I replaced the OEM 15T front sprocket with an inverted 14T Moose Racing XR650R sprocket at 1500 miles. I am currently at 4100 total miles on the bike using the stock chain and stock rear 45T sprocket (2600 total miles now on the newer front 14T R-sprocket). I really like the 14/45 combination compared to the stock 15/45 gearing, but after reading what akarob posted back in 2009, I want more.
I am about to install a new Shinko 244 5.10x18, so I thought now would be a good time to swap out the rear sprocket with one that is 48T. I have read numerous posts recommending replacement of both sprockets and chain, such as this one found at http://www.dansmc.com/rearchain.htm:
First question - Am I low enough on the mileages to get away with replacing only the rear sprocket without having to change out the front sprocket and chain?? With regard to the front sprocket / rear sprocket / drive chain combination of components, is there a general rule-of-thumb for how many miles you can go and still be able to change out individual parts without having to replace everything as a set??
I saw a recommendation from rebelventurer for a supplier on eBay named dirtparts where you can get steel front and rear JT sprockets along with an RK X-Ring Chain as a package for right at $100. The cool thing about it is they normally set you up for what is needed for the stock configuration of your bike, yet will allow you to customize your order. If based on the answers to my first question I find myself needing to get a new chain and front sprocket, I plan on getting the following:
14T front R-sprocket - JT Part No. JTF1307.14 (SCM415 Chromoly Steel Alloy)
48T rear L-sprocket - JT Part No. JTR301.48 (C49 High Carbon Steel)
110 link RK 520 XSO X-Ring Chain (they said they could go up or down in length, whatever is needed)
Second question - I've read about a zillion posts stating that the stock chain with 110 links will work just fine with the 14/48T gearing, but I want to get the shortest length possible in order to maximize my future range of adjustment. Could I go as short as 108 links, or should I just stay with 110?? It seems I lost almost half of my range of adjustment when I went from a 15T front down to a 14T, but going up from a 45T rear to a 48T may offset that.
(Damn!! I'm a long-winded son-of-a-b!tch)