Question about Woosh and Cassette


Just Joined
May 2, 2019
On the Woosh website it says

'You want a rear motor but your rear wheel has a cassette. We have a CST kit, it's mostly the same but with XF08C motor, please ask us before ordering'

Given that the hub comes already built into the wheel why does it matter what my old wheel has?
What is a CST kit?

Is this purely if you want to keep using the same cassette you have on your old bike?

If anyone can answer these questions would really appreciate it! Thanks


Esteemed Pedelecer
Jun 8, 2018
Yes, that is only important if you want to reuse the cassette.
Also the cassette will be much easier next time you need to remove it.
If you go for the freewheel version make sure it is compatible with your current cassette or you may end up having to change the shift levers.

CST kit:
Note: the CST is 36v against the 48v if the SWX02


Esteemed Pedelecer
Jun 12, 2011
Just to make sure you understand, there are two types of cassette gears.
1. Freewheel gears screw onto a boss on the hub. Normally 7 speeds is the max, but can go to 8 speed with a bit of jiggery pokery.
2. Freehub gears, also known as cassette gears, slide onto a spline on the hub. Normally 8 speeds or more.

A CST motor has the the spline for freehub gears and other motors have the boss for the freewheel gears.

In bike speak, a freewheel means the gear cluster that used to be called a cassette, and a cassette is a freehub gear cluster.

Laser Man

Jul 1, 2018
Michelmersh SO51
Most bikes made for the UK market have freehub/cassette gears (they slide onto splines attached to the wheel) so the Woosh XF08 kit allows you to re-use the gears from your existing bike, saving a bit of dosh.
(Freewheel gears are more common in Europe and very common in the rest of the world (except USA)).
The splines on the XF08 kit are for 8, 9 or 10 gear cassettes, though you can use an old 7-speed cassette if you fit a spacer.

I've fitted XF08s to two bikes and find them excellent - plenty of go in them and gentle on the battery too.