sti cable inline barrel adjuster??
 

Is the inline cable barrel adjuster necessary for STI levers? What side should the barrel be on? Rear derailleur or Front?

You should at least have one for the rear if your frame doesn't have barrel adjusters at the cable stops. This way, at least you're able to tweak cable tension while riding.

You need some kind of adjuster for the front. Most Shimano rear derailers have a built-in adjusting barrel, so you don't really need one for the rear.

Sheldon "Adjustment" Brown

Most rear derailleurs have an attached barrel adjuster so, if I only had one inline adjuster, I'd use it for the front shifter.

If you're referring to a Shimano set of 2: one with the barrel adjuster and the other with the lever, the barrel is for the front, lever for the rear.

thanks. Can anyone point me to a website that discusses proper sti cable length?

It's whatever length gives you the right cable tension to make your gears match your index shifters.

I like both front and rear adjusters so I can tweak while I'm riding if necessary.