mickey_

I'm interested in getting involved with the cycling club at my school (mostly recreationally, seeing as I don't have $2500+ to spend on a good bike). I have a fixed/free flip flop hub, and what I want to do is keep the 17t fixed cog on for riding around campus, and put a 13t or 14t cog on the freewheel side for use on the track. I figure that, since there's no need for extreme backpedaling on a track, the lack of a lockring won't be a terribly bad idea, and it'd be much easier to just ride to the track on the 17t side, remove the wheel, and flip to the 13t side. Is this idea so dangerous/stupid that it's not worth the extra 5 minutes it'd take to remove my 17t cog and replace it with the 13t?

Cynikal 

Most track racers don't use lockrings. You will be fine although you will need to adjust your chain length for that kind of jump.

roadfix

If your track allows it you're fine.

queerpunk

I would definitely hesitate to say that most track racers don't use lockrings, but also, no, it wouldn't be a problem. Just don't put significant backpressure on that cog. Gentle decelerations, you hear?

Additionally, something that's a bit easier than switching cogs is using the Miche cog/carrier system. I use it for track racing - I don't have a duplex-style hub on my track wheel, so I just pull the wheel off, de-wrench the lockring, swap cogs without using a chainwhip, lockring back on, wheel back on, and bam.

Jabba Degrassi

Does your local velodrome have a rule stating you need a lockring?

If not, just listen to queerpunk and don't try to pull any sick skidz.

ianjk

Is your bike legal for the track? I believe there are some restrictions.

bonechilling

My track disc doesn't even have provisions for a lockring.

Also, I don't know that most track racers don't use lockrings, but certainly many don't. They're discouraged at a lot of velodromes.

jdms mvp

think about it. there is no rule "Reason" to backpedal while in the 'drome

Duellist

Wait, there's a track in Philadelphia? Where? I've been wanting to try riding one for AGES.

peabodypride

There is not. The track is the Lehigh Valley Preferred Cycling Center, close to Allentown. Quite a ride out.

Duellist

Damn, that's what I thought. I'll get there this summer, though.

mickey_

Isn't that one in Lehigh Valley a really nice indoor one? I go to the University of Delaware, and I'm fairly sure we use an outdoor track somewhere nearby for most of our riding.

peabodypride

No, it's outdoor. That's the only velodrome around so it's where UDel goes.

operator

You do realize you'll be adding/subtracting links everytime you do this right? If real tracks don't require lockrings then it must be safe? It doesn't seem like there's anyways, even if you're not consciously doing it to completely eliminate any reverse pressure on the cog.

Explain please?

ban guzzi

I'lll side with Operator on the link issue. Adding/subtracting seems shady for reliability and safety, particularly if your brakeless. I've been told that a jump of 2 teeth up/down is safe with a given length of chain. Your making a large jump. I'd check with someone at your track what works best or just get yourself a nice Sram PC-1 set to your track length.
As for the lockring issue, I'd feel safer With a lock unless specifically told "Non!"

JohnDThompson 

Must be a recent change. 20 years ago they wouldn't let you on the track if you didn't have a lock ring installed.