Singlespeed problems: Surly Cross Check
 

Hi all, I'm having a few annoying issues whilst setting up my cross check SS.

My chain keeps falling off. Chain tension is good. chainline is spot on.

Before I order any SS specific or narrow wide chainrings or cogs, I'm trying to get my gear ratios chosen.

Right now my chainring is from a 10speed double, and the cogs i'm using are from a 10speed cassette. I tried using an 8 speed chain, which worked fine for a social ride bar crawl at a 39/14, no chain problem. Swapped over to a 18t from the same cassette for some cyclocross shakedown runs and after about 30 feet of riding off road the chain falls off. I tried putting on a narrower 9sp chain to see if that would help to no avail. I still have yet to try a 10sp chain. I'm using one of those 5mm hex bolt on skewers so I know I'm not pulling the wheel forward and losing tension.

Any tips, tricks, or suggestions for helping me out would be useful. I'm just trying to figure out gear ratios before dropping cash on SS specific drivetrain options

This is really annoying because years ago I would sketchily convert old roadbikes to single speed in the same method with no problems whatsoever

How do you know you are not pulling the rear wheel forward ? IME those bolted skewers don't work very well on horizontal dropouts. Also, you might consider chainguards for the chainring to keep the chain from dropping on rough terrain. A front derailleur works great as a chain retainer.

I agree with TT, something else is going on there I think. Is the cog secure on the cassette (no play)?

After a few trials and errors with different skewers, I am pretty confident that the wheel is not moving around.

I will go inspect my spacers and make sure they aren't moving and the lockring has a good grip, didn't seem like an issue but I will check.

I'll throw a front derailleur on for good measure to rule that out.

Is the cog possibly on backwards? If it's a ramped cog in conjunction with a multispeed chainring I would think that could wreak havoc..

Rather than go to narrower derailleur chains, I'd see if a 3/32" or 1/8" SS-specific chain improved the situation.

Do you have a geared bike? Just ride that around until you determine your happy ratio and then build the SS drive train from there.

Get some a chainring and cog with no ramping/shifting garbage. In the case of the chainring that does not require it to be SS specific, many inner road double rings have straight teeth. No way around needing a SS rear cog, just get a cheap one. Shimano stamped steel cogs sold as Shimano DX or DXR work great and are $10 or less.

The hex bolt QR is likely causing issues as well. The only thing that will hold as tight as a standard shimano QR is a DT Swiss RWS twist on QR. Or convert the wheel to a solid axle with axle nuts.