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Old 12-03-2012, 11:46 AM   #1
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Shifting issues

My bike is fairly new and it is probably due for a break in tuneup, but the LBS is pretty far and I think I should learn how to do most of this myself. I am fairly good at mechanics so I am not afraid to tackle this.

Cassette 12-25t
105 shifters (hidden wire model)

There is a delay when shifting into the 13 or 12 tooth gears. This happens either way I shift, up or down, the rest of the gears are fine.

This could be as simple as a clean and and oil but I suspect it may need a turn of the barrel adjusters? I would monkey around with it and figure it out myself but it's probably good to post up these problems for others to learn from.

Thanks!


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Old 12-03-2012, 12:25 PM   #2
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Which chainring are you on when it does this?


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Old 12-03-2012, 12:28 PM   #3
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I'm a stud, the big un'!

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Old 12-03-2012, 12:33 PM   #4
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Your rear derailleur should want to drop the chain to the small cogs automatically. Tightening the cable won't improve that. Loosening it might.Has someone been messing with the cables?
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Old 12-03-2012, 12:35 PM   #5
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No, it's been shifting great until recently. (Unless my two year old decided to play with the barrel adjusters?)

I haven't cleaned and lubed it since I bought it about 500 miles ago.
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Old 12-04-2012, 01:19 AM   #6
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Exclamation

Quote:
Originally Posted by synack View Post
My bike is fairly new and it is probably due for a break in tuneup, but the LBS is pretty far and I think I should learn how to do most of this myself. I am fairly good at mechanics so I am not afraid to tackle this.

Cassette 12-25t
105 shifters (hidden wire model)

There is a delay when shifting into the 13 or 12 tooth gears. This happens either way I shift, up or down, the rest of the gears are fine.

This could be as simple as a clean and and oil but I suspect it may need a turn of the barrel adjusters? I would monkey around with it and figure it out myself but it's probably good to post up these problems for others to learn from.

Thanks!
Interesting. The delay going into the 12 is possibly an outermost cog limit screw issue, especially when you say the delay is in both directions. If the delay were in only one direction, from the next biggest cog to the 13 and from the 13 to the 12, I'd say that was a barrel adjustment issue and would tweak it a quarter
turn clockwise to see if it makes the shift without delay. But if it's hesitating from the 12 to the 13 and from the 13 to the next largest cog, well, you can't turn the barrel adjuster a quarter turn in both directions, now can you? And what are the odds of it being 2 problems, limit screw and index adjustment, at the same time? Occam's Razor counsels against that. Hesitation from the 12 to the 13 and from the 13 to the next largest cog calls for a counterclockwise quarter turn to see if it makes it.
I'd eyeball the cage below the 12 to see if it looks like the limit screw is okay (that part of the chain closest to the 13 isn't touching the 13). Then I'd tweak the barrel a little going from low to high and high to low and see what happens.
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Old 12-04-2012, 03:04 AM   #7
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Interesting. The delay going into the 12 is possibly an outermost cog limit screw issue, especially when you say the delay is in both directions. If the delay were in only one direction, from the next biggest cog to the 13 and from the 13 to the 12, I'd say that was a barrel adjustment issue and would tweak it a quarter
turn clockwise to see if it makes the shift without delay. But if it's hesitating from the 12 to the 13 and from the 13 to the next largest cog, well, you can't turn the barrel adjuster a quarter turn in both directions, now can you? And what are the odds of it being 2 problems, limit screw and index adjustment, at the same time? Occam's Razor counsels against that. Hesitation from the 12 to the 13 and from the 13 to the next largest cog calls for a counterclockwise quarter turn to see if it makes it.
I'd eyeball the cage below the 12 to see if it looks like the limit screw is okay (that part of the chain closest to the 13 isn't touching the 13). Then I'd tweak the barrel a little going from low to high and high to low and see what happens.
You guys that can figure out this mechanical stuff amaze me - you lost me at limit screw and index adjustment - Occam's Razor I get but that is about it - Merlin you rock !
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Old 12-04-2012, 11:39 AM   #8
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It ain't me, just a well worn, grease stained copy of this guy: http://www.amazon.com/Barnetts-Manual-Analysis-Procedures-Mechanics/dp/1931382298
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Old 12-04-2012, 12:36 PM   #9
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Thank you for all of the advice on getting this resolved. I will check the bike over again this evening. The one thing I remember doing is taking the rear wheel off, maybe I did not put it back on centered or possibly didn't put enough tension on the quick release?

I just think it's odd that the shifting has been perfect for so long and now is acting up.
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Old 12-12-2012, 06:43 PM   #10
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any resolution?


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