Commuting - Need help mounting PB Superflash (seatpost is too thick)

I am riding a folding bike (Xootr Swift like this one (http://xootr.com/xootr/swift/bikes.shtml)) and the seatpost is too thick to take my tail light mount (Plant Bike Superflash). Because of the geometry of the bike there is no good place to mount it on my rear triangle and I don't have a rack or panniers. Any tips on mounting it to my bike somehow? I usually wear a backpack, but I find that attaching it to my backpack with the belt clip doesn't work very well because it tends to droop and point down and I worry that it will fall off.

Thanks in advance.

If you're not too concerned about leaving it on the bike, I'd just use two zipties.

Why won't it work on the seat stay, halfway between the seat tube and the tire?

I attached a PB superflash to my kid's trail-a-bike on the seat stay. Works great.

Why won't it work on the seat stay, halfway between the seat tube and the tire?

That seat stay is at a really shallow angle; I don't think the mini clamp will hold it far enough away to be able to orient the light vertically so that it aims straight back. It just works on one seat stay on my CAAD8, but on that Swift, it'll be pointing upwards.

Maybe that's a clue, though. Get a small extension of some kind, bolt one end to the miniclamp on the seat stay, then bolt the light bracket to the extension.

So:
miniclamp*||extension||*light bracket

The big, normal-sized clamp won't fit on that seatpost, even without using the rubber shims? 34 mm is a lot thicker than I thought; what about using a longer bolt instead?

I can get it on the seat stay, but only if it's pretty low (so as not to interfere with the brakes and the folding mechanism). It just doesn't seem as safe to have the light down really low on the frame- I am worried that drivers won't see it as well.

I may try the zip ties or the extension idea. A longer screw *might* work, but I'm worried that it would force me to bend the bracket at a funny angle.

Thanks guys.

Ah, ok --

Solution #1: Put it on the left seatstay so that more drivers will see it.

Solution #2: Get two lights, one for each seatstay. ;)

I cut out a wedge from 1/4 plywood, with a tab for the light mount.
The wedge slides under the seat.

http://i256.photobucket.com/albums/hh187/10wheels/bestseatmount.jpg

Get a Minoura Space Grip or something similar, mount it to the seatpost or seatstay, and mount the Superflash to the Space Grip.

http://www.easystreetrecumbents.com/images/gen_accs/sgblack.jpg

Get a Minoura Space Grip or something similar, mount it to the seatpost or seatstay, and mount the Superflash to the Space Grip.

http://www.easystreetrecumbents.com/images/gen_accs/sgblack.jpg

Dude that is a frakkin awesome idea. I have a similar problem with my massive rear suit pannier covering nearly all visible light mounts on my seat stay and rear triangle. I'm definitely going to try that.

I just used a longer bolt/screw if you have one lying around ...

Most bike shops have a box with miscellaneous mounting clamps of random sizes lying around. Try taking a measurement of the seat post and see if you can find something you can adapt.

Great thinking 10 Wheels.

I just zip-tied mine own.

Now that I think about it, having anything on the seatpost is going to interfere with the folding process. I may just stick with the rear triangle or I might stick it on my backback (or perhaps I will try the custom seat attachment).

http://i34.tinypic.com/b6o6kh.jpg