Re: benefits/ disadvantages of tensioner-less chain?
I forgot about chain tensioners on timing chains or belts. But I have never seen one on a motorcycle or dirt bike as part of the drive chain. There's a lot of engineering that goes into those bikes so I feel that tensionerless is how it should be in that case. Just my thought on it, others probably disagree.
I have been tensionerless the past few weeks. I just removed some links, took off the tensioner, put the wheel on as far back as I could (1-2cm till all the way back) and have been great since. With a perfectly true sprocket and frame clearance, you should be good to go without a tensioner. Your chain will stretch though especially if its a cheap china one. Only mostly during break in though.