Bicycle bottle dynamo generators

This type of dynamo is to be mounted on the front fork of the bicycle so the roller at the top of the bottle runs against the ribbed dynamo track that may be available on the tire when the dynamo is in the on position and that it does not touch the tire when it is in off position.

Mount the dynamo on the correct side of the bicycle depending on from which side the spring on the dynamo pushes the dynamo. If it pushes to the left then it should be mounted on the right side and vice versa. It may also be mounted on the rear fork.

Ensure the bottle is angled straight from the center of the hub. An incorrect angle will wear out the ball bearings in the dynamo. A weared out dynamo first makes screatching noises and then it gets very hard to turn. The roller should not skid when it rolls on the side of the tire - this is a common problem in wet weather. It should also run against the dynamo track as flat as possible to improve the grip. Some noises can be fixed by lubrication, to do so spray some oil between the roller and the bottle or remove the roller and spray some directly where the shaft goes down in the bottle.

The dynamo makes alternating current, not direct current. They are commonly rated as 6V but the voltage varies depending on the speed of the bicycle and may go much higher.

There are at least 2 types of dynamos, those with 1 pole and those with 2. They look almost the same, but they are not.

The 1 pole dynamo is often rated as 6V 3W. It is intended for a parallel connection of the front and rear lights. This dynamo uses the bicycle frame for the ground connection. Both cables from the lights are attached to the single pole.

There may be a small grounding screw on the dynamo mount part that grips around the fork between the big bolts that holds the mount. This screw is intended to be screwed so tight that it punctures the paint and reaches the frame metal. If you do not want to scratch your bike then it is perfectly fine to wire a small cable from some metal part on the mount that is connected to the dynamo and then attach this cable somewhere on the bicycle that has a metal connection with the frame, like some of the screws near the wheel hub on the fork. Current flows from the pole to the lights and back to the dynamo through the frame and back again. A common setup is a 2.4W bulb in the front light and a 0.6W bulb in the rear light that is totally 3W.

Dynamo pole -> front/rear light cables -> front/rear light -> bicycle frame -> dynamo mount -> dynamo.

The 2 pole dynamo is often rated as 6V 2.4/3W. It is intended for a serial connection of the front and rear lights, but it can also be run in parallel. This dynamo does NOT use the frame for the ground connection.

In a serial connection does the front and rear light cables have their own poles (in Sweden they are named S/Strålkastare for the front light and B/Baklyse for the rear light). Current flows from one of the poles through the cable to one light, through the bicycle frame to the other light and then back through the cable to the other dynamo pole. A common setup is a 2.4W bulb for the front light and 3W bulb for the rear light because of the serial connection.

Dynamo front light pole -> front light cable -> front light -> bicycle frame -> rear light -> rear light cable -> dynamo rear light pole.

In a parallel connection are the front and rear light cables attached to one pole together and the other pole has a cable wired to a grounding location on the bicycle frame. Like the 1 pole dynamo, the difference is that the grounding connection to the frame has to be made up. The light bulb setup is as for the 1 pole dynamo - a 2.4W bulb in the front and a 0.6W bulb in the rear.

Dynamo front light pole -> front/rear light cables -> front/rear light -> bicycle frame -> cable between bicycle frame and dynamo rear light pole -> dynamo rear light pole.

Do not attach only the rear light since it may overload it if it runs alone - attach both the front and rear light.

This is a personal note. Last updated: 2021-09-30 20:38:01.







Don't forget to pay my friend a visit too. Joakim