I apologize. I’m sure this issue is covered somewhere in the forum, but a search didn’t reveal it. I recently started switching the casette from my training wheels to my new 606s. Obviously, each time I swap the casette, the gearing sounds awful, as I’m sure the rear der. is not alligned to the cogs. My question is this: each time I swap out the wheels, is there a method to the amount of turns you give the barrel? If there is no science to it, is it just turn it until it sounds right? Also, is there a number of turns where you know you’ve done too many? And finally, can you strip out the barrel, so that each turn actually does nothing?
Thanks, and once again, I apologize for my stupidity.
The spacing on the cassettes should be the same- when I switch wheels, I don’t have to make any derailleur adjustments. You probably want to look into getting a small spacer for one of your wheels so they’re exactly the same.
Until then, no there isn’t s certain number of turns to the barrel adjuster. Put it in the 4th cog from the smallest. The chain should fall exactly between the cogs to it’s left and right. If it falls closer to the cog on the right (smaller), then you’ll need to turn the barrel adjuster counter clockwise (increases cable tension). If the chain sits closer to the cog on the left (bigger), then you turn the barrel clockwise (decreases cable tension). You can’t “strip” the barres, but you can unthread it all the way if you turn it too many times counter clockwise.
First off, all of my wheels fit just about the same. At most, a single click in one direction or the other is all it takes. Second off, make your adjustments using the barrel adjuster on the rear der, not the cable housing. That one is for when under way only, pretty much. It is also used for very very fine adjustments, and more often for the front than the rear, in my experience.
This is what I do, may not be the proscribed method but it works for me.
If I’m having slow shifts going from smaller to larger, I turn the barrel adjuster (on the rear der) a single click towards the wheel, or staring at it from the cable end, counterclockwise. If it won’t shift down well, a single click in the other direction. I make no more than a single click adjustment at a time until shifting becomes proper. If it is just making noise but shifting decent, an adjustment click or two in either direction will tell you which way to go, as the wrong way will usually make it jump to the next cog.
You can also sight the der by looking straight down. It should be pretty much dead straight behind the cog that the chain is currently on. Turning the barrel counterclockwise will move it towards the wheel. The dead straight down trick does not always work though. But it gets you pretty close and is a quick indicator of the direction you need to move the der.
You know you’ve done too many when a turn of the barrel adjuster shifts the chain! You can’t easily strip out the barrel but you can unscrew it completly.
If it is just a tiny amount off, you may be better off using the barrel adjusters on the cables rather than the one on the der.