masi61

I have some inexpensive Taiwanese red anodized cable barrel adjusters that mount on the treaded down tube bosses on my Veritas titanium road bike. These barrel adjusters thread into the bosses only, there is no tension spring on it. I guess I must have put some grease on the threads to make everything move easily but on a typical ride with my Veritas (which has Dura Ace 7800 2x10 mechanical shifting) I will start with indexing that is dialed in when I start but as I ride down the road, vibration makes the barrel adjuster move which de-tensions the cable just enough to make my upshifts off. I now would have to tweak the adjuster barrel on the fly, adding back some cable tension or just do the old up 2 clicks and down 1 click in order to upshift just one gear.

I was going to clean the grease off the threads and put some blue loctite on the threads and see if this cures the problem. But in the meantime I just thought I would post my query here to see if the loctite idea is my best bet or if there perhaps are better barrel adjusters that I could swap in that don't have this issue.

bboy314

Maybe adding a spring would solve this. Loctite would probably prevent you from being able to make adjustments while riding, you could probably accomplish the same by just tightening them down with a bit of force.

Iride01 

Seems odd they don't have a tension spring. But I don't claim to have used every type of down tube cable stop/adjuster made. Can you add a spring?

Most also had a plate with detents that the spring push against to fit detents in the knob.

masi61

I have some other barrel adjusters that work with a spring, I like the looks of my current ones (red anodized to match some other trim on my matte titanium framed road bike). I may see if enough threads engage on these adjusters.

By "tightening them down with some force" I assume you are referring to me adjusting the indexing with the loctite on the threads. And in that case it would be more of "turning them counterclockwise with some force".

masi61

Yeah it is kind of odd that these don't have a spring or detents like the Shimano and Jagwire ones. Mine I believe are "Far & Near" brand.

Iride01 

Sometimes the spring is in the knob and you don't see it. Are you certain these aren't missing a piece or are just worn out or lets face it, just cheap crap that looks pretty.

I wouldn't do the Loctite. At least not if road side repairs and adjustment are something you wish to be able to do easily. Just get some new. They aren't much.

masi61

I think you might be right that they are cheap crap. I at first thought that there was a hidden spring inside the knob. I will have check this out. I will post a few photos of what they look like when I get home.

HillRider

Give up on them and get a set of Shimano adjusters that used to come with every STI brifter retrofit set. Any older bike shop should have a drawer full of them.

masi61

Update - I found out why my Dura Ace 7800 rear shifting was so inconsistent - the inner wire was slowly snapping off. It finally broke off the other day when I had it in the stand and was doing bike maintenance. I have experienced this before on several occasions so I stayed calm and I was able to fish the head of the cable with about 1/2" of broken strands attached out from the shifter. I cleaned up the down tube barrel adjuster and tightened it almost completely down. I ran a new cable and re-used my compresssionless housing (it is Deore XT 5.5mm mtb stuff that is seriously stiff). I have also retrofitted a Dura Ace RD-7800 that has an aftermarket KCNC pulley cage. I could tell on the stand that the shifting precision and reliability was likely to be a step up with this combination. Yesterday, I rode 52 miles and never once did I have to touch the down tube adjuster barrel. It is much less stress when you don't have to worry about whether you will be able to complete a shift with a single click!