Front Derailleur Madness - Need Help!

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2011-05-19 7:31 AM

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Subject: Front Derailleur Madness - Need Help!

I have a frame with a 78 degree seat tube, braze-on SRAM Force front derailleur, and internal cable routing through the BB30 bottom bracket area of the frame. The problem is the cable rubs on the area of the rear cage pivot of the front derailleur. The contact won't let the derailler shift properly. It seems like the exit point for the cable is not in the right place - although I do not (yet) want to drill a hole in my frame.  If only I could get the FD to move forward, then I would have clearance for the cable exiting the frame to the cable stop on the FD.

I've tried running the cable through a small piece of tubing where it contacts the derailleur, but the cable tension still prevents proper shifting functions with RTC shifters. I have also already tried spacers between the hanger and derailleur, and boring out the mounting bracket (in efforts to move the mount and FD forward so the cable would not contact the pivot point of the FD).

Any recommendations on how to remedy this? TIA!

2011-05-19 8:33 AM
in reply to: #3507553

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Elite
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Subject: RE: Front Derailleur Madness - Need Help!
bdesotell - 2011-05-19 7:31 AM

I have a frame with a 78 degree seat tube, braze-on SRAM Force front derailleur, and internal cable routing through the BB30 bottom bracket area of the frame. The problem is the cable rubs on the area of the rear cage pivot of the front derailleur. The contact won't let the derailler shift properly. It seems like the exit point for the cable is not in the right place - although I do not (yet) want to drill a hole in my frame.  If only I could get the FD to move forward, then I would have clearance for the cable exiting the frame to the cable stop on the FD.

I've tried running the cable through a small piece of tubing where it contacts the derailleur, but the cable tension still prevents proper shifting functions with RTC shifters. I have also already tried spacers between the hanger and derailleur, and boring out the mounting bracket (in efforts to move the mount and FD forward so the cable would not contact the pivot point of the FD).

Any recommendations on how to remedy this? TIA!



I'd go to a bike shop that sells your bike. Talk to them and check out a bike similar on their flor. They may have a trick that makes it work.
2011-05-19 9:10 AM
in reply to: #3507553

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Subject: RE: Front Derailleur Madness - Need Help!

Sell the bike.

2011-05-19 10:04 AM
in reply to: #3507553

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Subject: RE: Front Derailleur Madness - Need Help!
Post a picture.
2011-05-19 10:21 AM
in reply to: #3507553

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Master
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Subject: RE: Front Derailleur Madness - Need Help!
It doesn't sound like this is set up as designed.  I'd take it to a mechanic that knows the bike brand and have them take a look at it.
2011-05-19 10:23 AM
in reply to: #3508022

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Elite
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Romeoville, Il
Subject: RE: Front Derailleur Madness - Need Help!
tjh - 2011-05-19 10:21 AM

It doesn't sound like this is set up as designed.  I'd take it to a mechanic that knows the bike brand and have them take a look at it.


it actually sounds to me like it may be the wrong deraileur. They have top and bottom pull. What the OP is using may be wrong. Hard to tell over the internet without pics.

2011-05-19 10:47 AM
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Subject: RE: Front Derailleur Madness - Need Help!

It is a bottom pull FD...working on getting pics.  Thanks!

2011-05-19 11:45 AM
in reply to: #3507553

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Master
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Subject: RE: Front Derailleur Madness - Need Help!

x2 to pics.

It's not out of the question that you have a bad frame.  There could be a manufacturing mistake in either the placement of the braze on or the location of the cable exit hole.

.....or the frame wasn't designed with the SRAM equipment in mind and switching to a shimano derailleur could be your solution. (yes, front derailleurs are compatible)

 

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