I am curious whether this may be possible or not. Is it possible to carry around a spare chain and fit it on your bike when or if you have a derailleur failure on the road? This is not a permanent solution, but more like a temporary fix so you can at least reach your destination. The gears wont work if you take the rear derailleur out of the mix, but I will still be able to pedal to my destination.
I have a few questions on converting to single speed without removing the cassette:
-> Does the rear cog have to perfectly aligned with the chain ring?
-> Do I need a chain tensioner?
The reason I am asking is because I ride trails and roads a lot, and no matter how careful i am, I seem to either bang it or smash the rear derailleur with on thing or another on the road or trail. I am seriously contemplating on switching to a internal hub gear, but for now, I need to work with what i have.
Any advice would be greatly appreciated.