Tire Sparx LED Bike Lights

Concept: 4 out of 5
Execution: 2 out of 5
Yeah, but: They're great while they last.

The Long Version: These are nifty little lights that attach to bike wheels by screwing onto schrader valve stems. They're motion-activated, so there's no on/off switch, and they run for a little while once the movement has stopped. They combine two really powerful attention-getting techniques, flashing and movement, and the bikes that I've seen with them really stand out. I especially like that they're visible from the side, since headlights and taillights don't help much for cars that are approaching from a cross-street.

But as effective and clever as they are, there are a couple of things that I'm not a fan of. For one thing, the screw-on thread is really deep - bordering on profound. I can't just half-tighten anything, so getting them on and off for the biweekly inflation is far more work than it needs to be. The other complaint is that they turn on really, really easily. Walking past them is enough to set them off. There's a handy extra set of batteries in the package, and they aren't there out of charity. I've read other comments that they can be very slow to activate, so I'm guessing that this is the Mark II edition - perhaps the next version will add a little "off" switch, or perhaps it will need a few seconds of acceleration before it triggers. When they do that, I'll buy another set.