for those of you that have a blackspire chain guide, or are planning on getting one, DONT, you will regret it. my chain came clean out of the guide system right before the step down at sea tac and i ate **** hardcore when i went off the step down with one foot on one pedal while sitting on the frame.....the chain guide just plain failed. it just slipped right out of the space between the bash guard and the "guide" piece and i thought i was gonna die!!!!! but ya, thats the first guide that i have actually seen that happen with. so ya, no black spire for me any more......what are people running these days, i have had E13s and i havent been that happy with them have they gotten better?? what else are people running and like??? give me some suggestions...and oh ya, its goin on an 06 SX Trail 2 with holzfeller cranks and the external bb...so keep that in mind