Decathlon has stepped up their ebike game even more. With this Rockrider E-ST 520 electric mountain bike they added a really impressive ebike to their line-up. The E-ST 520 has a lot of similarities to its bigger brother the E-ST 900. It, for example, shares the same amazing Brose T mid-drive motor. This motor was already impressive to see on the 2000 euros (1700 pounds) E-ST 900, but to get it on the E-ST 520 as well is just a steal! The E-ST 520 comes in at just 1700 euros (1400 pounds), at this price point it has some absolutely amazing specifications. In this review, I will tell you all the things to like about this stunning Decathlon E-ST 520 electric mountain bike!
The E-ST 520 shares the same Brose motor as its higher-priced E-ST 900 brother. It’s amazing to see that Decathlon could use this premium motor on an electric mountain bike that costs just 1700 euros (1400 pounds)! The company Brose is a large automotive part manufacturer that also produces top-quality electric motors for ebikes. The Brose electric motors are a textbook example of great German engineering. The motors therefore also compete with the best in class ebike motors from Bosch and Shimano.
The motor used on the E-ST 520 and E-ST 900 is the Brose “Drive T” model. It’s a mid-drive motor with an internal belt drive for extra smooth and quiet transmission. The motor has a built-in torque-sensing pedal assist, 70NM of torque, and 250W op power. The actual peak power will be higher in boost mode (300-400W), but the legal listed power is 250W. All these features make this motor truly outstanding, especially when you consider that the E-ST 520 only costs 1700 euros (1400 pounds)! Even at the 2000 euros price point of the E-ST 900, it’s an impressive motor!
The torque of 70NM is the most important specification of this motor. The torque of an ebike is the force at which the motor can rotate its axle. High torque is desirable since it will enable you to climb any hill effortlessly. This Brose motor has a torque of 70NM which is truly amazing for a 250W motor. Most ebikes, especially hub motor ebikes, will only produce around 40NM of torque. So 70NM is almost double this!
Torque-sening pedal assist
The pedal assist is of the torque-sensing kind. This means that the ST-520 ebike will measure the force you exert on the pedals. It will assist you with a certain amount of power dependent on the force you exert on the pedals and dependent on which assist mode you are in. This will result in the most natural-feeling electric assistance, the electric motor will become part of your body. Torque-sensing pedal assist is often found on high-end ebikes, so having it on this even lower-priced E-ST 520 is amazing to see.
Decathlon decided to alter the drivetrain of the E-ST 520 compared to the E-ST 900. Decathlon went for a Microshift Advent 1 x 9 groupset compared to the Shimano Deore M6000 1 x 10 groupset on the E-ST 900. This decision was probably made to lower the cost of the E-ST 520, which makes sense.
The Microshift Advent 1 x 9 still is a great group set for this ebike. It might not be as high quality as the Shimano Deore groupset on the E-ST 900, but it definitely isn’t bad either.
Having a good drivetrain is especially important for mid-drive ebikes since there will be a lot of added force on it by the electric motor. If you have a weak drivetrain in addition to a powerful mid-drive motor, you can possibly break chains and wear out cassette gears really quickly.
Decathlon thought of this as well, just like they did on the E-ST 900. Both ebikes use a strong 34 teeth front chainring with an anti-chain derailing system, which will handle up great against the high motor torque. Decathlon also installed an ebike specific chain on the E-ST 900, this is the KMC E9 Sport. The E-ST 900 uses the KMC E10 turbo chain, which offers just a little higher performance. But still, the KMC E9 will do the job absolutely fine as well.
Display and range
The E-ST 520 uses a slightly different display from the E-ST 900. It offers basically the same features but looks a bit less premium/sturdy. It still is a nice display that has integrated control buttons, which results in a small, discrete, and easy-to-use display mounted on the left side of the handlebars.
The display shows all the relevant information like speed, assist level, battery percentage, remaining range, trip distance, and more. With the buttons, you can set the bike into 3 different assist levels. The E-ST 900 features 4 assist levels, for the E-ST 520 they combined the economy and economy+ mode into one assist level. I think that this difference doesn’t matter all that much since you will still have a good amount of controllability with 3 levels.
Range and assist levels
|Assist level||Name||Power||Range (Estimate)|
|Assist level 0||Off||+0%||–|
|Assist level 1||Economy||+60%||95 kilometers, 60 miles|
|Assist level 2||Standard||+120%||70 kilometers, 45 miles|
|Assist level 3||Boost||+320%||25 kilometers, 15 miles|
These 3 assist levels give you great control over the amount of power you want to use. In the economy mode, you can expect a range of about 95 kilometers (60 miles). In the Boost mode, you can expect a range of about 25 kilometers (15 miles). This range can be considered excellent, especially when you consider that you won’t ride in this mode all the time.
The battery of the E-ST 520 is made out of the same high-quality Samsung SDI 18650 lithium-ion cells that are in the E-ST 900. Having brand-name cells inside an ebike battery is always important for reliability, performance, and safety. Decathlon also mentioned that you could have LG-MG1 18650 cells in your battery, depending on where your model is produced. Both the LG and Samsung cells are of great quality, so you don’t have to worry about this.
The E-ST 520 has a slightly smaller capacity battery than the E-ST 900. The E-ST 520 has a 420Wh (36V, 11.6Ah) capacity while the E-ST 900 has a 502Wh (36V, 14Ah). This comes down to a 16% smaller battery capacity. I think this still is a great capacity for an ebike with this amount of power. The E-ST 520 is also around 16% cheaper than the E-ST 900, so you actually get the same capacity/price ratio as the E-ST 900, which is excellent.
The battery also is removable which makes it convenient if you want to charge the battery inside. The charger that is included is a 36V, 2A charger. This is a slower charger compared to the 36V, 4A fast charger that comes with the E-ST 900. Charging from 0 to 80% will take about 5-6 hours with this charger. It would have been nice if Decathlon provided a fast charger with the E-ST 520 as well, but at a lower price point, some cost-cutting can be expected. This is where one of those cost savings shows. For most riders a 36V, 2A charger will still be good enough though, especially if you only charge at home.
The frame is made out of the same strong 6061 hydroformed aluminum tubes used on the E-ST 900. The frame is covered by Decathlon’s lifetime warranty for mountain bike frames. So you probably don’t have to worry about it falling apart. The welds on the frame are neat and the paint quality is nice as well.
The frame actually looks exactly the same as on the E-ST 520. Decathlon probably just used the same frame, which makes sense. This isn’t a bad thing since the E-ST 900 frame is excellent. So the only difference with the E-ST 900 is its paint job.
The battery is integrated into the frame and can be slid in easily. Once the battery is in, the battery can be locked down. Preventing someone from stealing your battery.
The E-ST 520 only comes in one color compared to the two colors of the E-ST 900. This is a silver color with fluorescent green accents. I think this color scheme looks nice, Decathlon in general always gives their bikes a clean and modern appearance.
The E-ST 520 has Tektro TKD88 hydraulic brakes installed in combination with 180mm discs. This combination gives the ebike plenty of stopping power. The E-ST 900 has a bit higher level Tektro TKD32 hydraulic brakes installed. Both Tektro models do their job perfectly, but don’t expect the absolute highest performance from either of those brakes.
The E-ST 520 uses a RockShox 30 Silver front fork. This is a quite entry-level suspension from RockShox with 120mm of travel, adjustability, and a lockout feature. This front fork isn’t the best that RockShox has to offer, but it definitely suffices. The E-ST 900 has a bit higher-level RockShox Judy suspension, which is expected at its higher price point.
The suspension of the E-ST 520 still allows for comfortable light trail riding or serious off-roading. Both can be done without a problem.
The E-ST 520 comes with 27.5 inches by 2.5 inch wide tires. This is quite a wide tire for a mountain bike which will result in a lot of off-road grip. They also offer a good level of protection against punctures and are tubeless-ready. The E-ST 900 has even wider 2.8 inch wide tires, these will offer more grip but also lower the efficiency of the ebike due to higher rolling resistance. I would say that 2.5 inch wide tires are plenty big enough for most riders, 2.8 inch wide tires definitely aren’t absolutely necessary.
The tires are installed on 23mm wide wheels. These wheels are off the thru-axle style that provides great stability and a precision fit. They are also easy to remove if you need to do any maintenance. They are a great fit for the E-ST 520.
E-ST 520 a good commuter as well?
The E-ST 520 is a great ebike for daily commuting as well. You will have an ebike with high-quality components, a powerful motor, great range, and a nice pedal assist. This makes it perfect for daily commutes as well. You will also get the added benefits of a mountain bike, like nice front suspension and big tires for amazing grip. You could also add a luggage carrier and mudguards to make it truly suitable for daily driving. Therefore I would say this E-ST 520 is suitable for casual riders, commuters, and semi-professional mountain bikers.
So whether you are looking for a great off-roading machine or a nicely riding daily commuter, the E-ST 520 will do the job. If you are a bit more professional mountain biker you might want to spend the extra money to get the E-ST 900. It will have a better groupset and improved brakes and suspension. This will be worth the extra money if you really push the bike to its limits.
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Decathlon has built an e-bike that provides insane performance for only 1700 euros (1400 pounds). The E-ST 520 features much of the same components as Decathlon’s already really competitively priced E-ST 900. The fact that the E-ST520 shares the same amazing Brose T motor, Samsung battery cells, and frame as the E-ST 900 is just unbelievable. For 1700 euros you can’t get more value anywhere. With this ebike Decathlon made a high-quality, mid-drive electric mountain bike available for the masses. No other brand has come close to delivering the same or better performance at this low of a price point.
The E-ST 520 is also really attractive for people that don’t necessarily want to go mountain biking. It’s a great casual ebike as well, that can be made more practical by installing a luggage carrier and mudguard.
If you are in doubt between the E-ST 520 and the E-ST 900, I would say: only go for the more expensive E-ST 900 if you are a semi-experienced mountain biker. Most consumers will not push the ebike to its limits and therefore won’t really notice the difference between the E-ST 520 and E-ST 900. The E-ST 520 will then simply offer more value. If you, however, want the biggest possible range and you value this a lot, then you should probably also go for the E-ST 900 with its 16% bigger battery.
If you want a high-quality electric mountain bike that offers the best in class value, this ebike is the one for you. For 1700 euros there will simply not be a better option available. Decathlon has done an absolutely amazing job with this ebike and I really can’t recommend this ebike enough!
If you have any questions, want to start a discussion, or need some support, please use the comment section below. I will respond to you within 24 hours.