epl

If I change to a standard crankset do I have to get a new chain or will the one I have fit?

JohnDThompson 

With larger rings you will likely need a longer chain.

Retro Grouch 

Depends.

Chains can only be adjusted in 1 inch increments. If your chain is on the longish side with the 50 tooth compact crank, it may still be OK with a 53 tooth chainring. If it's on the short side you'll definitely have to add an inch (2 links) of chain.

The smart thing to do is to gingerly try to shift into the big/big gear combination. If it shifts in and out with little effort you're good-to-go. If you feel like you have to force it into that gear combination, you need a new longer chain.

Applehead57

You probably do want a new chain, assuming yours is well used.

If it's in good shape, you could always add a masterlink or two to gain the necessary length.
Your chain will be just fine with more than one masterlink.

Retro Grouch 

So how does that work? A masterlink replaces a wide link. To add more than 1 you first have to remove another wide link from the chain.

Wanderer

How much bigger are you going on the big ring? If the same, no problem.

wrk101

Great point, keep the large ring the same size, and you are golden.

epl

good info. I will see if I can't mess this up. Thank you.

Bill Kapaun

You might have to move the FDER up a bit.

DaveSSS 

What the heck is a "wide link". I know now, you mean outer plates. You should NEVER put several master links (outer plates) next to one another on a chain and of course you need the inner plates and rollers to go with it, to make one inch of chain.

With modern flush-pin chains there really is no good way to add one inch of chain.

joejack951

If he's going from a 50 to a 52 or 53, and the current FD isn't mounted way too high, he will have to move the FD up. In the one standard to compact swap I did, I was surprised at the significant diameter difference between a 50T ring and a 53T ring.

DaveSSS 

A little calculation will show that it's 2mm per tooth.

enock111

If you saved the extra links from the chain that the bike has on now then just buy two snap off pins for the chain (make sure you buy regular for shimano or sram and extra thin for campy) and add two more links other wise you may need a new chain. The chain will be sized right if when the bike is in the smallest cog in the back and the largest in the front the derailer is pointing straight down, this is always the best way to size a chain and see if it is the right length.

Bill Kapaun

WHERE do people come up with this garbage.
The on;y "safe" way is to go BIG:BIG to make sure you don't bend/break parts in case you inadvertently shift to that combination.

https://sheldonbrown.com/derailer-adjustment.html#chain

DaveSSS 

Actually, using the length that produces the minimum tension in the little/little insures the maximum wrap capacity for any RD. The big/big will not suggest the longest possible length unless the largest cog also corresponds with the maximum wrap capacity. If you set the chain length with a 12-23 cassette and then switch to a 12-27, the chain will be 1 inch too short. The little/little would provide a length that works with either one.

If you've got a setup that exceeds the RD's wrap capacity, the big/big insures that nothing will be damaged, but the chain might hang loose in several of the smallest cogs. The big/big method can also match up ends that can't be joined. In that case, add 1/2 inch, so the ends will mate properly. The user needs to decide if he can avoid the big/big or if the smaller combos not being useable is preferred.

The big ring little cog combo has the problem that one length may have the cage angling back a little and one inch shorter will have it angling forward. That's how my bike works, so the little/little is the better indicator. In my case, the longer length tensions the chain and provides maximum wrap capacity.