Originally Posted by PaulRivers

Personally, I can see a use for someone wanting a cheaper tire sidewall dynamo system, but I have trouble recommending them because they remove a lot of the benefits you get from a dynamo of a always-with-you-no-maintenance-only-drawback-is-initial-cost system. You'll need a front tire that actually has a dynamo track, they may or may not work worse in the rain or inclement weather, they steal one of your two water bottle cages...