So I bought a velocity deep v from a guy through craigslist and the wheel came with an 18t cog and lockring. I wanted to switch to my 16t cog and got the lockring off with ease, however the cog simply will not come off. So far I've tried using wd-40 which hasn't worked and I need suggestions on how to loosen this cog and reasons as to why it may be so tight.

use the wheel and the chain to pull the cog off... sometimes chainwhips suck to pull off a cog. take the chain off the chainring and drape it over the bb.

put the rear wheel on and tighten the axle bolts so the wheel wont move out of the dropouts. put the chain on the cog and double it over itself until the chain doesnt spin and there is no slack between the cog and the bb. make sure you turn it the right direction to get the cog off. grab the tire and keep the bike stable and just turn the wheel like a steering wheel. the cog will spin off. you can also do this in the reverse process to put the new cog on...


https://fixedgearbikes.blogspot.com/2...-rotafixa.html

Thanks, I'll try this

i wouldnt use wd40 on any bike part i own, its very corrosive. its so tight because when the other guy used it he probablly backpeadled alot instead of using breaks alot. since its a reverse thread, the backpeadling motion tightens the cog more. only way to get it off is to giv' 'er

giv' 'er**********??

If the reverse rotafix won't do it, there's any number of things the previous owner could have done that would cause problems: Loctite and JB-Weld are the first 2 which come to mind.

lockrings are reverse threaded, not cogs. backpedaling causes the cog to come off, hence why riding brakless on suicide setups are, well, suicide.

oh, and don't do this like I did lulz



you can try applying heat with a torch if it seems really stuck. probably what i should have done

so since the lockrings are reverse threaded which I didn't realize, that means that I should turn the cog the opposite way that I turned the lockring DOH!

WD40 isn't corrosive (it actually prevents corrosion), it's just not a great lubricant. Backpedaling loosens cogs. It's spelled "brake."

Sorry to rail, but come on, seriously?

Yep, the cog is standard lefty loosy threading.
Now have fun getting it off

What you said... times a bunch.

i dont have the orig pdf. if you look at the orig pic on the top of the link i posted, you will see what i mean by doubling the chain over. on the bb it is simply just around the bb and pulled tight

Yea i figured it out from the pic, thanks

What the heck happened?

When this happened to me it was because there was no grease used when the cog was installed.

I went down to the LBS and they got it off for me with this

https://www.ride-this.com/index.php/p...t23t-cogs.html

and about a four foot length of steel pipe for leverage.

hub came shipped with cog installed. i laced it up halfway to get leverage to take it off (couldn't lace full since the cog was in the way of the spoke holes). was cranking on it, didn't notice the movement i was getting was the hub shell flexing instead of getting actual rotation. next thing *clink* and i get this.

kroil it.

My last seized cog was an absolute mofugga and nothing worked. I ended up clamping the cog down in a vice to get it off. Trashed the cog, but got it off in the end.

Put the back wheel against a wall, have somebody hold you up, and put your weight on the pedal in the reverse direction. Can also be used to tighten cogs in a pinch.

cool story bro