Hi, I've been having problems with my x rated exile jump bike. The chain would just fall off from the back, I shortend the chain before it work for a while and now the problem has come again. I've thought about getting a new chain because I've cycled that bike a good load from when I had it 5 days each week. So yea and for a Dirt Jump bike what chain would you reccomend would a chain made for a mountain bike work?
I had this cahin in mind: https://www.theboardroom.ie/shop/bmx-...n-theboardroom
but it that's good take a look at the others: https://www.theboardroom.ie/shop/bmx-parts/chains
which one would you use for a Dirt Jump bike? Thanks for the help

Have you tried just tightening the chain tension? Loosen the axle nuts, pull the rear wheel tight against the chain, and re-tighten the nuts, just tight enough so the chain doesn't bind when you turn the cranks. Use a box end wrench. An adjustable will just round off the corners. You'll still have to re-tighten from time to time. Getting it right will also take some practice. The nature of the beast.

If you really need a new chain, any quality 1/2" x 1/8" chain will do. We like the SRAM PC1. A multi-speed mountain bike chain is too narrow for single speed cogs. But unless you got the bike used, it sounds like the chain is not worn enough to be the problem.

Have you tried just tightening the chain tension? Loosen the axle nuts, pull the rear wheel tight against the chain, and re-tighten the nuts, just tight enough so the chain doesn't bind when you turn the cranks. Use a box end wrench. An adjustable will just round off the corners. You'll still have to re-tighten from time to time. Getting it right will also take some practice. The nature of the beast.

If you really need a new chain, I can only tell you that mountain bike chains are made for derailleur-equipped multi-speed cogs that are too narrow for single-speed cogs. Without seeing your current chain or measuring the width of the cogs I wouldn't want to make a recommendation

hmm well I have tried doing all the above, the problem which I have is that, I have pulled the rear wheel outwards to tighten the chain but when I start to cycle the wheel starts to pull back in. I have an old bike with a decent chain I'll switch the chains and see how it goes but thanks for your reply

I'm going to guess that your axle nuts don't have the teeth they used to, or were swapped at some point with some that are not serrated on the inner surface. Get a new set of proper nuts, and make sure you tighten them down securely on the droputs, which may need to be filed a little to make everything bite right.

Serrated flat washers are an option, too. Back when many more bikes had bolt-on wheels we stocked some that had some pretty sharp points around the perimeter.

OK, we have to identify the actual problem, and the type of bike.

I gather it's a single speed, but please confirm. Also say whether it has rear suspension or not as this makes a tremendous difference. If it does have rear suspension, a photo will be very handy, or an accurate description of the pivot points and linkages.

Now the problem.

Is the wheel moving forward causing chain slack?
Is the chain tension OIK, ie. slight visible slack at ll times, yet the chain falls off?
What else should we know?

A chain can derail even if everythins is spot on if for example the sprocket has a damaged tooth, the chain line is off slightly, or the tooth profile isn't right to pick up the chain as it approaches. This will be worse on a jump bike because the chain is bouncing around and can deflect sideways, then snag and climb up onto the tips of the teeth and derail.