They would be sealed bearings, but the kind that have removable seals.
It is very easy to clean them and lube them.

On 12/29/2010 5:36 PM, whit3rd wrote:
On Dec 29, 11:32 am, tiredofspamnospam.nospam.com wrote:
I had tried the other day injecting my sons racing lube into the
bearings....
I'll probably go for more serviceable bearings.

The sawdust environment is NOT kind to 'more serviceable'
bearings. I wouldn't bother with any system meant for
frequent maintenance, just get more sealed bearings with
the manufacturer's lifetime grease. It'll work for you.
"High quality" grease is only a few dollars a kilo, trust the
manufacturers' selection.