Kona Ute Electric Conversion

I have wanted to make a longbike for a while. As a dealer for Kona parts, I can get a Ute, so I decided to go for it.

The Ute is a long wheelbase cargo bike. For 2010 it comes with front and rear disc brakes. It comes as a 700c bike, but my only motor sitting around was a 26" model. I am working on lacing up a 700c motor but I don't have the right size spokes yet. So I quickly assembled it with what I had available. Fill size images can be seen in the Photo Gallery Here.

It is a work in progress, but it is rideable. It has a BMC 600W Speed (V2S) rear motor, standard 30A BMC controller and a random assortment of 36V battery packs. Even at 36V it is good for around 25mph. I have some 48V Li Ion packs on the way, I will claim one for myself, I expect a top speed of over 30mph with them.

The great thing is that there is room for a whole family grocery trip back there, even with the batteries. And there is no need to figure out a rack mount. With this capacity, all day riding and touring should be possible. I am thinking about a west coast tour ride at some point.

On its maiden voyage I just threw the battery packs in loose. I plan to try other battery mounting options as time goes on. It rode pretty well with a 26" wheel in back and a 700c in front. The big 2.35" Big Apple made the 26" close to a 700c in size. It is nice to know that monster tires do fit. And with discs front and rear you could put 26" tires/wheels on it if you wanted to.

For a later ride I did a grocery trip and came back with 4 12-packs of soda, a gallon of milk, enough groceries to fill all the bags on the bike, and I had my batteries in the bags. That was probably over 100lbs of stuff. The bike handled the load. Really heavy loads just sitting in the bags can sway a bit, which makes the whole thing wag a bit in the back. As long as I rode and pedaled smoothly everything was OK. But if I wiggled around on the bike or shook the bars while riding (remember, I was doing a test), the back end magnified it. If I had the kind of load that I could lash to the top of the deck or secure on the sides on the Ute that amount of weight would be fine.

Here are some details of the build such as it is.

I installed a nice wide mountain bike riser bar. This eliminates the upright riding position of the stock bars and is a personal preference. I am a regular cyclist (no electric assist) too, and the single sided clipless pedals seen in the crank pic below go along with that. I don't even notice the long back end of the Ute when riding, BTW. Another note is on the light. I runs on its own stock battery for now. DC-DC converter power is on the list of things to do. Any good eBike can be an endless source of projects if you want it to be.

The Ute comes with a 26-36-bash guard crank. I installed a road triple crank. But then the chain interfered with the stock kickstand, so I installed an Esge model where both legs fold up on one side of the bike. With the 11t small cog in back I have a big enough gear to allow me to add pedal power at all speeds.

The controller held in place with my version of bailing wire and duct tape: zip ties and inner tubes. It will get a better installation in time. I will do the same with the batteries, too. The BMC controller is nice, I will stick with it for now. Maybe in the future I will swap in an Infineon. But I like the 36/48V jumper on the BMC controller, and its sustained 25A output is plenty for me. Even at 36V it can handle the big hills where I live.

The bike comes with a very nice drivetrain for the price. But, as usual, Shimano trigger shifters will interfere with twist throttles. The solution is Sram thumb/thumb style trigger shifters. If an 8 speed cassette fits back there, I will install Sram Attack models. It will require extra long shifter cables, which I have at the ready.

I will post an update after making some changes to the bike.