Decathlon’s entry-level Rockrider E-EXPL 520s proves that e-bikes don’t have to be expensive to be fun. Outdoor specialist, Decathlon offers a massive range for full-suspension e-bikes and the Rockrider E-EXPL 520S is a full power, 29er e-bike with 140mm travel and a category 3 rated frame. So it’s clearly designed for trail riding, not thrashing enduro tracks, but it’s still a really capable, fun package, and one of the best budget electric bikes you can buy for under £3k.

Decathlon’s Rockrider E-EXPL 520S is fun, fast and affordable.

Decathlon Rockrider E-EXPL 520S Need to know

• Full power e-mtb with 140mm travel
• Brose Drive T motor with 70Nm torque
• Four power modes, plus Boost
• 500Wh removable battery
• 29in wheels with asymmetric rims and 2.4in tyres
• Fully adjustable air-sprung  X-Fusion suspension
• Two-piston Tektro brakes
• Four frame sizes, S to XL
• Weight: 25.86kg (57lb) size L

Frame and geometry

The full alloy frame on the Rockrider E-EXPL is available in four unique sizes, small to XL. And what’s really cool is, Decathlon has rider height recommendations right next to each size option on its website. So, at 181cm tall, that puts us squarely on the size L, which is designed for rider heights between 175 to 184cm.

With a 60mm stem the Rockrider shows it has a trail bias.

So how did it fit? Like a glove. With a 477mm reach and short 430mm seat tube, the size L Rockrider leaves plenty of room in the cockpit to manoeuvre, without the bike ever feeling cramped when sat down spinning along flatter sections of trail. Yes, the 60mm stem feels a touch too long for more technical terrain when compared to the other bikes in this test, but it’s cheap to swap out for something shorter. Just be aware that the electric cable from the handlebar mounted remote runs through the inside of the handlebar and out the bottom of the stem faceplate. If you’re looking to sharpen the steering or adjust your weight balance, then we’ve got loads of recommendation in our stem buyers’ guide.

A crystal clear display is tucked neatly behind the handlebar.

The colour handlebar display is neat and functional, and it sports all the usual metrics including a percentage-based battery level indicator. Rockrider has also resisted the temptation to introduce more confusing terms for each of the four power modes, instead it stuck with 1, 2, 3 and 4, with 4 being the most powerful option. There’s also a separate button on the remote for “Boost” mode, which takes you straight to full power if you’re in a lower power setting – handy for surprisingly sharp climbs.

Good times are guaranteed when shredding the Rockrider E-Expl 520S.

Housed inside the oversized down tube is a 500Wh removable battery. It’s side loading, which makes it really easy to remove, and more secure than a bottom-loading battery, as found on the Polygon. The cells power a chunky Brose Drive T motor which boasts 460W peak power and 70Nn torque.

The Brose Drive T-motor is smooth and quiet in operation.

Now, if Brose rings a bell, it’s probably because it also manufacturers motors for Specialized and SRAM. And while this isn’t the same motor found on the Specialized Turbo Levo or SRAM Powertrain equipped bikes, it has familiar traits. Namely, it’s really, really quiet when pedalling, and because it’s a belt driven design, there’s no annoying freewheel rattle from the motor when coasting down bumpy trails either. Yes, it’s not got as much torque as the Shimano EP801-equipped Polygon or the Yamaha motors in this Affordable E-bike shootout, but it’s got more grunt and similar range to a lot of modern mid-power e-bikes costing three times the cash.

So, our only real complaint with the e-bike system on the Rockrider is that it takes about eight hours to charge the battery. Also it’s a linear charge, so it also takes four hours to get a half charge, which means you can forget about stopping at the pub for lunch and getting your battery topped up while you refuel.

Suspension

With an air-sprung fork and shock it’s relatively easy to adjust the 140mm travel suspension on the Rockrider to accommodate different rider weights. There are a few nuances though. When setting the sag on the X-Fusion Pro R rear shock, you need to be aware that the blue o-ring does not go all of the way to the end of the shock body, even at full travel. So factor this in when measuring shock sag. Also, we found that the shock bottomed a little too easily on drops and jumps with 30% sag, so best run the shock a little firmer, as this bike will definitely encourage you to send it.

With 30% sag on the shock we found the rear suspension bottomed too readily.

On the 140mm X-Fusion McQueen R Air fork, there’s a really wide range of rebound adjustment, but only a very small window where the fork doesn’t top out harshly or feel way too slow to return on repeated hits. So its really worth taking your time to dial in the rebound damping on the fork, after you’ve set the sag.

Air-sprung and oil damped, 1he 140mm X-Fusion fork needs dialling in for maximum performance.

With a slender 34mm chassis, it’s clear that the Rockrider is a trail bike, not an enduro bike, but even with the smaller stature fork, we had no issues with steering precision or control, so we could still get the Rockrider to go exactly where we wanted it to even on trails that would be considered enduro.

Components

With size focused bar widths, stem lengths and seat post drops, Decathlon is clearly sweating the details. As such, our size L test bike came with a 760mm width bar, a 60mm stem and a seat post with 150mm drop.

Size specific droppers, stem lengths and bar widths improve fit.

With the Ergo lock-on grips that look and feel really similar to expensive Ergon grips, the bar width creeps up to 770mm, which is perfect for trail riding, especially when dodging tightly-spaced trees. And while the 60mm stem doesn’t feel too stretched, if you’re riding steep descents a shorter unit would really help to get your weight back more easily. The stock dropper post remote has a nice light lever action, but the plastic construction does feel fragile, so be careful not to knock it on anything. Also with over 50mm of exposed seat post poking out of the frame, there’s lots of room to upgrade to a 200mm dropper post at a later date if you feel the need.

Moving the Tektro levers inboard improved stopping power, but we still wanted more grunt.

Rockrider has sensibly opted for big 203mm brake rotors front and rear to maximise the stopping power of the twin-piston Tektro M276 hydraulic brakes. But even so, there were times when we had to revert to two finger braking to keep the speed of the Rockrider under control. So you’ll want to move the brake levers 40mm inboard of the gips to maximise the mechanical advantage of the longer lever blades. Which means you’ll also need to swap the position of the 10-speed shifter with the brake lever to keep the shifter within easy reach. We’d also recommend winding the lever position in a touch, because not only does this make the lever blades easier to reach, it makes the action of the Tektro brakes feel less wooden too.

MicroShift’s 11-48t cassette and clutch Advent X derailleur has you covered.

With a 10-speed Microshift Advent X drivetrain the Rockrider gives you a wide range 11-48t cassette and smooth, accurate shifting. The derailleur has a built-in clutch, with an on/off switch, to reduce chain slap and it works in a similar way to Shimano’s Shadow Plus units.

A mudguard and ample chainstay protection keep everything clean and quiet.

We also really like that the shifter pod has rubber textured paddles, and just like the motor, the MicroShift drivetrain was impressively quiet in use, in part thanks to the excellent chainstay protection. Best of all, it won’t cost a fortune to replace the drivetrain when it eventually wears out.

Performance – How it rides

That’s not to say the Rockrider was completely silent though. On the very first outing the spokes in both wheels could be heard popping and pinging as we threaded the Rockrider down some fast, techy trails. And after just one ride, there was some noticeable play in the rear end of the bike, where the rear axle, main pivot and spokes in the rear wheel all needed tightening.

Jumps for show, corners for dough… the Rockrider does both

With the bike in the work stand we notice that the Rockrider uses asymmetric rims to help balance spoke tension, which again shows the attention to detail here. Some of the suspension hardware also uses small T25 bolt heads though, so be careful not to round them out when cinching them up.

Climbing

With a commanding climbing position, long 460mm chainstays, and that 60mm stem keeping your weight forward, the Rockrider dispenses with steep ascents with relative ease, especially in full power mode. In fact, even towards the end of one ride, with the battery capacity below 10% and the bike in limp mode, I had no problem catching up with a couple of riders on their fancy mid-powered e-bikes on a fire road climb.

More power than most mid-power e-bikes make climbing easy.

If it’s techy climbs that get your heart racing, the limiting factor here is of course tyre traction. It’s not that the tread pattern of the 2.4in width Rockrider tyres is lacking, it’s just that the rubber compound is too hard, so it tends to ping off wet roots and rocks, rather than wrapping around them to find traction.

Your more likely to spin the rear tyre than run out of gears.

With the relatively tall 351mm bottom bracket height, we never clipped a pedal on rocky climbs, even with the longer 170mm crankarms. Sure, experienced riders will crave a lower BB height, but for anyone getting into e-bikes for the first time, the extra pedal clearance the higher BB affords will no doubt be welcome.

Descending

And it’s the stock Rockrider tyres that hold the E-EXPL back on the descents too. The tread pattern and profile are both good and the fast rolling compound helps extend the range of the 500Wh battery too. However, if you want more control for rallying rather than touring, we suggest fitting a softer compound front tyre, and keeping the stock front tyre as a spare for the rear.

Riding on the edge of traction was fun, bit this bike has more to offer.

If you want to take the Rockrider’s descending capability to another level, we’d also recommend fitting a shorter stem as this will make it much easier to shift your weight back and help prevent the fork from diving too much when it gets steep and rowdy. Overall we had no problem achieving a balanced suspension response and the Rockrider instantly gave us the confidence to ride trails well beyond its design remit.

Steep or deep, you can send it on the Rockrider.

Yes, the damping in the fork can feel crude at times, and even choke on bigger hits, but the general level of control the Rockrider offers for such an affordable bike is nothing short of impressive. And no, it’s not lost on us that we are suggesting you could transform the Decathlon Rockrider E-EXPL 520S to make it better at riding trails it was never designed to handle, but we think you’ll have more fun this way, even if you reduce the life expectancy of some of the components. Also, given that this model is currently discounted to £2,699, you’d be crazy not to make some upgrades.

Decathlon’s Rockrider E-Expl 520S redefines what an entry-level e-bike can do