funkybioped

Hey guys/girls. I was looking for help converting a junker into a winter bike. Lots of snow, ice, freezing rain, and slush here so I was converting it into a single speed. So far I have cleaned the bike up a bit, pulled off the dérailleurs and pulled off the crusty chain. I was wondering if anyone knows if I can just shorten the chain and make the bike a single speed with the current cogs and crank. Just remove the derailleurs tighten the chain around a selected set of cogs? Just to keep it cheep and reliable for winter.

icepick_trotsky 

One thing you need to be sure of is the chain line. When you don't have derailleurs, you need to space the chain ring and the cog so that it's a perfectly straight line parallel to the frame. That limits your option for using the shortened chain on current cassette setup you proposed.

Andrew R Stewart 

Basic answer is yes. Simply removing the ders and choosing a cog combo that both meets the gear ratio goal, and has a reasonable chain line is the devil of the details. The lack of this being likely is one of the motivations to get a crank and rear wheel/cog that's single speed specific. Andy.

clengman

Having a single cog and single chainring makes it a little easier to keep everything clean, too. What kind of crankset do you have? Threaded hub?

dabac

On a geared bike, the chain, chainrings and sprockets are all made explicitly to derail easier. Better to leave the derailers in place, and use whatever method available (limit screws, short length of cable etc) to lock them in place in one specific combo. The usual problems with externally gears bikes and winter is cables freezing and preventing shifting, not the derailer as such.
It won't look as clean, but it'll give you the bulk functionality of a SS w/o issues of "magic gear" and chainline tweaking.

corrado33

Agreed, however I've never had my derailleurs freeze. Admittedly my bikes are all garage kept (attached, but not heated.) The main problem I have is snow getting packed into the cogs of the cassette, preventing shifting into certain gears. When it's THAT snowy though, I barely get out of my lowest gear.

funkybioped

Thanks for all the answers and help. Much appreciated! Here are the reasons I am thinking of keeping the derailleurs off and just running a "SS" the bike was a junk rescue, the drivetrain is pretty beaten down from being left outside. Lots of rust and gunk, I'd guess it was only ever oiled with WD40 or something cause there is so much crud. I tried a quick clean up and decided that the chain was too far gone, sticking rusted links just crud impacted derailleurs made me think they were done to but after removing the rear and pulling the pullies apart I realized it's actually really in good shape. Very little rust inside which I found kinda weird. The spring freed up and came pretty clean with some degrease and toothbrush. The pullies freed right up and spin great now. I could put it back on, I only took it off cause I guessed it was too trashed for use. I figured it would be easier and cheaper to build single speed for winter. Cleaning is going to be difficult for me over winter Nd I have other good bikes that work well I just don't want to kill them. I love riding them.