Which x/o-ring chains fit 05+ yz125?

Ive been using a DID ERT2 chain and aluminum rear sprocket but would like to try a longer lasting chain, just worried about the extra width of the chain hitting the cases. I've used a Regina ORN6 on a previous bike and it never needed adjusting.

Anyone with a 05+ yz125 running any of these chains?

Primary Drive Xring

DID VT2 Xring (narrow but expensive)

Regina ORN6

Renthal R3


I ride/race MX 99% of the time and wash my bike anytime its muddy. If the xring chain and alum sprockets still arent holding up I'll try the ERT2 and steel sprockets to see how that compares. If I'm still not happy I'll just do the xring/steel combo and be done with it.

DID ERT2 is your best bet cause this chain is the most trusted chain in supercross and motocross racing and that what you want eh!

My last 3 chains have been the ERT2 and I have not been happy with the wear. I adjust my chain about every 3 rides. Not sure if its the chain or the alum sprockets wearing out fast but I'd like something a little longer lasting. I'll give the xring chain/alum sprocket a shot, then try an ERT2 with a steel sprocket and see how that goes.

The Xrings have less of a power drag that the regular O'ring chains. For what that's worth.

I use a 520 Did X ring on my 250 and it lasts bloody ages along with my Talon/Rental sprockets!

My last ERT2 barely longer than the stocker... It required adjusting every 2-3 rides which is the same as what I got on the OEM chain anyway? Starting to think it's abit over rated.

Keep in mind that with aluminum sprockets, you will have much shorter chain life than with steel or other hard/tough material. A lot of the adjustment requirements comes from the sprocket's high wear rate, not the chain itself.

I've decided I'm tired of stuff wearing out so fast so I'm ordering the narrow DID xring and Supersprox Stealth sprocket.

I've decided I'm tired of stuff wearing out so fast so I'm ordering the narrow DID xring and Supersprox Stealth sprocket.

Everyone I know that has ever bought a sidewinder has loved it, and they last and last and last. When my current set wears out, that's probably where I'm going. They're pricey, but supposed to be worth it. I believe that some if not all versions have a substantial wear guarantee. You have to buy their chain as well as the sprockets. It isn't exactly the same pitch as a regular chain. I suppose that is one way they can offer the warranty: they force you to use their chain instead of some cheapo version that then kills off the sprockets. Take a look at their offerings.

I've been running X-ring chains with RMA aluminum sprockets with great results. 116 hours on my current RK X-ring chain and I changed the front and rear sprockets out at 60 hours when they started to hook. I'll run this set till it dies, but I'm betting I can get 150 hours out of this chain. And thats on a YZ 250 riding moto in sand/mud/etc!

if using steel sprockets front and back and steel chain, wouldnt that be hard on the transmission?

If so, every bike I've owned more than a few months has had a tough life.

The shock absorbing function of the clutch hub is there for that reason. Some street bikes have a elastomer cush drive in the rear hub for that reason, and there is a spring loaded cam affair in most shaft drive motorcycles for that as well.

look at cars and trucks: there are either springs in the clutch disc for manual transmissions, or automatics which don't need it with the torque converters; that's it.

There is no cushioning effect for aluminum sprockets. They're used as weight reduction of unsprung weight, and considered sacrificial. For national class riders where every ounce counts, plus they most likely have a sponsor or two, who cares? Change them and the chain every race. The rest of us plebes, and especially those that either don't race or race at a local level just for fun, the costs of keeping up with aluminum is quite high. Not that long ago, you either lived with it, or bought the heavier steel items. Now there are all sorts of alternatives: steel teeth on aluminum centers, titanium, stainless, high grade chrome moly with extensive cutout sections for lightness, etc. You're no longer stuck with either heavy steel or light and fragile aluminum. The anodizing on the aluminum sprockets is good for about one MX heat, then it is gone, which puts you right back to square one.

Sorry for the wordy version, but that's the answer.

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