JohnB. wrote:If the rest of the grinder turns out well but you are unhappy with the burrs there are other 38-40mm burrsets that should fit. It is disappointing that they claimed they were 48mm just as it's disappointing to now see OE doing the same.

Maybe another grinder maker will now measure the burr as the diameter of the hand that grips the grinder. Then all competitors will have to follow suit. Then it won't be long before the burr is measured as the circumference of the earths land-space that is not already claimed by another burr.

But in all seriousness, would it be as simple as slotting in another set of similarly sized burrs? I doubt it. The collars are clearly very different. I for one would not have bought another 38mm burr grinder if I had known.

JohnB. wrote:If the rest of the grinder turns out well but you are unhappy with the burrs there are other 38-40mm burrsets that should fit. It is disappointing that they claimed they were 48mm just as it's disappointing to now see OE doing the same.

Rappy wrote:(It should be reiterated that this particular burr is commonly referred to in other situations as a 38mm burr. and they clearly state it is 48mm.)

To be fair, I think Rok's call on the burrs size is correct. It was us who unconventionally assumed the measurement to be inner diameter(ID). For example, what we commonly call 68mm Titan Conical is referring to the OD (71mm for Robur). 38mm conical refer to the OD as well, with 30mm ID.

To clarify, there're two version of small conical burrs(correct me if I'm wrong):

i) 38mm OD, with 30mm ID- used in Hausgrind, Lido 1, and Rosco Mini
ii) 48mm OD (Including the burr collar) - used in Lido 2, Rok, Solis/other electric grinder?

But it is not as simple as burrs size, there're different burrs geometries in each category (38mm & 48mm) that come into play, exactly as mentioned by OE.

If bigger burrs are better, should we be more happy with the Rok now?

But all these assumption that bigger burrs=better are inherently flawed, really. It's just plain ignoring the other factors that is probably more important.

And another point I think should be made known(recall reading it somewhere, probably from OE), there're only a handful burrs manufacturer in the world (discounting private burrs maker & Malhkonig). Most of the time the burrs you see are probably from the same manufacturer.

Edited for correct infomation

@samuellaw178
No its not as simple as burr size, but we are talking about burr size. So while we are, lets get things straight.
There is a misunderstanding in your post. When ROK says 48mm burr they are not even referring to the usual OD of the Outer burr, which on the LIdo2 is 40mm, on the Hausgrind/Lux/Solis etc. 38mm. So 48mm was never assumed to be the Inner Diameter of the burr. But ROK are even referring to 48mm including the collar around the outer burr. This is what is unconventional. The Solis burr is 38mm on the OD of the outer burr, but according to OE and also logic, there is a 5mm collar (Diameter is twice the radius, so 10mm). So this is where the measurement of 48mm is coming from; a novel interpretation of burr size.

@ Ronald,

I see, it was just me who assumed it was ID then. I suppose they(the manufacturer) categorize the collar as part of the outer burr since they're one piece. How do you know the collar is 5mm though? In any case, it doesn't say anything about the Rok's burrs being 38mm with 5mm collar. It may be similar to Lido2 of 40mm with 3.85mm collar.

But 38mm or 40mm, I think they would perform similarly with burr geometry having a bigger influence.

I will have the Rok grinder from the first 300 and the upgrade to ceramic, I also do have 2 Rok (Presso) coffee-makers, its an Must have for this nice working on the road espresso-makers, these are the better choice for a good coffee from A to B !!

Size is not everything or always better.

I'm happy!

"upgrade to ceramic"

Why are people so excited about the ceramic burr option? From the comments on Indiegogo, it seems like they are concerned about the steel burrs wearing out faster than ceramic. How much coffee is everyone grinding that they're worried about burr wear?

I wonder how long it would take to wear out the steel burrs if one continuously ground coffee without stopping? Probably years.

Electric commercial grinder in a cafe, yes. A one shot manual never.

Don't forget the steel burrs will pass the 3' drop test and the ceramic ones will not.