Introduction: Bike Handlebar Extension (customizable)
If you have a 3D printer, you will be familiar with the "what can you make with it?" question and the obligatory follow-up "that's nice, but can you make anything else besides toys?"
This handlebar extension allows you to put extra bags on your bike and is a good example of functional 3D printing. In this instructable, I'll review the main design requirements and why they make it a good candidate for additive manufacturing. As always, if you want to print it for yourself, you can get the STL tailored for your bike using SOL75. an online customizer.
Step 1: Design Requirements
The first issue is how to attach the beam securely to the handlebar. Since we want to hold the bag at a distance from the handlebar (with the distance depending on the bag), we should expect large twisting moments for longer beams.
Additionally, since it's going on a bike, it would be nice if it wasn't super heavy. As a reference, ready-to-buy alternatives are usually made in titanium and weigh 150g (5.3oz). They are quite expensive though (about 100 euro/$).
Step 2: Why 3D Printing
Clamp design attachment
To attach the beams to the handlebar, I've chosen a clamp design where two parts come together in the exact shape of the tube. Note that this is only possible because 3D printing allows us to customize the clamp to the exact measures of the handlebar! Handlebars do not have "standard" diameters and are often tapered, with the center section thicker than the outer ones. Therefore, without customization, we would need to re-design a component for every bike, which seems a waste of time.
Looking at the beam, it might remind you of the structure of a crane or some industrial machinery. That is no accident; triangles are very stiff elements, so the overall result is a rigid but light structure. 3D printing makes it a lot easier to produce such complex geometries, without too much effort. Imagine trying to make a similar structure out of wood or welded metal; maybe you could do it (I couldn't), but it will take a lot more work than just hitting print!
Step 3: Final Notes
Overall, I am quite happy with the result. It seems to hold up well, it was a lot cheaper than buying it and if I change bike or handlebar, I can just print a new one. If you'd like to print it, I've made SOL75, an online customizer that allows you to tailor it for your bike (and your 3D printer).
Thanks for reading until now!
It is a large print, so it takes a while. On my printer it was about 4 hrs for each beam.
In the end, the total mass of the two beams came at about 90g, so very similar to the commercially available alternatives.
Since this is to be used outside, you might want to use a material that won't bake in the sun (like ASA, which has good UV resistance properties). On the other hand, I have used PLA, because that was all I had laying around and it held up fine in the Italian summer.
Slipping attachment point
To increase friction between the clamping part and the handlebar, I've put a section of an airtube between the two. It seems to work well, but maybe it is not necessary for you.