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General Category >> Technical >> Musashi rear derailleur cable keeps busting
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Message started by dhansen on May 19^th, 2013, 8:29am

Title: Musashi rear derailleur cable keeps busting
Post by dhansen on May 19^th, 2013, 8:29am

http://sphotos-a.xx.fbcdn.net/hphotos-ash3/919561_10201124708823010_206124675_o.jpg

My shifter cable keeps breaking all the strands right were the cable first contacts the rear derailleur - any ideas on how to stop this from happening?

This is the second time in 3 months I'll be replacing the cable.

Thanks.

Title: Re: Musashi rear derailleur cable keeps busting
Post by Monkeywrangler22 on May 19^th, 2013, 8:55am

I'd guess you have a burr somewhere in that section of cable path. The burr would wear at the cable strands and sever them over time. Can you dismount the der, and clean it really well and then maybe use a q-tip to investigate the cable path for something that snags the q-tip? That would be the burr if you find one. Then you just have to sort out how to remove the burr.

Title: Re: Musashi rear derailleur cable keeps busting
Post by jayg on May 19^th, 2013, 11:20am

The edge of the plastic cable ramp on SRAM X-Series derailleurs puts a sharp bend in the cable when the chain is on the smaller cogs. The cable strands eventually fatigue and the cable starts fraying. Just checked the cable on my Carbent equipped with an X0 derailleur and found it to be frayed in the same location as the frayed portion of your cable. Not that many miles on my bike since the last cable change. If your Musashi was equipped with the SRAM Rival derailleur originally installed on factory assembled bikes, you wouldn't be having any cable problems. Its design is totally different than that of the X-Series. I've never experienced a cable failure on my Musashi equipped with a Rival derailleur.

Title: Re: Musashi rear derailleur cable keeps busting
Post by rmillay on May 19^th, 2013, 12:12pm

The Shimano rear ders put the cable loop in the rear cable housing, where it is protected. The SRAM Rival is a Shimano-style derailleur. SRAM's smarter looking rear ders leave that loop unprotected. I notice a lot of gritty-looking dirt on the chain and derailleur. That can't be helping things. If you ride much in sandy or gravelly roads, you might need to clean those parts more frequently.

Title: Re: Musashi rear derailleur cable keeps busting
Post by FlyingLaZBoy on May 20^th, 2013, 7:26am

Good photo, Dan -- I'm with Jay, I would chalk it up to the sharp bend, especially since that is where it looks like the strands are breaking... Guess I need to check my Xstream X9 -- although I've never had a DR cable break!

Title: Re: Musashi rear derailleur cable keeps busting
Post by dhansen on May 21^st, 2013, 3:36am

Mike at Easy Street filed the edge rounder and smooth, installed a new cable and greased the channel. It seems to shift smoother now but not as crisp. We'll see how long this lasts.

Thanks for all the help.

Title: Re: Musashi rear derailleur cable keeps busting
Post by FlyingLaZBoy on May 24^th, 2013, 7:57am

Looked at my brake cable there on the Xstream, and there's no fraying going on whatsoever at the moment...

PB