Question about how cog and hub selection effects chainline

On my current bike, I’m using a Surly track hub with a Surly 1/8" cog and a Shimano 105 crankset with 107mm BB. The crankset gives a chainline of roughly 43.5mm while the cog/hub combination is 42.12mm according to Sheldon brown’s info here: http://www.sheldonbrown.com/chainline.html.

If I’m reading this properly, using a Dura Ace cog with my Surly hub will deliver a 43.31mm chainline, which is closer to the crankset end of the drivetrain. Do I have this correct or am I missing something?

I need a new cog anyway. If going to the DA cog will get me closer to my crank’s chainline, it’ll be a win all around.

Chris

just lay your frame on it’s side and stomp on the rear triangle till your line looks good.

Go with the DA cog.

Because it will align my chain better or simply because it’s Dura Ace?

Chris

[quote=“allencb”]On my current bike, I’m using a Surly track hub with a Surly 1/8" cog and a Shimano 105 crankset with 107mm BB. The crankset gives a chainline of roughly 43.5mm while the cog/hub combination is 42.12mm according to Sheldon brown’s info here: http://www.sheldonbrown.com/chainline.html.

If I’m reading this properly, using a Dura Ace cog with my Surly hub will deliver a 43.31mm chainline, which is closer to the crankset end of the drivetrain. Do I have this correct or am I missing something?

I need a new cog anyway. If going to the DA cog will get me closer to my crank’s chainline, it’ll be a win all around.

Chris[/quote]

This one.

  • Lucky “Bandit” Tarck

Cool. I’ll go with DA then.

Chris

Go with whichever cog you like. IMO, EAI>Surly>DA for cogs. IRO cogs are also decent and very similar to DA in shape. I use all 4 on various different bikes. As long as you’re within 2-3mm, and running a slight bit of slack it should be fine. And if you’re using a 1/8" chain on a 3/32" drivetrain, the chain will run straight despite that difference.