Martin Baker

For sale - Tacx Flow Ergotrainer. Excellent condition, works great, smooth
operation.

Features current and average power (watts), speed, HR and cadence. Operates
in ergo (constant watts) or slope (variable watts) modes. Includes wheel
block, and skewer, cadence sensor, and head unit. And I'll throw in a couple
of tires to burn up on the trainer.

http://www.tacx.com/producten.php?language=EN
&ttop=Flow&lvlMain=16&lvlSub=56&lvlSubSub=79

This is probably the least expensive way to add a power training regimen to
your workouts. I have a pretty low tolerance for indoor miles but I will say
that power intervals on the Flow make the time go by pretty fast and make
the whole thing, dare I say, tolerable. You might even find it fun!

$300