it should have 1 inch to 3/4 inch slack in it
If you do not still have your chain tensioner attached you need to slack the four bolts on rear end housing pull rearend tight as possible and retighten your four bolts
chain too tight or something is seized up
From the middle of the 2 sprockets you should have about an inch of slack or play in your chain when you lift up on the bottom of the chain with your finger if it looks a lot more then that adjust it but you don't want it to be too tight.
When adjusting a chain on a bicycle, it should be tight enough to not sag or come off the gears, but loose enough to move smoothly without causing excessive wear on the gears or chain.
The garage door chain should be tight enough to prevent sagging but not too tight that it strains the motor. It should have about 1/4 to 1/2 inch of slack for optimal performance and safety.
You need to start by adjusting the middle chain . At the front of the center chain is an eccentric , loosen the two bolts and rotate it to tighten . should be as tight as you can get it . After you do the center then you do the front .There is an eccentric for the front chain also . It should be as tight as you can also .
You should be able to move the chain up and down aprox 1/2" with your fingers.
A bike chain should be tight enough to prevent it from sagging, but not so tight that it causes excessive wear on the gears and chain. Optimal performance and longevity are achieved when the chain has a slight amount of slack, allowing for smooth movement without putting too much strain on the components.
dheck tention on drive chain, probable too tight
they keep your chain tight
Half inch to an inch of slack in the middle is just right.
On either side of the rear tire, there is a nut at the back of the frame with a locking nut over top it. Loosen the locking nuts. then loosen the other nuts. pull the tire back until the chain is tight( I know this is bad, but I usually just hit the axle nut on either side with a hammer until the chain is tight. not recommended) . When the chain is as tight as you want it, tighten the screws and you're good to go. Don't pull the chain too tight though. Your rear brake will lock up. The rear break pedal should be tighter than it was before, but not so tight that you can't back the bike up. There are guides just behind the axle nut on either side that are marked. These will help you make sure that the rear wheel isn't misaligned. If you go past the arrows though, you need a new chain. You need a new chain often ( I've put 17,000 miles on my bike and I'm about to start on my 3rd chain).