I might get flamed, but what 1 X 7 Drivetrain?
 

I going to buy a used Fuji Cross cyclocross frame and have a LBS build it as a 1X7 commuter bike for my daughter. This bike will be used in the Chicago area with no hills to speak of. I have a set of new 700cx32H wheels with a Shimano 14-34T, 7-speed cassette on the rear.

I need to select a drivetrain, including the front crank. Any suggestions?

Michael

1x7, 8 or 9 is GOOD.
suggest mid level "mountain bike" components, as due to the popularity of mountain bikes;
they offer the best balance of cost, longevity and ease to obtain.

Do you have a parts box with some old 7 speed stuff in it? Even Shimano 2200 which is their lowest end road stuff is 8 speed at this point. Even Sora is 9 speed now. Unless those are some really nice wheels, you might look at the options of a whole bike. You can get a Motobecane Fantom CX for $550, which is about what you will end up paying, maybe even less, than if all you have right now is wheels.

How much are you getting the frame for? Add that to what the rest of a parts group and you will have your answer. Buying an entire bike part by part adds up pretty fast.

the 14-34t is the megadrive cassette so you'd need a long cage derailleur for the back and use a chain keeper for the front with something as cheap as an older shimano Deore LX or DX crank/bb... even a sunrace crank would do and be cheap enough... or go a shimano 105 compact crank for city commuting...

you would need an older shifter and might need to go downtube friction or just go with deore or alivio(?) 7sp trigger shifters which can usually be found on older mtb bikes at used bike shops... hell even go a bar-end shifter and have it in friction mode... would be great and cheap to do!

I'm actually building up a 1x8 cross bike right now. I'm using an older XT rear der, a 12-27 cassette, and a set of Sugino messenger cranks with a bashguard on the outside, a 39t ring, and a chain retainer on the inside. So far so good.

And one of your best options might be barend shifters in friction mode.

Hey, there'a a guy on the commuter sub-forum w/t exact same question...spooky! :D

Its so wierd.

Thanks for the help.

Michael