So I just received my Magic Shine Jr./Cree light in the mail (have to say it wasn't that much when I ordered it). I'd really like to be able to leave the battery pack on the bike when locked up, so I was thinking about ways to mount the battery pack that would make it difficult to steal. Has anyone come up with a "theft proof" battery pack holder? Pics?

The down tube shifter mounts on my bike are empty, so I was thinking they might work as some sort of mount. Thoughts?

Also, if someone does end up stealing the pack how difficult is it to find/construct a new pack?

Not trying to be a smart-ass, but I went to one of these with a locking skewer:

I fabricated my own battery pack it was 5 rechargeable flashlight batteries
in plastic holders , (radioshack)
in series .. across the support dowel in my saddle bag, 5x1.2v=6v
wire runs along the frame to the light.

Now I use a nightrider sport battery pack, same thing, 5 cells in series ,
but a set of High Capacity NiMH batteries in a waterproof container
[the sport is also used as a dive light]

I've zip tied my pack for my Cygolite Rover II. I know they make stainless steel zip ties which should be more difficult to cut.

So, I would *love* to do something like that. But, I love me some light. Are the dynamo headlights out there equivalent, say, to the SSC P7-C driven at about an amp? Most of the dynamo headlights seem rather weak, but I know there are LED ones out there. Seems like the "6V-3W" on the hub implies that all you're ever going to get out of it is 0.5 A, but I don't really know much about power/dynamos.

I put my pack into a plastic tube holder and ran the lead out the cap. Then I zip tied to the rack.

You can get more secure by buying a plastic project box from Radio Shack. Their online shows a 3x2x1 box with a screw on cover. I think that should fit the two cell pack you have. If not, they got larger size. Do you have a rack? If so you can drill some holes in the box and mount it to the rack with nuts and bolt or even bolt it to the slot on the rack mounting arms. Otherwise you can zip tie or hose clamp it to the frame.

Supernova makes a pretty good dynamo LED light

The 18650 batteries in the pack are 2.8-3.7V - two wired in series for 6V. Crees use 3W. I think he was saying he uses that hub dynamo to power that headlight.

Actually, the very reason I don't have a good answer for this question is the reason I use a flashlight. No solution I could come up with could meet decent standards of reliability, weatherproofness, and ease of removal. So I finally just figured I'd use a flashlight. Still wouldn't mind a dynamo setup but it seems like I'd have to settle for less light.

Is it really difficult to remove the pack when you lock up? The only way it'll be truly "theft proof" is if you take it off the bike.

I wonder if you could make one that fits into your seat tube. Might make recharging more difficult, I guess. I like the idea of it being completely hidden though.

How many lumens do the best flashlights put out? I believe the best dynamo lights put out between 200 and 300 lumens. I didn't think the flashlights put out more than that. (though to be fair one could use 2 flashlights).

Well, the DealExtreme copy says it's 900 lumens. They claim that's "manufacturer rated". It's a SSC P7 C-bin, which appears to be rated at 7-800 lumens if I'm reading the PDF correctly on the SSC site. Obviously measured lumens would be subject to various losses, but I'd bet it's more than 2-300 lumens. Battery life on high is about an hour, which works for me.

I don't doubt that the beam could be a bit more efficient. Since it's not designed for a bike, there's a fair amount of the beam that's not illuminating the road. I'm not terribly disappointed because it still helps people see me.

In the interest of setting the record straight, I just found someone that measured the draw on high as 2.25A (not roughly 1A as I mentioned before).

Yeah, most of the lumen ratings for dynamo lights are believed to be fairly accurate, while the ratings on cheap flashlights and such are believed to be rather overblown. For example the Magicshine 900 is believed to be 400-500 lumens in real life. I seem to remember that even the best single flash putting out less light than the Magicshine, though...

And as you say, the dynamo lights tend to waste less light off to the sides.

I dunno. If you live in the twin cities in Minneapolis I'd be happy to compare my dynamo light vs your flashlight and see how they match up in real life, haha!

+1

If I'm locking my bike somewhere, everything easily removable goes off the bike, but I use backpack so...

Supernova E3 triple claims 800 lumens and it does use dyno. I use E3 pro myself and quite happy with it.

Thanks for the offer, but I live in warmer climes. The info on the Magicshine is interesting, though, thanks. I believe the light I'm using uses the same emitter as the Magicshine, so I would imagine the outputs are similar. The Magicshine figure is likely an upper bound, actually, since the head is bigger and presumably the wiring may be better, etc.

Interesting stuff! I remember being pretty amazed/happy that my new flashlight could compare with a 20W MR-16 (although not overdriven).

Would that have spared me the sight of the skunk to the side of the road, who almost ran out in front of me? At least I would have been less stressed if I hadn't seen him. Cute buggers but I really don't want to hit one.

I wrote the thing you're responding to, but even so +1 on your thought, haha. :-) Seriously...I don't know why I wrote "waste less light off to the sides" when I actually prefer more light off to the sides. I ride MUPs here, and *terrible* for rabbits and critters where I really value that light off to the sides...