- Aug 27, 2015
I put this bike together for my boy last winter but am just getting around to writing this thread. It's a Walmart Mongoose King Kong. The bike is pretty solid with a steel frame and some cable operated disc brakes that work really well. The brake levers have a nice long stop screw so you can set it so the lever is always close to the bar for small hands. The only thing I would wish to be better is if it had sealed bearings in the wheels and steering stem. I put on the BBS02 that I took off my bike after upgrading to the BBSHD. It works out really well as far as parental controls too. I have the max amps set at 8 right now but I have the PAS disabled (my boy is used to the throttle from his OSET 12.5) and the throttle set for "by displays command". So that lets him adjust the power level with 9 settings to what he feels comfortable with. In the advanced settings (that he doesn't know how to access) I set the top speed, usually between 10 and 15 mph depending on where we are riding. The build was pretty easy but did require cutting of the BB on the frame. I used a 68mm BBS02 and the mongoose had a 100 mm bottom bracket. So some of the things to consider on this small bike is it has very short crank arms and a 36T chain ring. Here's what I did, I cut as much as possible of each side of the BB. This was limited by the welds of the chain stays. I was able to remove enough to mount (I also had to dent in a spot on the chain stay just a little) the motor but not enough to use the lock nut. Then I cut the sprocket off the original right crank arm and used the both original crank arms. Next I used a chain ring adapter and a race face 36T. This provided a perfect chain line. Perhaps one could duplicate this build but with a 100mm BBS02 but that would require 2 changes 1. Short unicycle crank arms (they are the right length but no offset) 2. The use of an offset chain ring to get a good chain line (offset chain rings are limited to a min of 42T). For a battery I used 2 6s 3ah lipos, they are cheap compact and last an hour or two before recharging. I put those in a small Roswheel bag that's made to fit on a full size bike up near the steering stem but on this little bike fills the whole triangle perfectly. The whole thing turned out really well and the price point was still under the OSET 12.5 or the Yamaha PW50 I bought him in the past and with this bike we are not limited where we ride. It would be great to see Luna add something like this to their complete bike line up. Based on the response I get from people when my boy rides by them, there is market for kids e bikes.