A guide to fitting a CargoPack to the Trek Checkpoint
Trek is one of the most well-known brands on the cycling market and is regularly used across all disciplines in both racing and touring. In this guide, we will focus on the Checkpoint, which is one of Trek’s gravel offerings.


Newer models of Trek bikes are fitted with a Universal Derailleur Hanger (UDH). If your bike is equipped with the UDH, you will require an axle with a 1.0mm thread pitch along with the Tailfin UDH Adaptor. If you’re unsure, use our Axle Guide to check your bike. Both the Universal Thru Axle and the UDH Adaptor can be purchased as part of your CargoPack order. Additional adaptors can be purchased separately, if needed, too (see below). Please note that, although a SRAM component, the UDH is also used on bikes with Shimano and Campagnolo groupsets.
If you are instead using one of SRAM’s Transmission derailleurs, you won’t have a separate derailleur hanger, so a different adapter is required. You’ll need a SRAM Transmission Adaptor to fit our Universal Thru Axle.
For example, if you are using a Red 13-Speed Transmission rear derailleur, you’ll require our specific adaptors in your order.


For smaller frames and when using a dropper post, we recommend packing smaller/softer items at the front of the bag. This can help when clearance is limited. For optimal fit on smaller bikes, or for a slightly lighter set-up, our SpeedPack is also available.

Configure your Tailfin order
In this guide, we’re showing the CargoPack (alloy, without pannier mounts). See our comparison guides to help choose the setup that’s best for you, based on your riding plans.
For simplicity, we’re using the Universal Thru Axle. It includes all thread attachments needed and is also required on bikes with SRAM’s Transmission derailleurs.
Before placing your order, you can check what axle your bike requires by using our Axle Guide, which will also show if any additional adaptors are required.


The best way to check is to have a look at the rear of your bike frame, where your derailleur attaches to the frame.
You may have a frame made before this change, though, which requires a different axle thread. If your Trek does not use the UDH frame standard, then you’ll require the 1.75mm thru axle, with no additional adaptors.

Assembly
Use our assembly guides to put together your CargoPack. You’ll need a Torx (T25) tool and a torque wrench to do this.

Fit the new Universal Thru Axle
Now your CargoPack is assembled, just one part remains: fitting it to your bike. To do this, you’ll need to install the new Tailfin Thru Axle. In this guide, the Universal Thru Axle and UDH Adaptor are shown.
Follow the steps below to install the new axle:




You can leave the Tailfin thru axle fitted even without the CargoPack attached. It’s normal for threads to show on the drive side, and it is just as safe as your original axle, as the number of axle threads engaged with the frame is the same. To remove the Universal Thru Axle, loosen it from the driveside of your bike.
For Checkpoints using the Tailfin Universal Thru Axle and adaptors, see our video guides below:
Attach your CargoPack
The last step is to attach the CargoPack to your bike. It’s often easier to do this standing behind your bike.


Secure the Seat Post Connector in place and ensure it’s locked shut. See our quick guide on how to correctly attach the Seat Post Connector. When using a dropper post, secure the strap around the area below your dropper stanchion (you’ll need 30mm of clearance to do this).
Now you’re ready to ride!
Additional products
The CargoPack has an 18L internal capacity with an extra 3L when using the side mesh pockets. The Checkpoint shown in this guide can also carry additional items, and, if you need extra storage, consider these options below:


Featured items: 3.8L Half Frame Bag, 0.9L Rear Top Tube Bag, Bar Cage with 11L Bar Cage Bag, and Small Cargo Cage mounted to an alloy arch without pannier mounts.





