I've had no success finding a less expensive third-party bag for my Brompton Electric C 12-speed with extended seatpost—they were either too small or comically large (looking at you Rhinowalk)—so I bit the bullet and purchased the Brompton Transport Bag. According to the website,
Compatibility
A Line, C Line, P Line, T Line, Electric C Line and Electric P Line
However, I recently installed the advanced roller rack and the bag seems a little small for the folded width including the rack.
Does anyone use the bag with a rack? Has it held up? Torn? Busted a zipper?
Also, TIL that securing the strap around the bike is not optional. It's actually the strap supporting the weight of the bike, it will slip right out of the bag if you don't secure it around the frame.
by TsukimiUsagi