What is the Benefits of Using the T-Slot Tracks Over the Clamps On Crossbars for Thule Cargo Box?

Updated 09/19/2025 | Published 09/12/2025

Products Featured in This Question

Thule Motion 3 Rooftop Cargo Box - 21 cu ft - Black Glossy

(4)

$1179.95

T-Track Adapter for Thule Cargo Boxes with PowerClick

(29)

$59.95

Question:

I have the Thule Motion 3 L cargo box with the power clamps and the Thule Evo wing bars that have slots. I do not like how the clamps put pinch dents in the wing bars, and I want to order the T track adapter kit to use instead of the clamps. Are there any advantages to using the T track adapter kit over the clamps besides no dents, is it stronger than the clamps, or makes the box mount a little closer to the roof? What are the advantages or disadvantages of using the T track kit over the clamps? I have already ordered the kit from you…

asked by: JOEL V

Expert Reply:

Hello Joel,

Since you’ve already ordered the T-track kit # TH27PQ, I think you’re going to be pretty happy with the change. The biggest win is that you won’t get those annoying pinch dents in your WingBar Evos, because the box mounts directly into the T-slot instead of squeezing around the bar. That also makes for a cleaner look and usually drops the cargo box just a little closer to the roof, which can slightly help with wind noise and aerodynamics. Another nice perk is that the attachment is a bit more secure, someone can’t just flip open the clamps from outside, so it feels more solid overall. You’ll also find it easier to fine-tune where the box sits along the bar, which is handy if you’re working around a shorter bar setup or want the hatch to clear better.

The trade-offs are mostly about convenience. The PowerClick clamps are super quick and tool-free, with that built-in torque indicator that tells you when you’re tight enough, while the T-track kit takes a little more time to install since you’ll be sliding bolts into the bar slot and possibly parting the rubber strip where they go. Once it’s set up though, it’s rock-solid. Just keep in mind that the kit doesn’t actually increase the weight rating of your box, your bars, or your roof, it’s simply a different mounting method, so your limits stay the same. In short, if you value a cleaner, sturdier, more “finished” setup and don’t mind spending a few extra minutes installing, the T-track kit is definitely the better way to go.

What do you mainly haul around in your cargo box?

expert reply by: Kate F

Joel V.

9/18/2025

I don’t plan to haul anything too heavy just duffel bags, sleeping bags and dog beds. I have three large dogs that need space in the back of my SUV or they start to squabble like little children on a long car ride. Thank you for the response, it has been very helpful.

Kate F.

9/19/2025

@JoelV It will be prefect to keep your dogs happy =) Sounds like they live a good life! My pleasure Joel! If you ever have any questions in the future, you know where to find us.