Ergon BA3 E Protect ebike/enduro backpack review

The latest version of Ergon’s Enduro backpack is loaded with innovative ergo features but do they actually work on the bike? We’ve been taking it on epic days all summer to find out

Ergon BA3 E Protect backpack
(Image: © Guy Kesteven)

BikePerfect Verdict

Fans of firm padding on a stiff, tough bag with tons of storage admin will love the Ergon, but others will find it lumpy and heavy


  • +

    Adjustable back length

  • +

    Super durable build

  • +

    Tons of pockets

  • +

    Expandable to 17-litres

  • +

    Back protector upgrade


  • -

    High price

  • -

    Heavy weight

  • -

    Back pads are lumpy

  • -

    Unstable unless cranked tight

  • -

    No specific battery stowage

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Ergon’s BA3 mountain bike backpack has been around for a while and comes loaded with tons of ‘ergo’ features and storage organisation. This latest one also gets an ‘E’ to suggest it’s particularly suitable for ebikers.

Even with tons of harness and shape adjustment, the hardback fit doesn’t sit well with everyone and body separation it adds reduces stability. Is it good enough to be considered as one of the best mountain bike backpacks on the market?


Starting from back to front Ergon doesn’t produce the BA3 in two sizes anymore. It's just extended the sliding ladder system for the straps to four positions. The straps are then anchored on alloy D rings so they can ‘float’ to the right angle for your shoulders. There’s no alloy skeleton in the back, but both sliding insert and main back panel are stiff with two massive flank pads and two hip pads lifting the bag off your bag for ventilation. The super-long wrap back velcro hip belt can be trimmed to length, and the chest strap sits on sliding ‘rails’ with the option of adding a GoPro ‘spider’ ($/€19.95) across the front too.

The main compartment is 15L but expands to 17L with a separate back protector and bladder ($/€32.95) section against the back panel. There’s another outer section full of mesh pockets and pump sleeves and the interior is all dayglo lime green to make spotting contents easy. A stretchy helmet sleeve, zippered waist pocket and armour straps provide external cargo options. You get a separate pullover rain cover too and the whole bag is built like a tank.


That tough construction means Ergon bags have always proved super tough when we’ve tested them before but it means you’re putting nearly 1.4kg on your back before you’ve even put anything in it.

While all the adjustability is theoretically great, the hip pads concentrate all the load in just two spots and it took a lot of shifting about to stop numbness on longer rides with heavy loads. While the pads do seem to help ventilation, lifting the bag so far off your back undermines stability. That means unless you crank the straps and belt up tight it’s very keen to climb over your shoulders or lurch off to one side when things get steep and sketchy. Unsurprisingly inserting the CE-rated back protector makes things even stiffer and less body-hugging.

Despite the ebike tag, the only potentially suitable battery sleeve is right in the outer section of the bag where it affects stability most. It’s not long enough for a full-size Shimano or Bosch battery either so when we went on double battery missions the cell just had to lurch around in the main compartment. Again, not ideal for stability.

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If you like a stiff and prescriptive fit on a bombproof bag with tons of pockets and other stowage options, plus an optional back protector then the high tech Ergon is worth the spend. If you want something body hugging that spreads pressure and stays stable when you’re getting wild then look elsewhere.

Tech spec: Ergon BA3 E Protect backpack

  • RRP: $179.99 / €179.99 / £159.99 (including back protector) $139.99 / €139.99 /  £129.99 (without back protector)
  • Weight: 1390g (including rain cover)
Guy Kesteven

Guy has been working on Bike Perfect since we launched in 2019. Hatched in Yorkshire he's been hardened by riding round it in all weathers since he was a kid. He spent a few years working in bike shops and warehouses before starting writing and testing for bike mags in 1996. Since then he’s written several million words about several thousand test bikes and a ridiculous amount of riding gear. To make sure he rarely sleeps and to fund his custom tandem habit, he’s also penned a handful of bike-related books and talks to a GoPro for YouTube, too.

Current rides: Cervelo ZFS-5, Forbidden Druid V2, Specialized Chisel, custom Nicolai enduro tandem, Landescape/Swallow custom gravel tandem

Height: 180cm

Weight: 69kg