Drive Chain adjusting plate moving
 

So I loosened the rear axle nut and adjusted the chain slack yesterday. After a short ride the adjuster plate moved in a few mm making the chain very loose. The axle nut was torqued down to 70 ft-lb.

Anyone know why this could be happening?

Also, what position are the 2 adjuster bolts supposed to be in? (if you have adjusted it before you know there is that space between where the bolt is loose and turning it does not adjust)

The 2 adjuster bolts go in whatever position gives the correct chain slack. You set the chain, tighten the axle bolt and your good to go. Have your torque wrench checked.

Should be some index markings to get you in the ball-park. Sight down the
chain/sprockets to see that they are all lined up correctly.
There should also be a 'replace' mark on the indexing to tell you
when the chain has worn-out. If you are all the back on the
adjustment, you need a new chain/sprokets.

Ern

MadHattr, thanks, but my chain and sprocket are new. I understand about the markings and their use for alignment, but still my problem remains;
I adjust the the chain slack (its near the new side), I torque down the axle nut properly, but after a ride there is too much slack.

For me it's always been a trial and error thing. Best thing to do is approach it with a clear headed objective mind and don't get frustrated. Like you, sometimes I'll set my slack, take it out for a spin, come back and find that it's totally loose and way out of spec. Why does this happen? Hell if I know. What's the solution? Do it over and tighten it again. Also remember that the chain will lengthen a little bit when it is heated.

I will agree also that the adjusters are not particularly accurate nor easy to read and do have a bit of slop in them. I count the number of turns to get me even on both sides, then I center the chain on the sprocket so that it tracks evenly down the middle and doesn't rub solely on one single side while I spin the tire.

Another thing you will notice is that once you have everything all lined up, when you torque the axle nut, the wheel will shift and get cock-eyed again, so you'll have to compensate for that shift when it's time to torque it down.

Finally, make sure that the threads on the axle and the nut are free of grease. If they're not totally dry it'll loosen up on you.

You sure the axle is moving? Or is a crap chain loosening?

Incognito, thank you...

boredandstroked...is DID a crap chain?

slightly besides the point is that the f4i's chain adjuster has 2 design flaws, one is that the adjuster bolt has a gap between tightening and loosening the chain and the second is that there is no lock nut for the adjuster bolts.

DID normally isen't crap but stuff happens.
As for the adjusters, they aren't flawed. The adjuster bolts don't matter after you've tightened the axle bolt. Normally after tighening the axle bolts I'll tighten the adjuster bolts a tiny bit to keep pressure on em.