Scroll back about 5 pages for my take on the Mykle and the Radwagon. Bascially as @MCamb says, change the brakes for ones that work and don't look back, just consider it part of the purchase cost. Most cheap/unbranded mechanical disc brakes are best in the scrap metal bin and not on a bike, there are good ones though, but when the basic Shimano ones are only about £30-40, and £50-60 for the Tektro ones with the right connection for the motor cut off switchs, its a no brainer.
Scroll back about 5 pages for my take on the Mykle and the Radwagon. Bascially as @MCamb says, change the brakes for ones that work and don't look back, just consider it part of the purchase cost. Most cheap/unbranded mechanical disc brakes are best in the scrap metal bin and not on a bike, there are good ones though, but when the basic Shimano ones are only about £30-40, and £50-60 for the Tektro ones with the right connection for the motor cut off switchs, its a no brainer.