Turning the barrel adjuster on the rear brake cable of my older Cannondale touring bike doesn't seem to have any effect. No matter which way I turn the barrel, the cable doesn't appear to lengthen or shorten, and hence, the brake pads don't move either nearer to or farther from the rims. Do these simple adjusters break or perhaps I have turned too much at some previous time and it needs to be "rethreaded"? Do you typically need to replace them over the years? Most important, is there a good site with instructions for learning how to remove, inspect, and repair/replace barrel adjusters? Thanks. I'd rather be riding than posting, but brakes are getting bad!

Your not going to see much movement in the cable, but the adjuster is for adjustment, not setup, and there should be enough movement for tweeking final setup/as needed on the road.

Just saying older Cannondale is a bit vague as well, if asking about a specific part, knowing the brand/model/part number is useful.

While adjuster barrels can and do break it's not a common happening. But it is pretty simple observation skills that help one figure out if a nut or bolt is moving lengthwise. Andy.

Some of the older brakes had a barrel adjuster AND a nut under it. the nut could be round with a rubber ring on ity like the Shimano N600 such as these.

Shimano 600 Brakes ? $45 | Toronto Vintage Bikes

Adjusting the cable was done by HOLDING the barrel asdjuster and turning that round nut with the black rubber ring on it.

An image of your brake would be most helpful in seeing what the problem might be.

Cheers

Sorry to have been too brief -- wife says otherwise. It is a 2001 Cannondale T-800 and the barrel adjuster is in-line along the cable, well away from the brakes (Avid Shorty 4) or the controls (Shimano Tiagra STI Dual Control levers). Maybe I'll just try tightening the cable from the brake end, if you think turning the barrel alone might not show significant movement.

Thanks, but the barrel is in-line, far from brakes or controls, and there is no visible nut.

Note that there are two basic types of barrel adjusters.

1- the barrel is threaded to a stationary part and moves in and out as turned
2- the barrel adjuster slides into an unthreaded part and a threaded ring is turned to move it in and out.

It's possible that you have the latter type and are using it wrong.

There's every chance in the world that I'm using it wrong, but my "simple observation skills" tell me that I can turn the adjuster clockwise for ten minutes and nothing visible will happen. Then I can turn the adjuster anti-clockwise for twenty minutes and still nothing visible will happen. It never comes to a "stop". Not even the amount of metal ferrel (?) showing at both ends of the plastic barrel changes. If I hold the brake lever down, I can't turn the barrel adjuster either way. That's why I thought the mechanism itself might be broken, or that I had previously unscrewed something inside beyond the point of no return. I really don't know how the mechanism works in order to shorten or lengthen the cable. (or have that effect, anyway). I can take it to my LBS or I can buy a replacement and take this adjuster out and dissect it to understand how the mechanism works, but like I said, I'd rather be riding! But I'm still optimistic that I'll get the understanding I need from Bike Forum.

If you have a "stationary" adjuster, turning it doesn't do anything. It doesn't thread into the frame. It uses a threaded ting of some kind to jack it in and out. If you can't get it to work, consider slackening the cable at the pinch bolt -- You don't need to unthread it just pull it back an inch or two -- and pull the adjust uniy out and see if it's a single threaded part or two parts threaded to each other.

It's entirely possible that you're missing one part of a two part adjuster.

Okay. I hadn't thought about how many different things qualify as "barrel adjusters"!!! I don't get out much, I guess. The ones I have look very much (but not exactly) like the SRAM ones for sale on Amazon or like the ones being installed in the YouTube video.

https://www.amazon.ca/Indexed-Inline...lnk-ca-c230-20 or https://www.youtube.com/watch?v=2zUhwdXj7wc

My Cannondale has the same type of barrel adjusters on the front and rear derailleur cables as it has on the brake cables. I don't understand how they work and, hence, if they ARE working. Wouldn't there be a "stop" somewhere as you turn the adjuster, and you couldn't go any farther? Or is it possible to go TOO far in turning and "unthread/disengage" what ever mechanism is inside the plastic barrel? The barrel adjusters that are often used on bikes near the brakes make sense to me -- a threaded bolt with a nut that moves up against a fixed piece of metal. But how do MY inline barrel adjusters work?

The adjuster you linked is an inline type. It's basically a turnbuckle of sorts. Turning the whole thing does absolutely nothing You have to turn the central barrel while holding one end (or both) so it doesn't turn also. Usually friction against the housing holds it for you and turning the middle is all it takes, but if the threads are dry or corroded, the thread friction may be more than the end friction so you need to take charge.

Yes, there is no stop per se. At one end it bottoms out and you can't go farther, but at the other end, you can continue until you run out of thread and the part disengages. If you go too far and disengage, it's not too hard to line it up and get it started again, but it does take a bit of conscious effort.

Thanks, thanks, thanks for this explanation! It makes sense that the adjuster would not be operating as it did 15 years ago when the bike was new! I'll have to give a close look to see if I can sort it out now. Thanks again for your patience and help, FBinNY.