ok, this is kind of random, but maybe someone knows what's going on.

i just went out on a little ride at lunch. probably a mile each way, up a big long road. Before leaving the house I had adjusted my chain tension by moving the wheel back in its dropouts.

So I got this weird slippery feeling twice. First when starting out from a light, I stood up on the pedals and started hammering away, and for a split second the rear wheel spun like it had hit a patch of ice, then caught, and I was off. Weird. Then I was slowing to a stop as I reached my destination LBS, and as I applied backpressure the same thing happened, but backwards slippage this time.

I thought maybe it could be soft asphalt, or melty tar, or something like that--it's a hot day here, hot for Oakland anyway. It really didnt' feel like tires "skidding" on dry pavement, it was much too smooth for that. It felt like I was suddenly riding on glass for a brief moment. I couldn't check the road surface the first time, and the second time, I looked out into the street and couldnt see any swaths of soft tar I had passed over. On the way home it didn't happen. I checked chain tension and bolt tightness (and cog tightness) before heading back home.

Has This Ever Happened To YOU?

It sounds like your lockring may be having some issues.

arrr, that's what i was afraid of...i will give it the once-over this evening

yeah. you're feeling the cog slipping. assuming your lockring fits on there tightly, it's loose, too. don't ride like this, if you can help it (or at least crank hard to tighten the cog and then don't skid or skip until you can get it tightened), you run a real risk of stripping the threads on your hub and totally ruining it.

go to the bike shop and have them take the cog and lockring off, clean the threads, apply loc-tite and re-assemble everything. give it a day for the loc-tite to dry until you skid on the wheel, and you should be good for a while.

that sounds good. i don't skid or skip, but i do use backpressure to slow down almost always. i am gonna give the lockring removal a try myself, but i will have to get me some legendary loctite. it's a real track hub (not a bumbike thingy), so i wonder what's going on down there...shouldnt the lockring be held on by the backpressure?

obviously i will have to check and see what is going on, but is this an indicator of a worn out hub? or what?

anyway, this is why i have two bikes. the greyhound is back on the stand. poor gal.

i wouldn't recommend using loctite on a real track hub, but i'm sure others disagree.. make sure that the cog is on really tight before you put on the lockring. use a chainwhip or something like the rotafixa method (search the forums for info on this) to get it on as tight as possible. once you've done this, put on the lockring with a hook spanner or something of the sort. be very careful when you do this, as too much pressure can cause the cog or lockring to back off of the threads (especially if it is a cheaper hub) and destroy it. long cheater bars and such are a "no."

your cog may be too skinny. as in, no matter how hard you tighten the lockring it won't be doing any good, the lockring will bottom out before it can do it's job. get a wider cog or maybe there's a shim/washer/spacer that you can stick in the mix that will do the trick.

OK. I took off the cog and lockring last night, and took a good look at the hub threads.

The cog is a relatively new-looking SOMA. I didnt' check the width specifically but it seemed to cover the threads well if memory serves.

As I removed the cog, two little hairs of metal came off the hub. I cleaned the threads of the hub and lo and behold, it looks like two rotations of threads have been stripped off the side closest to the center of the wheel.

I posted a large photo at http://www.flickr.com/photos/41385865@N00/24284041/ and if you download it, it'll be even larger, if you want to see what I'm talking about.

Unfortunately, this is the first time I've removed the cog and lockring, so I can't say whether the hub looked like this when I got it.

so...is this a stripped hub? i am guessing yes. good thing I have another set of hubs on the way and am planning to build a new wheelset. but phooey. anyway. thanks all for your help.

hmm. prognosis not great.

looks like the two innermost rows of threads are totally gone. you might be able to get a cog on there using some loc-tite or maybe even jb weld (but you'll never be able to re-use that hub or cog again), but with almost half your threading gone, i'd be extremely wary of just screwing another cog on there.

also, i wouldn't use that soma cog. people here have had issues with soma cogs not being wide enough for some hubs, and causing exactly this problem.

the cog screws all the way on, but since it's not wide enough, it doesn't extend far enough past the end of the cog thread area, where the lock ring can engage it properly. thus, the lock ring doesn't put any pressure on the cog, leaving it able to move backwards.

get an EAI or Dura Ace cog and lockring.

life is too short to buy crappy cogs and lockrings.

conversely, crappy cogs and lockrings can make life shorter when they strip your hub in traffic.

"life is too short to buy crappy cogs" -- yeah, i hear that! I'm curious about the spacing issue, and will reinstall the cog and lockring to check it out--but I won't ride on it!

Like the hub, the cog is what came on the bike when I got it. I plan to get a new cog to put on my new wheelset, and while I am at it, a new chainring to fiddle with my ratio so I can get smaller/ DA cogs, etc.

OK, so this confirms my suspicions. I guess this hub/wheel will serve as a singlespeed for some future guest bicycle. thanks yo.

I can almost guarantee your cog is too narrow. I've been having this problem lately with Soma cogs and IRO hubs / ProMax hubs. I tried using a little spacer. It worked on the IRO hub, but on the Pro Max, the first time I skidded hard I destroyed the spacer. I switched to a Dura Ace cog and the problem went away. I avoid Soma cogs at all costs now. Does anyone know if the Surly cogs are the same width as Dura Ace?

yeah, from here on out it's DA, EAI or (genuflect when you say it) Phil. FTD, as we used to say back in the day (in colorado, in fact). I guess I will offer up the Soma on the int'l cog exchange, caveat emptor.

edit: ok, your opinions please, since this hub and cog are worthless for much of anything (other than a freewheel...shudder), should I stick together a bumbike setup for some as yet undetermined bike? If your answer is yes,or more accurately, "why not?", then please help this newbie with these questions:
--where d'you get loctite? At the hardware store?
--Would it be a better idea to put it together on the fixed side (with the stripped threads) or on the freewheel side (with a BB lockring)? I'm talkin' safety considerations here only. If the freewheel side is the better side, I will have to decide if I want to give up the freewheel side entirely or not.

Your comments are appreciated.

do it, i had the exact same problem with a suzue hub and went the route described below. it worked great.

i'd use jbweld, not loctite, and do it on the stripped side. put a bunch of jbweld on the cog threads, then crank that puppy down. do the same for the lockring and it will NEVER come off.

that way, you can still run a freewheel on the other side if you want.

you can get jb weld at the hardware store.

thanks dolface. i will do just that. this way i'll have a wheel to ride whilst I build up my new set.

i feel like i just earned my "stripped-hub patch," and maybe my "lockring removal patch." i guess i'll put 'em on my fixie-scout uniform next to my "skid patch" - bwa haha! omg lol

seriously though--shouldnt we have patches?

yeah. jb weld the cog on and it'll probably be fine for a long time. again, just pick a gear you know you'll want for a while.

as for surly cogs, people reported the same "narrow" problems with those cogs, as well. supposedly they were being redesigned for 2005. i haven't heard an update, and personally, i'd avoid them when you can get a known-good DA or EAI cog for just a few bucks more.

update:

i glued the cog and lockring to the hub with JB Weld. I've taken it for a couple short rides and it appears to work fine. I've grunted up a few hills, skidded, all that.

it is SO good to be uncoasting.

Before I glued it, I threaded on the cog and lockring to check whether the cog was wide enough. The lockring did not appear to bottom out. But I could be wrong. Either way. All hubs from here on out get Phil or EAI cogs.

Thanks all for your kind wisdom.

yes. yes we should.

right then. patches:

- brakeless
- trackstand
- convert-it-yourself
- wheelbuild
- stripped cog
- skid patch (lol)

just to start with. any other ideas? also not sure where they should go...little stickers on the toptube? actual patches, on the leg of your pants just above where you roll 'em up? on the flap of your messenger bag?

Nothing so pedestrian. We'll pull a tooth for each milestone.

i had this problem awhile ago on a new hub. i tightened the cog on by hand an then used a lockring tool to tighten the crap out of the lockring. the problem was that I didn't tighten the crap out of the cog first with a chainwhip. so now I always use my chainwhip while securing my track cogs.