Minimal dynamo light mount

[J-D Bamford]

When I migrated from a randonneur frame to the Roadini, I decided to forgo a front (rando-style) rack and bag. This is what I came up with.

When I migrated from a randonneur frame to the Roadini, I decided to forgo a front (rando-style) rack and bag. I flirted with different light mounts on the market, but was underwhelmed. I had good experience previously with the Velo-Orange light bracket, but wasn’t sure if one would hold its position well on the Roadini’s hourglass fork bosses (and I didn’t want to crank too tightly on any bolts or star washers which might crack this pretty bike’s paint).

I found inspiration when I spotted thinwall aluminum tubes at the hardware store. This one was 12” long and cost $2.49. I cut it to length, flattened the ends, eyeballed thru holes, and mounted it using flat washers to keep the thin aluminum from being sheared by a torqued bolt or nut. Really pleased with its simplicity… and the tube hardly weighs a thing.

Importantly, this setup doesn’t have much lateral strength. It’ll be fine for regular riding. But if you were to drop the bike or lean it up against something the wrong way, the whole bracket assembly could be pushed/bent towards the spokes. If this aluminum tubing doesn’t last, I’ll re-do this with stronger stainless tubing which will be at least somewhat more laterally stiff.

And yeah… I haven’t landed the coaxial cable yet. I’m expecting a SON coaxial hub adapter to deliver soon, and will be using SON’s coaxial plugs to quick release. I might extend the coax long enough to have a left-side light mount, but for now it’s too short so will try it right-side and see how the light pattern (and cast shadow) play out.

[P W]

Approved.

Because I love a hardware store hack.

Even tho a Nitto light mount and wrapping the wire around the fork blade would have achieved more or the less the same thing, with less weight and finagling.

But, where’s the fun in that!?

P. W.

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On Aug 2, 2025, at 3:20 PM, J-D Bamford <isp...@gmail.com> wrote:



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[Peter White]

Good luck if you don't see something on the road slightly to the left of center, because your rim and tire are blocking the very wide beam of the Edelux II, and it's moving to your right.

To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/7AF8D7CC-9BC5-499E-B77E-603EB2771B1F%40gmail.com.

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Peter White

[Mathias Steiner]

I've mounted a light (Lumotec Eyc) similarly to the LEFT low-rider fork mount and found no problems.. but I did worry about blocking the light from view of people coming out of side streets on the right. 

In practice, this was not an issue because the beam reached around the tire quite a bit -- the blockage was maybe 30 feet ahead.
I also mounted a white blinky strip on the other fork leg, just to be sure.

I"ve since put on a small front rack and am mounting the light to that. The improvement is worth it.

[Steve]

Another point of view (forgive the pun):  I've come to favor mounting a  light on the right hand side of the fork to best illuminate the edge of the pavement - that's where the grunge generally hides.  It can also be helpful in situations where I may feel it advisable to hug the shoulder - blind curves, fast cars approaching from ahead and behind, etc.  

Steve in AVL

[Patrick Moore]

Elegant! I suppose that the wheel does not throw enough of a shadow to be annoying?

I might do something like this for the IQ XL in just installed on my Matthews dirt road road bike, since various constraints mean that my other headlamp mounting options are just below the bar as presently with bar-clamp mount (but lamp would be covered by rain cape in the event) or on the fender (would prefer to mount where removal of fender does not affect position), or on one of the fork legs.

My fork crown is not drilled, and I can’t drill it because I spec’d a very deep threaded fender boss inside the crown.

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Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum

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[J-D Bamford]

Since i had a spare light bracket set aside for a future project, i doubled up and now the setup has good lateral strength. Regarding other comments… putting a bracket directly on the hourglass boss would risk cracking the paint (assuming the light is bolted tight enough, with star washer, to eliminate rotational slip). At least that’s how it seems. 

As for the shadow cast… we’ll see how it looks IRL. My daughter and i totally messed up a SON coaxial adapter (soldering) today, so for now no actual in use report (and no ability to lengthen the run and relo to left fork blade). Might end up resorting to the plain spade connectors, which really aren’t so bad. 

[Matthew Williams]

J-D: Clever!

I dislike clamps so I added a bottle boss to my handlebars, to receive the fastener for the SON Edelux headlight bracket.

[Jay Lonner]

I admire the DIY ethos, but does that still qualify as a minimal mount? The CYO is a proven design that uses less metal. Since you’ve ditched a front bag/rack, is there another reason you’re avoiding mounting your light at the fork crown?

Jay Lonner

Bellingham, WA

Sent from my Atari 400

On Aug 3, 2025, at 2:11 PM, J-D Bamford <isp...@gmail.com> wrote:



To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/5a19e1f6-2021-4bf9-99ea-39a729ae8005n%40googlegroups.com.

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[Peter White]

Do yourself a favor and try a fork crown mount. Compare how the beam on the road surface compares between the two mounting locations.

Remember all of those groovy old French bikes with the flashlights attached to the left side of a front rack? The reason that worked is that the optics of the flashlight concentrated the meager light output of the bulb into a small patch so that you could at least see something on the road surface. With a modern LED headlight such as the Edelux II, you not only have a headlight that produces a much brighter beam, but that beam can be many times as wide and tall as those old incandescent bulbs in the cute old French flashlights.

To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/5a19e1f6-2021-4bf9-99ea-39a729ae8005n%40googlegroups.com.

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Peter White

[Menos Joven]

The WonderLight! We thought that was light!? Hehe. Better than nothing I suppose. :)

[Minh]

Aesthetically I am a fan, but do you really need the rod? with double mounts isn't that strong enough just at the hour glass?  getting it a little away from the fork will help with shadows but like PJW mentions, wheel shadow will still be a problem.  

if you keep the rod, one alternative wiring option that I like is to run the wire straight down the rod and use shrinkwrap the full length so it looks seamless.  

[J-D Bamford]

This was a journey. Originally I wanted to go with a smaller handlebar bag (perhaps 6L) and avoid the weight of a rando rack and its boxy bag. But my prefs for a tall/skinny 6L handlebar bag (like this, https://www.bagsxbird.com/product-page/tail-grab-classic-edition) meant that it would hang low enough to block a fork crown-mounted headlight. So in the end… I chose to embrace my old Ruthworks 10L rando bag and bought a Mark’s rack to pull it together. So now I’m back to trad rando headlight mount off the rack, left of the wheel 

Thanks much to all the suggestions and prods :-)

I still haven’t connected the light. Gonna order another coaxial adapter and a few feet of coax to extend the run… and we’ll see if I have more success soldering it on my second try. Otherwise I’ll fall back on spades and they’re really not that bad.

Of note… I drilled the diving board so that I could mount the Mark’s rack 3cm closer to the head tube. There’s about 3mm clearance to the sidepull caliper.

[Peter White]

Please post another photo from the left side of the bike so that we can see exactly how the headlight is attached.

To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/ff824dcd-43e7-474d-b850-f5bd078bcb95n%40googlegroups.com.

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Peter White

[J-D Bamford]

Apologies… I must have been more excited by this build nearly feeling dialed-in and forgot someone might want to see how the light mounted, lol. It’s just a standard V-O bracket, cranked tight with star washers so there’s no tendency to droop. Held tight today over 25 miles and 3000’ of climbing and descending over some unimproved roads. 

The rough curve in the rack stays is complements of a large log.

Happy Sunday, all!