Bikes | Features | Events | Books | Tech | Magazine | About | Messages | Classified | Links

more bike profiles...

Bike Review - Posted 29th January 2010
Home -> Bikes -> Road Tests and Profiles ->

Vincent Comet

Vincent twins are beyond the reach of most classic bike enthusiasts these days. But less than half the price still secures the 500cc single...

If you're considering buying a Vincent Comet then the model you are most likely to find on the market today is the Series C. Phil Irving's first engine design for Vincent was an OHV 500cc single which appeared in 1934 in standard trim as the Meteor, and in sports form as the Series A Comet. These bikes were in production between 1935 and the outbreak of World War Two. The short-lived Series B was then developed from the A, and then the most successful version, the Series C Comet arrived in 1948 and was built until 1954. A very few Series D Comets were assembled over the next couple of years as the Vincent concern wound down.

That was then... 1952 Vincent Comet

80% of the components used in the Series C Comet were shared with the twins, so there's no doubt that you'll be purchasing an authentic example of Vincent engineering. The single cylinder, high-cam motor runs overhead valves with a light alloy head and barrel and a shrunk-in cast-iron cylinder liner. The engine's 84mm by 90mm bore and stroke gave a capacity of 499cc, which provides to an output of around 28bhp at 5800rpm. The more sporting variants ran compression at 7.3:1, while the initial model was set up somewhat softer at 6.8:1. Even then it would pink on pool petrol, but as higher quality fuel returned to the pumps so the engine could be tuned accordingly.

...This is now. This 1952 Comet was sold recently by Venture Classics (

The rear cylinder of the big V-twins is missing, but structural integrity is retained by a cast-alloy frame strut. The Comet eschewed the complicated servo-clutch mechanism of the big twins and used a more conventional multi-plate set up. This transferred power to the four-speed Burman gearbox which differed from the big twins by being a separate unit, secured by mounting plates. When new the positive-stop gearchange mechanism was rated as being 'decisive in movement and pleasurable to use' with neutral easy to find from above or below.

And this is the other side... 1952 Vincent Comet

The Comet, like the bigger Vins, boasted superior, seven-inch twin brakes at front and rear, operated by rods rather than cables. The front one was described as 'strikingly efficient - light to operate and powerful, and progressive in action' while the rear needed considerably more pressure to activate fully. This was apparently part of the design, to prevent inadvertent locking of the rear wheel. For its time the braking certainly was impressive, drawing the Comet to a halt in just 26-feet when travelling at 30mph, no doubt aided by the efficient Girdraulic front fork.

Vincent Comet - Series C Touring Vincent Comet - Series C Touring

This helically-sprung hydraulically-damped fork system suffered very little deflection under braking, with controlled compression keeping the tyre firmly in contact with the poorly-surfaced roads of the time. The downside to this link-type fork is that at lows speeds the steering could feel heavy and an unfamiliar rider could be caught out with steering head roll which is an unpleasant experience. The cure is to go slightly faster - anything over 10mph should do -- but the rider's reaction is usually the opposite, and closing the throttle then exaggerates the wiggle into an alarming sway from side to side. At speed, the Comet's steering and roadholding were considered 'a sheer delight… which makes the maximum contribution to safety'

...This is now. This recently restored 1951 example sold at auction in winter 2009 for £9600. It had been stored for 58 years prior to restoration and had not been used on the roads since its rebuild

The Comet utilised dry sump lubrication, 6-Volt electrics with a 50-Watt Miller dynamo and an auto-advance Lucas magneto. The rear suspension was also hydraulically damped. It weighed 390lb dry or around 415lb fuelled, with a seat height of 31 inches. The Comet was capable of up to 90mph with comfortable cruising at 65mph. First gear would reach nearly 40mph while top gear would pull cleanly from 20mph or so. The frugal rider could easily achieve 80mpg at a steady 50mph.

...This is now. This 1953 Vincent Comet was sold at auction in autumn 2009 for £7250, needs a complete restoration. It was described as being 'largely complete'

The Comet initially cost £190 then the price rose to £240, and later it went higher still to £258. This included lots of high-class perks, like sturdy prop-stands provided on each side of the machine and tyre levers, tools, grease gun and such as standard equipment, plus fully adjustable footrests and Vincent's famous flat handlebars with wrist-angle adjustment. The Comet was finished in Pinchin Johnson's 'best stoving enamel' with some sparkle provided by the heavily chrome-plated exhaust, controls, bars and wheel rims. Rider who wanted to spend less could buy the Meteor, which was less highly tuned and came with a lower spec, while the sporting Grey Flash served the competition market. The Grey Flash was billed as being 'by Black Lighting, out of Comet' - the mind fair boggles…

Vincent Comet - Series C Touring Vincent Comet - Series C Touring

Road tests of the time loved much about the Comet although they didn't find it to be faultless. They praised its smooth running and excellent road-holding, although the power delivery at low revs was felt to be 'harsh' as a consequence of the auto ignition control. Starting from cold required a hefty swing of the leg. Top-end clatter from the valve gear was noticeable enough to warrant comment in 1950, which means it probably sounds like a tribe of tap-dancing cattle to the modern ear. The exhaust note was considered 'dull-toned' and too loud for riding around town especially if accelerating hard. Plus, some vibration was apparent, as we say; a bulb holder fractured while one Comet was on test with one magazine…

Vincent Comet
On reflection, the photographer should have spotted how shiny the tank was...

Classic Projects on Now...

In 1980 Royce Creasey found the Comet to be considerably less than half a 'proper' Vin-twin, saying; 'the overall effect of the bike is spoiled by its meagre power delivery. Until fairly high engine revs are reached throttle movement merely results in more noise being generated… and although the bike seem quite fast it lacks the balance of better 500s from other manufacturers… I found the Comet a considerable disappointment.'

However today the Comet has definitely found a cult following. Owner Andy Bone argued that his Comet deserves the title 'the best ever British classic bike' in RC55. Values have never quite reached the giddy heights of the twins, however, and you'll be able to find a roadworthy example for around £10k, with restoration projects fetching anything from £5000 to £8000. A mint, fully restored example with interesting history could go for £15,000, and there are still enough Comets about for them to come on the market at regular intervals.


More info on the Comet is available in the magazine: it's been featured in issues RC15, RC38, RC42 and RC55.

Those Vincents get everywhere...

Vincent HRD Owners Club:

Like this page? Share it with these buttons:


More Classic Motorcycles on Right Now...

Bikes | Features | Events | Books | Tech | Magazine | About | Messages | Classified | Links

More Bike Profiles...

RedLeg Interactive Media

© 2017 The Cosmic Motorcycle Co. Ltd / Redleg Interactive Media

You may download pages from this site for your private use. No other reproduction, re-publication, re-transmission or other re-distribution of any part of this site in any medium is permitted except with the written consent of the copyright owner or in accordance with the provisions of the Copyright, Designs and Patents Act 1988.