How can I spin a dynamo wheel at road speed for bench testing?

Asked by: Kevin Gonzales

Do dynamo hubs slow you down?

Do dynamo hubs slow you down? Dynamo hubs have a very small effect on your speed. But it is very small. It depends on what you’re using your dynamo to power too.

How much does a dynamo slow you down?

The least-efficient hub will slow you down:



A low-power device like a Garmin GPS would likely cost me around 20 seconds per hour in comparison. That said, dynamo lights are my number one reason for using a dynamo setup, and I’m happy to lose a couple of minutes per hour at night for sheer convenience.

How do dynamo wheels work?

A dynamo is a device typically located in the hub of a bike’s wheel that converts the energy generated by the wheel spinning to electrical energy. That power is then used to run front and rear dynamo lights on the bike, providing always-on illumination without the need to charge lights.

Are dynamo hubs heavy?

P-Series dynamo hubs are ideally suited to wheel size from 646 to 716mm at 6V3W output. They are very light weight beginning from as low as 390g.

What is the most efficient dynamo?

One of the most powerful dynamo hubs currently on the market is the Shimano UR700. At 25 kph, it can produce a peak output of around 5.5 watts to a USB charger. To compare, the SON28 only puts out about 4.5 watts at that same speed.

Is a bicycle dynamo AC or DC?

A standard dynamo creates a direct current (DC) – a one-directional flow of electrical charge. A bicycle dynamo creates an alternating current (AC), which reverses direction occasionally.

Do dynamo hubs make noise?

If a hub dynamo causes a rattling noise, its axle is not clamped well in the fork. The reason may be sluggish threads that lack grease or wrongly fitted small parts.

What is wheel hub dynamo?

A hub dynamo is a small electrical generator built into the hub of a bicycle wheel that is usually used to power lights. Often the hub “dynamo” is not actually a dynamo, which creates DC, but a low-power magneto that creates AC.

How do I choose a dynamo hub?

There are three different power specifications for dynamo hubs: 1.5-watts, 2.4-watts or 3-watts (all at 6-volts). Given that touring and bikepacking is often conducted at speeds below 25KPH/15MPH, the most powerful option (3W) is necessary for charging USB devices, and it’s the best for low-speed lighting too.

Which one is the correct disadvantage of dynamo?

These disadvantages are: The sliding friction between the brushes and commutator consumes power, which can be significant in a low power dynamo. Due to friction, the brushes and copper commutator segments wear down, creating dust.

How much power does dynamo produce?

Most dynamos are designed to produce ~3W (watts) of power at that speed.

How do you make a homemade dynamo?

Quote from video: Around the motor I'll get somebody to hold the motor. And then I pull the string. The ends of the string. And I have the motor connected to a bulb.

Can a bicycle dynamo charge a phone?

Mobile phones can now be recharged while riding a bike.



Phone firm Nokia has released a charging kit that uses a dynamo powered by a bicycle’s wheels. Any cyclist wanting to re-charge their handset using the kit will need to maintain a speed of about 4mph (6km/h), said Nokia.

What is the efficiency of a dynamo?

The highest-performing dynamo hub can average 50-60%* efficiency when charging while the lowest-performing hubs averages between 30-35%*.

Can a bicycle dynamo charge a battery?

The dynamo will charge the battery as long as its voltage is higher than the battery’s voltage. You are correct, as your battery approaches a full charge, it will be around 14 volts and the dynamo is rated at 12 volts, so it will not be charging in this situation if it is actually 12 volts.

Do dynamo hubs make noise?

If a hub dynamo causes a rattling noise, its axle is not clamped well in the fork. The reason may be sluggish threads that lack grease or wrongly fitted small parts.

How much power does dynamo produce?

Most dynamos are designed to produce ~3W (watts) of power at that speed.

Are dynamo bike lights any good?

Dynamo lighting is reliable, durable, environmentally friendly, more difficult to steal, and extremely convenient. Having lights permanently mounted on and powered by your bicycle means you’ll always be well lit.

Are flashing lights on a bike legal?

The 2005 RVLR amendment means that it is now legal to have a flashing light on a pedal cycle, provided it flashes between 60 and 240 times per minute (1 – 4Hz). The amendment also allows a single flashing light so long as it meets the minimum brightness standards.

Are dynamo bike lights legal?

Dynamo powered lights are legal even though traditionally they have gone out when you stop (modern dynamo systems have ‘standlight’ technology which means that the light stays on for a while after you have stopped – another German legal requirement).

Is it law to have a bell on your bike?

Bike bells aren’t required by law, except if you live in South Carolina, Georgia, New Jersey, or New York. These regions have made it compulsory that a bell must be equipped on the bikes. However, even in these states, the law is not very much enforced, and not many adult bikes are seen there with bells on them.