rishardh

Building up a new bike and wondering if this is necessary. Any thoughts?

AndrewP

Only if you dont have a tension adjuster on the downtube or at the gearshift. You can only make the adjustment when there is no tension on the cable, so they are no use while you are riding along.

trekkie820

I disagree. You can use them with tension on the cable, but it takes two hands. If you have no other barrel adjuster from the shifter to the derailleur, then yes, you need one

rishardh

Can it go out of adjustment when in the small ring? ie. due to no cable tension and road chatter.

Panthers007

There should be some tension on the FD cable even at rest on the small chainring.. Other wise the shift would use up part of it's travel taking out the slack. Likely you wouldn't be able to get on all the chainrings.

There are in-line adjusters available, but I'm not sure where I saw them recently. If it comes to me, I'll edit this.

zzyzx_xyzzy

Inline adjusters have a history of going out of adjustment for me as I ride. If you're going from a handlebar shifter to a downtube stop, the Jagwire 'mickey' adjuster is cleaner:

HillRider

All of the votes in favor of an in-line adjuster assume you are going to have index front shifting. If that's the case, I agree you need one somewhere in the system.

If you are using friction shifting (downtube, barends) then no, you don't need one

DaveSSS 

Neither of my LOOK 585 frames have any adjustment for the FD shift cable tension. All I do is screw the low limit screw in 1/2-3/4 turn, attach the cable while pulling it tight, then back the screw out to it's normal position (set without the cable attached to provide about 1mm chain clearance in the little ring and largest cog). I rarely have to adjust the cable for an entire season.

JanMM

Much less need for cable tension adjustment on the FD than on the RD.

HillRider

For a double that's correct as the limit screws pretty much locate the cage. For a triple, the ability to do the fine cable tension adjustment is much more important.

rishardh

My LBS gave me a JagWire cable adjuster that were indexed so they would not go out of adjustment. Unfortunately they are for Shimano Brifters and they go in where the cable comes out of the Brifter on the side and I am going to go with SRAM.

ryker

+1.

AEO

actually, on some levers it's important to have an inline even with a double.

my DA 7800 STI double to ultegra 6600 FD doesn't index in a fine enough increment where the chain won't fall off, not shift or rub on the cage in top gear without the inline properly adjusted.

very temperamental FD/shifter combo compared to my triple setup which has no inline adjuster and runs a 105 9sp FD and veloce shifters.

onbike 1939

Yes you can use them under tension but it would be a mistake in my opinion. To do so causes the outer cable where it meets the adjuster, to partially unwind and this gives problem. Better to go to small chain ring and then adjust.

tellyho

I think an inline adjuster is worth having, but not strictly necessary. It just makes tuning the FD a hell of a lot easier.

rishardh

Got some inline adjusters. Looks like there is no harm in running one. It came in a pair. I decided to do the rear as well to keep things symmetric

joejack951

I've never heard of this occurring or had it occur on any of my bikes. Anyone else have this experience?

In my mind, I'm thinking that a highly tensioned cable would be less likely to unwind, assuming that a cable is likely to unwind in the first place.

Panthers007

The problem with working on the FD from the tall chainring is that often times - the adjustment is lost. You can't shift onto the small ring. I always adjust cable-tension with the FD on the small so it's relaxed - or has a bit of tension. After working on these for awhile, you just "know" what is correct by feel. Another common error is at the cable anchor-bolt on the FD. Some people are afraid to really screw the bolt down to hold the cable - out of the legitimate fear that it'll strip. Shimano says to apply 44 - 60 inch-lbs. I go with the high-side here. Using a good torque-wrench, it often is amazing how tight this really is. Give it a try sometime if you can get access to a calibrated torque-wrench.

Another problem is improper positioning of the cable with the anchor-bolt. You want to figure out where it will be subjected to the most tension/pressure. This is to prevent it from slipping. I aim to have the cable take a full 90-degree turn under/over the mounting-plates around the bolt.

HillRider

This can be a real problem with Shimano front derailleurs and often leads to indexing problems.

These derailleurs have a small tab to the left of the anchor bolt and it seems the cable should be routed under this tab and between it and the bolt. That's not right. The cable should go over this tab and then through the groove in the arm and under the bolt and washer. Run incorrectly, the indexing doesn't move the derailleur the correct amount.

Panthers007

One big reason for this problem, HillRider, is Shimano. They do not provide so much as a description of the correct routing. Leave alone a picture or diagram. It requires an understanding of physics to go at it 'blind.'

It took me a few tries back yonder to figure it out. Are you listening, Shimano??

onbike 1939

As quoted in my post I'm talking of the outer cable housing here which is in compression, not in tension. By adjusting the in-line adjuster when the inner cable in under tension on the large ring, the end of the outer is forced against the stop on the adjuster and eventually the parallel wires of the outer become bared.

joejack951

Oh, I was confused by "outer cable" in your first post. Now that you mention "housing" it make more sense. But, the adjusters I've seen let you use a standard ferrule on the end of the housing. Unless the ferrule is spinning on the housing, all the rotating friction simply acts on the ferrule and has no effect on the housing. If there are adjusters that don't allow this, I guess it could happen.