How to pick a front derailleur
#1
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 230
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From: Texas
Bikes: '88 Peugot 12 spd road bike, Nishiki hybrid, JC Penney 10 spd
How to pick a front derailleur
Bought a GT outpost on CL and am having a problem with the front derailleur in that it will not drive all the way to the small sprocket. There was no brand on it and it was in bad condition. I bought a similar replacement (Shimano NEXAVE) at the co-op but having the same problem. Not attaching the gear cable, just trying to adjust by using the limit screw. The derailleur is bottom pull and 31.8 diameter.
The bike has an Acera rear derailleur, can I just buy an Acera front derailleur and expect it to fit?
Thank you.
The bike has an Acera rear derailleur, can I just buy an Acera front derailleur and expect it to fit?
Thank you.
#2
Junior Member
Joined: Nov 2017
Posts: 93
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From: A Dutchman in Budapest, Hungary.
Bikes: Koga Miyata GranTourer 1985, Koga Miyata Adventure 1992, Cinelli Sentiero, Giant Terrago 1993, Presto Amsterdam 1975(?), Dahon Classic III Stainless
The L limit screw is all the way out and it still won't shift to the smallest chainring? There's a chain on the bicycle, you're turning the cranks, and it won't go from the middle to the smallest chainring?
First thing to check is the position of the derailleur - is it on straight (parallel with chain), is it on low enough (as close to chainrings as possible).
First thing to check is the position of the derailleur - is it on straight (parallel with chain), is it on low enough (as close to chainrings as possible).
#3
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 230
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From: Texas
Bikes: '88 Peugot 12 spd road bike, Nishiki hybrid, JC Penney 10 spd
Yes that is correct, limit screw all the way out, will not jump to the small chain ring when pedaling, derailleur aligned straight, and height is about right. I've adjusted front derailleurs before but have never run across this problem, usually with no cable attached I can use the limit screw to adjust them properly. I'm assuming I have the wrong type of derailleur.
#4
Really Old Senior Member


Joined: Feb 2007
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From: Mid Willamette Valley, Orygun
Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3
Sounds like the BB spindle is too long.
Have you changed the cranks or BB?
Have you changed the cranks or BB?
#5
Francophile

Joined: Nov 2015
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From: Seattle
Bikes: Lots
Here’s my thought. Is the “tail” of the front derailleur hitting the chain stay? Some derailleurs are rather long and if they are mounted to low on the seat tube, they will hit the stay.
#6
Really Old Senior Member


Joined: Feb 2007
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From: Mid Willamette Valley, Orygun
Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3
Change that to TOO SHORT!
#8
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From: NW,Oregon Coast
Bikes: 8
Not Shimano specific..
triples add a deeper pusher plate to deal with greater differences in chainring diameters, the mid to larger difference has to be 10t..
I have the same FD on 2 bikes , older over the BB shift cable routing requires a 52-42.. 26 , or the cable interferes with the bottom of the FD,
Under the BB riute I have a 50-40 ..24...
....
triples add a deeper pusher plate to deal with greater differences in chainring diameters, the mid to larger difference has to be 10t..
I have the same FD on 2 bikes , older over the BB shift cable routing requires a 52-42.. 26 , or the cable interferes with the bottom of the FD,
Under the BB riute I have a 50-40 ..24...
....
Last edited by fietsbob; 02-11-18 at 10:38 AM.





