Velocette 5 Speed Gear Set

About The Velocette 5 Speed Gear Box

The Velocette 5 speed gear set has been designed to fit the standard Velocette road type gear box shells with only one small, at home, modification to part of the ratchet change mechanism.

All the gears have 3 undercut engagement dogs for fast changes and positive retention.  We supply both shafts with all the gears assembled plus three selector forks, cam plate and actuating pawl, or with a layshaft bearing carrier which replaces the standard kick start boss should you not require the kick starter.

Alternatively, for road use,  we can supply a kick start ratcheted gear, in which the cast standard kick start boss is retained.

The gearboxes are supplied with a 19 tooth sprocket, additional sprockets are available as required.
Our ratio's are as follows:
               
1st Gear     21 - 27 x D.R    = 2.250:1    29%
2nd Gear    23 - 21 x D.R    = 1.598:1    18.9%
3rd Gear     27 - 20 x D.R    = 1.296:1    14.95%
4th Gear     27 - 17 x D.R    = 1.102:1    9.25%
5th Gear                             = 1:1    
               
Drive ratio                  16 - 28       1.75:1    
               
Overall reduction       1st   -   5th     55.5%

The Velocette 5 speed Gear Set Manufacture

The manufacture of gears is mainly with EN36 steel, of British Manufacture. The gear blanks are turned on a CNC lathe, the teeth are then cut either by hobbing or shaping, depending on the design of the gear. This is followed by milling of the dogs and lightning holes. The gears are then sent for heat treatment and on return are finished by grinding.
Aluminium components

Aluminium components, either castings or billet, are generally machined. Aluminium specifications used are NS8, HE30, and LM25. Following machining and inspection, the components are usually either hard or decoratively anodised.