Changing Gear on the move and it jams

[tradesecrets]

This problem is becoming more annoying to say at least .. it mainly happens whens I change from Middle Cog to 1st and for some reason the chain gets jammed ..at times forces me to stop get off the bike or revert the gear back to the last setting .



I've never experienced this in all my years untill recently ..

 

[Maz]

My initial thought is that the derailler (the thing that physically moves the chain from one ring to another) needs a bit of adjustment.
What bike is it?

 

[I like Skol]

I guess you are talking about the chainset, dropping from the middle chain ring to the granny ring? If I am right then I have also suffered this and I think it is due to worn chainrings causing the chain to hook onto the teeth and then jam between the chainrings and the chainstay.

I would check the condition of your chainrings and if they are worn then consider replacing them individually or even as a whole chainset as the cost of a replacement rings can sometimes be more than a full chainset.

 

[zacklaws]

I guess you are talking about the chainset, dropping from the middle chain ring to the granny ring? If I am right then I have also suffered this and I think it is due to worn chainrings causing the chain to hook onto the teeth and then jam between the chainrings and the chainstay.

I would check the condition of your chainrings and if they are worn then consider replacing them individually or even as a whole chainset as the cost of a replacement rings can sometimes be more than a full chainset.

I have the same problem on rare occasions and finally at the weekend I managed to replicate it on the workstand and its exactly as described above.

But last year I fitted an SRAM chain as I could not get my usual KMC at short notice and the problem was very persistent from the moment I fitted it, then I became aware of how much tackier the manufacturers lubricant was compared to the KMC, so when I gave it a coat of Finish line wet it stopped sticking to the chain rings and the problem was solved

 

[Zoiders]

Are you spinning the gears so they are lightly loaded or giving it some welly and hoping for the best?

Spin, don't grind, also remember that STI thumb shifters need to be held down until the shift has finished.

 

[photography27]

Are you spinning the gears so they are lightly loaded or giving it some welly and hoping for the best?

Spin, don't grind, also remember that STI thumb shifters need to be held down until the shift has finished.

didnt know that about sti shifters, maybe that might be my answer to my shifting problem!!
thank you indeed

 

[I like Skol]

also remember that STI thumb shifters need to be held down until the shift has finished.

Not when dropping onto a smaller ring (front or rear), just press and release and allow the chain to drop onto the next smaller ring. 'Overshifting' when moving to a bigger sprocket/ring as zoiders seems to be describing can help but isn't necessary when the rear gears and cable are well adjusted and the cable moving freely. It does make a big improvement in shifting at the front mech though when moving to a bigger ring.

 

[Zoiders]

Not when dropping onto a smaller ring (front or rear), just press and release and allow the chain to drop onto the next smaller ring. 'Overshifting' when moving to a bigger sprocket/ring as zoiders seems to be describing can help but isn't necessary when the rear gears and cable are well adjusted and the cable moving freely. It does make a big improvement in shifting at the front mech though when moving to a bigger ring.

You are right with rear shifters as yes youc an sweep through sveral sprockets at one but most MTB type front shifters will only let you go up one ring at time and the pawls will have difficulty engaged inside the shifter unless you let it change up smoothly by spnning the drive train.

Shifting down under pressure can do nasty things as well.

 

[Cubist]

It could also be a chainline problem. Make sure you are in the larger three or four sprockets before you try and move to the granny, otherwise the chain may hang up in the cage of the derailleur

 

[yashicamat]

I get this occasionally on my touring bike that uses bar-end friction shifters, so it's probably not an indexing/adjustment issue. I think it's got a lot to do with shifting technique; I get the issue usually when I am a bit optimistic about a gear I'll get up a hill in, then have to drop down to the inner chainring while on the hill. If I'm quick (and have enough momentum), a very quick backpedal of about 1/2 a rotation usually clears it. I think the key is, as has already been mentioned, to try to keep the loading on the drivetrain to a minimum when shifting.