Paradoxical

Hello,

I have a 2010 Cannondale F9 that I've been using for riding around St. Louis. I have put somewhere around 2,000 miles on it, since the beginning part of December. The bike has on it an Acera rear derailleur.

As the miles have accumulated, I occasionally found that upshifts took an annoyingly long time. As a remedy, I would turn clockwise the adjusting barrel, located on the derailleur. However, the adjusting barrel can no longer be turned. A safe assumption probably is that it has run out of thread. I am curious about what must be done, in order to reset the barrel to the tightest position and further allow adjustment to be made.

What I've done:
I took the bike to a close shop. The good tech wasn't there. The less competent guy seemed confused about why I would turn the adjusting barrel clockwise. Now, I'm a computer geek, but thinking about this myself, it does seem to me counter-intuitive to loosen the cable over time, by turning the adjusting barrel clockwise. However, turning it clockwise remedies upshifts, which take longer as miles accumulate. Now, back to what I was saying. The less competent guy tooled around with the RD, and by the time he was finished, it wouldn't always shift from 5 to 6. Afterward, I turned the adjusting barrel clockwise, which fixed that issue. But, the adjusting barrel STILL will not further turn clockwise. I am, essentially, where I was before he touched it. I probably will take the bike back to have the better guy look at it. But, I am damn frustrated at this point.

I just want it to work, and I only today rode 10 miles of the planned 30+ miles, because the guy did essentially nothing.

Incidental information:
The chain has recently been replaced, as it was found to be the cause of rubbing on the FD inner plate. Also, the cassette has been replaced, because the chain was randomly skipping teeth on the smallest cog. The chain was replaced by the better tech and seems to operate just like the old one. I myself replaced the cassette, using a spare, which was installed on another rim that I use for my trainer. While an experienced person might find relevant these facts, I am led to believe that the RD simply needs to be adjusted, and the adjusting barrel simply can no longer be used as it is.

Thank you, very much, for your input.

Happy riding!

Andrew R Stewart 

You need to base line your gear system. With so many parts randomly replaced it's no wonder that you have problems. The hanger could even be bent and no one might have checked for that.

First thing I would do is to detach the rear gear cable from the der. Then check it's range of movement toward the outside. Does it move freely enough to shift into the small cog consistently? How sloppy is the upper pulley on it's bushing? Lube the pivots and pulleys, unthread the adjusting barrel a bit, lube the cable as it travels through the casing loops. Reattach the cable and by pulling the cable check the der's inward travel to the large cog. Only after confirming the der's movement and limit of such do you set the cable tension. The coarse cable tension is by the anchor bolt, fine tune with the now freely moving barrel adjuster.

This is real basic der adjustment stuff and should only take a few minutes to go through. If the der's pulley is real sloppy, if the adjuster is frozen in it's threads, if the pivots are getting stiff/tight from corrosion a replacement der might be the lowest cost and get the biggest benefit. If the cable is stiff/has lot's of friction in it's casing then replace them. It's sad that the shop has a wrench who can't assess a cable operated der system on duty AND won't suggest to wait/come back for the more experienced guy to look at it.

As an aside I wonder about you're cadence and gear use. You hint at what is a common manor in riding, using the high gear cog a lot. That it wore out before the other cogs is no surprise to me given what I might read between the lines. About the only time my commuter's chain see's the high gear is when I remove the wheel. Andy.

zacster

I'm just guessing a bent hanger myself. Whenever there is some mysterious problem with shifting that no amount of adjusting seems to correct it turns out to be a bent hanger. If the other parts are bent that is usually a little more obvious. But it also sounds like the cable system is problematic, so maybe new cable/housing. Housing can be more of a problem than you think as the length of it vs. the cable must be constant. If it compresses you'll have sloppy shifting. Also if the barrel adjuster slips around you have the same thing.

spdracr39

Bent hanger or bad cable.

Paradoxical

Andy, Zac and SPD: Thank you, for the awesome feedback. I will get back to this thread a bit later and give a more thorough reply.

bikeman715

+1

Bill Kapaun

How often do you clean/lube the RDER cable?
Since an upshift is accomplished only by RDER spring tension, a dirty/sticky cable will result in delayed upshifts.
Turning in the barrel adjuster just provides more cable slack, which "seems" to help for a bit, while causing you to have to "overshift" when going to larger cogs.
A slipping cable in the RDER attachment could also cause similar symptoms.
There should be no good reason you have to continue screwing in a barrel adjuster. The problem is elsewhere.

Paradoxical

Bikeman & Bill: Thank you, for your feedback.

Paradoxical

All of the consideration here has indicated to me that one or more problems exist at the rear section of the drivetrain. This prompts me to think about the abrasion marks that the RD sustained during the time before I switched to multi-directional cleats. I didn't think that likely could have been the issue. Perhaps, I did not believe it as a possible cause due to mental acrobatics. But, due to the time pressure caused by other goings on and the importance to me of maintaining 150-miles-per-week, I decided yesterday to replace the cable, housing and derailleur. For curious parties, the replacements are Jagwire and an Alivio RD.

Andy, Zac, SPD and Bikeman: It will be on my list to become familiar with the mechanical details about cables, housings and rear derailleurs, so that I can feel confident about doing the troubleshooting of those components. I'm sure that it can't be much more difficult than changing a cassette or BB, which I have researched. I just need to do it. And, that is a true statement, because I feel sure that I will yet cycle hundreds of thousands of miles and again tackle issues like that.

Bill: I can't be sure if I have ever noticed shifting issues at a time when the bike was dirty. It has gotten quite filthy before. That should read: All capitals: DIRTY. However, I certainly don't do enough cleaning. I live in an apartment and lack options. I occasionally take it to the manual car wash. [I don't need to hear about not getting highly pressurized water into the BB or hubs.] Really, I need to figure out a way to clean areas like the RD during the interim, without making a mess. Also, keeping clean the RD cable is reason that I should become familiar about the mechanical details of dealing with the RD and cable sooner, rather than later.

Andy: You have correctly read between the lines. Riding in too high a gear is a bad habit that I've been addressing over the last week or so. Since I read some material about cadence a couple of weeks ago, the realization has slowly sunk in that it doesn't make sense to more greatly expend energy by slow and arduous pedaling. To ensure that my cadence matches the terrain makes fun riding and often I feel the rush of mid-to-high exertion. My cassette wear will be, in the future, evenly distributed. But certainly, that wear will include the smallest cog, as frequently I use a 1-2% grade trail. Barreling down the negative slope side allows a very comfortable cadence on the smallest one.

Again, thanks to all of you, for your thoughts!