Monthly Archives: January 2019

Ebike update: chain works, new handlebars and electric brake

Got myself half twist throttle. Old thumb lever is now used as brake. It is much more comfortable. Electric braking works great! Thanks to enormous direct drive hub motor, braking force is huge. Only very steep hills cannot be braked with this alone. Slowing down before turn can be almost always done with ebrake. Brake pads will probably last eternity. Braking does charge battery, but recovered energy is insignificant in long run.

VESC speed controller manages braking in very clever way. When speed is high enough, it PWMs motor phases to actually boost BEMF voltage higher than battery – current flows to battery. When RPMs are too low, it just shorts phase wires and all the current flows inside motor phases. In this mode which engages at ~6km/h motor is hard to turn.

This bike has non-standard steering stem of 21.2mm diameter for 22mm handlebars. No standard part of today’s era fits. 🙁 Clamp for handlebars is 22mm. So I needed to find tall handlebars (but no ape hangers) for 22mm clamp. After a lot of searching I finally bought handlebars for Simson Enduro 50cc motorcycle. Little heavy but very solid with shiny chrome. On the left there is heavy duty cell phone holder from RAM-MOUNT. I love it and also use it on motorcycle.

I got myself the biggest and most comfortable seat available in the store. Also new seat tube with clamp. Old one is incompatible. End of ass pain.

I managed to fit freewheel on motor and now I am able to pedal. Nice and slow pedaling saves me about 100W of power. And provides backup in case of drive failure. From ~6 test rides, nothing faulted yet. I am playing with idea to make it fix gear. That would save cables and levers on handlebars for other stuff. And less to go wrong. With motor I never needed to shift anyway.

I bought new tires, suitable for ebikes. Schwalbe Marathon Plus Tour. Not exactly cheap but they work well. Even for light offroad. Rolling resistance is lower.

 

A lot of other stuff needs to be sorted out. But I love this machine. With tall handlebars I can finally ride it without pain. Riding position is very natural and comfortable.