How can front derailleur effect rear gearchanges?

Ask for advice or share your fettling tips
User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

How can front derailleur effect rear gearchanges?

Postby Bustacapp » Fri Feb 22, 2013 21:39 pm

To cut a long story short I've removed my front mech cable and was wondering why I can't shift through all my rear gears any more? I was planning to use just rear gears on a ride tomorrow but not likely now. The high/low settings on the front mech seems to make a difference but I've got no idea why?

User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

Re: How can front derailleur effect rear gearchanges?

Postby Bustacapp » Fri Feb 22, 2013 21:52 pm

I may have been talking crap. I think the rear mech might be affected by attempting to change gear on a stationary bike.

User avatar
rozzer32
Posts: 3061
Joined: Sat Dec 12, 2009 19:38 pm

Re: How can front derailleur effect rear gearchanges?

Postby rozzer32 » Sat Feb 23, 2013 00:21 am

I blame ribble.
**** Pro Tour Pundit Champion 2011 *****

User avatar
smidsy
Posts: 5256
Joined: Tue Jan 17, 2012 20:52 pm

Re: How can front derailleur effect rear gearchanges?

Postby smidsy » Sat Feb 23, 2013 08:12 am

Bustacapp wrote:I may have been talking crap.


No, surely not. :lol:
Yellow is the new Black.

User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

Re: How can front derailleur effect rear gearchanges?

Postby Bustacapp » Sat Feb 23, 2013 09:28 am

Actually it has affected the rear shifter. It has become very stiff. Thanks for the responses, I'm off to Halfords for a new cable in a mo so I'll ask someone who actually knows something.

User avatar
smidsy
Posts: 5256
Joined: Tue Jan 17, 2012 20:52 pm

Re: How can front derailleur effect rear gearchanges?

Postby smidsy » Sat Feb 23, 2013 10:46 am

Bustacapp wrote:I'm off to Halfords for a new cable in a mo so I'll ask someone who actually knows something.


Would that be on the way to or from Halfords :?: :mrgreen:
Yellow is the new Black.

User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

Re: How can front derailleur effect rear gearchanges?

Postby Bustacapp » Sat Feb 23, 2013 10:51 am

All is well. A new cable was all that was needed. Thanks for the tips.

User avatar
smidsy
Posts: 5256
Joined: Tue Jan 17, 2012 20:52 pm

Re: How can front derailleur effect rear gearchanges?

Postby smidsy » Sat Feb 23, 2013 10:56 am

Just to calrify, the fact that you did something with the front mech will not have been the reason.

If a new cable was needed for the rear mech to function properly it would have been needed even if you had not touched the front mech.

The front and back mechs work independantly of one another so touching one does not affect how the other works.

Of course someone who actually knows stuff will be along soon.
Yellow is the new Black.

User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

Re: How can front derailleur effect rear gearchanges?

Postby Bustacapp » Sat Feb 23, 2013 11:35 am

smidsy wrote:Just to calrify, the fact that you did something with the front mech will not have been the reason.

If a new cable was needed for the rear mech to function properly it would have been needed even if you had not touched the front mech.

The front and back mechs work independantly of one another so touching one does not affect how the other works.

Of course someone who actually knows stuff will be along soon.


The front mech cable was removed and the low screw was adjusted in such a way that it affected the position of the chain. Or something.

User avatar
nicklouse
Lives Here
Posts: 80713
Joined: Thu Mar 20, 2003 12:14 pm

Re: How can front derailleur effect rear gearchanges?

Postby nicklouse » Sat Feb 23, 2013 11:49 am

Bustacapp wrote:
smidsy wrote:Just to calrify, the fact that you did something with the front mech will not have been the reason.

If a new cable was needed for the rear mech to function properly it would have been needed even if you had not touched the front mech.

The front and back mechs work independantly of one another so touching one does not affect how the other works.

Of course someone who actually knows stuff will be along soon.


The front mech cable was removed and the low screw was adjusted in such a way that it affected the position of the chain. Or something.
?
of cause if you adjust the rear mech low screw it will effect the rear mech. nothing you do to the front mech will change anything on the rear.
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown

User avatar
smidsy
Posts: 5256
Joined: Tue Jan 17, 2012 20:52 pm

Re: How can front derailleur effect rear gearchanges?

Postby smidsy » Sat Feb 23, 2013 11:53 am

Bustacapp wrote:The front mech cable was removed and the low screw was adjusted in such a way that it affected the position of the chain. Or something.


That makes complete sense. If the front mech was pushing on the chain it would affect the chain line. This then means the chain does not move as freely as it should.

This does not affect the operation of the rear mech though (just the chain running) and certainly would not have been cured by a new cable.

But the bloke who actually knows something and took your money would know that :roll:
Yellow is the new Black.

User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

Re: How can front derailleur effect rear gearchanges?

Postby Bustacapp » Sat Feb 23, 2013 12:14 pm

smidsy wrote:That makes complete sense. If the front mech was pushing on the chain it would affect the chain line. This then means the chain does not move as freely as it should.

This does not affect the operation of the rear mech though (just the chain running) and certainly would not have been cured by a new cable.

But the bloke who actually knows something and took your money would know that :roll:


I didn't take any advice in the end. I merely bought a cable, fitted it and the both the front and rear gear changes started working properly. I didn't touch the high screw. Perhaps the tension of the cable pulled the front derailleur into the correct position and thus aligning the chain. Who knows (or cares).

User avatar
Bustacapp
Posts: 910
Joined: Thu Aug 16, 2012 13:37 pm

Re: How can front derailleur effect rear gearchanges?

Postby Bustacapp » Sat Feb 23, 2013 12:15 pm

nicklouse wrote:of cause if you adjust the rear mech low screw it will effect the rear mech. nothing you do to the front mech will change anything on the rear.


I didn't touch the rear mech at any point.


Return to “Workshop”

Who is online

Users browsing this forum: g00se and 1 guest