Holmboyz
PR Addict
Just purchased a new set of sprockets and a DID 520 ERT3 chain for my yz450. I installed the set and adjusted the chain to recommended slack. When spinning the wheel I noticed the tension on the chain would shift between normal to extremely tight. When I watched the chain on the rear sprocket it would climb off the teeth on a small section and then go back into the grooves near the top. When I ordered the parts from Rocky Mountain ATVMC they said the chain i usually get (Renthal 520 R-1) was out of stock so I did asked them if the ERT3 would work and they said yes. I took this DID off and put on the previous chain and the fit was perfect. Any ideas what's going on? I thought a 520 was a 520 and all I needed to do was adjust the number of links? BTW: The sprockets are the same I've used in the past.