'The big problem is water': UK ebike owners plagued by failing motors

Repair business is booming as owners complain of their units needing to be replaced up to five times

Is it the UK's seemingly incessant rain? A poor design? Or maybe the way they are being ridden or cleaned?

Why are so many owners of electric bicycles complaining that their motors need to be replaced so often?

Some mountain bike owners with fourth-generation Bosch electric motors describe how they had four or five - yes five - replacement motors[1] fitted during the two-year warranty period.

Owners of other brands say theirs have only lasted 800 to 1,000 miles.

The problem appears to mainly affect those riding mountain bikes in all weathers, particularly in Wales and the UK's other wettest areas, because they are not sealed properly against water ingress.

This week, one of the UK's leading independent ebike motor specialists, the eBike Motor Centre[2] based in Fordingbridge, Hampshire, told Guardian Money it was being sent about 250 motors a month - of all types - from owners desperate to find a cost-effective fix to problems including failed bearings, failed torque sensors and water damage to circuit boards.