DO NOT RECOMMEND.
DO NOT RECOMMEND. I had previously left a 4 star review as I was really happy with my rear wheel 100g kit. Unfortunately after a few months the rear wheel started making a very loud grinding noise. I contacted 100g and as others have said the customer service is the biggest let down. They're slow to reply. Now several months later I still have the same issue. I'm considering cutting my losses and throwing it in the bin. I've had endless emails back and forth asking for videos and pictures. They did send a replacement controller. I had to pay £16 postage. This did not work either. Basically if it works it's great. But if anything goes wrong (I'm in the UK) your on your own and screwed. Can not recommend.