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Shifting is almost impossible
#1
My wife's road bike has Shimano Sora shifters with a triple front derailleur (stock). The thumb switch on the front shifter is VERY hard to use and she can't do it when she's riding. I did a full adjustment of the front derailleur but it didn't change anything. One thing that I noticed is that the shifter works smoothly when the shifter cable is unattached from the derailleur, suggesting that the shifter itself can do the work, but not when there is a "load" on the line (when it is attached).

Not the best shifters in the world, but I only want to invest the bare minimum to keep it working smoothly so I don't like the idea of spending 100+ to replace the shifting system.

Any suggestions as to how I might narrow down the problem more?

The bike is a Jamis Satellite 2010 and otherwise in good condition.

Thanks.
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#2
try flushing the mechanism with silicone spray... Remove the cable first, then manipulate the shiters while spraying it inside...
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#3
(05-28-2013, 09:55 PM)bobtravers Wrote:  try flushing the mechanism with silicone spray... Remove the cable first, then manipulate the shiters while spraying it inside...

thx. I'll give it a try. You mean taking apart the mechanism before flushing it?
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#4
No, Shimano shifters are not designed to be taking apart...

Do it while the shifter is on your handlebar...
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#5
(05-29-2013, 01:07 AM)bobtravers Wrote:  No, Shimano shifters are not designed to be taking apart...

Do it while the shifter is on your handlebar...

ok. thanks.
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#6
(05-28-2013, 11:25 AM)Pixelshot Wrote:  My wife's road bike has Shimano Sora shifters with a triple front derailleur (stock). The thumb switch on the front shifter is VERY hard to use and she can't do it when she's riding. I did a full adjustment of the front derailleur but it didn't change anything. One thing that I noticed is that the shifter works smoothly when the shifter cable is unattached from the derailleur, suggesting that the shifter itself can do the work, but not when there is a "load" on the line (when it is attached).

Not the best shifters in the world, but I only want to invest the bare minimum to keep it working smoothly so I don't like the idea of spending 100+ to replace the shifting system.

Any suggestions as to how I might narrow down the problem more?

The bike is a Jamis Satellite 2010 and otherwise in good condition.

Thanks.


Oh I won't flush anything into the shifter since it's too new of a bike for grease to harden up. It's bad advice for such a new bike since you'll end up flushing out good grease until you eliminate other possibilities before trying that.

Now here's some key information that you provided. As you mentioned, the shifter works fine when the cable is unattached. It shifts fine. That indicates that it's more likely not the shifter. It could be something wrong with the front derailleur, cable, or cable housing or cable routing issue. There could be a kink along the cable in the cable housing.. Obviously there's some kind of friction going on...

I would just get new cables and housing for the front and lube up the front derailleur at the pivot points and spring.

One more question, are you saying you have a hard time down shifting to the lower gear on the front? saying that it's too hard to press?
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#7
(05-30-2013, 10:58 PM)haykong Wrote:  One more question, are you saying you have a hard time down shifting to the lower gear on the front? saying that it's too hard to press?

The thumb lever is hard, the other is not. At times it's impossible to push, as if there is a block. I'm pretty sure it's not the cable system - I've tested that and it seems relatively fluid. It may be the derailleur itself since it's hard to move outward by hand - but that's not the direction it has trouble with. So, I'm back to the shifter. Note that it seems to be most difficult to shift when the gear is set to the largest cog (away from the bike) when the load on the cable is the strongest.
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#8
Doesn't your shifter do trims? and not just two clicks..

Ok road another bike forum with someone who had the similar issue as you but on a double vs triple crankset

http://www.bikeforums.net/archive/index.php/t-771467.html

Note the OP from bike forums solved it by reading through Shimano's PDF on front derailleur setup...

He summed it up in this... which worked for him:


"All right, I think I have this thing figured out.

First I studied that Shimano PDF and came up with how the shifting is supposed to work on a double. To upshift, a single stroke is required to engage the big ring. An extra trim stroke may also be required but this will not click. To downshift, you must reverse the upshift. If the trim was done on the upshift, the first click will reverse the trim and the second will engage the small ring. This seems to index shifting with a friction component but I honestly think that that is how it works.

Then I adjusted the front derailleur with the following steps:
1. Mount the derailleur, checking position and rotation angle.
2. Set the L screw correctly so that inner cage plate does not rub chain on lower cogs.
3. Remove the H screw.
4. Attach the cable.
5. Adjust cable tension and test upshifts. Since the H screw is gone, that will not factor into the upshifting. I think this is better than pulling the cable with your hands but some may disagree. You must only be careful not to overshift the trim. If you do, the downshift will be difficult.
6. Replace the H screw and tighten to prevent overshifting the trim stroke.
7. Fine-tune.

The result is relatively smooth shifting on the front derailleur. With the right trim, the only combinations that generate noise are the smallest two cogs on the rear and small chainring on the front. Small-small noise happens even with the front derailleur removed and I believe that they are caused by the chain rubbing on the big chainring. This is an "illegal" combination anyway. "
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#9
(05-31-2013, 06:43 AM)haykong Wrote:  Doesn't your shifter do trims? and not just two clicks..

Not sure. I'm used to my other bike's bar-end shifters which are nothing like these.

Thanks for the info and link, sounds like it might help.
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#10
Are you sure your cable is routed properly? It sounds like the shifter works fine without the cable attached and the derailleur sounds like it is working properly as well. It should be hard to move outward.

Take it to a local bike shop. It should be an easy fix and not very expensive.
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#11
I've had this problem when the derailleur is jammed or if the cable tension is too tight.

I guessed that the ratchet inside the shifter requires a little bit of slack, as when it rotates when you press the thumb lever it seems to briefly tighten the cable very slightly and then let it out. If the cable too tight (very tight) it can't move so the thumb lever feels like it is stuck.

You'll probably find if you take the cable off the derailleur and put tension on it yourself by hand that it still shifts fine. Check that you can move the derailleur manually/by hand, perhaps with the chain off.
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#12
Hi:
I have the same bike and it has the same problem. Did you solve the problem? If so how did u fix it?
Thanks
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#13
You've determined the shifter works OK without the cable, but not with it. The next step would be to see if the derailleur works when you pull on the cable by hand. If that is OK then there is only one variable left - the cable. It would be likely that the cable housing is kinked or there is too high friction between cable and housing. It's quite easy when the cable is detached to move the housing back and forth to check for catches or friction.
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#14
Noted a definite difference in the coil springs on various Shimano derailleurs in our limited 'livery', including several 'parts' bikes. The troublesome unit had a coil spring wire thickness of .070 ...thousandth's of an inch. The spring that I retrieved from a working smooth unit, mic'd .066 wire thickness.

All is fine after the spring swap. Easy now to twist the grip on the younger grandson's model, the one that he always had trouble with. Also noted a difference in the angle of the heavy spring's tail, in reference to the hook. The tail was angled such that it was increasing the tension even more. be sure to install with the tail resting against the cross pin, not the derailleur's internal framework itself. Of course we did all of the previous suggestions, before finally investigating the spring tensions.
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