Aero Saddle Case / Radar Mount for Canyon Aeroad 2025

I was tired of ugly, non aerodynamic saddle bags and separate radar mounts on my sleek Canyon Aeroad. This saddle case design combines the functionality of a saddle bag with a radar mount into a single, aerodynamic, hard case integrated into the seatpost and saddle rails. All mounting features are rigid and outside the airflow. This Aero Saddle case is specifically designed for the Canyon Aeroad SP0077 Seatpost and a Garmin twist lock mount. The case primarily mounts to the top light mounting hole in the Canyon seatpost SP0077 with 1x 30mm M4 bolt & washer. The case also rests on the saddle rails, to which you should further fixate with tiewraps, this locks in all degrees of freedom (lateral & rotational). The volume of the case is about 300ml: it easily fits a multitool, CO2 cartridge / nozzle, Dynaplug set, minor spares for your bike, a spare “locking beam” and a small lock. I expect you could also fit a a non-tubeless set: a multitool, CO2 cartridge / nozzle and a TPU tube. I recommend to add in a plastic bag wag as filler to avoid rattling. Mounting instructions: Insert the tiewraps before mounting. Insert the case into the saddle from the back / top -→ it is easiest to intert the wings of the case where the saddle rails are widest apart. Insert the M4 + washer and ensure the front of the case touches / is aligned with the seatpost. Tighten down the tiewraps, it is essential that the wings of the case are resting on top of the saddle rails! Tighten the M4 screw last! Design & print considerations: I tried to keep the design as small and light as possible (<50grams), hence the simple locking mechanism and top mount with tiewraps. Using a screw mount would come at the cost of internal volume of the top section of the design, bigger case, more drag & weight etc. This is an emergency tool pack; aero first, ease of access second, ease of installation third. The backplate / Garmin mount position is optimized for the Coospo TR70 bike radar. This radar has the same size as the Garmin Varia rtl 515 (96mm long, 40mm wide). If necessary, you can easily change the position of the Garmin mount on the “backplate”. Please share if you do (I do not have the exact Garmin Varia mount position, I am not buying micro-USB in 2026). The tolerances have been developed for ASA printing (I recommend ASA for this application anyway because of the outdoors deployment) Special attention was given to the M4 connection point on the seatpost. When the case is not resting on the saddle rails properly (see mounting instructions), this area is exposed to a large torque. If you do your own slicing, I recommend to do so with a 50% infill and 4 perimeters to have sufficient strength around the M4 bolt area (the design has no infill otherwise). Due to the shape of the backplate and the case the use of print supports is unavoidable. These supports for the case are easy to remove. Removing the print support out of the volume for the garmin mount is a bit more tedious, it is facilitated by 2 holes on the side where you can insert a screw driver / pliers. The “locking beam” principle intentionally has a lot of resistance (you do not want this jittering out under road vibration), this loosens up a bit after a few uses. If necessary, you can increase volume of the case in Fusion 360 design by: increasing the width of the 4th cross-section extending the length of the case (positioning construction plane 5 further backwards) If you change the dimensions a lot, you might need to redo some of the fillets and chamfers due to the updated position of the polygons. I have run through >10 prototypes developing this and have ridden hundreds of km during the process with various iterations of the design. It has come at a point where I would love to hear and see what others think of it and how I (or you) could further improve upon it! Future update: I am currently working on an update with fully tangential cross-sectional design rather than simple connecting lofts + chamfers. This should lead to an even cleaner design esthetic which most importantly might be marginally more aero. This is a bit tough for the shelling tool in Fusion 360 to generate so I am working through it in sections. This will probably come at the expense of easy modifiability so I might publish separately.