CHAIN SLACK, from where to where...

once your chain STRECHES you will adj for 1 in up for slackotstir:

 

Get it on the stand, and roll the wheel over a few times while pushing up on the bottom run until you find the TIGHTEST SPOT. Set tension so the tightest spot has the proper slack !!!!!~!!~!!!!!

After that, if the rest of the chain has way too much slack, you probably need a new chain, cuz it's done woe out !!

Adjust chain when it's cold, lube it when it's warm after a ride.

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Sorry, just noticed i repeated Grey's post, but it's an important detail and needs repeating........

 

Yeah, I had a camshaft so chain was not an issue. I didn't know how important this was. Seems like whether it is 1" from rest to top or bottom to top it does not matter, which is a good thing.

 

It does matter. With 2" of slop you'll be in trouble. Not only will the chain "whip" back and forth with throttle on/off movements. It's Possible to ride up on the counter shaft sprocket and hit the case. It will also put undo stress on the chain by snapping it with quick throttle movements.

What you're actually accomplishing is when the bike is on the ground with rider the swing arm is basically level, straight back from the countershaft sprocket. At that point the rear sprocket and cs sprocket are in line and the chain would have just enough slack not to be tight pulling on it's self. Which is the best tension for a chain. Loose enough not to pull itself tight and tight enough not to "ride up" in the sprocket teeth. The roller of the chain should sit in the bottom of the teeth against the sprocket. This is in a perfect setting.

In the real world the pivot point of the swing arm in not in the same location as the center of the countershaft. So the swing arm moves in a different arch than if it was centered with the cs which would be the perfect arch. So you need a little more slack in the chain for the difference in the archs difference from center to center of the two sprockets which changes as the swing arm moves up and down. This then tightens the chain in one position of the swing arm and has more (than perfect) slack in another position of the swing arm.

If you get to much slack The chain will rise up off the sprocket and the pressure point will be on the teeth up on the side of the tooth instead of being against the sprocket/tooth bottom. That's where and why the sprockets wear the way they do.

So the adjustment is a happy medium between those two archs/centers. If your chain is to tight it will wear faster and you'll have to adjust sooner/more often. If too loose (on slackside/bottom) it will cause slight jerking because of whipping from to much slack/tension under different throttle positions. (on/off quickly)

You will also notice after time when you get the right amount of slack you may not have to adjust your chain for quite awhile. It's in the happy zone of not to tight, not to loose and doesn't wear as much so you don't need to adjust it all the time. Of course your mileage may vary depending on chain and maintenance.

Start out with the TOTAL slack of 1". 1/2"up 1/2" down. It doesn't matter wear you take your measurement on the chain plates itself. Just take the measurement from the center point between the sprockets. Give or take. It's not an exact measurement. It's a close "Happy Zone" measurement because it's changing all the time.

 

Gray thanks for the education. Good post.