Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

front derailleur issues...

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

front derailleur issues...

Old 03-07-12, 07:27 AM
  #1  
GordoTrek
Senior Member
Thread Starter
 
GordoTrek's Avatar
 
Join Date: Nov 2011
Location: Rochester, NY
Posts: 1,342

Bikes: 1962 Carlton Franco-Suisse Custom,1968 Raleigh DL-1/Tourist, 1971 Holdsworth Professional, 1973 Holdsworth Mistral,1973 Raleigh Gran Sport,1974 Raleigh Grand Prix, 1993 Trek 2200 Composite, 2011 Trek 7.3FX

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
front derailleur issues...

ok... i have recently rebuilt my trek 930 with newer parts,
i went with the same parts just new..., the only major changes i made to the drive train was, i went from a 7sp freewheel to a 8sp cassette in the back, i replaced the back/ front derailleur/bb/ and crankset with all new components, copied the same sizes for everything from the original parts

everytime i adjust my front derailleur i get chain noise/rub on the outer part of the derailleur,when its on the big cog in the front and into the new 8sp cog in the back
i can't get it perfect, its a shimano slx triple front
https://www.amazon.com/gp/product/B00...00_i00_details

any thoughts would be great, really getting frustrated..
GordoTrek is offline  
Old 03-07-12, 08:40 AM
  #2  
DCB0
Banned.
 
Join Date: Apr 2011
Posts: 937

Bikes: CCM Torino 76

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
What shifters are you using?

In my experience, to get a front derailleur perfect you often have to begin at the beginning - which means disconnecting the cable, loosening the bolt clamping the derailleur to the frame, and realigning and attaching everything. THe height and angle of the derailleur (outside of the cage 1-3mm above the big chainring, perfectly parallel with the chainring) are crucial.
Also, if you swapped cranksets, are you sure you got the correct bottom bracket length? If you changed cranksets and kept the same BB length as with the old crankset your chainline might be off.

Also, are you sure the deraileur cable is routed through the pinch bolt properly? THere is a very common mistake when routing the cable that seems to be correct but winds up causing excessive cable tension and poor shifting performance.

Go the parktool.com and follow their derailleur setup guide to the letter, without skipping any steps. If this does not work... then.. well... I don't know... maybe you should give up and ride a single-speed
DCB0 is offline  
Old 03-07-12, 08:57 AM
  #3  
MilitantPotato
Subjectively Insane
 
MilitantPotato's Avatar
 
Join Date: Jul 2008
Location: Saint Louis, Missouri
Posts: 802

Bikes: '09 Rodriguez Adventurer Custom, '08 Trek 7.3Fx

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Are you cross chaining? If not, start fresh on the front setup.
MilitantPotato is offline  
Old 03-07-12, 12:46 PM
  #4  
GordoTrek
Senior Member
Thread Starter
 
GordoTrek's Avatar
 
Join Date: Nov 2011
Location: Rochester, NY
Posts: 1,342

Bikes: 1962 Carlton Franco-Suisse Custom,1968 Raleigh DL-1/Tourist, 1971 Holdsworth Professional, 1973 Holdsworth Mistral,1973 Raleigh Gran Sport,1974 Raleigh Grand Prix, 1993 Trek 2200 Composite, 2011 Trek 7.3FX

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
i did everything that park tool suggests, still getting that noise, i did notice however that my chainline is a tad off, i did get the same bottom bracket size as the original, however the crank is new but the tooth count is the same, as the original... am i wrong ?
GordoTrek is offline  
Old 03-07-12, 12:53 PM
  #5  
himespau 
Senior Member
 
himespau's Avatar
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 11,716
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 2475 Post(s)
Liked 1,041 Times in 613 Posts
You're not using road shifters and mtb derailleurs are you? That'll throw your front shifting off as the pull ratio is different in Shimano.
himespau is offline  
Old 03-07-12, 01:03 PM
  #6  
Bill Kapaun
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 12,580

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1311 Post(s)
Liked 512 Times in 392 Posts
Did you use EXACTLY the same brand/model crank?
The BB is determined by the crank you use, not what WAS on it.
Most newer cranks use a shorter BB spindle, so if that's the case, your BB is probably too long.

Exactly what crank & BB did you use?

Last edited by Bill Kapaun; 03-07-12 at 01:20 PM.
Bill Kapaun is offline  
Old 03-07-12, 02:20 PM
  #7  
GordoTrek
Senior Member
Thread Starter
 
GordoTrek's Avatar
 
Join Date: Nov 2011
Location: Rochester, NY
Posts: 1,342

Bikes: 1962 Carlton Franco-Suisse Custom,1968 Raleigh DL-1/Tourist, 1971 Holdsworth Professional, 1973 Holdsworth Mistral,1973 Raleigh Gran Sport,1974 Raleigh Grand Prix, 1993 Trek 2200 Composite, 2011 Trek 7.3FX

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
here is the crank i got
https://www.amazon.com/gp/product/B00...01_i00_details
and here is the bb
https://www.amazon.com/gp/product/B00...00_i00_details
68 x 127

sorry read it too quick... not 175, 127

Last edited by GordoTrek; 03-07-12 at 02:43 PM.
GordoTrek is offline  
Old 03-07-12, 02:36 PM
  #8  
DCB0
Banned.
 
Join Date: Apr 2011
Posts: 937

Bikes: CCM Torino 76

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
175 is probably the length of the crank arm, not the bottom bracket. THat crank wold likely be best fitted with a 113mm bottom bracket. Your stock crank was probably fitted with a 122 or 127 bottom bracket.
DCB0 is offline  
Old 03-07-12, 02:40 PM
  #9  
cny-bikeman 
Mechanic/Tourist
 
Join Date: Apr 2007
Location: Syracuse, NY
Posts: 7,510

Bikes: 2008 Novara Randonee - love it. Previous bikes:Motobecane Mirage, 1972 Moto Grand Jubilee (my fave), Jackson Rake 16, 1983 C'dale ST500.

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 482 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by GordoTrek View Post
That does not tell us which UN 54 you got - different chainlines. Here's what I got by Googling "bottom bracket M361"

https://techdocs.shimano.com/media/te...9830667768.PDF
cny-bikeman is offline  
Old 03-07-12, 02:48 PM
  #10  
GordoTrek
Senior Member
Thread Starter
 
GordoTrek's Avatar
 
Join Date: Nov 2011
Location: Rochester, NY
Posts: 1,342

Bikes: 1962 Carlton Franco-Suisse Custom,1968 Raleigh DL-1/Tourist, 1971 Holdsworth Professional, 1973 Holdsworth Mistral,1973 Raleigh Gran Sport,1974 Raleigh Grand Prix, 1993 Trek 2200 Composite, 2011 Trek 7.3FX

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
im guessing my bb is too long, i didn't know cranks were affected by the length of the spindle , not really sure how i would of known this, its not in the item description.. i guess that's the game you play when you order online...
GordoTrek is offline  
Old 03-07-12, 02:56 PM
  #11  
himespau 
Senior Member
 
himespau's Avatar
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 11,716
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 2475 Post(s)
Liked 1,041 Times in 613 Posts
https://techdocs.shimano.com/media/te...9830667768.PDF seems to imply you want at 123 mm spindle. If you got the UN54 with the 122, that probably would work. Unless I'm reading that all wrong.
himespau is offline  
Old 03-07-12, 03:02 PM
  #12  
himespau 
Senior Member
 
himespau's Avatar
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 11,716
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 2475 Post(s)
Liked 1,041 Times in 613 Posts
Would 4 mm really make that much difference in chainline on a derailleur bike? On a non-derailleur bike, sure.

To me your original description sounds like you're just cross chaining and in that case the sound is perfectly normal. It's your bike's way of saying, "stop doing that, I don't like it." But then I don't know what I'm talking about most of the time.
Originally Posted by GordoTrek View Post
everytime i adjust my front derailleur i get chain noise/rub on the outer part of the derailleur,when its on the big cog in the front and into the new 8sp cog in the back
i can't get it perfect, its a shimano slx triple front
You don't want to ride in the big ring in front and the big cog in the back (or the small ring in front and the small cog in back. That's just bad news. Hard on your chain and gear teeth.
himespau is offline  
Old 03-07-12, 03:38 PM
  #13  
Bill Kapaun
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 12,580

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1311 Post(s)
Liked 512 Times in 392 Posts
According to the Shimano tec docs, you want a 113MM BB for THAT crank.

So much for replacing the "same" parts. They aren't!
Bill Kapaun is offline  
Old 03-07-12, 03:57 PM
  #14  
himespau 
Senior Member
 
himespau's Avatar
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 11,716
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 2475 Post(s)
Liked 1,041 Times in 613 Posts
Originally Posted by Bill Kapaun View Post
According to the Shimano tec docs, you want a 113MM BB for THAT crank.

So much for replacing the "same" parts. They aren't!
Where are you seeing 113 mm? I don't think you can just look straight down between the two tables as the columns don't line up well. The 113 mm is for the UN26E and the Crankset table says he needs the UN26K and the bottom table says the UN26K is 123 mm. At least that's how I read it.
himespau is offline  
Old 03-07-12, 05:48 PM
  #15  
whitefiretiger
I love custom cruisers
 
whitefiretiger's Avatar
 
Join Date: Dec 2011
Location: Lincoln, NE
Posts: 310

Bikes: Versato Riviera 21spd cruiser, 2005 Schwinn Typhoon cruiser 700c wheels, Ocean Pacific cruiser 6spd suicide front brake, 1993 Giant Acapulco SS conversion project

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by DCB0 View Post
THe height and angle of the derailleur (outside of the cage 1-3mm above the big chainring, perfectly parallel with the chainring) are crucial.
the 1-3mm above the big chainring are you talking with the fd in default no tention or when pulled out and over the chainring?

ive never gone about it that way. i install about where i think it should be and if it doesnt work quite right ill change the position.
whitefiretiger is offline  
Old 03-07-12, 05:59 PM
  #16  
Al1943
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by DCB0 View Post
What shifters are you using?
That's a good question.


Originally Posted by himespau View Post
You're not using road shifters and mtb derailleurs are you?
Another good question.
Al1943 is offline  
Old 03-07-12, 06:02 PM
  #17  
CACycling
Senior Member
 
CACycling's Avatar
 
Join Date: Feb 2008
Location: Oxnard, CA
Posts: 4,565

Bikes: '08 Fuji Roubaix RC; '07 Schwinn Le Tour GS; '92 Diamond Back Ascent EX

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked 5 Times in 4 Posts
Originally Posted by whitefiretiger View Post
the 1-3mm above the big chainring are you talking with the fd in default no tention or when pulled out and over the chainring?
New Shimano FDs (at least all I've seen) come with a piece of tape hanging below the face of the cage that has pictures of teeth on it. You line the picture up with the teeth on the big ring when the FD is all the way out and make sure the cage is parallel to the ring.
CACycling is offline  
Old 03-07-12, 06:07 PM
  #18  
whitefiretiger
I love custom cruisers
 
whitefiretiger's Avatar
 
Join Date: Dec 2011
Location: Lincoln, NE
Posts: 310

Bikes: Versato Riviera 21spd cruiser, 2005 Schwinn Typhoon cruiser 700c wheels, Ocean Pacific cruiser 6spd suicide front brake, 1993 Giant Acapulco SS conversion project

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by CACycling View Post
New Shimano FDs (at least all I've seen) come with a piece of tape hanging below the face of the cage that has pictures of teeth on it. You line the picture up with the teeth on the big ring when the FD is all the way out and make sure the cage is parallel to the ring.
interesting. i tend to buy take offs from lbs. i love it someone drops $3k on a ned bike and has the parts upgraded before taking it home and the oe parts are new and cheap but dont come with dirrections.
whitefiretiger is offline  
Old 03-07-12, 07:25 PM
  #19  
Bill Kapaun
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 12,580

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1311 Post(s)
Liked 512 Times in 392 Posts
Put the chain on the middle ring.
Shift to 4th.
Eyeball the chain line.
Shift to 5th.
Repeat.
Does the chain seem to angle equal amounts on either side of lining up exactly?
IF not, what cog does it seem to line up properly with.
8 speed spacing is 4.8MM between cogs. IF it lines up perfectly with 6th, your chain line is (2.4+4.8) 7.2MM too much. Lines up with 7th? Add 4.8MM more etc.
Bill Kapaun is offline  
Old 03-08-12, 08:43 AM
  #20  
DCB0
Banned.
 
Join Date: Apr 2011
Posts: 937

Bikes: CCM Torino 76

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
https://sheldonbrown.com/chainline.html

According the the Sheldon Brown article linke above, chainline on a MTB is likely supposed to be 47.5mm. If it is an older bike it may be closer to the road trip[le standard ot 45 mm. To determine whuich measurement to use, measure the distance between the locknuts on the hub - it should be 130mm or 135mm (Call this measurement the O.L.D.) , then measure the distance between the edge of the drive-side locknut and the centre of the middle cog, or (in the case of an even number of cogs) the centre of the space between the two middle cogs (call this measurement C). The formula for determining the chainline (CL) is: CL = (O.L.D./2) - C.
THen measure the distance between the middle chainring and the centre of the seat tube. If it is within a mm or two of the CL number calculated above, then chainline is not the problem. If it is not close to the CL number, then you need to purchase a bottom bracket spindle that is different in length of the current BB by twice the amount your CL is off.

For example, if your hub has an O.L.D of 130mm, and the middle of the middle cog is 20mm fromt he drive side locknut, then your chainline is (130mm/2) - 20mm = 45mm.
Then if you measure the distance between the seat tube and the middle chainring and it is 52mm, you need a bottom brackt that is different by:
(45mm-52mm) X 2 = -7mm X 2 = -14mm, or 14mm shorter. If you had a 122m bottom bracket, you would go to the size clostest to 122-14, or 108mm.

As for the 1-3mm above the big ring standard, I usually set the derailleur so it is perfectly parallel with the chainrings when viewed from the top, then pull the derailleur out by hand so the outer edge of the cage is direclty over the big ring, then measure the gap. In my experience you don't need to use a ruler calipers for this - just set it 'real close.' Having the cable attached during this operation just complicates things, IMHO.
DCB0 is offline  
Old 03-08-12, 02:17 PM
  #21  
GordoTrek
Senior Member
Thread Starter
 
GordoTrek's Avatar
 
Join Date: Nov 2011
Location: Rochester, NY
Posts: 1,342

Bikes: 1962 Carlton Franco-Suisse Custom,1968 Raleigh DL-1/Tourist, 1971 Holdsworth Professional, 1973 Holdsworth Mistral,1973 Raleigh Gran Sport,1974 Raleigh Grand Prix, 1993 Trek 2200 Composite, 2011 Trek 7.3FX

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
wow, a lot of great responses, thanks for all the help, after re adjusting everything from the start i was able to get it without any noise, i have a 127mm bb, and i guess according to the docs i needed a 123, however its not affecting my derailleur at this point...
i hope im not hurting it, but i don't see how
GordoTrek is offline  
Old 03-08-12, 02:38 PM
  #22  
DCB0
Banned.
 
Join Date: Apr 2011
Posts: 937

Bikes: CCM Torino 76

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by GordoTrek View Post
wow, a lot of great responses, thanks for all the help, after re adjusting everything from the start i was able to get it without any noise, i have a 127mm bb, and i guess according to the docs i needed a 123, however its not affecting my derailleur at this point...
i hope im not hurting it, but i don't see how
If the BB spindle is 4mm too long, that probably means your chainline is off by 2mm... not a big deal. THe only consequence of this is that the chain will be at a slightly tighter angle between the crank and the cassette when in certain gears, which will increase the rate of chain wear when in those gears.. Avoid cross chaining (no big chainring-biggest 2 or 3 cogs or or small chainring-smallest cog combos) and you should be fine.
DCB0 is offline  
Old 03-08-12, 02:47 PM
  #23  
whitefiretiger
I love custom cruisers
 
whitefiretiger's Avatar
 
Join Date: Dec 2011
Location: Lincoln, NE
Posts: 310

Bikes: Versato Riviera 21spd cruiser, 2005 Schwinn Typhoon cruiser 700c wheels, Ocean Pacific cruiser 6spd suicide front brake, 1993 Giant Acapulco SS conversion project

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I just remembered that when I was younger I had a 1-piece crank 15spd bike that the cd never seemed right on and I pulled the crank out and there was a stack of washers between the chainring and cone about 1/2" thick. I pulled one washer out and put it back together and prob solved. Crazy things happen. The craziness part was it had never been serviced and was that way new.
whitefiretiger is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Troul
Bicycle Mechanics
16
08-16-16 05:46 PM
mzr
Bicycle Mechanics
7
09-24-15 10:46 AM
avidone1
Bicycle Mechanics
12
02-28-15 09:48 PM
fuji8
Bicycle Mechanics
9
06-06-13 12:39 AM
TheManSuit
Bicycle Mechanics
4
06-04-13 08:36 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.