Cog size related to tightness?
 

Hey all,

I'm just wondering whether the size of the cog makes an appreciable difference in that cog's tightness on the hub? Seems to me the bigger the cog, the more leverage (larger diameter) you put on it to tighten it against the hub. Case in point, when I bought my current wheelset, it came with an 18 tooth Suntour cog. It took two guys and a lever extension on the chainwhip to get the cog loose (no locktite found on the hub either). I've never experienced that with a 16 tooth cog.

Yep. I think that you are on to something there. I have always wondered about that, and you have explained my thoughts prefectly....

Torque teh force for tightening/untightening, its calculated by multipling force*radius the force is exerted by.
So if you exert teh same force on the pedals, the torque is higher on larger cogs, making them tigther.

But when skipping or skidding the torque trying to unscrew them is also greater.

So the lesson is... if you want to remove a large cog -- remove lockring, remount wheel, and do a few skip stops to loosen it (only if you have brakes though).

you get street cred if you try to do this down the hills of san francisco BRAKELESS!!

i had something similiar happen in berkeley last year when i spun the cog off my khs. let me tell you, even coasting at 5 mph to a stoplight was quite the scare. but the phil's are tanks now and the other two times my toestraps broke weren't as hairy. anyways, when your fixed gear all the sudden is coasting, it is a huge scare.