How To Tighten A Bike Chain
In this Videojug film, a seasoned bike mechanic shows us how to properly tension the chain on both single speed and derailleur type bikes.
Hello, my name's John from On Your Bike, in London. I've been a bike mechanic for twelve years. I'm going to show you a few things about bikes, things like saddle height and setting it up so that it's the correct size and a few maintenance tips as well.
How to tighten a chain on some bikes which haven't got the derailleur, which is the gear changing mechanism at the back? If it hasn't got one of those, then it's more than likely going to be something like this, which is a single speed bike. Sometimes, the chain can get slack, in which case, you need to undo the bolts which hold the rear wheel, move the wheel backwards and then retighten, so that you've got about an inch of movement in the chain. This one's been tensioned correctly, and this one's fine.
If you find that you've moved the wheel back and it's still not getting any tighter, then you've probably got to replace the chain because the chain is stretched. After you've changed your chain, then you should be able to adjust it correctly, so that you've got the same amount of movement as this bike. This one's got a derailleur and it's got a spring, and what that does is pull the chain, and that's what keeps it tight.
The only time you'd ever need to change these is if the chain is stretched or the chain is just too slack and it's not been able to be tensioned. .