Modular Bicycle Disc Brake Bleeding Syringe Holders

Introduction:

I wasn't impressed with the offerings for holding disk brake bleeding syringes, so I made this system for my shop. These don't require extra hardware to assemble. I particularly don't like the design of the rear holders because rear triangles vary considerably between bikes, so this system mounts to the rear thru axle instead of the frame. The system consists of 3 vertical bases (handlebar and rear thru axle, front thru axle), 3 lengths of vertical extensions, 2 lengths of horizontal extensions, a syringe clamp end, and 3 sizes of fork clamps ends, and a set of axle adapters. The extensions allow for rotation. These components can be mixed and matched in various combinations to fit the requirements of your setup. You can use the linked rubber straps, print straps, use nylon or velcro webbing or even dropout clamping force to attach these to the bike. 

Rear Thru Axle Base:

This design mounts to the rear 10 or 12mm thru axle or quick release skewers (with adapters). The axle has a fairly consistent relationship to the rear caliper across bike models, with the main variance being rotor diameter and location of the caliper bleed port. With the syringe attached to the caliper it will hold itself up, you can strap it to the rear stays, dropout, etc, or clamp it in the dropout with provided spacers. 4.5mm and 5mm skewer adapters for non-thru axle rear ends are included. The base can be positioned anywhere between the dropouts along the thru axle. The minimal parts needed for the rear are the thru axle base, short vertical extension and syringe end. 

Handlebar Base:

The handle bar base fits the 22.5mm diameter section of the bar near the brake levers. It has a top mount and two side mounts for extensions. The minimal parts needed that will work for most setups is the handlebar base, short vertical extension, long horizontal extension and syringe end. 

Fork Leg Mounts:

There are 3 different sizes of fork ends: 45mm, 37.5mm, 27mm. For reference, the 45mm fits my Zeb. The 37.5mm fits a Judy. The minimum setup for the fork syringe holder is 1 fork end, 1 horizontal extension and 1 syringe end.

Fork Thru Axle Base: 

As an alternative to clamping something to the fork leg, I've made a fork version of the rest thru axle base with the same advantages. The minimum setup for my 38mm Zeb, is the front thru axle adapter, short vertical extension, one long and one short horizontal extension and the syringe end.

Example Set

For my bike, the minimum total parts I need are: 

• rear thru axle base (1) or just the fork thru axle base w/ axle adapter

• handlebar base (1)

• fork thru axle base (1) or fork leg mount

• a mix of short, medium or tall vertical extension (2-3)

• long horizontal extension (1)

• short horizontal extension (1)

• syringe ends (2)

Attachment: 

All of the parts strap to either the bike or syringes with strap pins. These are designed to fit rubber MODL Infinity tool straps or similar. The pins hold up well with these rubber straps. I have also included some adapters that allow you to use 1 inch wide velcro or other webbing straps instead of the rubber ones. I prefer the grippy rubber. 

Axle Spacers (Optional): 

I've included a full set of spacers for various front and rear axles. By using these spacers you can tighten  the front or rear dropouts against either thru axle base eliminating the need to use straps to secure either  base to the bike. You will still need to strap the handlebar base to the handlebar. You will need a drive side and non drive side for each.

For my bike which is 15x110 boost (RS torque caps) front, and 12x148 boost rear, I need the following:

• 15x110 (31mm Dropout) - Front

• 15mm (31mm Dropout) Front Adapter

• 12x148 - Rear

• 12mm - Rear Spacer

Reusing The Fork Thru Axle Base:

Instead of printing 2 different bases, you can print just the front thru axle base and use it for both front and rear calipers using the provided 12mm or 10mm adapters for your rear axle. Note: that this base is shorter and may require additional vertical extensions. 

TPU Straps:

If you only want to use 3d printed parts, I have designed some TPU straps found below. You will need to print these in something really soft like TPU 85A. 95A is too hard for the pins on the syringe holders. There are also links for these allowing you to connect them. 

Printing:

Printing all of these pieces in PLA+ at .20 Strength works well. Some minor cleanup of the rotating interfaces can be done with a razor knife, but it works pretty well regardless. I've found the interfaces can rotate and snap together well enough that they stay together even when upside down. The key thing is to ensure that the strap pins are solid.