Replacement Side Rails w/ T Slots for Retrax XR Tonneau Covers on a 2020 Ford F-150

Updated 09/21/2026 | Published 09/17/2026

Products Featured in This Question

Replacement Side Rails for Retrax XR Series T-Slot Accessory Hard Tonneau Covers

(1)

$480.95

Replacement Side Rails for Retrax XR Series Hard Tonneau Covers - T-slot Style

(3)

$519.79

RetraxPRO XR Hard Tonneau Cover - Retractable - Aluminum - Matte Black - Accessory T-Slots

(102)

$1999.99

RetraxONE XR Hard Tonneau Cover - Retractable - Polycarbonate - Matte Black - Accessory T-Slots

(34)

$1649.99

Question:

Does this fit a 2021 ford f150 stx i already have a retrax cover on it i just want to swap the rails out

asked by: David

Expert Reply:

Unfortunately, it does not David but I have a couple that will fit your 2021 Ford F-150 STX depending on what length your bed is. I have listed them below:

5-1/2' Long Bed - Replacement Side Rails for Retrax XR Series Hard Tonneau Covers item # RTT-82381 - Designed for the item # RTX47SR cover.

6-1/2' Long Bed - Replacement Side Rails for Retrax XR Series Tonneau Covers
item # RTX75QR - Designed for the item # RTX72GR cover.

Both of these sets of replacement rails come with the accessory t-slots that can be used to mount ladder racks and crossbars. They're designed to replace the ones that come with Retrax XR Series covers and come with new mounting clamps.

What do you plan on mounting to the new accessory rails once you get them installed? Feel free to answer this and throw in any other questions you have, where it says Add Comment.