Rear hub temperature

[Burchy]

Just completed greasing the drive shaft splines and took the bike for a shakedown spin, about 20 miles.  No issues ,so pleased with that, but when I got back I noticed the rear hub was quite warm.  In 7 years of ownership, I can't remember ever checking the temperature of the hub before. 

Can anyone else let me know whether this is normal.  It wasn't "hot" but quite noticeably warm.  Thanks in advance!

Yes, the bevel box oil is up to the correct level.

[Boomer]

It's turning 135bhp through 90 degrees, so I'd expect it to get warm.
Even with oil there is some friction there.

[Robbieben]

The oil in the differential gets warm quite quickly and will be quite warm but not hot to the touch after a short ride.

[Burchy]

Thanks both.  I kinda knew that it was OK, but the usual paranoia kicked in