BAKFlip MX4 vs F1: Same Ratings, and the F1 Costs Less

For most trucks, the BAKFlip F1 is the one to own. BAK builds it and the BAKFlip MX4 to the same 400 lb evenly distributed rating and backs both for 5 years, the tailgate works on its own with either cover shut, and both clamp on with drain tubes. The F1 swaps the MX4's aluminum top skin for fiber-reinforced plastic (FRP), comes with a two-thirds open position RealTruck spells out, and cost a little less on six of the seven same-truck, same-bed Amazon listing pairs we compared. Its water record reads better too, on far fewer reports.

The F1's risk sits in its panels. Each one is an FRP skin over a foam core with an aluminum underside, and the complaints are specific: a top surface that broke down in a year and a half, cores that soaked up water, panels that warped in hard heat. The MX4's problems are better documented: leaks at the front corners, and on covers built since BAK's Gen 3 redesign, rails that fight you on install and faults out of the box. We rate the MX4's leak risk high. The F1 has no leak-risk rating from us, because its water record is too thin to rate.

Pick the MX4 over the F1 for only three kinds of truck: one that will carry a rack on T-slot rails, which only the MX4 TS has; one parked in snow country, where the EZ-Lift version takes weight off the fold; and a Maverick or a Tacoma, where the MX4 is the only one of the two with a listing we confirmed.

Where the two part ways

What the F1 changes:

• The top skin: FRP in a textured gloss black instead of the MX4's textured matte aluminum. The Amazon listing calls FRP heat resistant and virtually dent proof.
• A middle position: fold it partway and buckle straps hold the stack over the front third of the bed. RealTruck's MX4 page describes only the fold to the cab, though a five-year owner's post says an older MX4 folds to its last panel and straps there, so ask before you count this as F1-only.
• Price: a little less than the MX4 on six of the seven matching listing pairs. The seventh, the Ram 6 ft 4 in with the split tailgate, went the other way.
• Water: F1 owners who describe their own bed mostly report little or none. MX4s leak more often as they arrive.

What only the MX4 offers:

• Versions: the TS with T-slot side rails for a rack, and the EZ-Lift with a lift assist up front. The F1 has no rack rails, and BAK's F1 install sheet says not to tie cargo to the cover or its framework.
• More trucks: confirmed listings for the Maverick, the 3rd and 4th gen Tacoma and the Gen13 F-150's 8 ft 2 in bed.
• A longer record: far more owners, and earlier covers that ran five to nine years.
• A quicker install, on paper: RealTruck quotes 30 minutes or less for the MX4 and less than an hour for the F1.

Shared by both: the rating, a warranty that stays with the first owner, panels that latch themselves shut with no key, and rail channels that carry water forward to drain tubes. RealTruck publishes a weight for neither.

The spec sheet, line by line

Every cell comes from RealTruck's product pages, with the Amazon listing filling in where RealTruck says nothing:

Read the rating the same way on both. 400 lb assumes the load is spread across the whole closed top with the truck parked; weight concentrated in one spot is a different case, and RealTruck gives no figure for it on either cover. BAK's F1 install sheet also says not to drive with objects on top of the cover.

The warranties match word for word, and so do their limits. Both cover only the original buyer, so a used F1 or MX4 comes with none, and RealTruck lists the same two easy-to-miss conditions on both product pages: clear snow and ice off the cover before you open it, and don't tow the truck from the rear with the cover installed.

Fiberglass top or aluminum top

Neither skin wins outright; each fails in its own way. The MX4's matte aluminum scratches easily and dents if you chop packed snow and ice off it, even with a snow broom, and its underside dents too. Hail has trashed one. The F1's top is sold on impact resistance, and we have no hail reports on it either way. Its failure is wear: on a Tundra the top surface broke down badly after about 18 months, and BAK covered it under warranty and let the owner move to an MX4.

Owners who've bought both lean MX4, two of three. One landed there through that warranty swap, and the other finds the MX4 way lighter than the F1 that rode on an older F-150; the third bought two MX4s and went with an F1. We count that as a point for the MX4, not enough to flip our pick: it's three people, and one of the moves began with an F1 failure BAK covered. Weight is disputed anyway: in a five-year owner's words, the F1 is easy to remove and not too heavy. RealTruck publishes no weight for either, and the 71 lb on the F1's Amazon detail table may include packaging.

Both cores are foam, and both can drink water. Two F1s failed when their panels soaked up water and got heavy, and MX4 panels do the same in hard-winter climates, which makes it a BAK design trait more than a reason to pick one over the other. If you lift the stack from the ground in snow country, the MX4 EZ-Lift is the one BAK with an answer for it: RealTruck says it cuts lift force to 10.5 lb.

Heat is murkier. One F1's panels warped, though the cover still fits and works, and its owner's advice is to leave the cover open or take it off when it gets very hot. The MX4's aluminum top gets hot to the touch in desert sun. Neither has enough hot-climate history for us to call a winner.

Age skews both records. Most F1 reports describe covers several years old, and the Amazon listing describes an upgraded rear seal, so they tell you how older F1s aged. The MX4's long record belongs to earlier versions, and the Gen 3 has drawn rails that are hard to seat, clamps that don't stay tight and covers that arrive scratched, with a broken latch or with latches installed wrong at the factory. Open the box and check the panels, latches and hardware before anything gets clamped to the truck.

Which keeps the bed drier

The F1, on a short record. On paper the two handle water identically: the panels ride low between the bed rails, rain runs into a channel along each rail, and drain tubes carry it out at the front of the bed. BAK's install sheet says the F1 is not airtight, and nobody should expect either to be.

Most MX4 water reports are leak reports. They cluster at the front corners beside the rear window, with the tailgate end next and the side rails after that, and hard rain sets most of them off; a replacement cover under warranty is no sure cure. F1 owners who describe their own bed mostly report little or no water, with what does get in coming at the tailgate end. The one real F1 leak came at the cab, where BAK's adhesive bulkhead seal let go of a LINE-X liner after a wash.

Some of that gap is sample size, which is why the F1 scores only a little higher on water and carries no leak-risk gauge. Seal either one the same way. Square the rails, route both drain tubes all the way out of the bed, add a tailgate seal kit if the gate end drips, and hose the closed cover down before the first storm. On a spray-in liner, clean the front wall with the supplied cleaner or isopropyl alcohol and let it dry before the F1's bulkhead seal goes on; with a drop-in liner, BAK's sheet says you don't need that seal at all. On a 4th gen Tacoma, the MX4's drain tube is twice the diameter of the bed's drain hole, so plan on a reducer or a drill.

Opening the bed: two-thirds or all the way

The F1's middle position is the one RealTruck documents, and it earns its place. Fold it toward the cab and stop at two-thirds, buckle the straps, and you can drive with the stack lying over the front of the bed. On a Gen14 F-150's 67.1 in bed that leaves about 45 in open, with the stack covering roughly the front 22 in. A load of mulch bags or a cooler and a few duffels fit there without standing the stack against the glass.

For the whole bed, both fold up to the cab and rest on prop rods, the MX4 leaning back toward the rear window, and RealTruck says each leaves the third brake light clear. Folded all the way up, either one blocks part of your view out the back. On a Colorado the MX4's stack blocks it entirely.

The tailgate doesn't separate them. RealTruck lists a dual-action tailgate seal for both, on most F1 applications, and the F1's Amazon listing says the gate closes with the cover open or shut. With a power tailgate, check that it opens and closes properly under the shut cover, and slide the cover toward the cab if it doesn't, as BAK's sheet directs.

Fit by truck: where only one is sold

Each cover is a different part number for every truck and bed, and Amazon carries a separate listing for each. A fit counts as confirmed below only when the Amazon product page itself showed it; part numbers and each listing's restrictions sit in the tables with the picks.

• F-150: both have confirmed 5 ft 7 in listings for the 14th-generation F-150 (Gen14, 2021 on) and the Gen13 (2015-2020). Only the MX4 has a confirmed Gen13 8 ft 2 in listing. RealTruck lists 6 ft 7 in F1 parts for both generations that we didn't confirm on Amazon, and no 8 ft F1 for the Gen14.
• Silverado and Sierra 1500 (T1XX): both have short-bed and 6 ft 7 in listings that work with the MultiPro and Flex tailgates, and neither short-bed listing fits the CarbonPro bed. Amazon calls the short box 5 ft 10 in; RealTruck calls it the 5 ft 8 in bed, and says the F1 for it won't work with factory bed storage boxes.
• Ram 1500 (DT): the F1 covers more of them. Both have a 5 ft 7 in listing for trucks without the multifunction split tailgate and a 6 ft 4 in listing for trucks with it. Only the F1 has confirmed 5 ft 7 in listings for the split tailgate (part 772226) and for RamBox trucks (772227RB); RealTruck sells MX4 parts for both, but we haven't confirmed them on Amazon. Amazon's RamBox listing says it fits with and without the split tailgate while RealTruck's notes say it doesn't, so confirm with RealTruck before ordering that one for a split gate. On a TRX, RealTruck says the bed bar has to come out for the F1.
• Tundra (3rd gen, 2022 on): we confirmed the F1 for the 5 ft 7 in bed and the MX4 for the 6 ft 7 in. RealTruck sells both covers in both lengths, but neither cover's listing for its other bed is confirmed here, so check fit for your truck. RealTruck says the F1 won't work with the Trail Special Edition storage boxes, and its tie-down cleats come out for the install and can't go back in.
• Colorado and Canyon (2023 on): both have a confirmed 5 ft 2 in listing.
• Tacoma, Maverick and Ranger: the MX4 has confirmed listings for the 4th gen Tacoma (5 ft, for trucks with the deck rail system), the 3rd gen (2016-2023, built around the factory track system) and the Maverick, whose listing reads 2021-2026 though the truck started in 2022. RealTruck doesn't offer the F1 for the Maverick, and its Tacoma F1 parts aren't confirmed on an Amazon product page, so check fit with the search links in the picks. Neither cover has a confirmed 2024-2025 Ranger listing, and RealTruck lists no F1 for the 2026 Ranger.

Several F1 titles on Amazon say 2026 where RealTruck's own fit line stops at 2025, and the fitment notes flag which ones, so confirm a 2026 truck with RealTruck. Amazon also carries third-party listings titled as aftermarket replacements for the F1; buy from the RealTruck store listings linked here.

Picking by job

• Most trucks, most loads: the F1. The MX4's rating, warranty and tailgate for a little less, with a documented two-thirds position.
• A rack on the cover: the MX4 TS. The F1 has no rack rails, and BAK sells its cover-and-rack pairing, the BAKFlip CS, as a separate product.
• Parked outside in snow country: the MX4 EZ-Lift for the lift assist. Brush the snow off rather than chopping ice off the top, whichever cover you own.
• A 5 ft 7 in Ram with the split tailgate, or a RamBox: the F1, the one with confirmed listings for both. On the 6 ft 4 in bed with the split tailgate, both have one.
• A Maverick or a Tacoma: the MX4, the only one of the two with a listing we confirmed.
• Buying used: ask for the part number. Standard MX4 parts start with 448 (the TS and EZ-Lift use 449 and 450), F1 parts with 772 and FiberMax parts with 1126; the FiberMax is BAK's other FRP folder, rated 300 lb with a 3-year warranty, which we haven't reviewed. A matte top means an MX4; gloss could be an F1, a FiberMax or BAK's aluminum G2. Neither warranty transfers.

F1 for most trucks, MX4 for a few

We'd buy the F1. It carries the MX4's rating, warranty and independent tailgate for a little less money, comes with a two-thirds position RealTruck documents, and the beds under it mostly stay dry. You pay for that with a thinner record and panels that draw specific complaints, so look the top skin over the day it arrives and keep the warranty paperwork.

Spend more on the MX4 for the TS rails, the EZ-Lift or a Maverick or Tacoma fit, or if a longer owner record is worth the premium to you. With either one, the rails going on square and the drain tubes running clear out of the bed do more for a dry load than the badge on the panels.