Mongoose Kong (fat tire) bike for child

Nov 13, 2020
Rensselaer, Indiana
I started this bike long ago. It's a Mongoose Kong 4.0 20" fat tire bike. I added an eRider torque sensing BB with 150mm (unicycle) crank arms. Front tire has a 1000W(?) direct-drive motor. I milled the torque arms. I made the ends for a Flipsky 75100 to seal it and fit on the down tube. I attached the 9.6Ah bottle battery to the top tube using rivnuts. It's running ADC Current mode using only the torque sensor. I tweaked the settings a bunch to make it smooth and give subtle boost/braking. It's been a success so far but she's already started to outgrow the bike so I have a longer seat stem on the way. It is a hoot to drive in the woods.

I think about writing a VESC app to handle cadence and brake inputs. I'd love to find a geared front motor that's clutch-free (or easily modified).

I applaud your using a Mongoose for the only thing it's appropriate for-- a kid who'll quickly outgrow it.

Maybe the next move for that kit will be to an adult size fat tire folder or minibike sized for a bigger human.
I dunno...IIRC I used a purple or blue mongoose bmx frame for the front half of CrazyBike2 way back when, and it's still on there... (albeit I'm not using the bike anymore, until I can use it to build the Cloudwalker Cargo Bike (someday)).

I don't recall the brand, but there was somethign I got off freecycle that was so bendy I could flex it in my hands, and made the mistake of using parts of it for the Delta T(r)ipper, especially the pedal boom, which twisted on every crank rotation.... :/