Hi, I'm having an issue with Niche grinder with its setting dropping down below 10. It was around 18-20 for same bean 3 months ago, and it's now 9. Is this normal for Niche? Or should I replace burr or spring that holds uppper burr?

Have you tried what I suggested to another user here:
Niche Zero: grind size mysteriously got much much finer

Post #4

How old is your Niche Zero? If you're within a few months of purchase, the grind size is changing as a result of the burrs seasoning in. There is no need for concern as this is a standard process for any grinder. The only issue begins if you start having to set the grind setting outside of the marked scale, just for measurability/repeatability, but there are ways around that.

Just to make sure, you don't mean that the setting changes during grinding, by itself, correct? Because that would be a concern, yes. But if you just mean that you used to grind at 18-20 and now you grind at 9-10, that's likely not an issue.

Thanks for the reply. I bought this 2nd hand 3 months ago. This has been with previous owner for about an year I believe. Burr setting does not change while grinding, so that's not an issue. I just find grind setting is getting lower as time goes... I also have an issue where top head grinds, or very tight when I try to assemble it back after cleaning. I'm going to try food grade grease and see if it makes any better.

Before you put food grade lubricant in your grinder, can you explain what you mean by "top head grinds, or very tight"??

The only place where you can (not a necessity) apply lubricant is in the collar threads.

Sounds like you need to clean the grinder thoroughly again and recalibrate.

Some people grind closer to 10. I've always had to grind between 4 and 12 on my Niche Zero. These differences are normal. There's not much that can go wrong with the Niche Zero. It's a simple design with top notch burrs.

Are you saying that the grind setting is changing on its own, or that you now need to grind finer for the same bean?

Grind finer for same bean. From setting 20 changed to 10.

I've attached a photo where I will place grease. Is this part safe to apply lubricant?

In the collar threads. Yes. No problem.

It won't do anything to your grind settings though.

Report back once you've cleaned and recalibrated your Niche.

You can check Dave Corbey's YouTube videos for this.

Cheers!

Thanks so much! I'll let you know