When I built the seven mudhoney I put a new XTR rear derailleur on it, much to my surprise the new XTR does not have a barrel adjuster any more .
So now that is out in the open we gots to deal with it. I tried these crappy inline barrel adjusters that had come on my cannondale, but they were worthless.
Ritchey has designed these barrel adjusters that fit in an STI lever
They are also sold under the Jagwire brand, which is good since only excel sells the ritchey ones. I like excel a whole lot, but ordering an $11 part from Colorado seemed goofy… I’d end up buying some other stuff I don’t need to make the order big enough to justify shipping. I picked up these for $11 from Speedgoat. They work like a champ, problem solved. It would easily work placed in the rear XTR derailleur, but it might be one more spot for mud to creep in to the cable.