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Old 03-02-14, 09:02 PM   #1
LONO100
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cant dial in the front deraileur. shifter to blame or deraileur?

i bought a used trek 1000 for my gf to start riding with me this spring. the bike needed some tlc, and ive got everything in good order except for the front deraileur which i cant seem to dial in. i do all of my own maintenance and assembly and have been doing so for the better part of 20 years, but i just cant seem to solve this issue.

the shifter and derailer look to be in proper physical shape, but i cant seem to get it to shift smoothly. i have the limits set, and it does indeed shift, but when going from the smallest sprocket to the middle sprocket, it takes a good amount of effort to get it to jump into the next ring. its even harder to get it into the biggest sprocket. ive replaced the cable and housing with a fresh set, properly lubed it, and have been tuning this thing for the past two days. ive tried putting more tension on the cable, but no difference.

like i said, it does shift, its just very sloppy and takes a lot of effort to get it to shift. im thinking its either the shifter thats toasted or the deraileur itself thats toasted. any opinions, suggestions, tips or help would be really appreciated. id hate to replace something if theres just one little variable that i am not accounting for. thanks in advance.
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Old 03-02-14, 09:11 PM   #2
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theyre both probably fine
it is more likely an adjustment issue
or cable / housing
or compatibility issue
or crankset / bottom bracket / chainline
etc

cant determine which from here
not enough details or pics

how much gap from tip of teeth on 3rd chainring to derailer cage when in middle ring?
define "good amount of effort to shift"? as in controls need excess pressure? delayed chain response ? etc?

Last edited by xenologer; 03-02-14 at 09:18 PM.
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Old 03-02-14, 09:19 PM   #3
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What kind of front derailleur? How is the shift cable routed and how does it attach to the front derailleur?
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Old 03-02-14, 09:23 PM   #4
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This is a long shot but I had the exact same problem and it was because the cable was routed on the wrong side of the anchor bolt.
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Old 03-02-14, 09:24 PM   #5
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If you grab the cable where it's exposed, mid down tube, and pull on it to try to shift does the ft shift well enough? How worn is the chain? Do the rings have shift pins?

Front shifting is the more technique and adjustment dependent then rear shifting, IMO.

Things to look at- Good der placement WRT the rings and good limit screw settings. The cable pulling shifting is a good way to set up the der specs without having the lever contribute it's aspect. I find that setting the inner limit to have the cage JUST not rub on the chain when in the rear's lowest (large) cog and then tensioning the cable so tight that it almost moves the der a bit w/out the lever pulled at all helps. Many of the Shimano STI and triple set ups have JUST enough cable pull from low to middle to have the chain be able to climb up on the middle ring. Starting with the cage and cable as close to the chain as possible means that when the lever is moved there is no take up of cable slack before the der starts to sweep. The cable and casing needs to be friction free and well seated in the stops and the casing caps fully drawn up. The cable needs to be routed properly at the anchor bolt. Up over the nub and bolt. Some of the Shimano ders have had threaded pivot bolts that can loosen. The pivots need to be free moving, lubed and if threaded also tightened. Are the rings in sync with each other? Worn rings with shift pins that are rounding off don't help. Chain wear also requires more der movement to shift well. Lastly I've known a lot of riders that don't fully throw the lever through it's complete movement as well as ease off the pedaling pressure during the shift. Some systems are more sensitive to this then others. Andy.
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Old 03-02-14, 09:31 PM   #6
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the first thing that I would do is disconnect the cable and how much effort does it take to move the shifter and can you move the derailleur by hand?
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Old 03-02-14, 10:10 PM   #7
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No actually the FIRST step is to get more information.

When did the problem start, or has it developed gradually?

If it started suddenly did any incident or maintenance procedure precede the symptoms beginning?

How old is the equipment - derailleur, levers, chain?

Without further info I would say that two likely causes are that play has developed in the derailleur pivots, the derailleur is bent/damaged, or side play has developed in the chain.
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Old 03-03-14, 12:39 AM   #8
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thanks everyone for all of the responses. i just bought this bike used for a couple hundred bucks. it rolled and pedaled but i knew it need a lot of work in the line of a complete tune up. ive dialed in my fare share of front deraileurs, and i always try to keep my limits between 1 to 1.5 mm between the chain and cages at both the high and lower limits.

as for the components, it is a shimano tiagra deraileur, and tiagra shifters. its a brand new cable and housing that i just swapped in. the chain was on there when i bought it, but it is fairly new. i have a chain measuring tool and its one of the first things i checked when i brought it home. the chain has less than 5% chain wear according to my park tool so im pretty sure its a new chain as the seller had told me.

i routed the shifter cable as all shimano tiagra shifters are routed. it comes straight out of the shifter, down the down tube, under the BB, and into the deraileur.

first thing tomorrow, ill take some pics and post. here's one more tidbit i forgot to mention: it seems to shift fine when the bike is on my bike stand, but when it is being ridden, thats when it seems hard to shift, and also shifts very sloppy.

thanks again everyone for all the help.
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Old 03-03-14, 02:04 AM   #9
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Please take a picture of exactly where the cable is attached to the front derailleur. I agree with a couple of other posters who said that it sounds like the cable is routed incorrectly on the bolt. If the cable is under the little nub instead of above it, shifting it will be very hard to do and it won't shift well. By putting the cable under the little nub or on the wrong side of the bolt, you are effectively shortening the cable throw but increasing the resistance. So the derailleur won't move as far per shift click and it will be harder to shift.
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Old 03-03-14, 06:35 AM   #10
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The difference between stand and road shifting confirms that cable tension and routing are not the cause, especially as the OP has already tried that. The difference on the road is that the derailleur is having to work against greater chain tension and there is more stress/pressure on the derailleur and chainrings.

The greater demands of shifting on the road can expose problems that don't show up on the stand, including:

Chain tension: Shifting under high pedal pressure will always be more problematic. The chain will resist being pushed, especially to a larger chainring if it is under high tension. However, I don't believe the OP would have that problem only on this bike or with his level of experience. People who have mountain bikes especially tend to be aware of the need to let off pedal pressure when shifting.

Poor positioning - the front derailleur must be at the proper height and rotation above the chainrings before adjustment is attempted. I also think this is not the cause, due to the OP's extensive experience, but positioning is easily found with a search for adjust derailleur.

Pivot wear - Most pivots are not adjustable, and after years of pushing a chain they can wear enough to develop play. When one shifts to a larger ring pressure is exerted on the inside-front of the derailleur cage. If the pivots have play the cage will be rotated slightly away from the chain, degrading shifting.

Cage wear - Every shift involves the chain rubbing against the inside of the derailleur cage. Over time that produces wear, and more importantly can create ridges that resist upward movement of the chain as it shifts to the larger chainrings. It's a more common occurrence on older equipment because of dual chainrings (always the same point of contact for a shift) and softer derailleur cages.

Chain side flex - Not the same as conventional wear. Normal wear, a lot of shifting and cross chain riding can increase the side flex of a chain, creating too much give when trying to push it to a larger ring. If the chain is indeed new it's likely OK unless it is of low quality, but one can judge side flex fairly well by putting the chain on the large chainring and a middle cog and pushing it sideways by hand. Compare the result to another bike with a newer chain that shifts well.

Bottom bracket movement - Again the OP has good repair experience, so I assume the BB is adjusted, but if the fixed cup is loose it may only show up under pressure. Any excessive side movement will degrade shifting.

Damaged chainwheel - Again, the greater stress of road shifting can magnify the impact of problems. If there is damage to the ramps or teeth it could degrade shifting.

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Old 03-03-14, 01:39 PM   #11
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Most Shimano triple shifters have multiple click-stops (detents). Don't expect the chain to climb from the smallest chainring to the middle with just one click. Most often you will need to go to the 3rd out of 4 click-stops to make this shift. You should be able to do this with one good shove of the brake lever. Just don't try to ease it in to the 2nd position. There should be 2 positions for the middle chainring. These can be used for trimming the front derailleur depending on if the chain is on the left side of the cassette or the right side of the cassette.
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Old 03-03-14, 01:46 PM   #12
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The problem is not present in the stand, so presumably the OP knows how to shift properly.

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Old 03-03-14, 02:10 PM   #13
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I agree with most posts here . Like removing the cable and try moving the shifter and the derailleur by hand . If the derailleur is hard to move by hand then there dirt or whatever in it which would need cleaning or the pivot has wear and it time to replace it . the shifter too can have play in it ,if so replace it also .
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Old 03-03-14, 04:58 PM   #14
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Twenty years is a tricky cutoff. If memory serves, that makes you a post Hyperglide mechanic.

This isn't a putdown, byt a reference to what you've worked with and your expectations. For example, if the middle ring isn't gated, you might be looking for better performance than possible.

Other factors may include, the condition or the ring, the tooth profile and/or the separation between the middle ring and outer which can make it difficult to bring the chain over to snag a tooth without dragging against the face of the outer. Wear in the inner cage plate might affect it's ability to wedge the chain upward, or the old cage may be more flexible than newer ones.

There's also the off chance that the middle ring is flipped over (inside out), or there's unfavorable facing so the inner wrong part of the chain meets the ramps or pickup pins.

All that is besides a sticky cable and/or some kind of worn shifter issue.
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Old 03-03-14, 06:38 PM   #15
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Quote:
Originally Posted by Al1943 View Post
Most Shimano triple shifters have multiple click-stops (detents). Don't expect the chain to climb from the smallest chainring to the middle with just one click. Most often you will need to go to the 3rd out of 4 click-stops to make this shift. You should be able to do this with one good shove of the brake lever. Just don't try to ease it in to the 2nd position. There should be 2 positions for the middle chainring. These can be used for trimming the front derailleur depending on if the chain is on the left side of the cassette or the right side of the cassette.
I have a Trek 1000 with Sora/Tiagra as well; I had it for over a year before a mechanic informed me that the front shifter has an extra trim position for the granny! I don't know if that will help you with your shifter sloppiness, but it does help you reach more cogs from the granny ring without chain rub. But I did find that, no matter how I adjusted, it was not possible to find a FD position that allowed every ring to reach all 8 cogs without chainrub. You should hope for 6-7 cogs per ring at best. And of course the biggest probable difference between stand shifting and riding shifting is chain load. Make sure you ease off while you shift!
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Old 03-03-14, 08:36 PM   #16
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thanks again for all the responses. ive done my own bike maintenance for almost twenty years, ive bought, built and sold dozens of bikes through the years, but let me stress that i am by no means a certified bicycle mechanic. im just a guy who loves tinkering, and i love bringing old bikes back to life.

i am always open to getting a different viewpoint to a problem, more heads are always better than one in most cases, so i welcome all opinions. here are some pics of the bike in question:











hope this helps in my quest to solving the sloppy shifting issue. i do have another bike with tiagra components so i am aware of the trim, and i have a bianchi with a tiagra group on it that i have been able to successfully tune myself, so i dont think the trim is the issue. its weird, hard to explain in words the sloppy shifting.

when test riding the bike and testing the shifters, i made sure not to put a load on the chain, i never shifted while climbing a hill, it was all done on flat ground with light pressure to the pedals. when i pull on the cable from the downtube, it shifts from small sprocket to the next larger sprocket, but will fall back down to the smaller sprocket when i let go of the cable. hope this gives a little more detail to all of you fellow DIYers out there. thanks again.
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Old 03-03-14, 08:49 PM   #17
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OK, I was going to suggest that you shift "manually" via pulling the cable at the downtube.


So, if it shifts cleanly and sharply when you do it that way, you know the FD is adjusted OK. Now it's about trim and smooth cable movement.

Two points.

How is it that both gear cables are passing to the left side of the head tube?
Get those donuts up away from the BB cable guide. They might be adding friction as the cable returns.
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Old 03-03-14, 09:20 PM   #18
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thanks for the tips NY, the little donuts are all worn out, i will probably have to get new ones because they keep sliding to the bottom. as for the shifter cables, it only looks like it from the picture, but the shifter cable on the right is routed to the right side of the down tube. you can see it ever so slightly in the top of the last pic.
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Old 03-04-14, 01:13 AM   #19
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Your middle ring looks pretty damn flogged. I bet your shifting would improve 100% with a fresh one. The other two rings are probably okay.

A steel one will be cheaper and last longer.

I liked FB's stab in the dark that it might be on backwards. I've uh, performed the experiment, and it totally kills the shifting, way worse than what you're experiencing.

Quote:
Originally Posted by Andrew R Stewart View Post
I find that setting the inner limit to have the cage JUST not rub on the chain when in the rear's lowest (large) cog and then tensioning the cable so tight that it almost moves the der a bit w/out the lever pulled at all helps.
This is the gospel. Then only fine-tuning of tension with reference to shifting performance each way, usually not necessary with newish gear.

Quote:
Originally Posted by RubeRad View Post
I did find that, no matter how I adjusted, it was not possible to find a FD position that allowed every ring to reach all 8 cogs without chainrub. You should hope for 6-7 cogs per ring at best.
Depends on the length of your chainstays. The whole cassette should be accessible from the middle ring on a touring bike, IME. Race bikes, it's usually 8/10 for the small ring of a double before the chain hits the big ring, never mind the FD.
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Old 03-04-14, 04:56 AM   #20
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thanks for the tips NY, the little donuts are all worn out, i will probably have to get new ones because they keep sliding to the bottom. as for the shifter cables, it only looks like it from the picture, but the shifter cable on the right is routed to the right side of the down tube. you can see it ever so slightly in the top of the last pic.
cut the donuts right off. No need for them on down-tube cable routing, they are always going to migrate towards the bottom bracket from vibration and cause more headaches... I've owned quite a few bikes with down-tube cable routing, never one with donuts

Can you take a close-up of the cable connection at the FD? It looks....off in that pic. And a pic so we can see alignment of the FD on the chainring (on large chainring). If its not parallel and at the right height, it can be problemtic (speaking from 13+ years of doing my own building - yep been there!)

Otherwise...I dunno. I Always fine tune on the bike myself. They shift a tiny bit different for me than in the stand.
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Old 03-04-14, 06:14 AM   #21
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I see no indication that you checked any of the items I mentioned, or for a reversed chainring (not reallyy a stab in the dark). Again, the cause must be something affected by increased chain tension while shifting. Please check the derailleur pivots and inner surface of the cage. Thanks.

p. s. You have an option that many do not - substituton. You can swap out another derailleur to confirm whether it is a factor. Also make sure the derailleur height and rotation is correct, as it's common to assume it's OK. As we have neither a side nor rear view of the derailleur it's my not possible to tell at this point.

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Old 03-04-14, 07:28 AM   #22
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That chainring is the right way around.
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Old 03-04-14, 07:36 AM   #23
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Of course - silly me, has the shift pins. Reversal is an issue with older systems.
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Old 03-04-14, 07:43 AM   #24
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Also it has sections between the bolts bent inwards; looks deceptive in the last pic but is obvious in the pic from under the BB.

As is the wear; that middle ring has done enough miles, and I'm tipping it's the single cause of the OP's issue. It's not extreme, but I can see all the shift-assisting going to crap with a fresh chain, along with the drive efficiency.

If I'm correct, the drivetrain will feel throbby under power in the middle ring, but not the others.
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Old 03-04-14, 09:31 AM   #25
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im pretty sure the chainring is on correctly, and i have inspected the cage of the front deraileur and it looks pretty normal. like i said in my original post i have inspected the deraileur and it looks physically proper, maybe i should have specified that i found the cage to be at a proper height and parallel to the largest chainring.

swapping in a front deraileur sounds like a good idea, but i currently dont have a spare one or even one on another bike that would work with this bike.

i am starting to think that maybe the chainring is indeed toasted and that maybe i might need some new rings.

thanks for all the great responses, this has been very helpful. once i get home today, i will a close up pic of the anchor bolt on the front deraileur, and also a few close ups of the chain rings so i can get some opinions on the wear on the teeth. thanks again everyone.
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