RK Racing Chain GB520MXU-120 Gold 520 Series Motorcycle Chain - 120 Link High Performance Narrow Clearance Off-Road & ATV Chain with UW-Ring and Connecting Link - Perfect for Dirt Bikes, Motocross, and Extreme Riding Conditions

After extensive research on all the chains currently available (2015) from DID, EK, RK, Tsubaki, Regina, Renthal and ProTaper, I have this chain on 3 bikes now. It is the most appropriate chain I can find for dirt bike use, from 125cc 2 stokes up to 450cc 4 stroke motocross bikes. It's narrower and lighter than any other high quality 520 sealed chain I know of and stronger at the same time. Check the specs! Rolls very freely for a sealed chain, even when cold. Rolls even better when warmed up like all sealed chains. I used to be a DID only guy. Their prices have become prohibitive for their best chains. I tried a DID VX2 and was very unsatisfied with the gold coating. It rusted just like a bare steel chain. I've switched to this "gold" plated RK MXU now and they have been great. I've used it on KDX and KTM 200's and 250's, all 2 strokes. I haven't had any issues with stretch or rust. I now lube my chains with cheap 90W gear lube to prevent rust on the outside after washing the bike just to ensure they don't rust, but for comparison, these chains remind me of the DID ERT2 unsealed MX chain for corrosion resistance but incorporate sealing for the same price. The good DID sealed chains like ERV3 are now about $170! Yikes!