On a holy quest to find the ultimate brake lights i bought 2 of these as replacements for my other working LED's.
Their brightness is better,but with ONLY the Running lights(parking lights) on they are at maximum illumination(parking + brake)
I tried them on my GS and also a Yamaha TDM900 with the same result,either maximum illumination or nothing.
When connected to an external 12v power source they work fine.
As both bikes brake lights work on a simple on/off switch idea it's got me scratching my head.
Thoughts please?   
old:
http://i66.tinypic.com/28rkyt4.gif[/IMG]
http://www.ebay.com.au/itm/111256295348?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

new:
http://i66.tinypic.com/oif71h.gif[/IMG]
http://www.ebay.com.au/itm/221816504261?_trksid=p2055119.m1438.l2649&var=520686555477&ssPageName=STRK%3AMEBIDX%3AIT

When you hit the brake switch (front or rear), they don't get any brighter, correct? I would guess the bulbs are wired wrong..... not the wires on the bikes, but the bulbs themselves.

Your right Rich about the lights NOT getting any brighter when either levers are depressed.
I "assumed" the polarity of all 1157 bulbs were the same,but that's something i need to check into......thanks.

PS: I tested this new LED against a normal incandescent bulb(not that it matters) and the active contacts WERE different/reversed.............well well. 

Wow, lucky guess! Haha....