Just got back from a 600 mile trip, and now the bike is making some scary noises when I accelerate from a stop. I only hear it when moving from a stop, and I think I'm kinda feeling it thru the rearsets. My immediate thought is something in the trans, as I can't see anything in the chain or sprockets, and the rear axle seems to be moving normally.
Ideas?
As you just had a couple of questions it sounds like you should take the bike back to who ever serviced the bike and see if they can explain the noises.
Is the chain tensioned correctly?
is the wheel mounted correctly? in the right holes?
was anything done in the area you are feeling the problem in?
if the noise is new and you can feel it as well as hear it I would have it looked at sooner than later.
Good luck
When in doubt, take it apart. My first thought is that the chain is wearing out and is due for a change. I would take off the chain and inspect it more thoroughly.
The chain dragging along the guard can cause a popping kind of sound but not really a crackling sound. The last time I heard a popping sound from my the drive train area was when I broke a tooth on a sprocket. It was only a single one though and sound kinda like the sound when you drive over a rock and it shoots out the side of your tire.
When your chain is loose and rubs on the udder during acceleration you'll feel it. Check that first then get it up on a stand, rotate the rear wheel and see what you can find. May be Cush drive rubbers that are flogged out. Put it in gear while on the stand and move the rear wheel back and forth, you'll soon find the problem if it's in the drive train.
Your chain my be dry/ruined. When did you last lube it?
The first and easiest place to start is the chain. I can't imagine a transmission making those noises (but I'm not an expert). Could also be that your sprocket is worn and you're getting the 'chain suck' effect where the sprocket/ chain won't let go of each other and after all the slack is taken up it releases sometimes with a cracking/ popping sound. You should be able to check for this by slapping her in neutral and rolling back and forth (engine off).
Good luck, hopefully that's what it is, would be a lot cheaper to fix than trans work.