Bicycle Mechanics - Fixed gear questions(newbie).

Hello, I am new to these forums, but a competent biker. I'm a student residing in Tokyo and I just recently bought a single-gear bike, it's really fun. Today I went to the store and bought a 17-Tooth cog(? If that's what it's called, still new to the terms.), fixed gear, it also came with a lock ring, but there is where the problem is... As soon as I could, I brought the bike to the store and I asked if they could transform it from a single-gear to a fixed gear, I gave them cog(?), they said yes. Couple minutes later, they said that the lock-ring that came with the cog(...) doesn't fit; my question there, is how could it be??? They asked me if I wanted to proceed with the installation and I said yes, they warned me that if I pedal backwards I can destroy my hub(?). Because I don't exactly plan on dying, and I heard that riding without a lockring is dangerous(I have brakes so I should be fine...right?) I want to know what exactly will happen if I pedal backwards while I'm on the road, what happens??? And my last question is, how can I put a lock-ring on it that actually fits(I'm bewildered about the ring not fitting), because I want to be cool and safer with 3 alternative brakes.

Thanks guys,
Meltedsnake~

does your hub have threading for a fixed cog? it will look like 2 sets of stepped threading. the outer threading will be smaller in diameter and have a left hand thread for the lock ring

No it doesn't have any steps, it has a removable mount I think. So if I change my Hub, I could get the ring to fit?

Unless you can lace the spokes into a new hub yourself, buying a fixed wheel or wheelset is cheaper and easier.

Some people put a fixed cog on a hub which does not have the reverse thread for the lockring. They use a lockring from an old three-piece bottom bracket because it has the same threads as a fixed cog or a singlespeed hub. They probably also use lots of loctite thread adhesive. However, since the lockring goes onto the same threads as the fixed cog in this case, they say it can come loose and unscrew itself when braking.

There is no way to loosen the lockring on a real fixed gear hub because the lockring threads are left hand threads and the harder you backpedal the fixed cog, the more you tighten the lockring.

Try the singlespeed and fixed gear subforum here on bikeforums. They might know more about it.

Thanks guys, this is helping a lot. I don't have the tools to dismantle my bike, but I'll get some soon. As for lacing the spokes, it looks pretty complicated but I'm sure I can manage, I am generally handy with this kind of work. Can someone list all the tools I need to remove my tiers, increase chain tension, and remove a cog? Again guys, very helpful, thanks.

Give a man a fish, yadda, yadda, yadda

http://www.lmgtfy.com/?q=sheldon+brown+fixed+gear







There is no way to loosen the lockring on a real fixed gear hub because the lockring threads are left hand threads and the harder you backpedal the fixed cog, the more you tighten the lockring.

Wrong. Backpedaling has nothing to do with tightening the lockring.

Wrong. Backpedaling has nothing to do with tightening the lockring.Of course it doesn't. Because if the track cog turns to the left from backpedaling, and imparts some of its rotation to the left threaded lockring, it can't tighten it. Because everybody knows they're called left-hand threads because you gotta tighten them to the right, right?

I love sarcasm:).

Cheers

Just that by being Left hand threaded the lock ring will,
in response to the pressure wanting to un wind from the larger
RH thread , tighten the left hand threaded lockring..

left hand thread .. lefty tightie, [CCW] rightie loosie. [CW]

so, ... OP needs a Track Hub in the rear wheel or live with a single freewheel gear..

Coasting is where a bike is better than walking..

I guess I do huh, I'll try to buy a track hub ASAP. Thanks everyone.