Gears won’t shift

[Sophie]

I have a Diamondback bike, nothing fancy and at first the gears wouldn’t even turn so I detached the cable and adjusted it and now the gear will move but the physical gears won’t shift off the highest gear (smallest cog). I’m pretty sure it’s a derailleur issue but I’m not sure how to tell what is wrong or how exactly to fix it.

[Jesper]

(04-19-2020, 03:45 PM)Sophie Wrote:  I have a Diamondback bike, nothing fancy and at first the gears wouldn’t even turn so I detached the cable and adjusted it and now the gear will move but the physical gears won’t shift off the highest gear (smallest cog). I’m pretty sure it’s a derailleur issue but I’m not sure how to tell what is wrong or how exactly to fix it.

Hi Sophie,

I responded to your query in the other thread ("Gear shift is stuck!") you posted on. I hadn't seen this one at the time so I didn't know what bike you had. Many types of Diamondbacks out there; does yours have front and rear derailleurs, or just rear? If you disconnected the cable off the rear derailleur the cage will "default" at the small cog or to where the limiter screw was set at due to the spring tension; the front if disconnected will also go to the smallest chainring sprocket (but a low speed/gear). Please clarify; when you say the "gear will move", are you talking specifically about the shifter (the part you grab to change gears while riding)? If this moves with the cable clamped onto the derailleur, but the derailleur itself does not then it sounds like a broken cable. If you have everything connected at the grip shifter and you unclamp the cable from the rear derailleur, then pull on the cable end; if broken you'll end up with part of the cable pulling out of the housing. I might be confused, don't worry, it shouldn't be to major unless the derailleur is "locked in place" due to rust/corrosion. How old is the bike, do you ride a lot in muddy, wet, salty (beach) conditions, and/or is the bike left outside to the elements? If you read my other reply to you in the other thread I hope it might be able to help. You should be able to push the rear derailleur (pull out towards you if the front derailleur) pulley cage inward towards the larger sprockets even with everything connected, but you will probably have to give the chain a little slack in order to go more than one or two steps on the freewheel/cassette because the chain won't be able to "flex" very much when the sprockets aren't turning during normal shifting; it's easier to get more chain "play with it off of the front rings. This is very easy to check with the chain removed, but if you don't have a "chain breaker" tool, or the chain has no master link to separate it then you can only test the derailleur as previously mentioned. You can update here, or message me. I'm sure there is someone out there who may provide a better answer, I'm going primarily on my experience with the type of bikes I ride (road '60s-'80s racing/touring, not MTB's). A photo would be helpful showing the specific part that is presently not moving. If the cable is good and the derailleur is "locked up" than your shifter should not be able to move either (maybe a tiny bit due to cable slack). It could be that there is too much cable slack, in that case unclamp the cable at the derailleur and pull out the slack before re-clamping. Make sure your cables are properly engaged in the shifter body itself, it they are not than the shifter will readily move without resistance since there is no longer tension from the derailleur(s) applied. Trying my best here, hope it gets you on the road/trail again. Oh, and by the way welcome to the "club"!

Please allow me to preach about the virus situation (Yes, I know we've heard it before): stay put if possible, wear any kind of mask when in public, wear gloves when making contact with all surfaces away from the house. I was potentially exposed last week by another worker who tested positive; we're both in healthcare. Irritated at that person for coming to work while not feeling well and ignoring our screening process which would have sent that individual to the ER for isolation and testing before contaminating part our the OR spaces/equipment, and our OR staff. Not fun!

Take care,
Jesper