Arrghh, chainsuck

[Hawk]

I've read the website... my chainring is new, my chain is also new.... My middle ring is smaller than the stock and the problem is only when switching from middle to lower (it's a triple).

It's really frustrating - it seems to happen when I am in a low gear at the back and switch down at the front. The chain starts to "twist" slightly as it moves down (it is under tension from the cassette/my extremely light pedalling) and then catches any thoughts?

 

[Pauluk]

When you say it catches, what do you mean exactly.
You have had a new chain, was your previous one stretched?
How many miles had your old chain done?

 

[Hawk]

Old chain was changed between 0.5 and 0.75% stretch (park tool used to measure that).

By "it catches", I meant that the chain does not reliably disengage from the middle ring's teeth when I change to the inner ring and is then pulled all the way round (as I pedal) until it catches under itself

 

[summerdays]

I had it on my first bike almost from new - and for me it seemed to fix itself when I changed the chain and due to a mistake I made (trying to join the chain sort of male:male ), the chain ended up one link shorter than it had been. Since then I've not really had the same problems that I used to on that bike. So in my case I presume the chain was a little too slack to help pull it off the ring. (It was incredibly annoying - to the point when I would avoid changing ring because I didn't want to have to stop and sort it all out).

 

[Pauluk]

The four things I would check first as they don't take long and are easy to eliminate:

Make sure the front derailleur cage is perfectly parallel to the line of the bike.
Check the low limit screw position.
Adjust the cable tension to see if the change down can be improved.
Check the chain length to double check this is correct. (I would use the large - large cog method).

Apologies if you have already set these up correctly but I'm a simpleton when it comes to mechanical things so always start with the easiest things first.

Good luck, hope you get it sorted soon.

 

[Hawk]

The four things I would check first as they don't take long and are easy to eliminate:

Make sure the front derailleur cage is perfectly parallel to the line of the bike.
Check the low limit screw position.
Adjust the cable tension to see if the change down can be improved.
Check the chain length to double check this is correct. (I would use the large - large cog method).

Apologies if you have already set these up correctly but I'm a simpleton when it comes to mechanical things so always start with the easiest things first.

Good luck, hope you get it sorted soon.

Thank you mate.

I tried all those happened to pop in to my LBS today for a few parts - the guy suggested that my FD cage may be a bit too close to the chainring teeth (i.e it needs to move upwards slightly)... just done that, will hopefully have solved it.

OR I can just avoid using the inner chainring altogether, getting there slowly...

 

[Pauluk]

I couldn't carry on avoiding the inner, I'd have to find the fix. Let us know how you get on if you fix it, its always informative.