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Schmidt Hubs - first impressions
A slightly adapted reprint of the article first published in Arrivee, August 1998

I must explain. I had been tinkering around with bulbs the day before and had quite by accident, fitted a 15W bulb into her front light instead of the 5W bulb she was expecting. Run time was cut from the expected 6 hours to under 2, but wow, what a light!

And talking of the 'wow' factor - here's a letter from Pamela Blalock in America -

"Wednesday we found the long anticipated box from the CTC on our front steps.

The HUBS. The HUBS are finally here.

Some of you may recall that I had mentioned a while back that John and I had ordered a couple of the cool new Schmidt dynahubs, based in large part on the *glowing* review from Chris Juden. To be honest, we hadn't even read the review (since we get our magazine surface). We'd just heard about it, but the reports on the review were *glowing*. We did finally get the magazine a few weeks ago, and the article is really superb, in typical Chris Juden style. Again, I highly recommend CTC membership, if only to see the great technical articles from Chris Juden.

So anyway we called and placed our order for the hubs and some extra Lumotec lamps, and a bunch of christmas cards, and other cycling greeting cards. Unfortunately the hubs were on back order, so we had to wait. John's been picking up some of my American instant gratification tendencies and was becoming as impatient and eager as I was. (especially with the recent thread on lighting here)

So don't you know the day they arrived, John had just had a large mole cut out of his arm, and couldn't build the wheels! So we carried them over to our friendly local wheelbuilder to be built up for us. Last night, we picked them up.

My single bike uses 26" (559) wheels, as does one of our tandems. John uses 700C wheels on his bikes, and our road tandem has 700C wheels, so the idea was to build one of each size, and we'd have power for any and all bikes. (the trike's hubs are all busy with brakes and gears, and apparently the system isn't recommend for it's wheel size anyway)

We decided to try them on the singles for today, and got mine set up last night.(John did his this morning) Now so far we have only been up and down the street in front of our house at night, but WOW! That Lumotec lamp is darned impressive. In addition to providing awesome light on the road, it is incredibly visible to oncoming traffic. Just standing in the road as John road up and down, it was amazing how incredibly bright this thing appeared coming toward me. WOW! And then I got on the bike and WOW! I'm sorry, am I getting repetitive? WOW! It was awesome. This lamp really, really puts out the seymours! Even if you don't go whole hog for the hub, the lamp is well worth checking out if you are less than satisfied with a current lamp)

(We got the standard - non led Lumotec - keeping things simple and separate. We also installed the 3 watt Reflectolite to better match power output. The 2.4 is actually brighter, but would likely blow due to power overload.)

Oh and then there's the source of power. First there was NO sidewall hum. I din't have to worry about using a specific tire, or having the gennie lined up properly with the sidewall, or slippage in the wet, or anything. And there was NO noise. Heck that's got to make you go faster, right!

And the proof happened this morning.

This hub is big. So big that I simply glued my Avocet magent directly onto it. Then we rode into work this morning, and boy did we FLY. My average seemed about 30% greater than usual. Talk about NOT a drag! It was an aid! And it was so much fun that we managed to slip in an extra 6 miles without me even realizing it (based on the number on the cycle-computer when we arrived). When they said 65% percent efficient, I didn't realize it would make me 65% MORE efficient ;-)

OK. OK, it dawned on me fairly early on that magnets or something in the hub was affecting my computer, but darn it felt good to see those big numbers anyway. Turning the light on didn't seem to make me go any faster though ;-) I wonder if I can just do away with the Avocet magnet and get reading straight from the hub ;-) For now we'll probably just move the computer stuff to the rear wheel, but I am curious what others (using this hub) have seen with regards to the affects on cyclometers.

We will truly give the new setup a real test over the next few days (tonights homeward commute, and some long rides this weekend) but I am certainly impressed so far.

The actual cost (including shipping from England) ended up being about $50 more than a comparable front wheel would be WITHOUT power and light.

Anyway, these are first impressions. Obviously we want to give them a bit more thorough workout, but WOW!

pamela "darn! daylights savings time is coming" blalock
chelmsford, mass, usa "

Further research showed, apparently, that it was indeed quite possible to run the Avocet direct from the generator magnets - it had to be re-calibrated because the Schmidt has 26 magnetic poles while the Avocet magnet ring had 20. However the beefy Schmidt magnets were generating far too much voltage for the computer to handle and it soon burnt out. Don't try this at home, folks ...

Geoffrey Boxall has also succumbed to Schmidt-mania -

"On Monday of this week I rode up to the C.T.C shop to look at the Schmidt dynamo. In a moment of weakness I let the moths out of my wallet and came home with one in my saddlebag. They have one built up and in a pair of forks and it is a persuasive demonstration! They had a basket of them in stock - 32 and 36h.

Wheel for wheel the generator and front lamp adds 1lb to the bike. I removed the 2.4W bulb and replaced it with 3W, running front only.

The wiring is dead simple. A coaxial looking cable 500mm long comes out of the lamp and finishes in two connectors which plug onto two spades off the generator. Wiring very neat and simple. A simple toggle (miniature) switch is at the back of the lamp - up for on - down for off - a sort of fail save arrangement I suppose.

Through my local 'lane tunnels' the effect was excellent. The light was white and even when I got off and walked there was sufficient light to see by. I haven't tried it at speed yet, I shall take it up onto the Ashdown forest and let rip down Kidds Hill, I know I can freewheel at 40 there. This will be a daylight test, if the bulb is still intact I shall be satisfied with the voltage regulation. The lamp has a built in reflector. The beam is flat and seems to be free from black spots. The rim of the lamp at the top will have to be blackened out, in fog it could throw too much light up into your eyes.

I am a convert - it is silent, doesn't seem to vibrate in use and doesn't dip in power much on hills. The skewer is an allen key job but I suppose this is an anti theft deterrent. You could always use your usual QR when riding in anger.

Conclusions - a lot of money initially but over time probably a money saver. No stress from carrying loads of batteries or wondering where the next set are coming from in the middle of Wales. Geoff."

Is 3W enough? Certainly, but - bright lights are addi ctive and I must confess Sheila and I are now both hooked. In a recent 400 we were running 5W lights from powerful (but not heavy) battery packs in a bunch where several other riders were running generators. Our lights drew plenty of admiring comments and were certainly the best around. I have seen several descriptions of generator setups where a second light can be switched in to give a total of 6W when conditions are favourable. Obviously the drag increases so this is best tried with an efficient low-drag generator such as the Schmidt or the Shimano.

Simply - hook up a second front light in series with the first, but with a bypass switch. On fast sections, switch it into circuit for 6W of light. If the light starts to dim or the drag gets too much, just switch it out of circuit to return to normal 3W operation. Another way to achieve this is to make the second light a 12V 6W bulb, this time in parallel circuit with a 2-way switch, giving either/or. It really works.

Note that most generator setups rely on voltage limiting built into the headlamp - so any extra lamps fitted should also be voltage limited. If the voltage limiting is put elsewhere, at the generator for instance, then these tricks won't work, as they rely rising voltage to give the extra power.

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