Cycling UK Forum

Just come across this article (by CJ no less) http://www.myra-simon.com/bike/dynotest.html

Has various graphs of power and drag to speed

meic wrote:If you are really bothered by the weight, the Shimano 3N80 is nearer to 500g and around half the price of the SON hubs.

The dynamo in XAP Bobs U-tube link is switchable so it isnt really a fair comparison to a non- switchable hub is it?

I keep getting tempted by hub dynamos, especially as the prices for the parts keep coming down. However that extra 300g weight for the hub is a lot of batteries. In fact 15 hours worth for the Ixon doing exactly the same lighting as the IQ Fly.

Does the shimano 3N80 (premium model?) work with the SON type lights? Any compatibility issues?

This hub http://www.spacycles.co.uk/products.php?plid=m2b10s133p2056 produces enough voltage used in a 700 wheel to run LED headlights. Its light and spins pretty freely without the lights on.
This light is liks a car headlight http://www.spacycles.co.uk/products.php?mode=search

531colin wrote:This hub http://www.spacycles.co.uk/products.php?plid=m2b10s133p2056 produces enough voltage used in a 700 wheel to run LED headlights. Its light and spins pretty freely without the lights on.
This light is liks a car headlight http://www.spacycles.co.uk/products.php?mode=search

That's a search form - not a light...
Only mildly of topic, 531colin - what would you recommend in terms of a bottle dynamo?

meic wrote:I keep getting tempted by hub dynamos, especially as the prices for the parts keep coming down. However that extra 300g weight for the hub is a lot of batteries. In fact 15 hours worth for the Ixon doing exactly the same lighting as the IQ Fly.

It depends on the use. For Audax type riding, you have a good point. For commuting, however, I really appreciate the fact that my lights are always ready - I ride the bike, and if it's dark they come on. Always. It's just one less thing to faff around with, which is worth a couple of hundred grams to me, and I would guess most commuters, unless it's a particularly long and hilly ride.

[XAP]Bob wrote:Just come across this article (by CJ no less) http://www.myra-simon.com/bike/dynotest.html

Has various graphs of power and drag to speed

many thanks Bob. That is useful. Shimano premium seems close to SON!

Narrowing down to SONdelux or 28 or Shimano nexus premium N80 at the moment.

My worry SONdelux is that it won't work with eVerk to charge my mobile/gps etc on long tours. Which leaves me with SON28 or Shimano N80.
I really don't care about price difference. Efficency and weight though might be a factor. Bomb proof durability is not too essential either as this is not an expedition to Mongolia.

Couple of points;
No dynamo light is like a car! It's not even as good as many cheap battery lights. The better LED ones are IMO plenty bright enough for road cycling. Here's a good beam comparison and a realistic explanation of the limitations;
http://www.peterwhitecycles.com/headlights.asp

The Dynamo test linked to above is a good indication, but it's a few years old and things have moved on. Newer models from both Shimano and Schmidt and LED's have transformed the lights.

spin the wheel by hand is a poor indication of the drag you'll feel while riding. The magnets attract and repel, the drag is the difference between, you won't feel that at slow speed. Even worse than wheel spinning is trying to turn a dynamo hub when it's out of the wheel, it'll feel more like a hub brake. As others have said, once it's on the bike you're unlikely to notice it.

Shimano Vs Schmidt, ha, there's not alot of mechanical difference, but the Schmidt exudes quality. After eight years one of mine needed new bearings, sorted quickly in Germany for 40 Euros. Because it's polished rather than anodised it also cleaned up to look like new. Even if the Shimano lasted eight years, what would be the chance of finding spares?

As you'll see from the beam pattern link above the Edulux and Supernova are the top rated lights, there's also Solidlights a British company that's among the best. My only experience is with Supernova, the lights are brilliant and the companies service matches that. They offer upgrades as better lights or lenses become available. but also advice if it's worth doing or not.
http://www.supernova-lights.com/en/index.html

I have Schmidt hub. When I first bought it, about five or six years ago, I used it with an E6 halogen front and a B&M Seculite rear. About a couple of years ago I upgraded the lights to Supernova E3 (asymmetric). The LED front is worth having just so that you don't have to change the bulb every few months, but its extra brightness is also highly desirable.
In either guise, this has easily been the most reliable lighting system I have ever had. Now, with LEDs front and rear I don't even bother to turn it off in the day (though, admittedly, I only fit the system to my bike during the winter months). My commute is a minimum of 10 miles, and often up to 25, on largely unlit rural roads. I can now see where I'm going and am completely confident that my lights are always available. - This wasn't always the case with the various battery systems I used over the years.
I am very hard pushed to notice any drag, there must be some but it is not a noticeable problem. The same goes for the weight - a rechargeable battery system that would give anything like the performance AND AVAILABILITY of my dynamo would weight quite a bit more. - Alright, if you can mange with a minimalist system that runs for just the duration of a short commute between recharges then it might be lighter - but you will almost certainly be caught without lights at some time or other (I did - several times. That's why I bought a dynamo hub!).
I have just fitted a basic Shimano dynamo with B&M D'lumotec front and D'Toplight rear to my daughter's bike, and that also performs very well - a good budget option.

Once my batteries went flat on a 90 mile tour and the backup light was not powerful enough to lit pitch black country lanes. I simply have not planned for such dark roads and was late for riding back home. I had one of the scariest rides of my life until I arrived back home! It was a very slow and careful ride. Another thing with charging is that the batteries go down by time even when you don't use them. Guesstimating battery level is not always easy. You always have to be aware of your usage and be in maintenance mode with battery lights.

Hopefully dynamo system is nothing like that..

Went through the same decisions two years ago and settled on a Shimano DH3N80 dynamo, plus B+M Cyo front light and a B+M 4 Lite plus at the rear. It works for me. Can't fault it. The front light will illuminate the full width of a country lane and out to 20m. Easily enough light to see potholes etc at any speed on my commute. The rear light has 4 LED's and the outer 2 face outwards and back at 45degrees. As soon as I fitted it, I found that cars were giving me greater space when overtaking. I think that a lot of LED rear lights are bright rearwards and at 90degrees, but as cars approach, they get dimmer and drivers don't realise where you are.

ersakus wrote:One thing I realised is that I have cantilever brakes and the brake cable will prevent mounting the front lights to the front fork!

What you need is a Zinkens dynashoe. No longer made but Gaz is selling one (but it's just gone). You attach the light to the dyna shoe, and the dynashoe to the brake boss.

The SON28 and the later Shimaqno dynohubs (3N72, 3N80, Alfine etc) are all much the same in terms of drag, output etc. Any differences are too small to detect with the legs.
The SON20R/SONdelux give lower drag at the expense of a higher minimum speed and a little less power at equivalent speed. Power difference is probably only of any significance for higher power demands such as an E3 Triple or an eWerk with a high load (a phone being a low load). The minimum speed is difference is only of relevance with halogen lights.

The SON28 is available in more options (drillings, some stub axles etc) than Shimano.
It's better sealed so you stand some chance of not wrecking it if you absent mindedly ride through a flood.
You have to send it back to Schmidt for overhaul & bearing replacement, but at least you can.

There are limited maintenance possibilities with Shimano hubs. You can strip and regrease the LH bearing, but if you try to do the same on the right you are quite likely to wreck the hub. Shimano will almost certainly not be interested except for guarantee replacement.
There used to be instructions on how to thread parts along the very thin wires without breaking them, but that website has since died and the internet archive sites don't have the vital photos.

andrew_s wrote:The SON28 and the later Shimaqno dynohubs (3N72, 3N80, Alfine etc) are all much the same in terms of drag, output etc. Any differences are too small to detect with the legs.
The SON20R/SONdelux give lower drag at the expense of a higher minimum speed and a little less power at equivalent speed. Power difference is probably only of any significance for higher power demands such as an E3 Triple or an eWerk with a high load (a phone being a low load). The minimum speed is difference is only of relevance with halogen lights.

The SON28 is available in more options (drillings, some stub axles etc) than Shimano.
It's better sealed so you stand some chance of not wrecking it if you absent mindedly ride through a flood.
You have to send it back to Schmidt for overhaul & bearing replacement, but at least you can.

There are limited maintenance possibilities with Shimano hubs. You can strip and regrease the LH bearing, but if you try to do the same on the right you are quite likely to wreck the hub. Shimano will almost certainly not be interested except for guarantee replacement.
There used to be instructions on how to thread parts along the very thin wires without breaking them, but that website has since died and the internet archive sites don't have the vital photos.

So, considering that SON will cost £40 just for minimum maintenance, one might as well get the Shimano one and when they are knackered get a new one and replace the old. I know this doesn't sound green but attractive.
I have replaced a hub before and capable of this...

ersakus wrote: Hopefully dynamo system is nothing like that..

Spares of some sort are still advisable. No system is completely proof against failure.
I once rode Menai to Dolgellau mostly in the dark after my (bottle) dynamo lights failed to work, and I once had a front LED dynamo light blow at >40mph on a fast descent.

I'd suggest a battery LED as well as any dynamo rear light, or a second light if you use battery rear lights. A small LED torch can work reasonably well as a bike light, and is handy for puncture mending etc, when dynamo lights aren't much good. I use a fenix LD20, with an O-ring to attach to the bars if required.

Modern hub dynamos are very good though, and plugging the light directly into the hub avoids the wiring problems that are the cause of most dynamo lighting failures.

ersakus wrote:

meic wrote:If you are really bothered by the weight, the Shimano 3N80 is nearer to 500g and around half the price of the SON hubs.

The dynamo in XAP Bobs U-tube link is switchable so it isnt really a fair comparison to a non- switchable hub is it?

I keep getting tempted by hub dynamos, especially as the prices for the parts keep coming down. However that extra 300g weight for the hub is a lot of batteries. In fact 15 hours worth for the Ixon doing exactly the same lighting as the IQ Fly.

Does the shimano 3N80 (premium model?) work with the SON type lights? Any compatibility issues?

In case the previous posts didnt make it quite clear, Yes the Shimano hub works fine with the B&M lights like the Cyo (which looks the same as a car light when one is following you!) and IQ Fly. I imagine it will work with the SON lights too but I havent seen any one willing to spend the money on such lights who wasnt willing to spend the extra for a SON hub.

If buying any of the B&M lights you must check and double check that you are buying exactly the model which you want. There are some low power LED lights like the Ixon rather than the IQ Ixon which is the nice one. All those extra letters in the name have to be watched.

The common complaint that I hear about the Shimano hub is that the connector block for the wires is a pain, especially if fixing punc*ures in the dark.

I completely agree with Andrew B about the benefit for commuters of fitting the system and knowing that you have lights without fail and not needing to check your battery status.
Some people do so many Audaxes that they even reach that point.