Originally Posted by darkmother
I used to run a rear derailleur as a chain tensioner, with two cassette cogs on the back of my winter bike. I locked the rear drailleur in place with a short peice of shifter cable running from the barrel adjuster to the cable fixing bolt. Then I could turn the barrel adjuster to shift between my two gears. It worked nicely, I could get off the bike and shift to my alternate gear in a few seconds.
Good idea! I thought about doing that just to fix the derailleur in the case that the limit screws wouldn't do the job- but never thought about tweaking it on the fly like that.
