Side projects – Pierre-Henri Medas

Protect Your Investment: Cutting Profiles for SRAM Red D1 and E1 Crank Arm Protectors

If you own a set of SRAM Red D1 or E1 generation crank arms, you know they are both beautiful and a significant investment. Over time, road grit, chain drops, and accidental scrapes can leave them looking pretty beat up—something I’ve learned the hard way with my older sets!

To combat this wear and tear and keep your high-end components looking pristine, I decided to develop a simple, effective solution: a custom-cutting profile for transparent adhesive protection film.

The Quick DIY Protection Solution

The process was surprisingly fast and yielded great results. Here’s what I did:

Design the Profile: I defined a simple profile shape designed to cover the main surfaces of the crank arm.
Print to Scale: Using my trusty little Epson inkjet printer, I printed the profile to the exact scale required for my crank arms.
Transfer and Cut: I carefully transferred the printed profile onto a sheet of transparent adhesive film (the kind used for bike frame protection).
Application: After cutting out the shape, I applied the transparent protector to the crank arm.

The result is a quick, aesthetic, and barely noticeable layer of protection that keeps the carbon safe and sound.

Confirmed Base Length

The profile provided is defined and verified for a base crank arm length of 172.5 mm. If you have a different length, you may need to scale the profile slightly, but the core geometry should remain correct.

Download the Cutting File

The cutting profile file is available for download here:

Crank protector – SRAM Red D1, E1 – V1 20251130 Download

A Note on Gravel Use

For those of you who frequently venture off-road or ride gravel, you might want to consider adding a little more material, especially around the crank arm edges/flanks. Gravel riding exposes the cranks to more direct hits from loose debris. Feel free to use my base design and adapt it for a thicker, more comprehensive wrap!

Sharpie Permanent Marker to 3D file

While planning the optimal tool layout for my mobile toolbox, I realized the essential Sharpie needed a proper spot. So I recreated the iconic permanent marker in 3D, adding realistic materials and logos just for fun.

The process was quick, and the final result looks quite satisfying.

Do you need the 3D files? Grab them on GrabCAD.

Adapter for RRP ProGuard Screw-On Mini Mudguard to fit Rockshox Pike and Lyric

Since the adapter isn’t included in the RRP Screw-On Mini kit, I set out to find one that would fit my RockShox Lyrik. Unfortunately, this adapter is rarely available and typically sells online for 10 euros—plus another 10 euros for shipping… and I’m cheap.

This custom design fits perfectly on the back of the fork crown and uses the RRP bolts provided with the original kit.

Only one extra M3 bolt and two M4 nuts are required.

Printed in PLA on my trusty Creality Ender 3.

Thingiverse 3D file link

Amazon link to the RRP Fender

Garmin Varia mount for BMC Teammachine SLR

Shine Bright!
I bought a Varia almost a year ago, but I wasn’t a fan of the elastic straps used to secure the bulky mount to the seat post. So, I designed a custom 3D-printed holder that fits perfectly with the original Garmin interface — or the Mr. Control Garmin adapter I had lying around in my spare parts bin.
The design is tailored to fit the back of the 10mm offset BMC Teammachine SLR seatpost. The lower bolt tightens against the saddle clamp hardware, ensuring a secure and stable attachment.

I printed the part using PLA on my trusty Creality Ender 3. The hardware shown is temporary, as I plan to upgrade to sleek stainless steel bolts and nuts, replacing the standard ones pictured here.

The final version assembled on the seatpost and its design in the background.

Thingiverse:
https://www.thingiverse.com/thing:6844047

Tool holder for my Teammachine SLR bottle cage

Riding without a tool isn’t an option for me… and forgetting to bring one is definitely something I want to avoid. Riding with pockets full of gear isn’t very pleasant either. So, reusing a Specialized SWAT Road tool and designing a tool holder that attaches under the bottle cage specific to the BMC Teammachine SLR was a cool project to work on.

The tool holder at the bottom of the SLR bottle cage

The tool holder clips securely at the back of the bottle, preventing it from moving or vibrating. A small fixing tab slides under the bottle cage and attaches to the lower bolt, sandwiching the whole setup in place. The tool is inserted into the holder from below, so you don’t need to remove the bottle to access it. The tool’s outer shape locks into the ramps of the holder, keeping it securely in place during the ride. The top face of the holder acts like a spring clip to hold the tool in position.

The attachment is solid, the tool stays in place, and the aesthetics are still as sharp as ever on the Teammachine SLR.

I have not shared this design as it’s quite specific to my own needs. Feel free to reach out if you need help.

Chainline tool: the ChainLineR

At work, I often need to quickly check the chainline of a crankset assembly. The ChainLineR is a simple gauge designed to make this process faster and easier, allowing you to measure your bike’s chainline and verify if it’s within the recommended specs for Shimano, SRAM, or Campagnolo.

While you can use a caliper to do this, it can be tricky to find a clear reference point to identify the center of the seat tube (e.g., the bottle cage bolt). The V-shaped design of the ChainLineR allows you to quickly center it on the seat tube or downtube, providing a rough but reliable reading of your chainline using millimeter markings.

An additional stopper allows you to place a ruler and get a more accurate read.

How to use:

Position the ChainLineR on any symmetrical part of your bike—ideally the seat tube or downtube.
Use the millimeter markings to read the chainline measurement.

Notes:

Some tubes may be asymmetrical.
The chainline for 2x setups is measured differently depending on the manufacturer. For example, Shimano measures from the inside of the larger chainring’s teeth.

Thingiverse:
https://www.thingiverse.com/thing:5519359