Stop your ebike hub motor overheating

HubSink does not make power. Your controller and battery do. HubSink lets your motor handle that power without overheating. Most customers turn their controllers up to more than double the power they could run before, many regularly run around five times because in real riding faster cooling compounds, and we guarantee your motor will handle at least double, or stop overheating at your current power, or your money back within 30 days. See the guarantee.

HubSink V2 fits standard direct drive hub motors with a 222mm to 238mm outside diameter magnet ring and at least 18mm of free space between the spoke flanges, including QS205, MXUS, Leaf, Crystalyte and 9C and clones. A larger version is available for the QS273. The QS273 version is a beta and needs a little adjustment to suit each bike while fitting, see the installation guide. See every motor it fits in our guide.

No. HubSink comes in six pieces, so even on a 17 inch moto rim with 10 gauge spokes they slide in and bolt together.

Black anodising improves the emissivity from about 0.09 to 0.89, so we did. Standard paint may insulate slightly, but very likely not enough to matter unless you are at the limit of the fins.

In testing, both with a FLIR thermal camera and in a wind tunnel, the spinning hub pulls air in from the sides of the fins and flings the warmed air outwards. Angling the fins 45 degrees or curving them gave no improvement, and straight fins outperformed every other option tested.

Turbulent flow transfers heat much better than laminar flow. Combined with the centrifugal action of the spinning hub, we found the axial fin design the most effective.