I just built up a fixed gear(my first build) and I decided to go with left side drive--just for the fun of it. I was wondering that since the wheel now spins the opposite as it would have with right side drive, would there be a problem with the cog unthreading itself? The pressure of pedaling forward is in the unraveling direction. Would the pressure of backpedaling counter it? Or is a lockring and loctite sufficient?

I have run left side for a year plus now. I am just using a surly hub and DA cog and lock ring. No loctite. No tricks. Just install them properly and you will be fine.

The only problem I have had is pedals starting to back out and messing up the threads on some cranks. So throw a drop of loctite on those and you will be good to go.

Only other thing to think about is your bottom bracket... if its not semetrical, you may be throwing off your chainline. If its an old loose ball type, you should just be able to turn the spindle around if you need too.

been considering goin lefty on my next ride. mostly just to be weird....is it possible to find pedals that are meant to be opposite?

No, but you could get tandem cranks to do it properly.

Of course, that's a lot of $ for a completely useless bike trick.

Thanks for the info. And yeah, I flipped the spindle so the chainline is straight.

And there are BMX bikes built lefty so you could probably get some parts at a BMX shop.

the issue is the interface between the pedals and the cranks. different pedals arent going to cut it.

a lot of people just put loctite as c4fl described and are good to go, but if you want parts that are designed for left side drive either get a bmx lsd crankset or a tandem captain's crank set.

or if you want to be fancy, fyxomatosis has a lsd campy track set for sale. but the for sale section seems to be down while mr. white's in san francisco.

edit: zacked wins

I've always thought that left side drive was fun, but I've never done it because I'm right handed, and carry my bike up stairs with my right hand. LSD would expose y clothes to the chain.

That said, would not eggbeaters work forward and backward?

yeah, except they would still back out of their threads. while bored i also thought you might get spd's to work if you screwed the cleat on backwards, but you might have to clip in backwards as well, which would be weird. or if you've got mks you could do what ryand did and switch the spindles.

yea i'm lefty.. and I carry on my left. I didnt realize how nice it would be until after I had done it. Now I know how you normal riders feel!

Also I was running eggbeaters for a while. They were fine engagement wise, but still backed out. once again. a single drop of loctite and I've never had another problem.

i used to have a lsd bmx.
i was toying with the idea of building up an lsd track bike... but decided against it.