Just thought I’d add to this. Couldn’t find instructions for servicing anywhere other than the above advice. Took the plunge. So simple you don’t need pictures. Less than 10 mins and my switch was back to factory glory.
Had it 12 months, ride a few times a week around sheffield, no problems. A great buy at £130. Best money I’ve ever spent on a bike without doubt. Don’t delay, get one, which ever one your pockets allow. From new I filled the top of the seat post where the cable attaches with loads of thick grease. Stops pretty much all crap getting in to screw up mechanism. Mine became sluggish on return last week after a week riding in Wales. It was the gas strut that had rattled loose and unscrewed, lowering in the black post so the lever wasn’t contacting the gas strut plunger. If yours is slow returning I’d check this. I managed to take it apart and fully clean/lube/tighten without releasing the cable in less than 10 mins:
Remove saddle & check cable/lever is depressing
Check to see if little plunger the lever presses is in contact (if not the strut has worked loose and lowered)
Release post clamp
Inside bottom of black post is a disc with holes – use slightly open needle pliers to try to tighten – if it screws in more there’s your fault. Nice quick fix!
If you want to clean, undo disc fully, gas strut mechanism will drop out.
Spray with your favourite cleaning fluid and re-grease.
At this point the post is free to extend/lower – unscrew the collar on the top of the black post and get rid of all crap.
Spray inside black post with something a little gentler and pump up/down
I used clean rags inside and out to get it all nice and sparkly before spraying with silicone lube
I checked the gas compressor worked in isolation and reassembled.
10 mins, some spray and dirty rags. As good as new!!!
Will now do much more often – maybe with thread lock to stop the little monkey from rattling loose.