250-500cc Chain and Gears

This winter my WR300 is getting a pretty decent refresh. I'm relatively happy with the stock equipment, but my chain is stretched pretty far now, and my sprockets are hooking.

I'm still pretty new and would like some advice on chain and gear sets. O-ring, x-ring? Steel vs aluminum gears? I'm pretty clueless. As for actual gearing, I think I may drop a bit since I seldom use 5th year anyways (road transfer sections) but I do use 3rd and occasionally 4th on the trails. We have pretty gnarly singletrack here, all roots and rocks, I may want to save 1st as a granny gear and never really use it.

I am replacing the driveline on my 300 this winter. I will be going with an o-ring chain (probably DID). I am still on the fence about rear sprocket material, but I can say for certain that a steel rear sprocket will last several times as long as aluminum (and the chain will probably last longer too).

Since my WR is my "race bike" I will probably stick with an aluminum sprocket and just replace it every season. The steel rear on my 610 is still good after about 6000 miles...

I am running stock 13/47 gearing on my WR and I will probably stick with that, it works pretty well for the mix of riding that I do. I wish 5th was a bit longer, but whatever.

I run 13:50 gearing for mostly single and two track in western Washington state. 1st gear for only the tightest stuff; mostly 2nd and 3rd for the rest. Rear sprocket is an aluminum/steel hybrid Supersprox (aluminum inner piece w/a steel ring of teeth). Chain is a DID VX2 x-ring chain. I'm very happy w/this setup. Over 1,000 miles on them and going strong. Don't forget to replace your front/countershaft sprocket as well.

I am running a Moose O ring chain, it's been good will probably replace with the same this year. I just run an aluminum rear sprocket...

using supresprox front and rear, o ring chain and oil it not wax as i find it sticks to dirt too much.
steelsprocets and watch the front more than the bac as on average it does 3times the revs as the rear and i found that its the more likly suspect for streched chain. correct me if im wrong or overly paranoid please

I've heard a rumour about rear sprockets being the same as a YZ of some flavour? Can anyone confirm this?

Also, the workshop manual suggests the gearing as 14/50, with a 135 link chain. Can anyone confirm this?

My WR is 13/47 (stock). Your best best is to count the teeth (or look at the number on the sprockets) and count the links.

Well, tomorrow is the club discount day so I had better figure out what I want...

JT sprockets okay? Any namebrand of chain I should not get?

all the brands are pretty good, long as you buy their more expensive chain...ive had good durability with tsubaki omega orings...a good chain is going to be towards 100 bucks, if its o ring and 50 bucks, i wold be very wary