Eric is correct. The SON hubs have a "pressure compensation" system which prevents the hub from sucking in moisture through the bearings as the air in the void spaces inside the hub contract when the hub goes from a warm environment to a cold one, or vice versa. I don't believe any other dynamo hub on the market has this system, which is not necessary in a non-dyno hub because the interior air volume is so much lower on a standard hub.
That said, I have two Shimano hubs that have been in service since 2011 and 2012, respectively, with the 2012 hub seeing winter use each year. Neither hub has had any issues so far. I also have an SP hub which is just now seeing its first winter, and no issues yet, although it's really too early to make a judgment on its longevity. I have a friend with an SP hub that did just fail after its third winter season. The bearings seized up. Whether it was from moisture penetration as discussed above, or from some other effect, I don't know. Anton On Friday, February 5, 2016 at 1:09:06 PM UTC-5, Eric Norris wrote: > > From what I’ve read, the SP hubs aren’t as nicely sealed as the SON. I > think the question about “air pressure” relates to the SON’s reputedly > better ability to deal with changing air pressure—you go from a warm house > to a cold, wet outdoor environment, and the air inside the hub contracts > and draws moisture into the hub as the outside air enters to equalize the > pressure. You can avoid this by letting the bike “cool down” to the outside > temperature before you get it wet. > > That being said, I’ve heard from people who have used SP hubs for extended > periods with no problems of this sort. If you don’t go from a warm house > immediately into a cold rain, you should be OK. > > --Eric Norris > campyo...@me.com <javascript:> > www.campyonly.com > campyonlyguy.blogspot.com > > On Feb 5, 2016, at 9:08 AM, Jim Bronson <jim.b...@gmail.com <javascript:>> > wrote: > > What air pressure system? The SONDeluxe is sealed. > > I know of the old oil-can style hubs, in case of a sudden change in > temperatures, could develop a pressure gradient and suck in moisture, but > that was fixed in production many years ago. > > On Fri, Feb 5, 2016 at 10:56 AM, Lungimsam <john1...@gmail.com > <javascript:>> wrote: > >> 1. How ling 'til it has to be serviced? >> 2. Who can service it? Any LBS or have to mail to them? >> 3. Does it have that air pressure system like the SON deluxe hubs do? >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "RBW Owners Bunch" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to rbw-owners-bun...@googlegroups.com <javascript:>. >> To post to this group, send email to rbw-owne...@googlegroups.com >> <javascript:>. >> Visit this group at https://groups.google.com/group/rbw-owners-bunch. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > ------------------------------------------------------------------ > signature goes here > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to rbw-owners-bun...@googlegroups.com <javascript:>. > To post to this group, send email to rbw-owne...@googlegroups.com > <javascript:>. > Visit this group at https://groups.google.com/group/rbw-owners-bunch. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
