We run two SP Hubs, a pd-8 on our tandem and a pv-8 on a bob yak trailer. The yak has only seen limited use but the tandem wheel is at [MENTION=205580]250[/MENTION]0 trouble free miles. I do not have any previous dynamo experience to gauge against but I would certainly recommend these. We have the light constant on and have not noticed the additional drag etc.