Bicycle Mechanics - In-Line CableAdjusters - WTF?

So I have these in-line cable adjusters on my new-ish (bought in June) bike:

http://i.imgur.com/ez61e.jpg

Never had them before, but they seem to be why neither my FD nor RD seem to be able to hold adjustment. Ghost changes, skipping teeth, and derailleur 'bouncing' on the rear; chain dropping down to the small ring and unable to shift back up on the front. LBS has adjusted these things twice. I have had to adjust them too.

I'm slowly finding my way around maintaining my own bike, and on my old bike I had my gears dialed in at the derailleurs, and rarely needed to adjust them at all. With this bike I cannot get my shifting sorted, and these adjusters seem to be the problem.

WTF is up with them? Is this normal for these adjusters? Are they really worth having, or just a pain like this? Should I just get rid of them entirely? Seems like just an added component to screw up a well-tuned bike.

I get that they let you adjust your shifting tension while riding - but big whoop? Why would you want to do that more than once in a blue moon - unless you need to because you have these things and they keep screwing up!?

In my old profession before I retired, if someone did not seem to have a grasp of the obvious we would ask them, whatareyounew? With avent of index shifting there has always been a need to adjust derailleurs on the fly. With the new through the frame routing, the adjusters on the downtube cable stops (or the cable stops themselves) have been removed so in-line cable adjusters took their place. For on thing, without the front in-line cable adjuster, there would be no way to fine tune the front derailleur at all. And once you get some mileage under your belt, you will learn that your once in a blue moon is more like every other week. Most derailleur drivetrain issues on newer bikes (especially those that route through the frame) are a result of cable routing; especially with Shimano and Specialized frames. Good luck with your riding and I'm sure in a short time you will realize there is an advantage to be able to adjust your derailleurs while riding.

Never had them before, but they seem to be why neither my FD nor RD seem to be able to hold adjustment. Ghost changes, skipping teeth, and derailleur 'bouncing' on the rear; chain dropping down to the small ring and unable to shift back up on the front. LBS has adjusted these things twice. I have had to adjust them too.

I'm slowly finding my way around maintaining my own bike, and on my old bike I had my gears dialed in at the derailleurs, and rarely needed to adjust them at all. With this bike I cannot get my shifting sorted, and these adjusters seem to be the problem.The problem isn't the adjusters. Mark their rotation by marking them and the cables with a Sharpie. You'll find that they're not rotating on their own.

Most likely the problem you have stems from excess cable-friction. Could be a cable-routing issue. Or badly-cut housing with crimped ends. Or extra friction inside the housing due to contamination, dirt, etc. In cases like this, I'll completely remove unbolt the cables from the derailleurs and remove from the shifters. Then re-insert into the housing and "floss" the inner cable in and out of the housing to see exactly how much friction there is. You'd be amazed at how much friction is introduced into the system by cutting the housing just 2" too short.

You may also be making too-coarse adjustments of your derailleur. Sometimes as little as 1/8 turn will be the difference between perfect and awful shifting with the newer many-speed (you didn't specify) gear systems. It is easy to give those in-line adjusters a "spin" and overdo it.

Index single cable shifting has the long cable between the control lever and the thing controlled.
when shifting was a skill and the lever simple friction, the adjustment was with each shift.

now, that the engineers have made it simpler.. everyone wants the mech to be like a light switch, on/off ..

On the same end as where you see if the clicks put the rear mech where the cog is,
used when bike is off the ground.. in repair stand, rear adjusters are excellent.


But, some combinations like newer Sram RD have no adjuster in back,
but with road brifters, no adjuster there either, no shifter boss adapter adjuster ..
so it gets put inline ..

When you buy a new bike, there's a certain amount of cable stretching (unwinding), and various ferrules settling in. Used to be, you'd take care of these with the adjusters on the down tube cable stops. Now that these are gone, in-line adjusters are your user-friendly alternatives.

Shifting issues on a new bike will be less the in-line cable adjusters, more just new bike break-in issues.

You don't actually need the rear in-line adjuster, since there's usually an adjuster out on the rear derailleur, but how would you tune the front if there wasn't an inline adjuster? Short of making adjustments at the derailleur cable anchor bolt...?

The usual issue I see with these is that when they are bottomed out, they will keep turning without doing anything, and sometimes if you go the other way, cable housing/ferrules will turn within the mechanism before the adjustment screw actually turns.

When you buy a new bike, there's a certain amount of cable stretching (unwinding), and various ferrules settling in.

It's all compression, not stretch. The inner section of a brake or gear cable is wound the other way; there's no unwinding. It's ferrules bedding in and such.

Try this: with the chain shifted to the small cog and ring, force the shifters to take up some cable without pedalling (not too hard, and release the tension not by shifting back but by pedalling). This should help bed in the housings.

If that doesn't work, do as Danno suggests and undo the cables, looking for sources of friction and kinked cables. Also see if you can improve the cable runs by shortening the housing, as 9 times out of 10 on a stock bike they're too long. Remember to account for the full range of movement of the bars.

A freehub body with excessive runout can also cause autoshifting on a narrow-chained bike; hold the cogs and spin the wheel to check it. A large oscillation is bad.

It's all compression, not stretch. The inner section of a brake or gear cable is wound the other way; there's no unwinding. It's ferrules bedding in and such.

Try this: with the chain shifted to the small cog and ring, force the shifters to take up some cable without pedalling (not too hard, and release the tension not by shifting back but by pedalling). This should help bed in the housings.

If that doesn't work, do as Danno suggests and undo the cables, looking for sources of friction and kinked cables. Also see if you can improve the cable runs by shortening the housing, as 9 times out of 10 on a stock bike they're too long. Remember to account for the full range of movement of the bars.

A freehub body with excessive runout can also cause autoshifting on a narrow-chained bike; hold the cogs and spin the wheel to check it. A large oscillation is bad.

"Stretch" is a common way of understanding the slight relaxation/unwinding of wound cables. Ferrules and various other bedding-in points of compressionless cable housing are certainly a more relevant factor, but since it all happens at the same time, "stretch" within the shifting system is a really easy way of explaining this to customers who wonder why their new bike isn't shifting all that well two weeks out from purchase of "A New Bike That Should Work Flawlessly, For What I Paid For It!".

If you don't mind misleading inaccuracies, sure.


...'Mr Pedantic' :p

Hrrm. This is all very interesting and useful. I suppose I can see the need for these on an internally routed frame (my previous bike has external cables, and side-cabled brifters, so I guess no need for in-line adjustment).

A couple of replies. First, the cables are not too long., If anything, the excat opposite. After takign that pic yesterday I noticed they are so short they are actually rubbing my headtube and roughening the paint job. Pretty pissed about that, actually.

Still a little confused why there is this need for constant adjustment - on my previous bike I would adjust maybe once every 3-4 months, if that.

I assumed it would be new bike cabling slowly "stretching" (or "comporessing") -but it has been 4 months, so I sort of expected it would have settled in by now.

Whatareyounew? Yep, thanks for being patient!

So, still not sure exactly what I will do, but some useful suggestions I can try. I suspect I will rip all the cable out and replace it entirely due to the rubbing issue. Does anyone suggest a specific type of inline adjuster that is more reliable? I still don't really trust the ones I have.

Thanks for all the good help! Much appreciated.

I'd be surprised if your adjusters aren't rigid.

I'd also be surprised if you were sold a new bike with housings that weren't a bit long, let alone too short.

How about a pic of the whole setup?

...but how would you tune the front if there wasn't an inline adjuster? Short of making adjustments at the derailleur cable anchor bolt...?


http://i.imgur.com/1nOUfl.jpg

Here's how I resolved this on a 'cross bike with top tube routing and campy levers that carried the shift cable under the bar tape.

I use different adjusters, they fit into the shifters, still Jagwire. They have a bigger barrel and maybe called STI inline shifters. A friend saw them and asked, they never have lost adjustment. He has the same inline adjusters as you do and every ride he says they go out of adjustment. Switch inline adjusters.

Earlier his summer, we had a batch of new road bikes come into the shop that would not hold adjustment at all. We finally tracked it down to the barrel adjusters. Once we switched to another brand, we had no problems. Off hand, I can't remember exactly which barrel adjusters had the problem, but they could be your problem. I'll see if I can find one of the offending adjusters to compare to yours.

[QUOTE=onespeedbiker;14789397 And once you get some mileage under your belt, you will learn that your once in a blue moon is more like every other week. [/QUOTE]

Something is wrong with your setup then. Once adjustments for initial cable "stretch" occur (maybe a couple) you should rarely have to ever adjust derailleurs.

I'd be surprised if your adjusters aren't rigid.

Oh well, sounds like there are some crappy ones out there.

As suggested earlier, mark your adjuster barrels with a sharpie. They can move on their own. Personally, I have no need of an inline adjuster for the rear, just use the adjuster on the RD. Something is needed for the front, however. If you have an adjustment at the cable stop, either downtube or headtube, just get rid of the inline ones.

Something is needed for the front, however.

You can get away without an adjuster for the front in a pinch, at the cost of a fiddlier set-up involving a little trial and error... I wrap the cable 180° around the pinch bolt and pull it tight with pliers; with a bit of technique you can adjust how tight it is, by choosing to help the bolt pull the cable as it tightens or not.

If you don't mind misleading inaccuracies, sure.


...'Mr Pedantic' :p

My experience in the shop is that most customers don't want to know the pedantic details of what's up with their bike, so unless you want to turn a 5 min adjustment into a 30 min lecture, much easier to nod head when customer acknowledges "stretch," turn some knobs, and hand their bike back to them, with customer being astounded that we don't charge them for a simple cable adjust on a new bike even though we told them they get free adjustments over the lifetime of the bike and a suggestion to bring the bike in for such when the shifting gets wonky 2-4 weeks out when selling the bike to them.

Anyone who wants the technicality of what's actually going on will be provided for...

Well, then you risk them mentioning the cable stretch the LBS told them about to someone knowledgeable, who then goes on to lambaste you as a bunch of no-hopers.

I think Mr Argumentative is more like it; I'd make it a 30-second lecture.

http://i.imgur.com/1nOUfl.jpg

Here's how I resolved this on a 'cross bike with top tube routing and campy levers that carried the shift cable under the bar tape.

I actually have that exact kind of setup on a commuter bike... but it's still an inline adjuster integrated into the cable/housing run.

Even with shifter housing under the tape, there's still enough exposed cable/housing between where it exits the tape and enters the forward frame cable stop to fit an inline adjuster.

Inline adjusters are useful at the front of the bike so you can make adjustments to shifting on the road, as you're riding. Otherwise, you usually don't need a rear adjuster for tuning the bike since there's a cable adjuster at the derailleur. Front is optional, too, since it is not as finicky as the rear when adjusting indexed shifting to work. Used to be, there were adjusters built into the cable stops, or adjustable cable stop nubbins that bolted onto downtube shifter bosses. With the way things have gone, many modern bikes don't have adjustable cable stops or internal routing that precludes adjustable cable stops, so inline adjusters are the only way you get on-road adjustability.

Well, then you risk them mentioning the cable stretch the LBS told them about to someone knowledgeable, who then goes on to lambaste you as a bunch of no-hopers.

I think Mr Argumentative is more like it; I'd make it a 30-second lecture.

I don't argue or get pedantic with customers, so if someone says stretch, I agree with them and adjust their bike in less time that it would take me to even explain what the difference between a cable and housing is... For anyone who wants to know the actual details, I'll take all the time in the world, or point them to one of our free weekend tech classes...

I had the in-line adjusters removed from my Bianchi Infinito and when they built my Colnago C59 I told them not to include them. Both bikes have in-frame cable routing.

To date, and after 1000s of miles I have not had any need for those adjusters.

The FD has always worked fine. If the RD needs adjustment, I can do it with the derailleur adjuster barrel adjusters.

Of course, this may not apply to everyone.

I rebuild bikes all the time, and they do not need regular adjustments made to the shifting mechanisms if setup properly the first time. My cross bike has no adjusters at all for the FD, in which case you can use the limit screw to hold the cage in while you snug the cable up, then back the limit screw back where it's supposed to be. So you can get a fine adjustment without adjusters, just a PITA. If your derailers do have the smaller adjusters on them, then really there is no need for the inline adjusters IMO.