Locking chain

[Svendo]

Another possibility is a cracked plate on the chain itself, which is sometimes protruding and preventing smooth running, like in this post.

 

[Thompson]

it does freewheel. We did stop and check while it was jammed once, and none of us could find anything wrong with the chain which was a bit annoying. I'll have a closer look at the chain and check all the inside workings with the Dad to see if we can see something better. thankyou