What's the difference, basically? Is the 501 an improvement in any way over the 500.

That's about it really – if anyone can enlighten me, I'd be very grateful.

Isn't it that one can be used with discs and one can't?

EDIT – actually looks like the 500 is a dynamo front hub.

EDIT Again:

They added an additional roller clutch in place of a ratchet assembly. That makes the 501 completely ratchet free and improves the quietness and smoothness of the internal assembly. An excellent upgrade, and I’m sure Shimano will incorporate that in more and more 3 and 8sp hubs as the new models come out. I’m glad mine is a 501, its worth it!

from here: http://hubstripping.wordpress.com/alfine-shimano/

I did think that but the version that On-One are selling is disc compatible, and yet apparently is the SG-S500.

*Edit*

Ok, thanks for that – so it looks like the 501 is the one to get then, and not the version that On-One are selling (unfortunately….).

I would double check with On-One which version they are selling. As it was a rolling change a while ago they could actually be 501 they have. Ask them to check the Shimano code on the box, I bet it is actually ISGS501

Mister P – Member
I would double check with On-One which version they are selling. As it was a rolling change a while ago they could actually be 501 they have. Ask them to check the Shimano code on the box, I bet it is actually ISGS501

It seems that someone asked them this on the 12th of August – unfortunately it seems to be the 500 that they're selling.

Either the 500 or the 501 will be fine

The 501 is an improvement, but not that massive in the scheme of things. It's more of a minor update.

BOTH are full disc compatible, but you need a shimano centrelock rotor too…