How Much Do Dynamo Hubs Really Slow You Down?

Summary

This analysis quantifies the speed reduction caused by dynamo hubs and associated components, referencing factors like rider weight, wattage, hub efficiency, and device power draw. The practical takeaway is that while undischarged dynamo hubs cause negligible drag, charging devices and powering bright lights can add several minutes per hour of riding, a trade-off most touring cyclists find acceptable for the convenience of self-generated power.