the time to change your chain is directly proportional on how you use your bike (fast acceleration and doing wheelies apply hard tension on the chains and therefore creates loose spots around the chain) and how well you maintain the chain. You should pop the rear end up on a stand and adjust the chain tension every so often (I do it about every 800-2000 miles as I do stunt the F2 a bit) and relube the chain with chain grease or lube (ever 600 miles).
Even if your bike gets wet, the grease/lube shouldn't wash off easily unless you used a pressured hose. When you adjust the chain tension make sure you find the tightest spot on the chain and adjust the tension to that spot. Depending on the bike, usually you should have an 1.25-1.5 inch worth of play going up and down from rest.
Now, if you notice that you have a tight spot and a very loose spot where you adjust the correct chain play on the tight spot and have something like 3+ inches worth of play, time to get yourself a new chain. If you incorrectly adjust the chain to be too tight, you risk of the chain breaking and could cause a wreck. Same goes for being too loose. If its too loose, not only would it be able to slap against the swingarm and cause damage (scratches but can grind into like a chainsaw), but you also risk the chain of falling off the sproket(s) depending on how loose it is. Hopefully you'll notice the sluggish performance of the bike and adjust the chain by then.
If you have an even wear pattern of the tension on the chain, then your tightest spot should "loosen" to the point of where when you adjust the position of the rear axel that you hit a notch or a marker on the swing arm saying "time to replace chain" or something to that effect. Check your bike's manual to be sure. Under normal vehicle use, depending on the quality of the chain, they should last atleast 15k miles (more with regular maintence). My stock chain that I'm still using on my F2 is still good but its getting to that point where I should start looking to get a new chain and I'm already at 21k.
As always, its better to give too much info then not enough.
Btw I'm also in the market for a new chain for the gixxer. I just got a +9 teeth rear sproket and planning on gett ing a -1 front sproket. I heard RX's were good.
Last edited by JBaz; 04-05-2006 at 09:33 PM.