Mornin'. I just replaced the burrs in my Rocky as well as the screen in my Rancilio Miss Silvia. I used to set the Rocky at approx "8". After replacing the burrs they are grounding out at about 28. My shots are still flavourful though much more watery. As an almost exclusively Americano guy I can work with this though I am at a loss as to why I cannot get thicker shots. Q. There is a set screw on the underbelly of the hopper. Could this have something to do with the burrs grounding out earlier???
Tapasguy.

The numbers are for reference only. See How to find grinder's true zero point and Rocky thread slop fix.

It sounds like a fast under extracted shot. As Dan points out, the numbers are for reference on that one grinder. Another grinder my be completely different. Just grind a little finer. New burrs may take a couple of pounds to get them broken in so you may have to make more frequent adjustments for the first month.

As Dave wrote earlier, your burrs will take a little while to break-in. The coarse to fine ratio of the ground may be completely different between the old burrs you have removed and the newer burrs thus you would get a very different extraction and taste profile.

Installing new burrs is akin to changing grinder all together, well, that is until the burrs settles after seasoning. It will take some time before you can relax. Until then you'll have to be on your toes and adapt to ever changing grounds characteristics.

The first few shots will see a lot of variation and it will reduce over time. The timing of the seasoning process depends on the nature and conditions of the burrs you have installed.

I have submitted a theory of the seasoning process here, What is burr seasoning? , but there was little reaction from the community so it is only a personal "educated" theory for now.

I hope this helps.

tapasguy - you have to find your "0" point and then go from there. You'll likely have to refind your perfect grinding point. You should be able to choke the machine off. I had alot better results with tuning things after the teflon tape mod (put a layer or two around the threads of the lower burr) FYI

tapasguy wrote:I used to set the Rocky at approx "8". After replacing the burrs they are grounding out at about 28.

With that much difference in the setting I suspect you may have installed the hopper 120° from its original position. (3 screws=120°). It really doesn't make any difference at all in the grind once you have it dialed in, but if you want to have the grind setting closer to 0, try reinstalling the hopper after rotating it.