mtzc

Being a complete noob to this I had an issue with chain rubbing, watched a few youtube videos, tried to fix it... created new problems.

I seem to have the chain running smoothly through all the gears. On my front derailleur I am able to go from the small cog to the middle cog then to the big cog, but when I want to shift back down to the middle cog I have to click the shifter with a little bit of force and it jumps all the way back down to small cog pretty loudly. This still seems to happen with the minimum amount of tension I can apply to it. The only way I can go from the big cog to the middle one is by holding the lever in, clicking the shifter then slowly releasing leaver and it seems to lock in the middle.

Any ideas what is wrong with it or if I've broke something?

.be

oldbobcat

You've got so much chain tension pulling the derailleur into the hight limit screw that it's shooting the shifter right past the middle position when you downshift. Loosen your front shift cable (lots) and then see if you haven't broken the shifter. Then take it back to the shop to have them get the rub out for you.

By the way, your style of shifting while the cranks are not turning forward is hard on your chain and chainrings. Keep the the chain moving while shifting.

Bill Kapaun

You might have mentioned what kind of shifters you have.
Your problem is typically found on trigger shifters that have had the grease get gummed up inside, preventing the pawl from engaging quickly enough to catch the middle position.
Pry open slightly and FLUSH with WD-40.
From the largest ring, hold onto the lever and EASE it down to the middle ring SLOWLY.
Usually after a few attempts, the pawl will loosen up and engage quickly.
You may have to repeat the Flush 1 or 2 more times if it's really gunky.

Zef

I recommend starting again:
(Assuming you have the height and angle correct...so that the bottom of the outer cage of the derailleur clears the teeth of the large ring by 2mm and the outer cage is parallel with the teeth of the large ring)
1. undo the cable where it attaches to the derailluer
2. shift to the large cog in the rear and set the low limit screw on the front derailleur so there is 1mm to 1.5mm clearance between the inner cage of the derailleur and the side of the chain.
3. make sure the front shifter is in the lowest gear setting, screw the cable adjuster in completely and then back it out 1 and a half turns, then pull the cable taught and refasten it with the derailleur anchor bolt.
4. Shift the front derailleur to the middle ring while keeping the chain on the large rear cog.
5. Check to see if the inner cage of the front derailleur is rubbing on the chain...if it is turn the cable adjusting barrel in slowly while rotating the crank arms forward until the rubbing stops. If the chain is not rubbing then slowly turn the adjusting barrel out while rotating the cranks, adding tension, until it starts to rub and then screw it in to the point the rubbing stops.
6. Depending on chainline you may not be able to eliminate all rubbing while in the middle ring and large rear cog combination. If this is the case after applying step 5, then repeat step 5 using the second largest cog instead of the largest cog.
7. Once steps 5/6 are complete, shift the rear derailleur to the smallest cog and the front derailleur to the largest chainring. Set the high limit screw on the front derailleur to so that you have 1mm to 1.5mm clearance between the outer cage of the derailleur and the side of the chain.
8. trim and cap the cable.

If that does not work then you need to have someone look at your setup to help determine if something is busted.
-j

5 mph

Man what a pain. Spent all afternoon - 2 PM to 6 PM messing with this. I think its the shifter.

alcjphil

This is a 5 year old thread without information about the bike in the original question

Andrew R Stewart 

Or in the post #5 ..

Still the likelihood of a gummed up ratchet pawl pivot is strong. Andy

5 mph

I was embarrassed to ask for more help. Its my other bike that I'm using right now,until my Giant gets fixed. a Specialized Sirrus. It hops from 3rd to 1st on the Downshift.
I don't really used 2nd or 1st anyway since the bike is so light, but I had to fix it. I tried releasing tension in the Shifter Cable, lowering the Derailleur, opening up the shifter and
spraying it with WD 40. I discovered the Shifter cable was binding where it come under the bike and cleaned the fitting. I thought I solved it but the problem is still there.

Bill Kapaun

Is that a frayed cable?

5 mph

I 've watched it drop from 3rd to 1st and missing 2nd It takes such a big drop no matter how much I change the cable tension or Limit Screw.
So I got curious and opened up the shifter
I may just leave it alone until the Giant gets fixed because. if I need 2nd, I can drop from 3rd to 1st and then upshift to 2nd.
If I take apart the shifter, i would be out without a bike ( kind of) My last bike is a single speed Langster I bought at a yard sale.(It scares me)
I just started biking in March, and i ride some 20 miles a day. There is so much to learn and you have to learn to fix themselves because the bike shops are overloaded.
I feel nervous with these road bikes and their skinny tires on the roads I use everyday. My Giant 29er feels so stable and safe and well balanced coming down hills with curves.

5 mph

At the end it is. I put one of those fittings on it one hour ago.

5 mph

Worked on it for 3 hours today.. Here is a video of what is going on that I posted on Youtube.

cxwrench

You're spending wayyyy too much time on this. Derailleur adjustments take minutes, not hours. I'd say your cable tension is wayyyy to high. Usually when this is the case it's near impossible to get the big chainring click in the shifter to engage, but yours does. I'd still try less tension. One thing to look for is the front derailleur moving up to the big ring then moving back a bit when you release the shifter. This means either not enough tension OR a loose high limit...or both.
It would take less than 2 hours to completely disassemble the bike and replace all cables/housing/bar tape.

alcjphil

Limit screws are just that, limits. They have no effect whatsoever on shifts in the middle. You should not be touching them

5 mph

on second thought you're right. I'm leaving it the way it is, Thanks

5 mph

Thank you.

cxwrench

One of the most important pieces of advice I can give is: Know you limitations. Some people are just not at all mechanically inclined.

Unless you're really close (you're not), go back to the very beginning and start over. New cable too. Make sure you follow all of the following steps.

1) undo the front derailleur cable
2) make sure the front shifter is in the small chainring position
3)make sure the chain is on the large cog in the rear
4)set the low limit at this point. you want about 1.0mm between the inner derailleur cage and the chain
5)attach cable, just pull it snug, not crazy tight
6)shift up to the middle ring, this is where you will adjust cable tension.
7)if your shifter has a trim function for the middle chainring you want it in the position that puts the derailleur closer to the frame of the bike than away from it.
8)adjust cable tension so the cage is about 1.0mm from the inner cage.
9)upshift(smaller cogs) 5-6 times and trim the front derailleur, the chain shouldn't rub on either side of the cage
10)upshift to the small cog, then shift to the big ring and see what happens. the chain should move up to the big ring and not push it over. if it looks like it's going over then tighten the high limit. if your frame has external cables you can do this by pulling on the cable by hand while slowly pedaling. also make sure the derailleur cage moves up to the big ring position but doesn't move back at all when you let go of the shifter.

This should take no more than a few minutes...if it does, stop and find help from someone that is a good mechanic. Hopefully they're a good teacher as well.

5 mph

......never mind....always better to be humble

but in all seriousness. I thank you for your help .
With deepest respect
5 mph

cxwrench

Lemme know what happens if you try again. Triples were all over the place as far as cable tension...Ultegra 9 needed more tension than Dura Ace 9. The key is what happens in big cog/middle ring. That basically tells you all you need to know about tension. Don't mess with it in any other position. Set the low limit very first thing, don't screw with it after that. Same w/ high limit, once it's correct, that's it. You're done, changing it won't get your anywhere.

ClydeClydeson

Hard to tell for sure form the video, but you might have the derailleur cable routed under the pinch bolt wrong. Many front derailleurs require the cable to run over a tab on a washer, then under the pinch bolt, but when you first look at it, it seems logical that the cable should run under the tab. Running the cable under the tab shortens the effective lever arm you are pulling on to activate the derailleur, which means the cable will have much higher tension, and that the derailleur will move further for a given amount of cable movement.

5 mph

Hello Mr Clarkson:
I had the same thought myself.last night and I found a post here on Bike Forums referring to the exact setup I have.
I am probably going to layoff a a day or two and try it Saturday
Many thanks
5 mph
https://www.bikeforums.net/bicycle-m...fter-woes.html

gsa103

Front deraileurs are pain to work on, especially triples. Don't be discouraged, you're doing this for the first time. An hour isn't unreasonable to get it running just right, if you're not used to the right order of adjustments.

I agree on checking the pinch bolt, that screws up the leverage and results in wonky shifting. Cxwrench provided a good procedure. Of note, many bikes with triples will get some chain rub when crossed chained (big/small or small/big). It's perfectly normal to not be able to use the biggest 1-2 rear cogs when on the largest chainring. You should be able to access the entire cassette from the middle ring.

wphamilton

It's likely been mentioned in some way or another, but I think it helps to take a step back and look at it logically from base principals.

If it skips the middle and otherwise shifts to the outside gears, it's pulling too far on the shift. The main thing to cause that is the lever is too short on the cable side of the pivot. So check how it's routed. That tab can cause it. Or even pinch the cable on the far side of the clamp bolt (if it's clamped on the near side) will sometimes do it.

Just make sure that the height and alignment of the DR cage are correct first, before fussing with it.

5 mph

Going to let it rest a while.
Can't thank everyone enough and appreciate your encouragement, advice and help.
Can limp along the way it is until I get my other Bike fixed Saturday.

5 mph

I took apart the shifter and the shift indicator (which wasn't working). Wish I had taken a video or pictures..
The shift indicator dissolved into parts after I opened it because of the tiny coil spring inside it.
I put it all back together and installed a new shift cable.
No changes to derailleur except at the adjustment screw at the shifter.
The downshift from 3rd gear to 2nd gear works now.and so does the shift indicator.
I'm not sure if the shifter was to blame or the shift cable, but I can definitely sense that it the shifter "catches" going from 3rd to 2nd.
It may have been the fresh shift cable since the original one was 16 years old. I examined it for imperfections or wear at the point where
it crosses under the bottom bracket and turns up 120 degrees.