Review: Cycle2Charge V3

Hub dynamos have become a major factor encouraging the widespread use by adventure cyclists of phones and GPS units for navigation, even when there’s infrequent or no access to wall sockets.

Key to making the arrangement work is a power converter, such as the Cycle2Charge V3. This turns the roughly 6V dynamo output into the 5V needed by the typical device, and provides it through a standard USB port.

Like several of its competitors, the V3 takes the place of the top cap in a 1 1/8in threadless headset system. There’s also a handlebar mounting bracket, which allows it to be used with a quill stem. Installation is straightforward, provided the steerer has an open bottom and a star fangled nut.

The wire connecting the V3 to its dynamo goes through one of the gaps in the nut’s fixing plates and exits the underside of the fork crown, so a hole would need to be made in an aluminium steerer bung or the converter mounted on the handlebar if used with, for example, a carbon fork with closed steerer.

The M6-threaded Allen-head through-bolt provided proved slightly short but was easily replaced. The V3 can be installed with the USB port facing any direction, with backwards the obvious choice to limit rain ingress. When not in use, the hard plastic outer cap can be turned to close off the port and keep out dirt and water.

The 115cm twin-wire power cord is ready to be connected to the dynamo in the usual manner, with no need to observe polarity. Depending, presumably, on the dynamo model used, the V3 puts out 0.5W at around 8mph (12km/h) and reaches its maximum of 1W at 13mph (21km/h).

It incorporates overvoltage protection to prevent component damage on fast descents, but that 1W maximum output – well short of the maximum from a typical hub dynamo – also means the V3 may not put out enough power to charge some devices reliably.

In that situation, Cycle2Charge recommends using it to charge a power bank while riding and using this in turn to dump-charge the device.

Verdict

Sturdy construction, easy installation, low cost and the neat USB port-sealing feature make the V3 an attractive choice in the competitive power converter market, although the limited maximum output may add complexity to the usage regime.

Other options

Sinewave Reactor £234.99

Waterproof, stem top cap charger with class-leading output and low-profile design.

Available in the UK: SJS Cycles

Igaro D2 Pro R3 £129.99

Metal body with two USB-C ports and IP69 waterproof rating but with no dedicated mounting system.

Available in the UK: SJS Cycles

First published in Cycle magazine, August/September 2024 issue. All information correct at time of publishing.