"in line" adjuster

[j beede]

My bikes have always had barrel adjusters for FD and RD located at the cable braze on on the down tube. The Cannondale road bike I bought yesterday has an "in line" adjuster where the FD cable exits the left brake/shifter assembly. It sure is convenient to reach, but it doesn't seem to alter cable tension when I turn it. The RD has no "while riding" adjuster, just the gray plastic adjuster where the cable enters the dérailleur at the hanger. Are there aftermarket barrel adjusters that I can add at the down tube braze on? Other ideas?
...j

[cyclerUK]

The inline adjuster should work.
Is it at the end of its adjustment. (keeps turning but doesn't wind out)?
If so then the cable needs un-clamping at the derailleur, screw the inline adjuster back in, pull cable tight and re-clamp cable.
If the adjuster still doesn't work then perhaps the threads are stripped.

There are downtube adjusters that, as you say, fit to the braze ons.
Both Campagnolo and Shimano make them. Do an online search under your usual suppliers or check out your LBS.

http://www.sjscycles.co.uk/product-Shimano-Shimano-Alloy-Braze-On-Down-Tube-Cable-Stops-with-Barrel-Adjusters-5511.htm

http://www.ribblecycles.co.uk/sp/road-track-bike/CSN-Cable-Stops-Gear-Lever-Pair/CSNAGRSZ250

http://www.chainreactioncycles.com/Models.aspx?ModelID=48659

Personally I find the Campag's harder to use when riding.