[Rear Derailleur] Gears up/down by one cog

[Infocus]

I don't exactly know how it happened. I've been trying to fix it for days but nothing works.

So let's say you had a 1-9spd derailleur:
If we would want to shift to the biggest cog we would go to the 1st gear, and if we would want to shift to the smallest cog we would go the the 9th gear. BUT that's not the case in my rear derailleur. I could only go to the 2nd smallest cog, and if I would want to shift to the biggest could I would only have to shift 8 times, this means that I would have 1 more shift to go (but shifting 1 more time would be ridiculous because it would go over the biggest cog and onto the spokes).

Do you guys know any solution to this?

[cny-man]

Although it's hard to navigate the tortuous path you took to describe the problem, the symptoms you describe exactly match a derailleur hanger that has been bent inward by the bike falling on its right side. It seems likely you have not worked on your bike before, so it's best to have a shop correct it - quick, not terribly expensive procedure.

[budstutor]

(12-14-2014, 08:24 AM)Infocus Wrote:  I don't exactly know how it happened. I've been trying to fix it for days but nothing works.

So let's say you had a 1-9spd derailleur:
If we would want to shift to the biggest cog we would go to the 1st gear, and if we would want to shift to the smallest cog we would go the the 9th gear. BUT that's not the case in my rear derailleur. I could only go to the 2nd smallest cog, and if I would want to shift to the biggest could I would only have to shift 8 times, this means that I would have 1 more shift to go (but shifting 1 more time would be ridiculous because it would go over the biggest cog and onto the spokes).

Do you guys know any solution to this?

---

Another possibility to the bent hanger reply is that your high limit screw is out of adjustment.  (not as likely as the bent hanger unless, as you said, you've been working on it and you happened to turned this scrrew in a bit) You say that you shift 8 times.  I assume that you mean hearing 8 clicks.  This is normal with 9 gears.  There are only 8 positions (spaces) between 9 gears.   If you shift into 9th gear and only get to the 2nd smallest cog, then shift 8 times you are back in 1st gear on your shifter and should be on the largest cog.  Take a really good look at your hanger or even take it of if it's the removable type and put it on a very flat surface.  If there is no "rocking' of it when pressed on the edges, it should be OK.  I'd suspect the limit screw to be the cause now.  One caution that I learned the hard way.  If you do have a bent hanger and it is aluminum and you straighten it and continue to use it; replace it soon.  I found out, aluminum loses its strength once bent and moved back and can break after a short time. Good luck.   Bud