As I posted in another thread, I'm looking at new LD bikes... and one of the things that will definitely be equipped on my new ride is a dynamo hub and lights. My question is this:

How important is the difference between the Shimano hubs and the Schmidt hubs? I see lots of statements from people that espouse both arguments... some say the Shimanos are just fine... no appreciable difference. Others say that they'd never consider riding anything besides a Schmidt SON hub.

When I look at quantifiable and measured data, I find that the SON takes about 1.5 watts to drive... and the Shimano takes about 2.2 watts. But what I don't know is how badly that small difference will weigh on me when I'm 350K into a 400K brevet. We all know that the little things add up...

I guess that I'm basically trying to decide if the SON is worth the price tag... almost three times the price of the Shimano hub.

What have you Dynamo hub riders done? What would you do differently if you were starting again?

I just ride my bike. I picked up the SON and have been very happy.

You can go to some online cycling power calculators if you want to work out that power drain. There is no free lunch, so the power to run your lights has to come from somewhere. Depending on what your sustainable power output is over a long ride you'll be able to determine what % that loss to the hub is taking away from your speed.

I went with getting a SON hub mostly because it was while I was spec'ing out a custom brevet bike and at that stage, I wasn't into taking shortcuts. I didn't want to revisit the decisions and wish I hadn't made compromises.

With that said, I've seen a lot of folks finish brevets with Shimano hubs, so I don't think that they're much of a physical handicap.

As a mental handicap, they might be a different story. If one is cutting their controle times close to the deadline, then they may lose hope if they think that they're being handicapped by the drag of a Shimano hub, eventhough the real reason for their tardiness may be wholly unrelated. It's just a very obvious (if inaccurate) scapegoat.

I've got a Shimano 3N-71 dynamo hub on a wheelset with studded tires that I use on a rigid MTB in winter. My tourer (which I also commute on when there's no snow on the ground) has a Schmidt dynamo hub. Both have worked flawlessly for the last few years, I would say that the difference is sort of like Campagnolo Record versus Campagnolo Chorus. The biggest functional difference is that the wiring on the Schmidt lights (or the Busch & Mueller lights that fit the Schmidt hub) is a good bit sturdier than the wiring on the Busch & Mueller lights that fit the Shimano hub. Another difference is that Schmidt now offers some really good LED headlights that work on the Schmidt hub, that may or may not be easily adapted to the Shimano hub. These new lights are supposedly much, much brighter than the halogen lights currently used with generator hubs.

Interesting test of a variety of generators:
http://www.vintagebicyclepress.com/VBQgenerator.pdf

In checking out Shimano's offerings I was underwhelmed by their quality. They just aren't all that nice. At the time, I thought "This is for the commuter, not the fellow who is going to put himself hundreds of kilometers away from home."

The Schmidt, OTOH, is easily equal in quality to any hub I've ever seen.

Speaking personally, anyway, I'm in Spokenword's camp: my brevet bicycle is one of those areas where price is little obstacle. I am very glad I spent a few hundred dollars extra to go with best-quality.

The SON28 is way shinier than the Shimano 3N71 (and available in super stealthy all-black), if that makes any difference.

Aside from the miniscule power differential required to drive the hubs at the same electrical output, I've heard similar reviews for both. Randonneurs talk about having a SON hub lasting for years and years through all sorts of weather and hundreds of miles; I've seen similar reports from commuters who put over a hundred miles a week, every week, on a 3N71 hub through rain/snow/summer heat, all with no problems.

i've done multiple long (300k+) rides using my shimano (3n71 model) dynohub, with it turned on all day/night (running front/rear lights). it certainly hasn't held me back. i might have finished a brevet a few minutes earlier, at most, but that's it.

the only bad thing i notice is a slight "buzz" when i hit ~40km/h, but i hear it's the same with the SON hub.

the only downside the 3n71 has, i think, is weight - the new 3n80 model should be much less heavy, and still cheaper than the SON.

also i *believe* the shimano hubs are more serviceable than the SON - can anyone confirm this?

My understanding is that the SON pretty much has to go back to Peter White for any service at all. Don't know about the Shimano.

My understanding is that the SON pretty much has to go back to Peter White for any service at all. Don't know about the Shimano.

and from what i've heard at my LBS, the shimano hub can be serviced at the shop (or by you if you knew what you were doing).

i think the SON hubs offer slightly better quality (at least i hope so for the price!), but for me the shimano makes sense. i think as long as you avoid tire-driven dynamos, you'll be OK.

When I look at quantifiable and measured data, I find that the SON takes about 1.5 watts to drive... and the Shimano takes about 2.2 watts. But what I don't know is how badly that small difference will weigh on me when I'm 350K into a 400K brevet. We all know that the little things add up...


Exactly how important that 0.7w is depends on how many watts your legs put out.
It will be around about 2-5 minutes over 400km. Calulator here (http://bikecalculator.com/veloMetric.html).

The 3n80 is supposedly better than the 71 and is 150gm lighter. I have no problems with my 71, its a nice unit. No problems with the shimano connectors either and can't see how they would go wrong if correctly installed.

As said above, buy a good LED light (or make your own (www.pilom.com), its not hard to do and very cheap). This will help you ride faster for longer during the night.

As another one stated, the Schmidt has to be serviced at Peter White's. In theory, the Shimanos may be serviced at most bike shops, but you can't pull the axle completely and it's very easy to break the electrical attachment; then it's toast.

I have had one Schmidt since 2001 (approx. 30-35 000 km, works as new) and one Shimano NX-30 since 2001 (approx 6-8000 km; I had to service it once, and to throw it away 1.5 years ago. I since has replaced it with a Shimano 3N71 and installed another one on my daughter's bike; both work well but have little mileage so far. It seems bearings have improved also.
As far as quality and resistance on the road, the Schmidt was definitely smoother than the old Shimano NX-30, but from the little experience I have, the newer 3N71 feels almost as good as the Schmidt. There is no perceptible notchiness when I ride the 3N71 with the light off and very little with the light on.


So should you go for the Schmidt?

One reason is aesthetics. If your bike has superb painting, your hubs are Phil Wood or Chris King, then you'll prefer a Schmidt hub. Apart from that, there are technical reasons. The 3N7x and 3N8x hubs are available only in hubs designed for 26"-700c wheels with 32 spokes (the 36-spoke version is vapourware). Schmidt hubs are available for in 24 to 48 drillings , with or without disc brakes, and are tandem rated. And there are also hubs for 20" wheels (at a given speed, a 20" wheel makes 50% more RPMs).

Finally, one interesting tidbit. The newer crop of LED headlights (IQ Fly, E-delux and E-3) are much more powerful and reach full brightness at a much lower speed. If you ride "decent" singletrack, it means you'll get some good light at 4 km/h and reach full brightness at around 6 km/h (from memory). Many randonneurs and fast riders use this to their advantage: they use a SON 20" hub on their 700c bike. which means lower resistance, and full brightless at 9-10 km/h, which is not bad anyways.

The 3N7x and 3N8x hubs are available only in hubs designed for 26"-700c wheels with 32 spokes (the 36-spoke version is vapourware).

Ah! Finally I see this in writing. Any word on if the new Shimano hub will have an actual 36 spoke option?

The 3N7x and 3N8x hubs are available only in hubs designed for 26"-700c wheels with 32 spokes (the 36-spoke version is vapourware).


You can get a 20 spoke 3n71 in the shimano wheel (http://www.shimano.com.au/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441782042&FOLDER%3C%3Efolder_id=2534374302037563&ASSORTMENT%3C%3East_id=1408474395181400&bmUID=1218612559027). Its somewhat nicer looking than the regular 3n71.

i think as long as you avoid tire-driven dynamos, you'll be OK.

Why is this mattm? I was considering this route as I will not need a dyno for nearly all of my riding. Seems like it would allow me to remove the unit easily when not in use. Then again I guess the dyno could be installed on a dedicated wheel. Plus when not needed the wheel dyno is disengaged from the wheel thus eliminating the drag.

Why is this mattm? I was considering this route as I will not need a dyno for nearly all of my riding. Seems like it would allow me to remove the unit easily when not in use. Then again I guess the dyno could be installed on a dedicated wheel. Plus when not needed the wheel dyno is disengaged from the wheel thus eliminating the drag.

not to speak for mattm, but the general prejudice against tire-driven dynamos is the increased drag when the generator is engaged and inconsistent performance during wet/rainy conditions. while there is some slight drag in a generator hub when the dynamo is not engaged, it is miniscule, and the drag introduced when the hub is running is tiny compared to a tire-driven dynamo. Folks I've talked to who've had tire dynamos describe it as basically stepping you back one gear in efficiency, which is signifcant.

I've got two Shimano 3N71's. I've noticed the "hum" on both when they're hooked to a steel fork. On my brevet 'bent, which has a carbon fork, no hum. As for the difference between drag between a Shimano and a SON, I wouldn't worry about it. Wearing a flappy, unzipped jacket will slow you down WAY more.

SP

not to speak for mattm, but the general prejudice against tire-driven dynamos is the increased drag when the generator is engaged and inconsistent performance during wet/rainy conditions. while there is some slight drag in a generator hub when the dynamo is not engaged, it is miniscule, and the drag introduced when the hub is running is tiny compared to a tire-driven dynamo. Folks I've talked to who've had tire dynamos describe it as basically stepping you back one gear in efficiency, which is signifcant.

Thanks. I was reading a bit more on Peter White's site about dynos. The information on the Shimano hub had more information useful to me about difference between Shimano, SON, and tire-driven dynos. If I end up going this route I am leaning towards a dedicated wheel with Shimano dyno for the times when I need lights (winter night riding after work and long brevets).

Why is this mattm? I was considering this route as I will not need a dyno for nearly all of my riding. Seems like it would allow me to remove the unit easily when not in use. Then again I guess the dyno could be installed on a dedicated wheel. Plus when not needed the wheel dyno is disengaged from the wheel thus eliminating the drag.

just in terms of wet/snowy conditions, i hear tire-driven dynos don't work all that well in those situations.

also i don't like the way they look! but that's just me..

not to speak for mattm, but the general prejudice against tire-driven dynamos is the increased drag when the generator is engaged and inconsistent performance during wet/rainy conditions. while there is some slight drag in a generator hub when the dynamo is not engaged, it is miniscule, and the drag introduced when the hub is running is tiny compared to a tire-driven dynamo. Folks I've talked to who've had tire dynamos describe it as basically stepping you back one gear in efficiency, which is signifcant.

Yup, that's exactly how I'd put it. The bottle generator I have adds about 1 cog's worth of drag. Since I do very little night riding, it's not a huge deal. I can always gear down a bit and up my cadence to compensate, but for a long distance rider that won't work.

The real dealbreaker for me with one is that it *will* fail in heavy rain. A Midwest style downpour will cause failure in about 10 minutes. (for east coast types, think tail end of a dying hurricane... that sort of rain) I haven't tested in longer rainstorms, since we don't get them out here, but I can't imagine it would do *well* in anything much past light rain.

The combination of rain and night riding with one of these suckers would be downright dangerous.

i have a bottle dyno on my bakfiets. there is a marked difference when i engage the lights.
i've never had it fail or slip. (i think my speeds are too slow on the cargo bike).
new baks come standard with a hub dyno. when my wheel or dyno fails i'll be upgrading.
i'll go shimano with roller brakes on the bak... but for a touring / commuting / rando rig i'd stick with the SON.

The 3N7x and 3N8x hubs are available only in hubs designed for 26"-700c wheels with 32 spokes (the 36-spoke version is vapourware).

Not true! I actually bought one this spring from Peter White. I did have to wait "a couple weeks" (which turned into 2-3 months) for him to get it in stock. So I wouldn't say they're easy to find, but they are out there if you have the patience.

Thanks for the update. I guess my information on the 3N-7x was about 1 year old.