Convert from 3x drivetrain to 1x with 3x cranks There has  been some teeth on my front chainring chipped away from knocking on some curbs. I'm thinking of buying a 1x drivetrain because I rarely change the front gear. Can I put a 1x chainring on a 3x crank? There are bolts on the cranks and I'm wondering is there a chainring that can fit in it. I have a Shimano DEORE M610 crank set. I'm doing this because I'm trying to save as much money as possible.
A quick google of "Shimano Deore M610" returns https://bike.shimano.com/en-EU/product/component/deore-m610.html

This shows there are 6 different cranksets in the groupset offering.  Yours is a triple which excludes a couple, but your chainrings could have a mounting hole size of 104mm or 96mm for the big ring.  

You need to identify your PCD or BCD dimension before buying a chainring.


We can see it needs to be a 4 hole mounting, not 5 hole.

There's nothing much to be saved by putting a 1x chainring on with its narrow/wide tooth design, because someday you will change gears by accident or on purpose, and then its a 1:1 chance your chain will go wrong when changing back to the big ring.   So you could remove the left shifter and wire, and permanently lock the front mech in one point using the limit screws.

Another thought - if you only ever ride on the big ring, then your big/big combination will have the most cross-chain angle.  This might be okay, or could cause premature wear on chain and chainring and cassette.   

You could look at running a single chainring on your existing crank, and removing the other two for weight savings.

You could even replace the entire right crank with a single, something like the Shimano FC-M6000-B2 from the same groupset, which looks like this:



This appears to be a one chainring crank.  You need to match the crank arm length (or change both sides)   You'll also need to consider the chainline, which is how far outboard from the centerline of the bike is the chainring.  On your triple it will be further out (more in line with the little cogs than the big cogs.)



For maximal frugalness, just replace the worn chainring.   If you're canny and good with your hands, consider buying a used bike with the right parts, combine all the good stuff onto your bike, and give away the ratty old one or use it as a beater bike.