Re: chain tensioner mod (in response to norman)
Thanks for that heads-up on the derailleur, that's too bad because it "looked' like it would work well. I think I will go and find a free wheeling pulley type thing with bearings as that should last for years. I still like the idea of a spring though. If you were to leave your bolt loose (with two nuts) and your spring was pulling upwards (instead of towards the rear) you would have that slot for play, allowing the spring to pull upwards. (look at your first pic) Nice clear pics, by the way!