Peterpan1: the weight is worth it. I live in NM, I do some touring with the extrawheel trailer on STEEP forest service roads in the Rockies. the discs are for long steep descents on washed out unmaintained roads. I am a musician and need to protect my hands, which are developing issues from all the hanging on to the brakes while being pushed downhill by the loaded extrawheel trailer (50 pounds including trailer weight).

interesting idea using a tandem axle. why would this (140mm spacing?) be better than the MTB spacing (135mm)??