[markwdaisy]

I'm building my first bike and am getting towards the final touches! Where I'm stuck, is do I set up the derailleur first or the chain? I mostly need the chain to do the derailleur, but I also can't size the chain until I get the derailleur into the lowest gear... sort of a chicken or the egg situation. Any one have any pointers?

 

[AKamp]

Derailleur first, then size chain, then adjust derailleur.

 

[jeffrjohns]

I say chain first if it is a 1x setup. Put the chain on the chainring and on largest coq at the back. Allow two link overlap, that is the chain length you will need.

 

[J.B. Weld]

I always install the derailleur first but it really doesn't matter. You don't need the derailleur to size the chain, just follow the manufacturers tech doc. Most want you to wrap the chain around the chainring and largest rear cog and then add 2-4 links. Shimano 12- sp is a little different.

You can roughly set limit screws with the chain off but all final adjustments require the chain to be installed.

I say chain first if it is a 1x setup. Put the chain on the chainring and on largest coq at the back. Allow two link overlap, that is the chain length you will need.

Some setups require more than a 2 link overlap.

 

[Battery]

It's been a long time but I used to set my derailleur alignment on the first cog and then installed the chain. For me, it was way easier to see the initial alignment without the chain in the way.