I have a 7 speed Jamis Boss Cruiser, 7 gears in back and one up front. I've been using it fine for several months now. Lately, the chain is coming off of the single front gear, usually after stopping at an intersection when I start back up again.
I took it to a bike shop and the guy claims the front gear is not the right type of gear, its the type of gear that's meant to work with a derailleur. He says that's why the chain comes off. I'm disinclined to trust him since it's worked without problems for almost 8 months. If it was the wrong gear, I would have been having problem before now, right? Is it true that there is a type of front gear for use with derailleurs and a type of front gear meant to be used as a single front gear?