Custom city cruiser with a Montague folding frame


New Member
This is my 2nd ebike build, I've been slowly putting this together for a while and it's finally in a state I'm happy to show off. I saw a guy riding this type of bike around and stopped him to ask what the brand was. I thought it'd be a cool Bafang mid-drive conversion because of the clearance. He actually bought his from Montague, they make folding bikes for the army or something like that. I did a bit of research and found the frames on AliExpress and bought just the frame alone for $200 and built it up from parts I had lying around from my first mid-drive conversion.

-Montague (or a clone) 26" folding frame
-Disc brake forks sources separately from the frame
-BBS02b 500w Bafang motor
-Slim frame bag with a cut at the front/bottom, I hide the extra wiring in there along with my keys/wallet/whatever
-9 Speed Alivio shifter / Cassette
-10 Speed Deore w/clutch drilled out to have the proper 2:1 actuation
-10 speed derailleur/chain on the 9 speed cassette gives a bit more clearance on either side of the chain for super smooth and clean chain motion. Feels and sounds awesome.
-520mm handlebars for sneaking through obstacles easier, can barely fit anything on here. perfect.
-26" fenders that fit the wheels like this were a pain to find but I managed. So far they've stayed sturdy and don't rattle around which is what I wanted.
-2x Custom spot-welded 6s2p battery packs (Cells are Molicel p42a 21700 cells rather than 18650) Connected in series (12s2p) which gives me about ~30km of pedal assist on max power.
-The 21700 cell size and high amp draw make it viable as a pedal assist battery at 2p
-I don't use a BMS and instead I plug each 6s pack into my drone battery charger and charge both packs at once. Recharging takes about an hour and then I can go another 30km.

EDIT: Ohh yeah the entire thing is housed in a custom designed 3d printed enclosure. This is v2, and v3 is in the works now to be more streamlined and integrate with the vertical tube better/hide the steel clamps


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