Old 10-10-09, 06:11 PM
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Join Date: Sep 2005
Location: Michigan
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Bikes: Trek 730, Bike Friday NWT, Brompton M6R*2, Trek 830, Trek 720, Dahon HAT060, Dahon HT060,...

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Originally Posted by PaulRivers View Post
I wonder a little if the differences between a folding bike and a regular bike (the wheel is half as big, does this mean a fork mounted light is lower? does it mean the smaller wheel makes a bigger blind spot? does a smaller more responsive wheel mean that you have more of a chance to react to things closer to you, whereas the less responsive bigger wheel makes light closer to you less relevant?). I don't really know, in the end I would lean towards guessing that it's mostly a matter of preference.
In both cases, I have mounted the lamp at the crown level, i.e. the difference is of the lamp above either 20" or 29" wheel. In terms of illumination of intermediate distances this should work in favor of the folder.

Originally Posted by PaulRivers View Post
While I certainly wouldn't mind if the Cyo put out a little more light closer to the big, my feeling on the subject is just different from yours.
There is no good excuse for a lamp not to illuminate intermediate distances. Given, however, how many lamps fail to do that, this is apparently technically not that easy. I have accumulated, over time, a couple of dozens of different dynamo lamps. To predict how the shape of a beam will work in practice all one needs is to shine the beam on a garage door. For a decent performance, the patch needs to have a uniform vertical extension just as well as the horizontal. From the past lamps, only two, Bisy/E6 and Nova, produced rectangular/trapezoidal patches and worked well in practice. IQ Cyo R yields comparable vertical extension to Bisy, in its brightest area, see:


IQ Cyo Sport yields more just of a horizontal line, like Lumotec or other secondary or tertiary halogen lamps. When I have time maybe I should a photo of both of those lamps together, for a comparison.

Originally Posted by PaulRivers View Post
I wonder if you ride, on average, at slower speeds that I do? On my commuter bike, I typically ride between 15 and 20mph.
I am certainly a slow rider and I am sure that matters.

Originally Posted by PaulRivers View Post
Imagine your're coasting downhill at 20mph and something magically appears on the road 5 feet in front of you. At that speed, at that distance, I'm already screwed. It doesn't matter whether I see it or not, there isn't even time for my brain to process it, then get my body to move before I hit it.
I fully agree with this. However, why not having a lamp that illuminates the intermediate distances as well?

Originally Posted by PaulRivers View Post
So at the speeds I ride at, I feel like the regular Cyo pretty much lights up that area "that matters".
I think that there may be many people who will feel that Cyo Sport is adequate for their needs. Many people have also liked Lumotec and to me it was always at best a second-rate lamp. One problem is with the area I ride through. The roads in Michigan are bad. You would have hard time finding this sort of quality anywhere in Europe, including Eastern. In addition, it is often windy and there are plenty of twigs lying around. When I can, I use sidewalks where bikes are legal and where there are hardly ever any pedestrians. The sidewalks bring obstacles of their own that are hard to see at night.

Originally Posted by PaulRivers View Post
One problem I have with the Cyo is that it's difficult to get the angle just right where it's illuminating far enough ahead on the road for my taste, but isn't so high that the main part of the beam hits people in the face. I've found I *have* to have it mounted near the fork or it always ends up to high for people, but the right height for illluminating the road.
When I mounted a lamp on a fork, it usually ended up being destroyed around a bike parking rack.

Originally Posted by PaulRivers View Post
And as I believe I mentioned earlier, I own a Ixon IQ, which supposedly puts out 40 lux of light - just like the Cyo Nearfield. It's not that I think it doesn't reach far enough, but I do feel like when it reaches far enough, the light isn't quite hitting the road intensely enough to light it up enough for me. I've hit twigs and stuff that were large enough to feel though the tire, but I didn't even see because of the brightness of the light. Haven't had this happen with the Cyo all the time like it did with the 40 lux ixon iq.
I do not think that peak illumination is in itself that important. Imagine that you use a laser with which you can beat any any other light source. So what, you will just see an illuminated point that brings you zero information about what is ahead of you. This is, of course, taking it to extreme, but I just want to make a point that lux # is not all that matters.

Originally Posted by PaulRivers View Post
I think both our opinions are interesting for other people trying to decide, based on their riding speed and personal preference for what kind of lighting they prefer. I just want to be clear I'm not trying to say you're "wrong" or something any more than I am, just that opinions vary.
Sure. However, in all of this, I have been surprise by my findings. I went after R, rather than Sport, based on rational reasoning. My anticipation, though, was that the difference between the two would be more marginal. I thought that Sport would be an OK lamp for the folder and now I regret that I bought it.
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