Bike Handlebar Alignment Tool Double Folding V6 ~160g 99% Support Free

What?

A Bike handlebar alignment tool that doesn't require hardware or tools or lasers - just hook it on the handlebars and go! The tool aligns on the handlebars and rests on the headtube. Slots in the gauge are sized for a variety of tire width. Initial handlebar dia is 35mm, but I've since added a 31.8 adapter if need be. 

Why?

Sometimes on occasion you just can't get that handlebar aligned well with the front tire. This gauge lets you see the end of the tire, as well as the sides (depending on tire width). Most times I can do it looking down from the bar to the crown. But a gauge never hurts! Also just a fun bike tool to put together and look at. I kind of designed this as a joke but also as a fun exercise in 3D printing capability! Also, who doesn't always like more bike parts!? 

You'll see a bunch of tricks in here to make no supports work. Tear drop holes, chamfers instead of blends, ironed surfaces, and more.

Doubles as a reproductive ornament at the Drs. Office when laid flat.

Assembly

Slide the pins into the gauge piece and headtube adapter pieces. Once the pins are slid in, you can fold the tool to lock in place! The tool is self aligning. The folding mechanism was designed to allow it to be printed on a printer as small as the A1 Mini.

Folding steps (once pins are assembled)

1. Slide bar hook pieces together over two pins, rotate together to lock in place

2. Slide gauge piece over two pins, rotate down to lock in place with bar hook pieces

3. Slide headtube adapter piece over two pins, rotate down to lock in place with bar hook pieces. (For you curly bar folks)

4. OPTIONAL - You can use bolts to secure the assembly, instead of pins. I recommend M6 x20 bolts and nylock hex nuts

Function

The arrow at the front should be aligned in the middle of the tire (sometimes there’s a seam as shown) - at the same time you can eyeball the tire sides and if they’re parallel with the width gauge (below the arrow), you should be aligned. You can always eyeball your handlebar to fork crown or fork lowers (near the axle), as a double check. 

Once everything's aligned just push the tool forward and tighten the stem bolts to torque spec. Or if you have a long enough allen key you can tighten the bolts with the tool in place. In V2 I narrowed the hook width to better allow tightening in place (V1 is shown in top down images).

UPDATE - I've added an experimental Fork Stanchion Alignment Add On - that slides into the headtube adapter.

Printing

Prints with no supports EXCEPT for one of the bar hook pieces. I added an ironed sacrificial plate below the one support for this part (IRON TOP SURFACE OF THIS OBJECT), that acts as a smooth print surface for the support (see .3mf file for details). So be sure to turn IRON TOP SURFACE for this object if not using my print profiles. Otherwise just use normal auto snug supports on the 31.8 Adapter Pins.

Printed in Sunlu PLA+ 0.3 layer height, 15% infill, 3-4 walls (bar hooks need to be stiff for it to work), with normal supports. ~160g of filament usage

I put a lot of time into this one. Licensing is non-commercial so any external sales of this on other sites are prohibited. I can also print it for you but cost may vary depending on location. (I'm in USA)

If you think of some design improvements I'm happy to try and implement them. 

Notes

If it's too loose for you, it's OK! You can always unite the two bar hooks together with glue (in the pivot points and alignment sections), in the model, or try the oversize pins. See my gluing photos. Certain handlebar configurations may need a little more rigidity. A “single piece” bar hook design (in my designs page) can be printed in one go as well, but requires snug normal supports, and thus, more filament. And also, in my experience, is much more prone to failure (especially on a bed slinger like the A1 series). I may also add a pin to the bar hook design to lock it in place.

Rev Log

2025/08/20 - Updated .3mf files with 99 % support free (only normal auto snug required for pins on 31.8 adapter). Enjoy!!

2026/04/17 - Added ForkStanchionAlignmentAddOn. I have not printed or tested it yet, so print at your own risk. Print vertically with normal snug supports for the tabs. I would start with the undersized by 0.1 version. Additionally, the push tabs have 0.1mm clearance to snap onto the headtube adapter. The inner material may be too thick, so I've added a stp file if you want to modify it in OnShape or your CAD of choice. But I also don't want the tabs to snap off. The idea is to use the add-on to align the bars on the fork stanchions instead of the visual gauge. Theoretically you could use both to dial in your front wheel straightness. 

2026/07/06 - Fixed Fork Alignment Add On - added it to profiles. It's good to go. A1 Mini version is shorter than the P1S version, due to the height restriction. Therefore, the A1Mini version likely won't work on all bikes (especially those with long headtubes). For H Series, there is the full model in the CAD files, that can be imported straight into the same profile. 

Purchasing

If you don't have a 3D printer and would like to purchase this item, Just send me a message on printables.