'Cammy' Velo cafe-racer by Peter Dobson

When you talk about specials the name that springs to mind first is Triton, but not every special involves Norton and Triumph bits. Peter Dobson meets up with Velofello Mike Vangucci.

When Mike originally purchased it, the Velo had a racing seat and tank which looked well, odd

Nowadays it's almost inconceivable that anyone would want to build a café-racer from a pre-war overhead-cam Velocette. But in the Fifties they were just old bikes, worth maybe fifty, sixty quid, if that, and hacking one about and fitting it with telescopic forks, swinging-arm suspension, clip-ons, rear-sets, and a monster petrol tank wasn't generally regarded as a sacrilegious act.
Even so, I was surprised to hear that Mike Vangucci, a life-long Velocette enthusiast, had acquired a MkI 'Cammy' Velo café-racer. Quite why he fancied it I can't be sure, though it will probably be a tale in many parts. Partly, I suspect, because he regarded it as rescuing a decent bike, rather as some people rescue dogs. Partly, maybe, as the thing was half the price of a MkI 'Cammy' in original condition. And, I suppose, partly too because he'd thought about rebuilding it to factory spec.
"The bloke I bought it from had gone into the costs involved," he says. "And it worked out to around £2500. But it steered so nicely and rode so comfortably that I thought I'd keep the teles and the rear suspension. Whoever built the bike had engineered it very well, but I didn't like the way the seat, front mudguard, and the tank were fitted. In fact, I didn't like the tank at all, but luckily it came with a proper Velo tank."
The bike had started out in life in 1935 as a KTS. The K stood for Kamschaft - the founder of the firm was German - and the TS stood for 'Touring Sport'. It came out in 1931 as a gentle version of the 'Super Sports' KSS. Down the years there were 11 camshaft models that shared the basic open valve gear ohc engine of 348cc - bore and stroke were 74 x 81mm - but in different states of tune for according to intended purpose, and with constant 'mods'. By the same token running equipment also varied. The KTS, for instance, had 19in rims, 3.25in tyres and touring mudguards.
Mike's engine dates from 1929, but has a later cambox. He discovered that the head and barrel had been copper plated - a Brooklands trick intended to improve heat dissipation - he doubts it made a scrap of difference, but it indicates that the engine may have once been raced, especially as it has the KTT-type roller mains and conrod.
As bought, the engine smoked terribly and actually had oil oozing out of the exhaust port and from the joint between the pipe and silencer and also from the distinctive 'fishtail' silencer. My reaction would have been dismay, but Mike enjoys a challenge and it gave him an excuse to go delving in its entrails. "There's a shim behind the timing side main bearing that prevents oil from the bottom camshaft bevel box getting through into the crankcase, and I reckoned that had split," he says. It had!
He also re-aligned the flywheels, fitted a new set of cast-iron piston rings, and put a knife-edge on the piston skirt that scavenges the bore and throws more oil onto the small end. "The compression ratio is roughly 6:1, it should be 6.5, but I found the inlet valve had just touched the piston, during some time in the past, so I turned quite a few thou off the edges of the crown," says Mike. He suspected a soft valve spring and checked them all with a set of bathroom scales mounted on a pillar drill. To test them he put each coil spring on the scales in turn, compressed them with the chuck to their installed length, and took a reading off the scales. As he'd thought, the inlet springs were weak.
According to Martin Arscott, Velocette expert and restorer (01442 862966), you really need the softest springs that you can get away with. "Too weak and you get valve float, but not too strong so that they will wear the cams. People have been known to run a 'Cammy' Velo without the inner springs. I wouldn't recommend it, but it does make for a wonderfully quiet engine. Though, of course, you mustn't miss a gear."
To lubricate the special Mike uses Morris's Monograde 40 mineral oil but keeping it inside the engine isn't easy, mind you, oil running down the fins of 'Cammy' Velos is a common sight. He says that he just "threw the thing together" and pretends to be surprised that it is absolutely oil tight. However Martin Arscott is impressed and so am I, but we simply don't believe that it was "thrown together."
Further evidence of the initial build quality is in the swinging arm, which was nicely made from 3¼4in diameter heavy gauge steel tubing. Other frame modifications have been equally well carried out, for instance, the back half of the original twin downtube frame was cut off just behind the gearbox and at the top end of the seat tube, and the home-made sub-frame bolted on. A rebuilt pair of AMC 'Candlesticks' provide the rear suspension. I admired the elegant rear mudguard stay. "It looks alright," Mike says. "But it's made of copper tubing which isn't a good idea. I re-used the alloy mudguard, but I've noticed fatigue cracks around the mounting points, which makes me think the bike has done a lot of miles. I replaced the front mudguard with one from a Gilera. The wheel rims are Akront alloy ones, which are in keeping with the café racer theme, and are 3.00 x 19in front; 3.25 x 19 on the rear, both fitted with Avon tyres," he tells me.

Originally built in the Fifties this special is still very indicative of what riders did with their bikes in that period.

Mike went on to say the teles came from an early, post WWII Model J Royal Enfield, which isn't outrageous as the KSS for 1948 had Dowty Oleomatic air-sprung telescopic forks instead of girders. Mike likes the Enfield forks saying: "They are softer than the teles on my 'springer' MSS which can really rattle my fillings. In fact, they are probably as good as the Dowty forks, and of course they don't leak air!"
Responsible for stopping duties up front is a 6in diameter twin front brake drum, another Redditch product, originally fitted to the 700cc Constellation twins. Its twin brake cables meet up at a balance bar at the front brake lever suggesting good braking, but Mike is not impressed yet. "The linings are brand new and not yet bedded in," he says. "It also needs a hefty grip, and the pull-off springs are far too strong."