flip-flop mismatch
 

if i have a 16t cog on one side, can i put a 14t freewheel on the other without messing up the chainline or having to make any adjustments?

Assuming that you have horizontal dropouts you are fine.

I can't find the source right now but IIRC every tooth difference in the cog/freewheel is a 1/4" difference in the placement of the axle in the dropout.

1 bigger tooth moves the axle up 1/4"

Right?

It won't mess up your chainline at all, but you may not have enough room. Spoonrobot is right, each tooth move 1/4 inch. So if you are making a two tooth differenece your wheel will move 1/2". As long as you have track ends, or horizontal drop outs you will most likely have enough room, but you may need to play around with your chain length.

i'm better off staying put with a 16t then, right?

Well do you have horizontal dropouts or trackends?

horizontal dropouts. but i dont like adjusting things.

Well, you have to get the chain tension right and the wheel straight whenever you flip the wheel whether you have a 16/16 or 14/16, assuming no chain tugs or similar device is in use, it'll be the same amount of "adjusting things".

If it's close to the backend of the dropouts with the 16T you might have to pull a chain link, but that probably only has to be done once.

you wont be adjusting anything more than you would be by taking your wheel off and putting it back on, its just a matter of chain tension

I might add, if you have these in your dropouts then you'll want to remove them:

http://images.andale.com/f2/115/106/..._adjusters.jpg

I believe it is 1/8" per tooth.

It isn't much, whatever it is and it certainly shouldn't require a change in the chain unless the wheel is seated right all the way at the back or all the way at the front of the dropout anyway.

:thumb:

http://www.bikeforums.net/showthread...=1#post5018993

do you have a bmx hub? 14t freewheel will not fit on a typical flip/flop hub...

Yes, by definition. If you take out 1 tooth, you end up with one extra 1/2" link, Half of that distance adds to the top of the chain, and half to the bottom, so you end up with the wheel moving 1/4" back.

EDIT: ACK... half that? I gotta read Sheldon's writeup on that.

Please link if you can find it, I've had no luck.

I'm not sure if he ever showed his work on that, there's just:

ON EDIT: Think I figured it out -- one extra tooth increases the circumference of the cog by one half-link. Half of that is on the inside of the chain loop and doesn't contribute to the chain length. The other half contributes equally to the top and bottom of the chain.

I would think it would change the circumference one full ink (i.e., the pin-to-pin distance or 1/2"). I must ponder this in my heart.

While you are pondering it, and imaging things, don't think of circumference at all. Picture the link coming out of the horizontal portion of the chain.

One full link is two half-links -- the half-links are 1/2" each.

It's not really a bad idea to have two different chainrings. If you prefer riding fixed and 16t is the best for your normal riding area keep that, and if you need less or more for certain hills or routes, go ahead and put that ring on your freewheel side. This is the beauty of a flip flop. It's almost like predestined gearing but still a lot less cumbersome.