Sunday, May 23, 2010

New Bike Details

The basic features of my new bike were described in a previous post. In this post I'll show some close-up shots, and explain some of the technical details.

This first shot shows the dashboard. Right now it's just a mockup made from twinwall plastic. (I have plans for a nice piece of plywood.) The computer is the Cycle Analyst 2.0 from Their new large-screen model would work better here. The switches control two front lights.

The second shot shows the front panniers, with the child seat base between them, and the power switch for the motor and lights behind that. The child seat itself fits into one pannier, as you see.

Now we see the child seat installed, held in place by a single bolt into the base. The seat is by Wee Ride, but most of it has been chopped off. The foot rests were very small, for example, whereas the panniers allow even a six year old to ride comfortably, in something like a kneeling position.

The seat base also houses most of the electrical connections, including the Cycle Analyst shunt, as can be seen when the lid is flipped up.

Here you see the motor gearhead, mounted inside the frame triangle. The motor is available from Cyclone, with the gearhead attached. This is the 24V, 360W version, and weighs about 3kg altogether. The controller is inside the motor case.

The planetary gearhead provides about 9.5 : 1 speed reduction, and the chain provides another 2.3 or so (32/14), for a total of about 22 : 1. This is using the middle (32 tooth) chainring. I can also use the large (42 tooth) chainring, for a total of 29 : 1, so that the motor runs at higher rpm. This means less current, and more range, but less power and a higher-pitched sound from the gearbox.

The motor chain tension is adjusted simply by sliding the motor up and down the mounting.

Here the motor itself is visible on the right of the gearhead. Rather conveniently, all the places where water can get into the motor are between the mounting plates, basically inside the frame. This is a nice feature, since the motor itself isn't supposed to be used in the rain. In this installation, however, it's fully protected. (I recently found out that the duct tape above the motor is needed for this.)

You see how the wire entry point is protected.

The battery is the black thing at the top of the rear panniers. This one is a LiFePO4 made by Li Ping of Shanghai. The specs were said to be 24V 20Ah, but actually they measure a little better than this on the Cycle Analyst. Ping had to put the cells together in a different way in order for the battery to fit into the space. The price was also very reasonable, so (to this point, only 1300 km so far) I'm very pleased with it. (The weight is about 5kg.)

Finally we see, from above, the attempt to make the whole bike aerodynamic. The idea was to approximate the familiar "tear drop" shape of aircraft wings and so on. I can't say I've noticed much drag reduction though! I wonder if joining the front and rear panniers together, with side panels of some sort, would make much difference?


  1. I like your project; I may borrow the front fairing/dashboard idea for my own CrazyBike2; yours looks a bit more workable than ideas I've considered so far (though mine will probably not be fiberglass, but rather soda bottle plastic cut to shapes and stapled or pop-riveted). :-)

    If you're interested in more ideas and/or sharing yours further, you should post over to

    If you'd like to see what my CrazyBike2 (custom-built semi-recumbent cargo bike) and DayGlo Avenger (regular upright cargo bike) are like in their various incarnations, you can see them over at

    I'll be adding your blog to my blogger subscriptions to follow your progress!

  2. Thanks M.E. I will see if I can post on endless sphere. And that's a nice rig!