork, originally designed to cope with the abnormal stresses of sidecar racing. The production racing Velocette KTT went on to become one of the most successful Junior TT motorcycles of all time and the most popular with the privateers who raced without the support of the big factory teams.
Production of the Velocette KTT ended in 1935, and it was the last Velocette model to use an open cam box and fully pressurized oil system. The model was replaced after World War II by the Velocette KTT Mk VIII.
The CS1 won the Senior TT first time out, in 1927 and even more remarkably an unknown rider Tim Hunt won the 'Amateur TT' in 1928. Open only to private riders on private machines Hunt won at a speed higher than the TT record. He used the same bike in different trim to take a Gold Medal in the 'Scottish Six Day Trial'.
Strangely further development bought little success and the push-rod Sunbeam and 4-valve Rudge proved dominant until Irishman Joe Craig reappeared on the Norton scene and helped design a new motor with Arthur Carroll for 1930.
Despite its failings the CS1 must rate as the best looking 'Vintage' bike ever, and riding it back to back with my 'Flat Tank Model 18' it is a huge step forward in both handling and comfort. The engine is mechanically stronger, with steel flywheel (replacing cast iron), bigger main shafts and bearings, and through-bolted cylinder studs.