Rear derailleur cabling...

Discuss light weight issues concerning road bikes & parts.
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Joined: Wed Jul 19, 2017 2:59 am

by Boshk

For mechanical rear derailleur, does it matter which way the cables are routed to the rear derailleur?

1) Typical route=exit BB, along the exterior bottom of the chainstay

2) cabling being route the same path as di2....through the inside of the chainstay....

by Weenie

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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Fewer contact points and fewer tight bends should be better.

Means route it on the outside of the bars, past the head tube and into the left side cable mount, crossed in/under down tube and then with an adequately large bend before entering the derailleur. For the last piece of housing by the derailleur there is a special kind that bends better called shimano RS900. Some bb cable guides on internal routed frames work better with a piece of greased liner. Keeps things working smoothly even when that area is dirty.

Don't really know if it does help but for anyone that has shifting issues I'd recommend the above suggestion. Take care measuring housing at the bars. Too much and it looks like a mess, too short and you will have trouble turning sharply.

In or outside the chainstay doesn't matter unless it's rubbing somewhere. Some people like the ease of cleanliness/moisture protection of external routing there better and some like the look of internal better.

Last edited by alcatraz on Tue Aug 28, 2018 7:23 am, edited 1 time in total.

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by mattr

As long as the frame is designed to take that route (has all the stops and holes) and it doesn't add significant drag/saw through a bit of the frame. It makes little/no difference.

Careful adding grease to liners, the grease can pick up and hold dirt that ends up inside the frame, Then it stops working. :oops:

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