Need a new Derailleur, which one please?

Page may contain affiliate links. Please see terms for details.
OP
OP
M

MBosh

Well-Known Member
@Ajax Bay - Does the out cable have to be cut to a specific length or just so it make a nice curve to the derailleur? I'll order that tool you suggested if this is the case and cut it myself. Thank you!
 

raleighnut

Legendary Member
@Ajax Bay - Does the out cable have to be cut to a specific length or just so it make a nice curve to the derailleur? I'll order that tool you suggested if this is the case and cut it myself. Thank you!
A nice curve is best, there is no 'fixed' length for that bit of outer.
 

Ajax Bay

Guru
Location
East Devon
just so it make a nice curve to the derailleur
"A nice curve is best". This.
Since you seem to appreciate quantative answers to questions (not unreasonably), I've done a quick check of a few of my bikes and the average radius of curvature of the cables to the RDs is 6cm.
This is what 'Sheldon' says: "The most common area for [excessive friction in the cables] is the short loop of cable housing that leads from the rear stay to the derailer. The front end of this housing is exposed to road spray from the front tire, and the resulting rust can seriously degrade shifting. This cable loop should be fairly long, so that it makes a very gradual curve. Many bikes have too short a housing loop here."
Regarding cutting the outer cable he then says this:
"the "compressionless"cable housing for indexed shift applications uses multiple straight wires sandwiched between plastic, and requires a fairly special tool to cut properly. When you buy such housing, you would do well to have exact length information so that the shop that sells it to you can cut it for you, if you don't have a suitable cable cutter. When you cut housing, the plastic liner gets squished a bit. It is helpful to clean and round out the opening with an awl or scriber. The final loop at the rear derailer is short and has a nearly 180 degree bend. I've taken to bending the piece of housing to the approximate shape it will be used in before cutting it.
"If you cut the housing straight, all of the longitudinal wires come out the same length, so when you bend it, the end of the housing acquires a slanted face, since the wires on the inside of the bend have a longer way to go around the curve. It is my belief that cutting the housing while it is bent makes a smoother, more reliable connection at the end of the housing. You must have a ferrule at each end of each piece of housing. This helps keep the hole in the housing aligned with the cable stop."
 
Top Bottom