On my way to work this a.m., I was backpedaling/skipping down a steep hill and felt a "slip". I will always know that feeling from now on, at first I thought it was my pedal. I stopped (brake) and when I started again I could feel the cog re-tighten.

I bought the wheel (lower quality hub), cog and DA lockring a few months ago and the tech at the LBS installed and tightened everything. I don't have the tools to re-tighten, but I think it's time to make that purchase.

My question is, could the lockring have just loosened, or is the hub certainly stripped, or is there no way to tell without taking everything off?

Thanks again from a newb...

Feel the lockring. Is it loose? If it is and you keep riding it, it will be stripped. Sorry, but this should be a really, really easy question for a newb to figure out.

Yeah, sorry to seem like such an idiot. The lockring feels tight, I can't move it with my fingers.

I guess I'm hoping that maybe the lockring just isn't quite tight enough, allowing the cog to slip a little under heavy backward load, and I will certainly be using the brake until I can get it checked out. It just didn't seem like this could happen without something being stripped permanently...

Sounds like something that happened to me when I first got a track bike. The cog probably wasnt tightened all the way. The lockring was tightened as far as it would go against the cog. So there was some tightening and loosening going on with the cog. What you should do- Get a lockring tool. Ride really hard for a few minutes, and stop using only the brake. Tighten the lock ring as hard as you can- remember its reverse threadded. Repeat one more time just to be certain. Thats how I did it.

Hammer and a screwdriver work in lieu of, if not better in some cases, than a lockring wrench.

Thats what I use and it works fine and dandy

shudder...

Buy a chainwhip and a lockring wrench. If you're going to be riding fixed there's no reason not to own these tools. Then take everything off and reinstall the cog, and this time don't be shy about tightening it down. As the poster above suggested, take a ride (up a hill, if possible) with no backpedaling, skipping, or skidding, and then install the lockring. Again, don't be shy about tightening it down.

Shudder all you want, but one of our best mechanics had his lockring loosen up a few times until he did this in a emergency situation, and it never came loose again to this day, after a year of riding.

thanks again, I've decided to invest in a couple good tools for Christmas! And maybe a stand.

I appreciate all of your help (and patience...) my main worry was that the hub was toast after only a few months. Damn, I am loving the commute on a fixed gear.

Of the family's 8 bikes, 4 need work (one headset, two bottom brackets, a casssette and now a cog and lockring)

Mmmmm, hozan lockring pliers.

Hammer and screwdriver worked fine for me with the hub lockring but not with the headset. You can torque the hub pretty tight but the headset is a little more finicky.

Search for rotafix - some will poo poo it, but I stripped a hub that I broke a chainwhip tightening the cog on (broke it because I couldn't tighten it any further by hand), and have tightened with a chainwhip as much as humanly possible with plenty of grease on the threads, and gently rotafixed the last two cogs I've put on, and they haven't budged, one in 8 months, the other for a year. Under a heavy rider who rides downhill to work every day.

A lockring spanner like the Hozan makes lockring tightening *much* easier than one of those bb lockring spanners that you get in e.g. the nashbar or performance cheapo tool kit. You need at least one chainwhip no matter what, so for fixed gear stuff, you might as well spring for the lockring wrench as well, as it's the only fixed-specific tool I can think of.

There should be a rotafix sticky or something, it's the best tip I've learned here.

Well I've seen the rotafix site a few times, but thought that was only if you didn't have a lockring? ie. converting an old road wheel.

Chainwhips are a waste of money unless you get a tomity one. And you can't. So... Save your cash and Learn how to Rota-fix. Its the ****ing ****. Also, please put a rag on the BB shell when you rota fix to save your paint.
But a lockring wrench is something I shoulda asked for for christmas... damn.

Rotafix to get the cog on tight, then install the lockring.

https://204.73.203.34/fisso/eng/schpignone.htm

is that the one?

I just finished rotofixing the cog and "tapping" the locknut tight with a hammer and screwdriver. I definitely felt the cog tighten when I rotafixed it. And the locknut tightened a millimeter or so. I appreciate everyone's help.

It sounds like it's too late, but grease on both the cog and lockring threads certainly helps both tighten and stay tight.

hozan lockring spanner or pliers for the win

Don't tap that thing, you need to ****ing wail on it. Take the wheel off the bike, sit on it so it doesn't move. Put the screwdriver in there securely, and ****ing whack it hard with the hammer. Repeat.