The Mk.I (distinguished by the exposed valve gear) was to continue until 1935, when it gave way to the more sophisticated (enclosed valve gear, so cleaner) Mk.II, for road-going use anyway. By then, the racers were differently ‘coded’ though the lineage was clear.
Mk.Is continued to give good service to sporting riders in ‘modern’ events into the 1950s, many ending up ‘on the grass,’ then had a new lease of life in VMCC sporting events.
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A Mk.I cammy Velocette has claim to be the best vintage machine out there. It’s light, lithe, short of wheelbase and massively confidence inspiring. Engines are tough and capable of outperforming most contemporary 500s.
Many have been used in competition over the years, so plenty have been modified and updated, meaning that the likes of ‘standard’, handchange KSSs and KNs etc., are few and far between; many have become pseudo racers.
Handling is taut and responsive, with the machine (particularly the KTT) most at home on A-roads, where its pace will surprise riders of more modern classics.
Model description and production years follow.
Velocette Model K
The original. Going on sale in June 1925, it continued in production until late 1928. Originally it had ‘Veloce’ on the 11⁄3 gallon petrol tank, to distinguish it from the two-strokes in the range, but by now, the public recognised the ‘Velocette’ name – and that was soon on the tank.
Built using KTT crankcases (which have the extra strengthening webs) and cylinder head, with a KSS cambox and an increased bore (up to 80mm) the KDT was of 415cc. It’s reckoned 22 were sold; there’s one survivor (shown), offered at Stafford in October, though it features a replica frame.
The most popular of the Mk.Is, with over 6000 produced from launch in September 1925 until cessation in mid-1935 (though the make remained for the Mk.II). Over production, they gained weight, became more sophisticated (lights, foot change, electric lights etc.) but got slower too.
By 1929 there were loads of different versions of the basic Mk.I – including the KNS (shown), the KN, the KNSS… different theories are volunteered for the ‘N’ suffix, with some saying it stands for ‘Normal’ (as opposed to S for Sports) while others volunteer it signified the 13 (as opposed to 12) roller big end.
The most famous cammy Velo. Launched for 1929, it had footchange from the start. Confusingly Mk.I to Mk.IV KTTs are developments of the same frame etc., with the factory not ‘officially’ recognising Mk.IIs and Mk.IIIs, while the Mk.V used essentially the same engine, in a different frame.
For 1930, road-going ‘cammies’ were just the KSS and the KTP. The ‘TP’ stood for ‘Twin Port’, much in fashion at the time, while there was also coil ignition (hence the different shaped timing chest) and electric lights as standard. Beset by ignition and performance problems (relating to the re-engineered head) it was dropped in 1931.