derailleur adjustments

[bonnie john]

i think i need to adjust the front 1 on my mountain bike

it is a 1991 diamond back apex in MINT condition, i bought it new and have hardly used it

when i am upshifting using the crank gears, i have no trouble going from low (small) to medium to high (big). but when i downshift on the front gears, it shifts straight from high to low, missing the mid cog altogether

also it will sometimes "jump" ( feels like chain slip ) when i am trying to pedal when a low rear (big) gear is mated with a high (big) crank gear

the apex has deore lx componentry with an XT front derailleur

so gurus, how do i do it. the manual is all double dutch to me

 

[wavinwayne]

Check Park Tools website for instructions.

 

[bonnie john]

i read it wayne, tried it no go

i need a symptom/problem/remedy chart

that's how my brain works

so, any suggestions please

 

[Redline955]

You should have barrel adjusters at the lever end of your shifting cables. Try turning the adjuster on the right side( for the rear D) counterclockwise to tighten the cable. If that doesn't work, turn it the other way. You probably just have cable stretch that needs to be tighetened up. Also, don't use the biggest/biggest gear combo. That's called crosschaining and wears the gears, among other things. Also, there may be an adjuster at the rear derailleur to fine tune it.

 

[bonnie john]

hi red, yep i understand crosschaining, but sometimes i have to do it for a sec or two. i do not ride like this

the MAIN prob is when i downshift from the big cog on the front derailleur, the selector misses the middle cog and goes straight to the small 1

i have adjusted cable barrel according to park tools and some youtube videos. also adjusted the limiting screws, they do not seem to have any effect on my problem. i have not seen my problem covered


this is driving me nuts, please help

 

[NYEngineer]

I'm trying to remember how I taught myself to do this.. First of all, get a new cable. Most of the time, shifting problems stem from old used up cables.
When you disconnect the existing cable from the derailler, the derailler will settle all in over the granny ring. Adjust the inner limit screw to set the cage directly over the small ring.
Install the new cable in the shifter and thread it to the derailler. While you have the end of the cable in your hand, pull on it and shift the shifter to insure the cable is all out or in the correct position for the derailler over the small gear. Adjust the barrel on the shifter all the way in and then maybe 3/4 of a turn out and install the cable to the derailler while keeping it as tight as you can.
Now shift the shifter and adjust the barrel to make it perfect.
Hope this helps.

 

[wantin150]

You can also try this:

Shift into the big ring. Now, WITHOUT turning the crank, downshift all the way. This will create slack in the cable. Pull everything out of the housings and inspect the cable. If it is OK, clean it with WD40 and wipe it down really well. Grease it up and reinstall it. The follow NYEngineer's advice for adjustment.

While you have the cable out, inspect the shifter itself. You may have a bum shifter.

 

[Bill Kapaun]

IF this has trigger shifters, your problem is the pawl gets gunked up and doesn't have time to "catch" the mechanism as it's "flying by".

Get a can of WD-40 or similar solvent.
Pry the case apart far enough to "flush" the mechanism. Let it sit for an hour.
Try it to see how it works. It may need this repeated once or twice.
Also. if it's still doing it after the 1st flush, shift from the middle ring ALMOST to the big ring, and then SLOWLY ease the lever back down, allowing it to "catch". This seems to help speed up the process.

Do NOT try to disassemble these, unless you have more skill than a Swiss watchmaker!!!

BIG Ring to BIG Cog is called cross chaining and is to be avoided. Ditto with Small:Small.
Just get off the bike and look how severe of an angle the chain is running at! You should be ashamed!

 

[Kestas]

Did you slide the front derailleur downward on the frame as close as you can to the sprocket?

 

[mpvue]

Originally Posted By: bonnie john
i think i need to adjust the front 1 on my mountain bike

it is a 1991 diamond back apex in MINT condition, i bought it new and have hardly used it

when i am upshifting using the crank gears, i have no trouble going from low (small) to medium to high (big). but when i downshift on the front gears, it shifts straight from high to low, missing the mid cog altogether

also it will sometimes "jump" ( feels like chain slip ) when i am trying to pedal when a low rear (big) gear is mated with a high (big) crank gear

the apex has deore lx componentry with an XT front derailleur

so gurus, how do i do it. the manual is all double dutch to me

it's a '91- which shifter type do you have? is it 2 buttons under the handlebar? It sounds like it. if it is, you have one of the early attempts at front indexing, never worked that well. I can adjust it, but I don't think I can put it into 500 words or less.
I will tell you this: after you get the position of the der correct (outer plate parallel w/ the sprocket, about 1-2mm above), set the limit screws (how far it goes in either direction) the rest is all cable tension.
if you have a top mount single lever shifter, it 'should' have a little lever on it that allows you to turn off the indexing. that is the preferred setup.
post a picture if you can.

 

[bonnie john]

that's great info t/y

the shifters are as you describe them, two buttons under the handlebar. can a later or different shifter be fitted ?

any pics greatly appreciated


Originally Posted By: mpvue
Originally Posted By: bonnie john
i think i need to adjust the front 1 on my mountain bike

it is a 1991 diamond back apex in MINT condition, i bought it new and have hardly used it

when i am upshifting using the crank gears, i have no trouble going from low (small) to medium to high (big). but when i downshift on the front gears, it shifts straight from high to low, missing the mid cog altogether

also it will sometimes "jump" ( feels like chain slip ) when i am trying to pedal when a low rear (big) gear is mated with a high (big) crank gear

the apex has deore lx componentry with an XT front derailleur

so gurus, how do i do it. the manual is all double dutch to me

it's a '91- which shifter type do you have? is it 2 buttons under the handlebar? It sounds like it. if it is, you have one of the early attempts at front indexing, never worked that well. I can adjust it, but I don't think I can put it into 500 words or less.
I will tell you this: after you get the position of the der correct (outer plate parallel w/ the sprocket, about 1-2mm above), set the limit screws (how far it goes in either direction) the rest is all cable tension.
if you have a top mount single lever shifter, it 'should' have a little lever on it that allows you to turn off the indexing. that is the preferred setup.
post a picture if you can.

 

[mpvue]

Originally Posted By: bonnie john
that's great info t/y

the shifters are as you describe them, two buttons under the handlebar. can a later or different shifter be fitted ?

any pics greatly appreciated


Originally Posted By: mpvue
Originally Posted By: bonnie john
i think i need to adjust the front 1 on my mountain bike

it is a 1991 diamond back apex in MINT condition, i bought it new and have hardly used it

when i am upshifting using the crank gears, i have no trouble going from low (small) to medium to high (big). but when i downshift on the front gears, it shifts straight from high to low, missing the mid cog altogether

also it will sometimes "jump" ( feels like chain slip ) when i am trying to pedal when a low rear (big) gear is mated with a high (big) crank gear

the apex has deore lx componentry with an XT front derailleur

so gurus, how do i do it. the manual is all double dutch to me

it's a '91- which shifter type do you have? is it 2 buttons under the handlebar? It sounds like it. if it is, you have one of the early attempts at front indexing, never worked that well. I can adjust it, but I don't think I can put it into 500 words or less.
I will tell you this: after you get the position of the der correct (outer plate parallel w/ the sprocket, about 1-2mm above), set the limit screws (how far it goes in either direction) the rest is all cable tension.
if you have a top mount single lever shifter, it 'should' have a little lever on it that allows you to turn off the indexing. that is the preferred setup.
post a picture if you can.

the 2underbar buttons are called 'rapidfire', 1st generation and they really suck. you can install any friction style shifter you want. check w/ a local shop, tell them you want a basic top mount shifter for the front derailleur. you might have to cut up your lever clamp to get it to fit on your handlebar.