This could possibly save someone one day... I was touring last summer and snapped my rear derailleur cable 35 very hilly miles from the nearest town. Derailleur was stuck in the highest gear... not good. After a minute of yelling some four letter words at whatever squirrels or birds happened to be around, I finally managed to jam some small bits of gravel from the roadside into my RD to keep it from moving down onto the smaller cogs without any cable tension. so I could at least make it up the hills without walking the bike.