I've got a surly hub and a dura ace track cog. On my fixie. I've been riding over the last two days, and last night a semi disaster struck.

First day I rode it, I went around the block and then triple checked the tightness on the cog, and then cranked down on the lock ring.

Last night, I went for a ride (about 5 miles) and I got some play between forward presure and back presure (resisting force). I stopped immediately and sure enought the cog was loose and the lock ring was also.

Perplexed, I wrenched on it to put some strong force on the lock ring after tightening up the cog again.

Back out, and it loosens up again.

What gives? The hub is going to get stripped if I tighten it anymore.

Is there an issue with my wieght (201) on an inexpensive hub?

Is a durace cog an issue on this hub?

HELP!

you gotta make sure the cog is tight. it might be that you backpedalled hard when the lockring was a bit loose, and your cog is tightened backwards against the lockring. in this case, tightening down the lockring will only tighten against the cog, but the cog will slide forward as soon as you put enough forward force into the pedal.

loosen the lockring, take a chainwhip to the cog and make sure it's tightened down hard against the hub. you can do this on the bike by applying the brakes and standing on the pedal. then tighten the lockring all the way down in the other direction.

i hope the issue is not deeper than that...

One other option:
Blue loktite. This can be dissolved when you need to do maint, etc...

You might have a slight problem with compatability. Depending on the brand of cog you're using, are you sure the lockring is tight against the cog itself? I've read somewhere that certain cogs do not have enough shoulder thickness and leaves a tiny gap between the cog and ring. I'm assuming you're using the 'fixed' side of the Surly hub and not the freewheel side.

I can see no gap between the lock ring and the cog.

I used (home made) chain whip last night to really pull hard on the cog, and put as much pressure as I could with out stripping the threads on the hub.

I'm using the fixed side for sure (the free wheel cassete is on the other side.. un used). But that's a good point..

If it loosens over the next few days, I'll locktite it. Hopefully it won't.. That would kind of suck.

I'm wondering if I'm to hard on it. I live in a really hilly area.

Flip flop Surly Track hub???
Not according to this:
Rear Track- Spaced 120mm to fit fixed gear frames. Stepped threading on both sides to accept a fixed gear cog and reverse threaded lockring. Yummy. (from www.surlybikes.com).
Unless you are running a rear MTN fixed/free...but those are factory spaced at 135mm...

I may be mistaken but the older surly hubs were fixed/free? I know the newer ones are fixed/fixed.

Are you using a large cog? If so, that may be causing the problem...

What's your definition of large?

...19...20...21...

Start from the beginning. Put the cog on the hub. Finger tighten it to the hub flange. Put the chain on the cog and chain ring( just like you were going for a ride). SLOWLY (you do not want to suddenly jam the cog into the hub) apply forward torque on the cranks and tighten the cog on (use your cranks as a whip). When it gets tight then put all of your force on the cranks to really get it on.

Next, put the lockring on and tighten. With a Surly hub and Dura ace cog I would put grease not locktite on the ring and cog. Hand tighten the ring, then get out your spanner and really tighten it up.

This seems to work for me.

Don't worry about overtightening the cog and stripping the threads, you are going to be putting a lot of force on it when pedaling. I tighten my cogs by putting the wheel in the frame and standing on the pedals!

That said, read the Surly instructions that come with the hub. Some cogs have slightly different threading. You want to make sure everything is matched up right. Also, the mention above about a small gap between the hub and the lockring is worth checking.

Sorry,
I was trying to say put the wheel back on the back (w/o the lockring) and slowly apply torque to the cranks (the cog will spin about a quarter turn. If you jam it on at this time, it may bite into the hub). Once you feel the cog stop, then put all of your weight onto the cranks to really get it on.

Next, remove the wheel from the bike then apply the lockring.

captsven - if your reply last reply was to my message, don't worry, I was responding to the original poster's worrys about overtightening. I was composing my message while you posted your and didn't even see it until now.

I use your method of tightening, except I loosely install the lockring and do final tightening while the wheel is installed so I don't have to remove it again.

I was just checking out Airbomb and Surly makes their own cogs.

You don't think that they would make a hub non-compatable with Dura Ace but only that works with their own cogs now do you?

I have never used anything Surly , has anyone else had a problem with this?

Well....I've heard of problems with Surly cogs when used with other hubs other than their own...... mostly threading issues...

There was recently a discussion on this on the fixed gear mailing list I subscribe to. Surly as well as some others use an ISO thread, but apparently some other manufacturers use a slightly different standard. In general, the consenses seems to be that things are close enough you mix and match the standards, but once you do, you should stick with your set up since the threads will slightly conform to each other.

I'll try to see if the mailing list is archived, I've deleted my copies.

Well, I skimmed the archives, but couldn't find it. There was a lot of discussion about it, so I'm surprised I wasn't able to easily locate it. You can look yourself, but you need to be a mailing list member
https://lists.davintech.ca/mailman/listinfo/fixed-gear

Eurasia cogs are also ISO threaded and are generally considered high quality. I've got a Eurasia on my MTB and a Eurasia and a Surly on my roadie, both bikes run Surly hubs. No problems with any of them. But then again, they were threaded for each other.

Found this:

ISO standard threads: 1.375 Inch x 24tpi (34.92mm x 1.058mm), fits English and Italian threaded hubs.

English thread 1.37 Inch x 24tpi.

Here is a link to Surly with a brief explanation.

It seems that the slightly different thread should not be an issue.

i think the problem here is that the dura ace cogs are simply too wide. i've seen it a few times at my shop. a dura ace cog doesnt leave a whole lot of room for a lock ring on surly hubs (or the suzue junior). since the lock ring can't go on fully it probably doesnt have as much "grip" as intended.

surly cogs have a bit of a narrower shoulder, leaving plenty of threads for the lock ring to grab onto.

This is what I feel to be the problem upon close examination. As it has spun off again, the bike is hung in the garage for inaction (no working brakes.. so it's not useful) until I can get back to the not so local shop where I got the wheel.

A little dissapointed.

But, I've got other bike to ride.

i had a problem with a surley 15T cog and my phil wheels. different threads, of course...but the surly cogs fit on my D/A hubs just fine.