Band Brakes

Band brakes can be used on hub motors which have a thread on both sides of the motor. The side of the motor which has wires coming out of it are the side used for a brake, the other side the gear cluster is installed.

Band brakes give quite good braking, somewhat better than normal caliper brakes. Though unfortunately because hub motors are made for chinese bicycles which are wider between the frame at rear (between dropouts) it can be necessary to extend out the bicycle frame to fit in a band or disc brake. The amount the frame needs to be widened can vary depending on the motor being used but is usually 2 to 2.5cm. The rear frame can be easily pulled out just using hands and feet but it may not be adviseable not to do on aluminium frames and alot of people just dont like the idea of widening the rear width if its a nice new bike.

So basically band brakes (and disc brakes) will not always be able to be used depending on the project situation.
Below a band brake installed on an el cheapo mountain bike from BigW. It was necessary to pull out the frame by about 2.5cm to fit in the band brake and 6 speed cluster on other side of the motor. The band brake is operated from the normal brake handles on handle bars.

Below shows the leather lining used as the brake lining, I was quite surprised initially to find it was leather but seems a very suitable material for the job, I've used the brake down some long steep hills in Hobart to the point where the brake was very hot indeed, but the lining was not damaged in anyway. There are other types of lining available but they can over time make an annoying squeelling noise and I think leather is the better material to use. It also seems to be very durable.
 

The brake drum screws onto the thread on the hub motor.
 

The drum sits inside the band brake outer case. The picture below shows the drum portion only in position, it can be
screwed on in the fashion shown below to make the width of space needed a bit smaller, flipping the drum over it is
a bit wider.

 

 
Pictures below show inside of the bandbrake on left and outside view of bandbrake on the right.
Note the size of the centre hole should be just enough to go over the axle. It plays an integral part in
the brake functioning correctly (i.e. the hole should not be drilled out any wider that just enough to
fit over the hub motor axle).
   

Below two views of the pivot arm and bracket which connects to the bike frame.Note the bracket that goes onto the bike frame should have two bolts in it, I only had one bolt at the time pictures were taken).
   

A simple pivot mechanism operates the band band via the brake cable

The brake cable goes through the middle of the spring. (note picture on the right shows only one
bolt holding bracket for bike frame in place, their are two bolts as shown in the first picture at top of this page).
  

I found it necessary to put the torque washer on the inside of the bike frame rather than on the outside of the frame
   

Below just shows nut and ordinary washer going into place.
   

The rear of the bracket that goes onto the bike frame has some notches punched into it which the nut sits in and it stops it from spinning
around when you tighten the bolt.



When the bandbrake is installed it is necessary to adjust it so that only a small amount of movement of the
brake handle on handle bar is used to apply the brake.
Step 1: loosen off the nuts on the adjusting screws shown below, tighten up the screws clockwise until the brake lining sits firmly against the brake drum (if you have the wheel off the ground will make things easier). The wheel should not rotate easily as the brake lining is sitting against the brake drum. Loosen off each of the screws (anticlockwise) with a screwdriver until the wheel will rotate freely (i.e. the lining is not rubbing on the brake drum). Make sure you tighten up the adjusting nuts so that the adjusting bolts cant move (check again that wheel still rotates without any rubbing of brake lining on brake pad).
Step 2: Once thats done then the brake cable can be adjusted in the normal manner so that the brake operates to suit how much movement you desire for brake to be applied.

Dimensions:

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