Hello there, MalcolmH,
Assuming that the ones in the picture are your wheels, yes, that model has specific freehubs,
The fitting to the hub was different to allow the fatter aluminium axle to fit through the cassette body.
However, they are serviceable, as they use cassette bearings inside the body:
-Undo the cones on the non-drive side.
-Tap the axle out towards the drive side. The outer bearing in the cassette body may come out with it.
-Knock out the non-drive side bearing to allow access from the non-drive side to the hollow retaining bolt in the back of the cassette body.
-Remove the bolt (M12 Allen key, RH thread) This will be very tight. Probably best to hold the AK in a vice and turn the wheel.
-Pull the body out of the hubshell splines, fit new bearings inside and out
-Reassemble.
If you do need to replace, the bodies are probably the same as one of the Novatec bodies which are also used by Fulcrum/Bontrager/Crank Bros etc. These have the hollow fixing bolt coming in from the inside of the hub, rather than outside, like Shimano ones.
View attachment 552057
Shimano Hyperglide pattern:
View attachment 552066
If the picture you posted is not your actual wheels, but a generic Spinergy pic, you may be in luck, as in all their other models, Spinergy used standard Shimano Hyperglide pattern cassette bodies
You can spot this from the ball bearings and a cone on the cassette side, with a steel axle, rather than the aluminium axle with a collar and grub screw in the model above.
On Shimano pattern bodies, remove all the axle parts and balls, then unscrew the cassette body with a 10mm Allen key on the hollow retaining bolt on the inside of the body.
Models as follows:
Mk1, carbon shell, steel axle, small flange on the non-drive side, Shimano HG pattern body:
View attachment 552058
Mk2, carbon (or aluminium) shell, steel axle, large machined flange on the non-drive side, Shimano HG pattern body:
View attachment 552059
Mk3, Aluminium shell, aluminium axle, large machined flange on non-drive side, proprietary pattern body:
View attachment 552060
And they reverted back to HG pattern on their later Roks XE: 6-spoke onto machined aluminium hub, steel axle, Shimano HG pattern body:
View attachment 552061
All the best,