Help with rear derailleur?

[BSciacca]

Hi All,

I'm new to owning and maintaining my own bike and have been having an issue with my bike that is about 2 months old. More or less, I am stuck in the highest gear on my bike (7). I physically can't crank the twist handlebar shifter down.

Did some research and troubleshooting, I physically "shifted" the derailleur itself left with my hand and was able to get the bike to shift into a lower gear (not as low as 1, I got it down to 3) but as soon as I rode, and shifted back up, I could not shift back down. I played around with the alignment and the Low Limit Screw, I really can't tell if it has anything to do with that or not. The derailleur hanger is fine and I can't see any physical damage anywhere.

I then pulled out the cable. It was moving freely when I shifted on the handlebar and the twist was cranking with ease. When I placed the cable back into the derailleur, it got stuck again and wouldn't physically twist shift down. I feel with this info i'm getting closer to zeroing in on what's going on but could use a little more guidance on how to get there before I give up and take it into the shop. I'm handy enough to do it myself, just can't figure out what to do.

It is a Shimano if that helps and If any pics would be helpful I can share those. Thanks in advance for any help.

[Joe_W]

(07-16-2019, 09:17 PM)BSciacca Wrote:  Hi All,

I'm new to owning and maintaining my own bike and have been having an issue with my bike that is about 2 months old. More or less, I am stuck in the highest gear on my bike (7). I physically can't crank the twist handlebar shifter down.

Did some research and troubleshooting, I physically "shifted" the derailleur itself left with my hand and was able to get the bike to shift into a lower gear (not as low as 1, I got it down to 3) but as soon as I rode, and shifted back up, I could not shift back down. I played around with the alignment and the Low Limit Screw, I really can't tell if it has anything to do with that or not. The derailleur hanger is fine and I can't see any physical damage anywhere.

I then pulled out the cable. It was moving freely when I shifted on the handlebar and the twist was cranking with ease. When I placed the cable back into the derailleur, it got stuck again and wouldn't physically twist shift down. I feel with this info i'm getting closer to zeroing in on what's going on but could use a little more guidance on how to get there before I give up and take it into the shop. I'm handy enough to do it myself, just can't figure out what to do.

It is a Shimano if that helps and If any pics would be helpful I can share those. Thanks in advance for any help.

Ok. first thing: after just two months the bike shop where you bought it should fix it. However, as we all like to learn new stuff, and you have begun to play around with it, below is what I would do. I am not really sure what can cause this, other than the cable being really in a bad state or the shifter bottoming out after the cable has slipped. But then you write that you cannot move the derailleur all the way in, which sounds like the limiting screw is too far in.

One more thing: it often helps to really start over again, be systematic about the changes. I guess that holds for most things, but we all tend to forget that (me too, oh yeah, all too often).

1. undo the bolt that holds the cable to the derailleur
2. really inspect the cables and housing. Look under the ferrules (the metal caps that the cable runs through) and try to see if there is something amiss (frayed cable) - maybe lube the cable. NOT with WD 40, as this is not a lubricant.
3. move the derailleur about, can it really reach all the way in and all the way out? Adjust the limiting screws if needed
4. turn in the barrel adjuster almost all the way, put the shifter into the highest gear
5. put the chain on the fourth smallest sprocket in the rear
6. reattach the cable, make sure it runs in the correct line! Pull it tight.
7. Turn the crank, watch the chain go to the smallest sprocket. (maybe you have to adjust the limit screw)
8. Shift down a gear (bigger sprocket). If the chain does not follow, tighten the barrel adjuster. Shift up again, down again. Does it work now?
9. redo the last step on the next two bigger sprockets, shifting to smaller sprockets in between adjustments.
   

[CharleyFarley]

(07-16-2019, 09:17 PM)BSciacca Wrote:  Hi All,

I'm new to owning and maintaining my own bike and have been having an issue with my bike that is about 2 months old. More or less, I am stuck in the highest gear on my bike (7). I physically can't crank the twist handlebar shifter down.

You didn't say if you bought it from a bike shop or a big box store such as Walmart. If it came from a bike shop, they should fix it. If it's from Walmart, you're out of luck. If you are unable to fix it, then to the bike shop it must go.

Personally, I've had a few bikes with twist shifters and found they were all quite stiff. I swapped out the twist shifters on my hybrid bike for lever shifters. Once you've had them, you'll never go back to the twisters.