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

Front Derailleur Too Big?

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 Too Big?

Old 08-21-13, 05:46 PM
  #1  
minorhero
Member
Thread Starter
 
Join Date: Jul 2013
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Front Derailleur Too Big?

Hello all,

I recently purchased a Shimano XT Front Derailleur FD-M761A Bottom Swing for my 2012 Felt Verza City 2. I installed it and have put about 6 hours of adjustment into it and can not get it right. Every video I watch or document I read says that the lower edge of the Front Derailleur should be between 2 to 5 mm (depending on who is speaking) above the largest chainring. I physically can not do that with my new Derailleur. Instead I am about 10 to 15 mm above the largest chainring. This is because the lower edge of the Derailleur cage is exceptionally close to the top of the middle chainring. If I lower the Derailleur anymore the lower edge of the Derailleur cage will physically touch the middle chainring.

I am subsequently having a lot of trouble with the Derailleur shifting gears, especially when under strain. When going up a hill it is very reluctant to switch from the middle chainring to the smaller, and once it even fell off all together despite having the lower screw adjusted.

So have I simply purchased the wrong Derailleur? Or is there something blindingly obvious that I am missing.

Thank you for any help.
minorhero is offline  
Old 08-21-13, 06:38 PM
  #2  
redlude97
Senior Member
 
Join Date: Sep 2011
Posts: 4,296
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1726 Post(s)
Liked 46 Times in 35 Posts
The problem is the FD you bought is for a 44T chainring when your crankset is a 48T. You want the M760A I believe
redlude97 is online now  
Old 08-21-13, 07:16 PM
  #3  
Burton
Certified Bike Brat
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by redlude97 View Post
The problem is the FD you bought is for a 44T chainring when your crankset is a 48T. You want the M760A I believe
There's probably something else going on. The FD-M761A is speced against a Deore XT (FC-M761) which is a 48/36/26T crankset.

Photos would probably help.
Burton is offline  
Old 08-21-13, 07:35 PM
  #4  
minorhero
Member
Thread Starter
 
Join Date: Jul 2013
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Burton View Post

Photos would probably help.
Got you covered on that one at least:



Attached Images
File Type: jpg
9bp5.jpg (98.3 KB, 32 views)
File Type: jpg
DSC_0013.jpg (49.7 KB, 28 views)
minorhero is offline  
Old 08-21-13, 08:44 PM
  #5  
no1mad 
Thunder Whisperer
 
no1mad's Avatar
 
Join Date: Apr 2008
Location: NE OK
Posts: 8,852

Bikes: '06 Kona Smoke

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 270 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Moved from General Cycling.
__________________
Community guidelines
no1mad is offline  
Old 08-21-13, 10:07 PM
  #6  
bobotech
Senior Member
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,253

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Burton View Post
There's probably something else going on. The FD-M761A is speced against a Deore XT (FC-M761) which is a 48/36/26T crankset.

Photos would probably help.
His bike has a 48/38/28 and I know exactly the type of problem. I recently tried using a Ultegra front triple derailleur on my 52/42/30 crankset and had the same problem as the OP. It turns out my Ultegra front derailleur was specced for the 52/39/30 crankset and those extra 3 teeth made a HUGE different in how high I had to raise the derailleur to clear the 42T chainring. It was almost unusable. Got the proper Ultegra derailleur and it works fine now.

The inner portion of the first Ultegra derailleur cage is QUITE a big larger than the inner portion of the front derailleur that I did end up using. I had to raise the front derailleur 10mm or more above the large ring for the inner cage to clear the middle chainring due to the incorrect derailleur.
bobotech is offline  
Old 08-22-13, 08:44 PM
  #7  
Burton
Certified Bike Brat
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by bobotech View Post
His bike has a 48/38/28 and I know exactly the type of problem. I recently tried using a Ultegra front triple derailleur on my 52/42/30 crankset and had the same problem as the OP. It turns out my Ultegra front derailleur was specced for the 52/39/30 crankset and those extra 3 teeth made a HUGE different in how high I had to raise the derailleur to clear the 42T chainring. It was almost unusable. Got the proper Ultegra derailleur and it works fine now.

The inner portion of the first Ultegra derailleur cage is QUITE a big larger than the inner portion of the front derailleur that I did end up using. I had to raise the front derailleur 10mm or more above the large ring for the inner cage to clear the middle chainring due to the incorrect derailleur.
I agree with your post - just not aware of any XT FD thats a good match for his apparent chainring combo. If XT is the direction the OP wants to take - it could well mean changing a couple chainrings or a complete crankset.
Burton is offline  
Old 08-23-13, 12:45 PM
  #8  
minorhero
Member
Thread Starter
 
Join Date: Jul 2013
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Looks like I need a different front derailleur. Any suggestions if I can't go the xt route?
minorhero is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ES_IMBA_KIM
Northeast Rides and Events
0
03-19-18 02:31 PM
bikebreak
General Cycling Discussion
1
05-19-13 04:01 PM
blilrat
Classic & Vintage
0
01-11-12 01:48 PM

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

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.