Which Chain and Sprockets: KX85

[JoeCharge]

My sons KX85 is going to need a chain and sprockets soon. I bought it used so I have no idea how much time is on the current components. There is quite a bit of range on the prices for these items. I would like to get the one that is going to last the longest.

He's not a racer. I can get a stock chain and sprockets on **** for $45. I'm guesing that would be fine. Rocky Mountain has a 'Primary Drive' brand that is low priced, then Renthal, and several other brands that are higher priced. Why the higher price? Will they last longer or is the higher price because they are lighter?

What about going to a 428 chain and sprockets (420 is standard). Any Pro's or Con's for that move?

 

[SHSPVR]

428 has a bigger Roller Diameter and more Roller Width so 428 recognized as a more heavy chain which is somethimg you want to use when pumping up the motor hosepower, etc, etc.
I just get a stock steel sprockets set and get RK Heavy Duty GB420MXZ and for stock chain they don't last long and waste of money I think and get a good Chain Lube like PJ1 Black Label Chain Lube.
Pro's with 428 chain and sprockets conversion it usely last longer then 420.
Con sometime you can run into clearance issue with the chain guard or cover.