Idea: Mounting Rail for Bicycle Stem

[ddrueding]

I'm tired of mounting stuff onto tubes with zip-ties; it isn't the right way to do things. The fit is poor, the appearance is clunky, and it is never that secure.

My thought is to weld mounting rails to the top and bottom of the bicycle stem, allowing secure mounting of a computer (in my case a Sony Ericsson x10 mini) on top and light underneath. By standardizing the dimensions of the mounting points on the rail I could then fabricate mounts for various things.

My thoughts were to make the rail 3mm thick with two 6mm holes 50mm apart. Attached is a rough sketch.

Other applications for a mounting rail could include the battery pack (top tube), tail light (seat post), cadence sensor(chain stay), bike pump (seat tube?).

Does anything like this already exist? Thoughts?

 

[jtr1962]

That is a nice idea. My handlebars always get crowded with all the junk I mount on them. The stem seems a natural place to put stuff.

I've yet to see anything exactly like you suggest. Seriously, I think the idea might be patentable. It's certainly marketable. The closest thing I've seen to allows one to declutter their handlebars is either the Speedpark Space Grip or the Minoura Space Grip. The former replaces the headset cap, the latter attaches to the handlebars.

 

[Howell]

Be careful welding to the thin walls of the handle bars or stem. The heat is almost guaranteed to weaken the metal. You could use rubber wrap (anti-rotation) and Velcro straps to mount an accessory rail.

 

[Howell]

Interesting.

http://www.terracycle.com/Merchant2...Code=T&Product_Code=accmt&Category_Code=Acmts

 

[ddrueding]

Thanks guys. I was first planning on mounting the rail the usual way, with a conforming partial tube under the rail secured with zip-ties (note the smaller holes on the bottom of the rail).

For the stem I'm actually envisioning a single plate that passes through a slot and is both the top and bottom rails at the same time. At that point the only load that any weld/epoxy would have to handle is tension/compression and there is twice the surface area to distribute said load.

For the other locations I'm having a harder time; my frame is super-thin carbon fiber. For sure I'm not cutting or drilling into it, which just leaves epoxy. Not sure how strong that can be, and which one would best adhere to the existing finish without damaging it.

 

[ddrueding]

I do like this idea. Any patent lawyers in the house? I would be interested in having it drawn up.

 

[Howell]

For the stem I'm actually envisioning a single plate that passes through a slot and is both the top and bottom rails at the same time. At that point the only load that any weld/epoxy would have to handle is tension/compression and there is twice the surface area to distribute said load.

I was referring to the heat of welding itself introducing micro-fractures into parts bearing your weight.

For the life of me I can't understand why you would be willing to make permanent changes and devalue your equipment with welds or epoxy rather than using a clamp.

 

[LunarMist]

I was referring to the heat of welding itself introducing micro-fractures into parts bearing your weight.

For the life of me I can't understand why you would be willing to make permanent changes and devalue your equipment with welds or epoxy rather than using a clamp.

But that is his MO.

 

[DrunkenBastard]

http://www.advrider.com/forums/showthread.php?t=722186

Should be just enough for you, leaving some open spots for future devices

 

[ddrueding]

I was referring to the heat of welding itself introducing micro-fractures into parts bearing your weight.

For the life of me I can't understand why you would be willing to make permanent changes and devalue your equipment with welds or epoxy rather than using a clamp.

Permanent changes to a $45 part? I'm not worried about it. Clamps are crap; they usually don't fit well, are bulky, and are a PITA to put on and take off because any position adjustments are lost. Instead of welding, drilling and epoxy could be used; I'm not the metal smith. Perhaps have a new part machined with the rail already integrated?

 

[Sol]

You could probably re-purpose a picatinny rail system. There are existing mounts designed to go around metal tubes with pretty solid integrated clamps and at the other end there are plenty of options for mounting various bits of kit (especially torches). For mounting a some things you'll obviously need parts custom made, but having a standard mounting rail would make it a lot easier to be sure they'll fit.

Something like this would probably work pretty well.

 

[ddrueding]

I'm almost done with the prototype design, and will have emachineshop.com knock out a few for me. This idea of designing something on the computer and having it physically produced is pretty thrilling to me for some reason. The revised design has enough of a foot on it that it could be epoxied to the bike and have some stability. All I need is to know what type of epoxy will work, and the dimensions of the light/battery JTR is producing so I can build their brackets as well.

 

[jtr1962]

I'm putting the battery box and light engine together for my light because I don't want to run extra wires. Do you prefer that option for yourself also, or would you prefer the battery box to be separate (in which case you could put it in one of your water bottle cages)?

The battery box needs to hold 4 of these plus a few small circuit boards. There doesn't need to be any provision to easily remove the cells on a daily basis, but there does need to be some way to open the box to change out the cells once they no longer hold a charge (that will probably take years of constant use to get to that point). I'm still not sure what material I'll be making it out of. PCB stock (i.e. copper-coated FR4) might be a good candidate. It's easy to cut, and fairly strong when soldered together. If you have any other ideas, let me know. A custom metal box, with holes tapped for mounting hardware, would be even nicer but beyond my capabilities.

I'm not sure any epoxy will reliably hold the bracket to your frame. For the stem, brazing it on would make sense.

 

[CougTek]

Why don't you manufacture the enclosure from emachines.com? If it works for SSDdrueding's prototype, it will work for JTR's light box.

 

[ddrueding]

Indeed, Cougtek. And I am anticipating building a chassis for the light as well eventually, but I haven't done any CAD work since high school, and I wasn't paying attention even then. It may take a long time before I can design anything that complex.

Having the battery and light combined makes a lot of sense, I'd prefer this as well.