Swap That Cog

Looking to get some more speed out of your steed? Or maybe you want to dial down the gearing to make those commute climbs a bit easier? In today’s post, we’ll walk through swapping a cog and getting everything geared just right for you!

Bigger or Smaller

First, let’s grab our new cog. If you’re looking to up your top speed and give yourself some more mph before your legs spin out, you’ll want fewer teeth on your new cog. If you’re trying to make it easier to get started from a stop or “flatten out” those climbs, you’ll want a cog with more teeth than your current one. Count up what you’ve got now, make sure you’ll be ok skid-patch-wise (if you do a lot of leg-locking), and grab the upgrade that’s right for you! 

Remove Lockring

Now, to the good stuff! First, we have to remove the lockring so we can get to the cog. Grab your trusty lockring wrench, and get twisting! Remember, the lockring is reverse threaded to keep the cog on there while you brake, so it’s clockwise (righty-loosey) to get it removed.

Once it’s removed, keep it close by and let’s get that cog off!

Remove Old Cog

If you’ve got a chain whip, pulling the cog will be super easy, just twist that puppy counter-clockwise (lefty-loosey) until it slides right off the hub! If you don’t have a chain whip, no problem – let’s rotafix this sucker!

Begin by pulling your chain off the chainring and let it hang from the bottom bracket.

Now, scoop up the slack by the cog, pinch the chain together and draw both sides up and over the cog. You should be looking at something like the images below, and you’ll find that trying to spin the wheel back will make the chain lock up (and put a nice counter-clockwise torque on the cog.

Now, just give the wheel a shove or three to overcome the cog’s tightness and get it spinning freely! Boom, cog off!

Install New Cog

To get the new cog on there, we’ll basically just reverse the last step. Pop some blue-loctite on the cog and hub threads to keep everything snugged up once you hit the road and twist it clockwise (righty-tighty) to get it on there.

Now, we’ll reverse the rotafix process to really tighten it down. This time, gather the chain below the cog and rotate the wheel forward until it locks up.

Then give it enough love that it locks that sucker down tight. The last thing you want is a travelling cog when you go to slow down (and a loose cog will strip your hub and make you need some new wheels as well).

Once it’s tight, we just need to get that lockring back on and we’ll be all set! 

Re-Install Lockring

Just grab your lockring wrench and that lockring you’ve been keeping excellent track of, apply a little blue-loctite to the threads to keep everything in one place, and get twisty!

Remember, this one’s reverse-threaded, so counter-clockwise (lefty-tighty) will snug it back up. Really lean into it because, again, you don’t want things to move around when you’re on the road.

Reinstall Wheel

Pop your wheel back on, dial in your chain tension, and hit the road! You probably want to bring your lockring wrench on your first ride because mashing on the pedals will sometimes pull the cog a bit tighter still and you’ll want to stop and tighten the lockring back down to the cog. That happens because your legs are more powerful than even the most serious rotafix/chainwhip, so a jam on the pedals can pull the cog even tighter on the hub. No problem for you, though – you’re ready for it. Snug the lockring back up and enjoy your new gearing!

Now, who wants to race?