looking at getting a dura ace track cog but read that there were compatibility issues with the surly hubs. i have formula fixed/fixed hub and want to make sure they are compatible with each other. can anyone help?

I have a dura ace cog on my surly hub :B

There won't be any issues. Surly hubs, DA cogs and Formula hubs have the same cog threading ( 1.37" x 24 TPI). Check it for yourself; on a site where you can buy any of these things they will usually mention the threading standard.

[Edit] apparently this is only true of cogs. Well at any rate, Surly cogs and DA cogs are both 1.37" x 24 TPI (according to internet sources), and Surly cogs definitely work on Surly hubs, so there shouldn't be any issue running DA cogs on a surly hub.

IIRC, I think the issues were having more to do with chainline.

Funny you should mention that. I just recently compared my 15T Surly cog to my 16T Dura ace cog. Both are 3/32". My digital calipers tells me they are the same width give or take a few tenths of a mm. I use both on a surly fix/fix hub with dura ace lockring. No problems.

My wife is running DA cog on Surly hub without problem. Just make sure to set up your chain line properly, and put the right amount of tension into the chain.

https://www.bikeforums.net/showthread...-ace-track-cog

here is the link to the thread where i heard about this being a problem. the conclusion it came to was that the DA cog is too wide for the surly hub, not allowing the lockring to tighten down properly.
I, however, i am not riding a surly hub, i'm using a FORMULA hub. i'm curious if i'm going to run into the same problem that this guy ran into.

The Surly lockring mignt be good to try if there's a problem with getting enough thread to tighten it up properly. It has a little raised lip that goes in under the cog and results in more lr threads grabbing. (see pic)

But I wouldn't let one forum thread with some vague hearsay type stuff cause me too much stress over a $15 cog, especially since other posters in this thread have had no problem. Maybe give it a try and report back.

ok thanks. yeah if it doesn't work it looks like that lock ring will. so far i've only heard one complaint so i feel better about it now. thanks.

Upon close examination of my hub, the lock ring on the DA side does seem to be slightly further out than on the Surly side. That extra space I see is tiny, I don't know how significant it is. They're both Formua lockrings, seems one is flipped over. I've had zero problems.
surlydura ace

Yeah because chainline could only be affected by the width of the teeth right

oh wow. thank you. do you do skids or anything with those?
do you think the surly lock ring pictured above would solve any problem that MIGHT be created by skidding?

I skidded, nothing happened.

I think what I'm recalling had more to do with where the teeth were on older Surly hubs that caused a weird chainline, not the actual width of the cog.

Funny. One person said that, but thats hardly a conclusion. I'm sitting here right now staring at my surly hub with DA cog and it works fine...and has worked fine for thousands of miles. There are plenty of threads left over for the lockring.

Not the width of the teeth, idiot. The width of the cog. The cogs are the same width with the teeth in the same position with respect to the width of the cog. They will give the same chainline with a given hub.

it was only the conclusion that the other thread i was looking at came to. i'm not saying its right or wrong its just what the thread said.

Is name calling really necessary?

When did you become the next Sheldon?

have you read operator's posts?

Is he worse than noobert?

If that's the case, I retract my statement.

He seems knowledgeable, but he also comes off as an ass a lot of the time

Operator usually knows what he's talking about but mostly comes off as an abrasive ass. I don't know if he really is an ass in person, or if he just has a really bad internet personality. Whatever the case, he's accustomed to whatever abuse he gets on BF, and mostly deserves it anyway. I owe him plenty of abuse.

Hahaha, nice.


FWIW Operator built my bike so I'm pretty glad he knows his ****. Over 10K kilometers and no bike assembly related deaths yet

I'm pretty sure he knows a few lifetimes worth of bicycle knowledge. I also enjoy reading his posts because I've never been on the receiving end of them. But he comes off like he's just a hair shy of dutret, which is still a few hairs too many.

toughen up biatches