I just got two bikes an early 90s Cannondale, and an old motobecane. I have not decided witch one I want to convert yet I was most likely going to put a flip-flop hub on it. Is it best to get shorter bolts for the chainring to convert the crank; what do I do if the sprocket and chain ring don’t line up? The moto has horizontal dropouts but the Cannondale does not how do I go about converting this (with out buy some $150 hub?) [White Industries]

Thanks for the help guys I can’t wait to get this bike going.

Ps I just got my new Kona Unit and it is awesome!

The Cannondale is going to be a *****, especially if you don't want the ENO hub.
Either you try the "magic ratio" or you do it fixed.
Basically, the answer is the motobecane.

the answer is to read this https://sheldonbrown.com/fixed-conversion.html

then figure out if french sizing or vert. dropouts are a bigger PITA

yea the (sheldonbrown.com/fixed-conversion.html) helped alot what do u mean by "french sizing or vert"???

Don't underestimate the amount of info on this man's site:

https://sheldonbrown.com/velos.html

Don't underestimate the amount of info in preceeding posts.

french threading... finding bottom brackets, headsets and stems and sometimes chainrings and pedals for old french bikes can be a huge PITA since the French decided to have their own set of threading standards

vertical dropouts are a huge PITA when it comes to converting a bike to fixed. you're going to have to find a magic gear ratio, or use the ENO.

decide which is the smaller PITA

Sell both, get something better for conversion.

magic gears:

https://eehouse.org/fixin/fixmeup.php

half-links are your friend.