es gan domāju, ka tā ir vieta kur tika savienota ķēde, un tā nelokas, ja nav speciāls ķēdes atvēršanas/aizvēršanas instruments, var to ķēdi palocīt turpu šurpu, nevis pāģēdes asīt bet sāniski varētu teikt.

Stiff links
If you have a regular, repeating skip or hitch every 3 or 4 turns of the pedals, you may have a stiff chain link. This is commonly the link where the chain was joined when it was installed. When the chain tool presses the pin through the chain, the head of the pin tends to pull the uppermost chain plate along with it, so that the two outer plates are squeezing together against the inner plates.

The easiest way to fix this is to bend the problem area of the chain into a "Z" shape, with the bad joint on the diagonal part, then flex the chain back and forth. This will slightly spread the tight plates, and free up the link.

If your chain has a link that has been bent in a chain-jamming incident, it can cause similar symptoms. Generally, the bent link (or the whole chain) will need to be replaced.

The easiest way to spot stiff/damaged links is to shift the bike into the small/small gear (the gear you should never actually ride in.) This gear has the chain at its slackest, and flexes it farther than any other gear, as it goes around the small rear sprocket and the derailer pulleys. Slowly backpedal while watching the chain as it feeds through the rear derailer, and you will usually be able to see the bad link jump.