Hub Dynamo and Light

JohnKempStarley

Hi
I've recently acquired a new toy in the form of a new wheel built with Shimano hub dynamo DH-3N80. I've combined this with a Busch and Muller Cyo premium light with a view to use this for summer night rides as well as all of the times I'm caught by twilight and darkness in winter. A fit and forget ( about batteries ) solution. I've detailed the whole setup and my thoughts on the beam quality at the link below:-

http://thelonewheeler.blogspot.co.uk/

I hope this helps anyone making the same decision I made as there are few reviews of the Cyo premium on the net.

DrLex

Nice write-up. I've been using a similar hub dynamo with a Philips RideSafe for a couple of winters, and it's been ideal - great beam pattern and no battery concerns. If I was buying now, I'd be choosing a front lamp with a USB socket to give me an alternate use for the electricity generated.

JohnKempStarley

Yes the B+M Luxos U was available and it has the USB output but unfortunately it cost around £103 as opposed to £50 ( now £46 I believe ) for the Cyo premium. The Luxos B is £63 but sadly B+M have omitted the enhanced lighting features of the U model, 90 lux flood and variable beam with speed. Also the Phillips saferide 60 was getting good reviews but Phillips have dropped out of the market from what I've seen which may not be good warranty wise. For now its nice to have a powerful beam and no thoughts of running out of power ( I still have my L2D in pocket just in case of electrical failure! ). When riding with the Cyo I keep thinking of a single dipped beam headlight and its not far off. Surprisingly if you look at the legal beam pattern for cars they seem to have about 60m throw, quite scary considering you can be doing 70mph( or more for many ) with that, especially considering reaction times of most people.

nevman

That is very helpful.Thanks for the blog.

JohnKempStarley

No problem hopefully it'll add a little more to the sparse info out there on this light. Pity I can't image the beam thats the awkward aspect of dynamo lighting. Peter White of New England has done a good job with his test rig but it's difficult to get exposure spot on to match everyones perception. What I do feel is that the Edelux 2 photo he has isn't much different to what I see with the Cyo at moderate speed. One area that others mention is that of lighting into corners as you turn. I do slow into tight bends as it has limited visibility to some extent but you could use a small headtorch if it were a big concern, so far I haven't found it so. The Luxos beam is slightly wider but I think less throw. I'm very impressed by the current technology but as I've come from a 180 lumen Fenix L2D I don't want people to be dissapointed in comparison to say 1000+ lumen lights. But the beam shape is very important here in efficient use of the lower output. It would be good if Fenix could offer a dynamo version of their BT20 light head as it too has shaped beam and outputs 750 lumens.

DrLex

JohnKempStarley wrote:

Yes the B+M Luxos U was available and it has the USB output but unfortunately it cost around £103 as opposed to £50 ( now £46 I believe ) for the Cyo premium. […]

On a budget and wanting USB output, I'd be buying the AXA Luxx 70 for under £60.
(Of course, if you're handy with a soldering iron, £5 of bits will get you a project to run from the dynamo instead of the lamp of your choice.)

Sad about Philips - I have the SafeRide 80 on my non-dyno bikes and used to recommend it. Should it stop working, I may have to mod. it to run from an external battery pack.

JohnKempStarley

If I wanted to have the USB charging feature now, I would most probably make it myself. Though there are cheap off the shelf products too. I'm an electronics engineer so it would be pretty straight forward. Thats why I like the state of the technology at present, its nice to see efficient light sources. It can only get better too. I would like to see the BT20 in real use too out of curiosity.

For now though I'm pretty happy with the Cyo premium it fulfils its purpose well. Today it was seriously gloomy as it has been for days with the temperature stuck at 6 degrees( don't live beside the north sea ). It was nice to ride with the daytime LED's on and simply forget about batteries.

atomicjoy

Having been hit by a motorist entering a roundabout straight into my leg and back wheel on the brightest morning of the year a couple of weeks ago, the thought that if being an 18 stone prop forward in bright sunshine isn't enough to be seen, daytime running lights might be a good plan. This on top of my like for the concept of generating my own power means I am planning to fit a hub dynamo, so I can be lit up without worrying about dead batteries for a nocturnal return.

Looking across the web, the options seem to be:
Shimano: perfectly good and reasonably priced.
SON: top of the range in efficiency, reliability and service, reflected in the high price
SP: approaching SON in the efficiency stakes, but not as well-proven, priced between the above

I am leaning towards an SP PV8, as it seems to hit the sweet spot for balancing efficiency (as an 18 stone prop I want as much of my leg power moving me, rather than being lost in a genny, as possible!) and cost, but would appreciate other people's opinions, particularly about its reliability.

The Rookie

atomicjoy wrote:

I am leaning towards an SP PV8, as it seems to hit the sweet spot for balancing efficiency (as an 18 stone prop I want as much of my leg power moving me, rather than being lost in a genny, as possible!) and cost, but would appreciate other people's opinions, particularly about its reliability.

Surely the wrong approach, as the power required to drive the bike at any given speed is much more than for a smaller lighter rider, then the amount taken by the dynamo is much less as a proportion of the total power, so a less efficient one for you makes more sense?

atomicjoy

The Rookie wrote:

atomicjoy wrote:

I am leaning towards an SP PV8, as it seems to hit the sweet spot for balancing efficiency (as an 18 stone prop I want as much of my leg power moving me, rather than being lost in a genny, as possible!) and cost, but would appreciate other people's opinions, particularly about its reliability.

Surely the wrong approach, as the power required to drive the bike at any given speed is much more than for a smaller lighter rider, then the amount taken by the dynamo is much less as a proportion of the total power, so a less efficient one for you makes more sense?

That's a respectable school of thought, but one I'l play truant from; yes, losses will be a smaller percentage of what I generate, but I more watts to move me so I'd like to keep as many of them as possible!

jockywilson

If you go down the shimano dynamo hub route, the best price I found online for a fully built wheel is from Rosebikes in Germany (assuming you're after a 700c wheel):

http://www.rosebikes.co.uk/article/atb- ... aid:581967

WIth delivery it works out at about £68. Dynamo lights are also cheaper in Germany, so worth buying together.

JohnKempStarley

I think Atomicjoy if your heart is set on the shutter precision dynamo then no debating of power losses, efficiencies will change that. Just the same as we all choose different bikes for one reason or another but I must agree that regarding your weight plus bike weight the speed difference caused by the dynamo losses will be seriously small ( in the order of hundredths of an mph ). Much smaller than simply the effect of your mood when riding I'd bet. The shimano 3N80 is heavier than the SP but the mass is at the hub so the wheel rim you mate it with is important. I have to say Rose bikes were very good ( come on UK you can compete particularly if you're a wiggle etc ). My Cyo premium light runs four leds in daytime ( low power ) not the main beam led that lights with a photosensor as I've the senso variant. Still ideal for being seen but the power loss isn't a great as the main light. If power losses as small as the dyno relative to your mass are so critical then you must also start looking at all areas of your bikes transmission, tyre pressures, tyre size, bike position for drag, clothing etc as these will all factor in significant ( but very small for most barring air drag ) power losses but as important as the dyno drag. With the Rose bike pricing on dyno's particularly shimano you could save money to spend on something else as a bonus treat.

I may not cycle at high averages myself( 15-17mph on my dyno hub cross bike at cruising heart rate ) but I must say that I've not felt any clear effect of dyno drag and I'm only a lightweight so I should. The advantage of the dyno hub have far outweighed any tangible reduction in speed.

atomicjoy

TO be fair the power/mass thing was somewhat tongue-in-cheek, and you're quite right that that a big factor is I would just feel better knowing I had the best value and efficiency bit of kit. I fear I'm a bit like team 3 in this on my own...

JohnKempStarley

Yes Atomicjoy I'm in group 3 too. When I was at work people could not believe the depth of product analysis I'd do for even minor purchase's. Very often months then I wouldn't buy anything. For me its aiming to get the choice right and also the cost so I don't feel my purchase was a mistake. It took me about 18 months to decide on my recent bike build even drawing frames on a drawing board to get the geometry right, I now use rattlecad which is very good.

I too was very tempted by the SP but I read somewhere that its power output was lower at low speeds( I was thinking it could have effect on very steep hills... 5mph etc ). So far I'm more than happy with the DH-3N80, its great on dull days or rainy days to have a light on without any thought of batteries. Also the beam of the cyo premium in full darkness was a very positive experience considering only 3W, but the optics use the light well not wastefully.

atomicjoy

JohnKempStarley wrote:

Yes Atomicjoy I'm in group 3 too. When I was at work people could not believe the depth of product analysis I'd do for even minor purchase's. Very often months then I wouldn't buy anything. For me its aiming to get the choice right and also the cost so I don't feel my purchase was a mistake. It took me about 18 months to decide on my recent bike build even drawing frames on a drawing board to get the geometry right, I now use rattlecad which is very good.

Phew, it's not just me!

I too was very tempted by the SP but I read somewhere that its power output was lower at low speeds( I was thinking it could have effect on very steep hills... 5mph etc ).

The graph at the bottom of the third page of this article suggests that there's not a lot, if anything, in it. I hope that doesn't upset you too much!

So far I'm more than happy with the DH-3N80, its great on dull days or rainy days to have a light on without any thought of batteries. Also the beam of the cyo premium in full darkness was a very positive experience considering only 3W, but the optics use the light well not wastefully.

I was thinking of the B + M pairing of a front Lumotec IQ2 Luxos Uwith a rear Toplight Line brake plus

JohnKempStarley

No the small difference doesn't bother me in the least. One of the mitigating factors in my choice was cost, basically needing a new rim and seeing the Rose offer for the single front wheel dyno combo. So the balance was tipped towards the DH-3N80. Lights wise the Luxos U looks good and peter white has done a good review with images. Sadly the Luxos B cuts too many of the light features as opposed to simply cutting the USB charge output to save cost. I'd have been tempted by the luxos B otherwise but the Cyo premium ( hardware used in edelux II ) looked excellent at £50. It may have slightly longer throw but narrower beam, its a subtle difference though. I'm out of work at present so I acquired the wheel and light as a birthday treat after saving my travel expenses from my voluntary work. Cue the violins...... anyway Norman Tebbit said I should get on my bike and look for work so the lights are part of that activity .