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Old 07-22-09, 08:59 PM   #1
akansaskid
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Shimano Says to Replace Plastic Ferrule with Metal on 105 Shifter Cable (??)

Right (rear) shifter cable broke right at the end of the cable housing ferrule leading into the shifter on my 105 STI shifter for the second time on my 6-month old bike. The first broke at 4300 miles, then again at 8300 miles today. (Leaving my 60-year-old knees with a 17-mile end-of-century ride over rolling terrain on the 11-tooth rear cog – ugh!)

LBS said when it broke the first time in April that it was a rare event. But during June’s Bike Across Kansas, they replaced at least 4 of these, all on 105s on bikes less than a year old. Shimano has told them that the problem lies with the plastic ferrule (the one that mates the shifter cable with the shifter itself) and it should be replaced with a metal one.

Wondering if anyone else has heard anything like this. Also wondering if it will really fix anything. The plastic ferrule (after 8300 miles) had a substantially elongated “hole” where the actual cable exits. If there’s that much off-axis movement, it seems a metal ferrule would abrade the cable quite a bit. But, too, perhaps that elongation allows the cable to move laterally inside the shifter, against parts or edges that abrade it. Dunno.
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Old 07-22-09, 09:05 PM   #2
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No experience with broken brifter cables myself but a suggestion if it ever happens to you again; screw in the rear derailleur's high limit screw to keep the derailleur under a bigger cog. You will still have a single speed but a more comfortable one.
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Old 07-22-09, 09:57 PM   #3
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No experience with broken brifter cables myself but a suggestion if it ever happens to you again; screw in the rear derailleur's high limit screw to keep the derailleur under a bigger cog. You will still have a single speed but a more comfortable one.
This is a bad idea because a mis-shift will destroy the delicate internals of your STI.

And yes... replace the plastic ferrule with a metal one. I use metal ferrules on all of my shifter cables now We don't even keep plastic ones in the shop anymore. It's better for all shift cable housing, not just STIs.
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Old 07-22-09, 10:33 PM   #4
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Ditto - I have a big bottle full of metal ferrules. Plastic is fine where there is no tension involved - mostly decorative & optional locations. Metal for everything else.
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Old 07-22-09, 11:29 PM   #5
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This is a bad idea because a mis-shift will destroy the delicate internals of your STI.
.
Excuse me? Please expound
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Old 07-23-09, 06:58 AM   #6
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This is a bad idea because a mis-shift will destroy the delicate internals of your STI.
Huh?

First, how can you "mis-shift" if the cable is broken?

Second, I only recommended it as a limp-home emergency measure. I assume after the OP gets to a suitable destination he will replace the cable and reset the limit screw. It's better than having to climb hills in an 11T cog.

Third, using the limit screws to control shifting is done all the time. I have a 9-speed Shimano cassette on a bike with 10-speed Campy Ergos. The 10th position is locked out with the low limit screw and the bike has run properly for 11,000 miles so far.
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Old 07-23-09, 07:33 AM   #7
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If you use metal ferrules, use either stainless or aluminum. Also use stainless cables. Otherwise, you can end up with rust seize where the cable enters the ferrule (and yes, I learned this the hard way).

+1 on using the limit screw next time, getting from 11 to 12 or 13 teeth helps a whole bunch when your shifter's broken. As HillRider mentioned, what you do to the limit stop has no bearing on the shifter; I'm hoping the previous responder misunderstood the question.
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Old 07-23-09, 09:13 AM   #8
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All Specialized road bikes come with plastic ferrules on the shift cables. I rode my Felt (105/Ultegra) for two years with plastic ferrules. My new used Giant (7800) has plastic ferrules. No problems yet, but I will probably use brass or aluminum ferrules next time I replace housings on my own bike.
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Old 07-23-09, 12:40 PM   #9
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I have seen a number of breaks with these plastic ferrules, both on road bikes (my own Trek 2120) and on the department patrol bikes.
I always replace them with metal.
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Old 07-27-09, 08:50 PM   #10
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Huh?

First, how can you "mis-shift" if the cable is broken?

Second, I only recommended it as a limp-home emergency measure. I assume after the OP gets to a suitable destination he will replace the cable and reset the limit screw. It's better than having to climb hills in an 11T cog.

Third, using the limit screws to control shifting is done all the time. I have a 9-speed Shimano cassette on a bike with 10-speed Campy Ergos. The 10th position is locked out with the low limit screw and the bike has run properly for 11,000 miles so far.
Ahh! I misunderstood. Yes, if you're just doing the limit-screw method to hold your chain on one chainring then that's fine. But, if you dial in your limit screws to keep yourself from overshifting too much you can strip the internals on an STI, I have seen this many times.
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