andre nickatina

So I'm running 49x19 on my bike, got a 16T cog for the other side of the hub today. Right now the hub sits about in the middle of the drop out. I have yet to install the cog... Will I have to break the chain and remove a link every time I want to flip the wheel, or is 3 teeth in my cogs a small enough difference that I can just reposition the hub in the dropout w/o changing the length of the chain? Merci.

marqueemoon

Why don't you try it and get back to us?

dylandom

i think u might have too, i think that's why one side tooth count compared to the other side should only be a difference of one. who knows.

blu3d0g

if your axle is all the way at the front of the drop outs with the bigger cog, you can probably flip to the smaller without removing links. 3 might be touchy, 2 is definitely do-able.

barba

I think the standard estimate is 3mm of axle movement in the track end for each tooth difference. 2 teeth is all I have ever tried.

andre nickatina

lack of necessary tools at the present time, sir

jim-bob

Maybe.

andre nickatina

well, if this is true than 9mm would equate to 3 teeth difference and i should be safe as the dropouts are decently long. thanks.

barba

Remember, you still need a bit more to get the chain on and off.

fatbat

If there's a problem, but it's close to fitting, you can try swapping out one chain link for a half-link. That'll bring the axle in and give you a little more dropout to play with.

dommer

if you shorten the chain so that the hub sits towards the front of the drop outs at 19t you might be able to keep the same chain length at 16t. just give it a shot

andre nickatina

^ ^ ^ good idea.

well, the dropout is 4cm deep, the hub is sitting ~1.8cm in the dropouts, and if i move it 9mm in either direction there should still be room... hopefully it's fine.

jwind

I think this will do it. My fixed/free hub is 48/16 & 48/18 and the axle is in the center of the dropouts with 48/16

goldener

here are some rules of thumb: 1 tooth change (ring or cog) = 1/8" axle movement in dropouts. of course, you also have to take into account the axle width.

to keep the same chain length, keep the sum of the cog/ring equal. thus 44*16 and 42*18 (both sum 60) yield the same chain length, i.e no axle movement in the dropouts.

chunts

I think popping a chain link in is probably easier that swapping chainrings when you flip the hub.

FWIW, i'd try it, and then try the half-link idea. I had to add a link going between a 16 and an 18 tooth cog because with the smaller it was right in the middle of the dropouts so the bigger cog pulled it all the way out.

goldener

true true..but jus addin some general knowledge on the topic even if it is not 100% relevant to the question...

enjoy

BuddyMike

I've only 2 two teeth as well. You might be able to get away with 3. Maybe.

scotthorrigan

i'm glad someone asked this. i am going through the same situation but my ratios are 49/15 and 49/18

Rikardi151

(not my idea, but a great one) You can always keep an extra link of chain with a masterlink on one end in your tool kit and size the chain for the smaller cog. When you want to use the bigger one, use a second masterlink in your chain to take it apart and splice in the extra link.

roadfix

Just spin that extra cog on the other side and find out. You do at least have a wrench to remove your wheel?

andre nickatina

good call, it escaped my mind that i had a crescent wrench lying around, i got tied up on realizing i have no lockring tool.

well, it sits right on the edge of the drop out for (almost) optimal chain tension, so i think the best idea will be to remove a link and try to seat 19T cog right at the other end of the dropout closest to the seat tube, or throw a half link in there if necessary.

thanks for the advice guys. looks like i'll be able to run both cogs without having to break the chain every time i want to change

12XU

I've been able to switch between 49/15 and 49/18 without any problems. I think I could even throw a 19 or 20 on there.

bitpartinyrlife

ran 19/16 on the back for several months, and with still enough in the dropouts fore of the 19 tooth to not have to deflate the tire to get the wheel off.

Teevoe

^
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Yeap...me too...running 700x25c tires and able to run 18t for the street and 15t for the track...but it's all the way up againts the rear though.

here's a picture...https://velospace.org/node/2535

andre nickatina

oh man, that extremely tight tire to frame clearance is a beautiful thing.