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Why can't I ever adjust front derailleurs?

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Why can't I ever adjust front derailleurs?

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Old 05-19-17 | 05:23 PM
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Originally Posted by himespau
Yeah, I always put it on the top side of the little nubbin or whatever (the nubbin is between the cable and the bolt). The first time I tried it a long time ago, I thought the nubbin was to keep it from sliding out, so I'd put it between the nubbin and the bolt and then through the groove, but I've already learned that lesson. I've heard that sometimes putting it there allows one to use a mtb deraileur with road shifters (or the other way around), but I haven't tried that.
Choking up on the cable routing, shortens the lever arm and increases cage travel with the same cable movement. Since your problem sounded more like borderline or inadequate cage movement, I knew the cable was routed correctly, and posted more as general info for anyone else.
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Old 05-19-17 | 08:34 PM
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Originally Posted by mongol777
Up until I switched couple of bikes to 11s Shimano (105 5800 and Ultegra 5800)- - FD cable tension was a never a big deal. But 5800/6800 FD requires pretty tight cable to get crisp shifts. So I bought this tool - BT-2 Cable Stretcher | Park Tool
And it is so good, I don't know why I waited so long. Setting any cable tension (brake or shift) is a breeze now
I did my first 11 speed a few days ago. For the high tension step I found this trick and it makes it really easy to get close for high tension.
.

Use a 6mm allen wrench to hold the cage out while you attach the cable. You still need a barrel adjuster to fine tune but it puts you close.

@hermanchauw brought it up but this video shows it. uTube - Shimano 11 speed Front Derailleur Tensioning Trick
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Old 05-20-17 | 08:53 AM
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Originally Posted by peugeot mongrel
I did my first 11 speed a few days ago. For the high tension step I found this trick and it makes it really easy to get close for high tension. Watch this.

Use a 6mm allen wrench to hold the cage out while you attach the cable. You still need a barrel adjuster to fine tune but it puts you close.

@hermanchauw brought it up but this video shows it. uTube - Shimano 11 speed Front Derailleur Tensioning Trick
Great trick for when out on the road without the tool! Thank you!
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Old 05-20-17 | 08:57 AM
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Originally Posted by Retro Grouch
Oh Man! I wish that I had known, I've got a couple of those and the only thing that I use them for is to tighten cable ties. I'd have let you have one of mine for a song. For front derailleur cables I pull on the cable with my needle nose pliers in one hand and tighten the clamp with the other.
Unless I am patient and take my time with cable cutting (heat up with lighter and cut while hot) I find the needle pliers deform/unwind the cable quite often. Not looking down on method which works for you (and worked for me in the past) - I love having dedicated tool which makes the job much easier. And yes - works great for zip ties as well!
Thank you.
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Old 05-20-17 | 09:14 AM
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Originally Posted by himespau
For some reason FD adjustment is something I just can never get right. Rears aren't a big deal, but fronts always leave me stumped.

This time, I'm trying to put together a bike for my wife. I'm using a set of 3x8 speed Shimano LX stuff I've picked up here and there over the years (on an old Cannondale ST-400 frame - 85 I think - if that matters). Everything's together without much trouble except the FD, once again. A lot of my problem seems to be that the default location seems to be too far inboard. The first click more or less centers the cage over the inner ring (maybe a bit closer to the middle) and the second click moves it to the middle. I've tried messing with the limit screws but that doesn't seem to be helping, just means that one of the clicks doesn't do much of anything.

I thought maybe the cranks were out too wide (even though I was using the 115 mm spindle BB recommended for the crankset, so I dropped it down to a 110 mm spindle, but that didn't help. I can set the cage centered over the inner ring and then put the cable on, but that puts a lot of tension on the cable in the inner position when it's supposed to be fairly relaxed and the shifting isn't great.

I'd thought that maybe I had a FD that was for mtb pull ratio and the shifters were for road pull ratio (even though they're both 8 speed deore LX) so I tried an unused (maybe 10 year old but still in packaging) 105 FD that I had sitting around. I still had the same issues with that. I don't have any mtb derailleurs sitting around (at least not bottom pull), but I could try picking up one and seeing if that has the proper ratio (the problem with that is the crankset has a 48T big ring).

Is there anything else I should be trying? I'm about to say screw it and pick up separate brake levers and some of those 8 speed SunRace thumb shifters (because of the friction on the left) and start over. I'd prefer not to do that because I've got all the other cables run and cut to length and don't want to start over if I can avoid it.

I'd love to hear any suggestions anyone might have about something I'm missing.

Thanks.
I think concentrating on the cabling isn't addressing the real problem. I suspect that your chainline is still what's at issue here. You should check it before proceeding.

Mountain bike cranks are narrower than most road cranks and this can cause problems when using them on road bikes. I suspect that you need a 107 mm bottom bracket. That 3mm isn't much but it may be enough to move the crank far enough inboard so the derailer can reach the outer chainwheel.
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Old 05-20-17 | 11:34 AM
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Originally Posted by cyccommute
I think concentrating on the cabling isn't addressing the real problem. I suspect that your chainline is still what's at issue here. You should check it before proceeding.

Mountain bike cranks are narrower than most road cranks and this can cause problems when using them on road bikes. I suspect that you need a 107 mm bottom bracket. That 3mm isn't much but it may be enough to move the crank far enough inboard so the derailer can reach the outer chainwheel.
That's something that I could try, though the shifters, derailleurs, and crankset are all the same series (I'm pretty sure anyway) touring 8 speed triple Deore LX, so I would have thought they'd have that figured out. I found a spec sheet somewhere that said that crankset was supposed to have a 115 mm spindle, so that's what I put on there first and then dropped down to 110. I suppose I could drop down another 3 mm as there appears to be room before the chain or rings would contact the frame, but it seems weird that that they'd specify something so much bigger than ideal. Oh well, at least bb are cheap.

Checking the chainline isn't hard, so I could do that fairly easily before too much else. Since I'm using a road frame and 130 mm hubs, should I be shooting for the narrower (according to sheldon) 45 mm chainline of a road triple rather than the 47.5-50 of a mtb triple?

Last edited by himespau; 05-20-17 at 11:37 AM.
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Old 05-21-17 | 08:21 AM
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Originally Posted by himespau
That's something that I could try, though the shifters, derailleurs, and crankset are all the same series (I'm pretty sure anyway) touring 8 speed triple Deore LX, so I would have thought they'd have that figured out. I found a spec sheet somewhere that said that crankset was supposed to have a 115 mm spindle, so that's what I put on there first and then dropped down to 110. I suppose I could drop down another 3 mm as there appears to be room before the chain or rings would contact the frame, but it seems weird that that they'd specify something so much bigger than ideal. Oh well, at least bb are cheap.

Checking the chainline isn't hard, so I could do that fairly easily before too much else. Since I'm using a road frame and 130 mm hubs, should I be shooting for the narrower (according to sheldon) 45 mm chainline of a road triple rather than the 47.5-50 of a mtb triple?
Probably the 45mm chainline but measure for both.
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Old 05-29-17 | 11:03 AM
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Looks like you're on the right track. I have a hard time measuring with all the stuff in the way, but when I put one end of my calipers on the middle ring, set them to 45 mm, and went as straight as I could up to the BB, it looked a fair bit closer to the drive side chainstay than the others. Assuming they're parallel, (I couldn't get my calipers in there to find the midpoint) I need to go with a shorter spindle. I'd have thought that going from 115 (recommended) to 110 (on their now) would be enough to correct for going from a 135 mm hub (FD and crankset are 8 speed Deore LX, so I'd assume designed for mtb hubs) to the 130 that's on their now (rear triangle is actually 128), but maybe going down to 107 will help. There is definitely room when the chain is on the little ring, where it's probably got 5-8 mm before it would contact the stay.
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Old 05-31-17 | 08:39 AM
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Originally Posted by himespau
Looks like you're on the right track. I have a hard time measuring with all the stuff in the way, but when I put one end of my calipers on the middle ring, set them to 45 mm, and went as straight as I could up to the BB, it looked a fair bit closer to the drive side chainstay than the others. Assuming they're parallel, (I couldn't get my calipers in there to find the midpoint) I need to go with a shorter spindle. I'd have thought that going from 115 (recommended) to 110 (on their now) would be enough to correct for going from a 135 mm hub (FD and crankset are 8 speed Deore LX, so I'd assume designed for mtb hubs) to the 130 that's on their now (rear triangle is actually 128), but maybe going down to 107 will help. There is definitely room when the chain is on the little ring, where it's probably got 5-8 mm before it would contact the stay.
As long as the inner ring doesn't contact the chainstay, you are good. Tuck it in closer if you need to,
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Old 02-14-18 | 01:28 PM
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Originally Posted by cyccommute
As long as the inner ring doesn't contact the chainstay, you are good. Tuck it in closer if you need to,
I just wanted to come back and say thank you (I've noticed a lot of threads where I never find out if suggested fixes did the trick). It took me a long time for other reasons, but it turned out I needed to drop down to a 107 mm spindle BB (at least with the UN55 I was using) and a new (well unused anyway, I bought it probably 7-8 years ago at this point) FD, but it seems to be shifting flawlessly now.

Looks "interesting" but shifts seem to work.

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