aquateen

I currently have a compact double and was thinking of going 1x9 on my cross bike. I assume I need a new crankset. Do people ever use track cranksets for this purpose?

flargle

You don't need a new crankset.

A lot of people are attracted to a single-ring because of the "simplicity" but you trade one set of problems for another. What's your current gearing? If you have 50/34, then try the Shimano CX70 46/36 rings.

aquateen

buying new rings is almost as much as buying a new crank plus i'm planning on using that crank for another bike.

ThermionicScott 

Historically (1x is NOT a new idea for cyclocross racing), people used their old crankset and substituted a big ring with no teeth to help prevent dropping the chain to the outside.

A track crank would look pretty, but wouldn't function as well on rough ground without a narrow-wide chainring or chain keeper.

aquateen

wouldn't there be issues here with chain line? that's why i figured a track crank might suffice

CBBaron

You don't need a new crankset, you will want a narrow wide chain ring, chain keeper or clutch derailleur. You can get by with just losing the front derailleur and one chain ring but my experience is that you will drop the chain too often with that combination.
Best choice is narrow wide and clutch derailleur but just a narrow wide should be sufficient.
Most 1X cranksets are just double cranksets with a single narrow wide ring installed.

Craig

CBBaron

Track bikes use a different chain line than derailleur based bikes. The rear hub on a track bike is only 120mm wide instead of the 130 or 135 of road and MTB bikes respectively.

aquateen

gotcha. i didn't even think about the difference in hub spacing

flargle

Multiple guys I know have dropped chains during races with narrow-wide and standard der. "Oh, I've tested it out, it works great!"

A cheap reliable setup is BBG bashguard on the outside of spider, singlespeed chainring (i.e. no ramps or pins etc), and N-Gear Jump Stop clamped to the seattube. I ran that for 2 or 3 seasons with no problems. I currently prefer 2x10 with 36/46 or 34/44, though.

ThermionicScott 

I forgot to +1 this the first time around. A regular front derailleur is the best chain keeper, and a set of "cyclocross chainrings" would probably do the trick.

justin1138

You probably want a crankset with a 110bcd or 130bcd so you can use a narrow wide chainring. I haven't seen any made with the 144bcd (most track cranks). That, and the 144bcd would limit your choice of front chainrings to 42? You may or may not want to go smaller then that. Your current cranks are probably fine, and all you would need to do to get going is get an appropriate chainring, get rid of all the stuff you aren't going to use anymore, shorten the chain and ride.

Like others mentioned, there are a few different ways to keep your chain on the bike. I'm in the camp that feels the wide narrow chainring works without further stuff. I've dropped more chains with my bike as 2x than with my bike as a 1x.

And a new chainring isn't going to cost you nearly as much as a new crankset, unless you're going really cheap on the crankset. And then you'd still need a better chainring anyway, or a bunch of stuff to keep your chain on...

aquateen

got it, thanks

09box

The 1x setup looks cool on a cross bike. That is all I have to input here.

hup

This is a 130bcd Ultegra crank with a plain old 38t inner ring, BBG 38t bash guard, and dog fang chain keeper. I don't race, but have been through some pretty mucky mud and snow and the chain has not come off (yet). YMMV.
1x9 11-34 w/ XT RD, Dura Ace 9 sp bar end shifter.

Kopsis

Yep, been there, done that Setup was fine using a wide/narrow with road RD until I hit a course that had a section of fast singletrack with some big roots. Dropped the chain three times in one race. Switched to an X7 clutch RD and haven't had a single drop in the dozen or so races since.

flargle

justin1138

maybe it's the SRAM derailleurs that like to drop chains then...

WiltingArtichok

I have a SRAM Rival crankset - took the large ring off and threw on a BBG bashgaurd and have been riding/racing it for several years with no issues.