Rockrider E-ST 520 Electric Mountain Bike Review

85 Comments

1. I have just bought the E-st 520 and am very pleased with it, but have found that in top gear (smallest cog) on the flat, the chain jumps every 5 to 10 seconds. Is this because the chain is too loose ? Decathlon offer a free service within 6 months so will take this up.
   Also, at speed on the flat, it feels like the bike could go up another gear or two.

   • Hi Paul,

     This issue could indeed be with too loose of a chain. If they offer free service, I would make use of that as well. Good luck!

2. I have the 520 whenever I put the bike in 0. it feels like the breaks are on even when in low gears
   Is this normal.
   When in 1. 2. Or 3. The bike is great
   This is my first e bike any reply would be greatly appreciated
   Thanks

   • Hi Pat,

     An ebike will always paddle a bit heavier when the power assist is disabled. You have some motor resistance and more weight, so this unavoidable. It however could also be that your brakes aren’t adjusted properly. You can simply check this by looking at the brake pads and seeing if they touch the disc when the brake is not engaged. If you spin the front wheel in the air, you will also hear the brake rubbing. If you hear this, your brake will need readjusting.

3. Just got first 100km with my E-ST 520. Im rather happy with this device however the constant creaks from the motor got me mad. it makes no difference whether to pedal on an electric motor or not .. Who experience also same problem? seems that something is tightly tightened inside the motor body..
   should i address to the service center, what do you think?

   • Hi,

     Creaks from the motor is not something familiar to me. I would contact Decathlon about this, to see if this would be considered normal behavior or not.

   • Hi kleaksa,
     I have a 520 and just done around 500 miles, the bike has been great and has just started to make a slight creaking sound around peddle usually when just moving off. I do not have a decathlon store within 200 mile so would be interested to hear how you get on, hopefully it nothing too major.

   • My wifes motor creaks – I took it in and they said it was a very tight seal and nothing to worry about.

4. Hi what panniers rack would you recommend for the est520
   Thanks Bob

   • Hi Bob,

     I can recommend the panniers rack 500 onesecondclip from Decathlon. It feels really high quality and is quite affordable.

   • I have the afore mentioned panier rack ie Decathlon 500 and it’s very solid and a good fit.

5. Hi Dean
   I have fitted Zefal mud guards on my 520 and they very effective.
   On front Zefal Deflector FM60 ( easy to remove if removing front wheel to put in car).
   On rear Zefal Deflector RS 75 ( fits well with Decathlon panier rack. Also can easy adjust gap between tyre and guard ). Also wide enough to fit s light or reflector to.
   All the best Ian

   • I bought the exam same front mudguard as you and I can’t get it to fit. The “parts” not sure what they are called that you insert into the front steering underneath are either too small or too large.

     • I did have a bit of a struggle with the part that went into steering post but after a bit of jiggling it just slotted in and I screwed the mud guard into it.

6. Thanks to Alan for the EST 520 controller manual.
   One little addition is :
   Error 31

   This one made me smile as I was getting it alot so was always at the back of my mind. After investigation by Decathlon. It basically means you have held the power on button longer than the recommended 2 seconds when switching the bike on. What a relief when I found this out. Cheers Ian

   • Hi Ian,

     Thanks for sharing, that indeed is a really stupid and funny error. This will definitely help others if they search for the error on the internet. So really helpful to share!

     • Thanks Ian, I will update my manual.

7. Thanks for your response Giello I wondered if that was the case. Or if they were using the cheaper batteries they fit on the 500 model which are non specific.

   • Luckily they don’t, if that was the case, it would be quite a scandal. Decathlon couldn’t permit to do such things.

8. Sizes. My wife as the small and I have the medium. Difference seems to be 1 inch in length (seat to handlebar and one inch in height.

   Just thought this might be useful to someone.

   Alan

9. I am very impressed with mine. It’s actually our second ones (first ones were stolen without the battery -hahahaha) and it does everything I want. I’ve even worked out what all the buttons do on the display and written a decent manual for it. If you want a copy, help yourself https://www.dropbox.com/s/daf4bykasx4boeq/Controlling%20the%20EST-520%20V2.1.pdf?dl=1

   Both my wife and I have them now and go on 20-30+ mile rides over the pennine hills whenever we can.

   We have changed the saddle for more comfy ones and added a rack and little tail pack, some mudguards and better lights.

   Alan

   • Hi Alan,

     Thanks for sharing your experiences! The manual will definitely come in handy for E-ST 520 owners. I am glad you and your wife are enjoying the e-bikes. Again thanks for sharing, it’s much appreciated!

   • Hi Alan,
     I’ve had mine for months now and still haven’t worked out how to change the screen info! Lol I can’t seem to download your instructions either though. (Maybe it’s me 🤔)
     Great bike though!
     Cheers,
     Jack Vardy

     • Hi Jack,

       I have been able to download the manual of Alan. I have created a google drive link of it as well. You might be able to open it this way: https://drive.google.com/file/d/1EakK7i-D51R74YC_ZKJgYdXu2u2IJDBI/view?usp=sharing

       • Thanks guys. A great help 👍

   • Thanks for the manual! But is there a method to know the battery status and the battery cycles number done? Other ebike models have the bluetooth with own app but this one haven’t any check.

     • Hi Trix,

       As a consumer, you won’t be able to check the battery status or the number of cycles of your battery. There also isn’t a bluetooth battery management system inside the battery that can be accessed. Decathlon itself will probably be able to check the battery status/number of cycles by opening up the battery and connecting special diagnostic tools. As a consumer, this unfortunately isn’t possible.

       • I have found some “hidden” status values which I reckon are the battery voltage and the percentage battery charge left. I think if you kept a record of those and the number of charges over time, you could graph out the battery status.

         Alan

         • Keeping a record of the battery voltage, won’t really give you all that good of an insight about the battery health. It would also be a hassle to keep track of this. Without a deep understanding of batteries and the technologies used in this specific battery, the data will be hard to interpret.

           My advise would just be to replace the battery when you find that your range has decreased to a point that it becomes impractical. It will probably take many years before this is the case with most owners. So I wouldn’t worry about it to much.

       • Thanks for your comments.
         Well, i think that I’ll ask to the assistance in the shop when at the end of December I will bring the bike for the free general check. Actually I have no battery problems, I did only 820 km with my e-st 520. Maybe I should check other parts like chain, transmission or tires.

       • Just a quick update. I have had the EST 520 over 4 months now and very happy, the Brose engine is very impressive and has handled all the hills I have thrown at it, it’s a bit like driving an automatic car in that you start to learn the optimum input you need to put in to get the returns out. I have put on a Decathlon luggage rack which fitted straight on and very very sturdy and Zefal mud guards which very wide and fit under the rack perfectly. I have carried some quite heavy loads on the rack plus back pack and the bike goes up hills as normal the only difference being it used more of the battery. The only negative to date is the battery alot of the reviews and Decathlon make alot on the Samsung or LG batteries they use which was part of my decision making as it is a major part and cost of the bike. So was very (very) disappointed to find the battery fitted is none of the above but a made in China Trendpower battery. So feel cheated on that front. Hope the above of use to others considering the EST 520

         • Hi Ian,

           Thanks for sharing your experiences with the bike!

           About the battery: like Decathlon states, the battery indeed are LG or Samsung batteries. What this means is that the individual cells that make up the battery (18650 cells) are from Samsung or LG. Both really great manufacturers of quality 18650 cells.

           It could be that the battery is assembled in China by trendpower. That however doesn’t imply that there aren’t Samsung or LG cells inside.

           So I can assure you that there are LG or Samsung cells inside, but that it is assembled in China, which is completely normal. A lot of batteries are assembled in China. So don’t worry, you still have quality cells inside, which is the most important about an e-bike battery.

         • Hi Ian, could you please tell me what type of mudgaurds you fitted on your EST 520. I’ve just got one and I’m looking to fit a pair if you can help.
           Thanks Dean

         • Hi Dean,

           The Btwin mudguards 300 for wheels between 24-28 inch should fit.

   • Hello Alan,

     I was wondering if you have a battery for sale as I had my battery stolen off my est900 as they couldn’t steal the whole bike. Hope you can help as in can’t afford the £400 decathlon want for a replacement.

     • Hi Gareth,

       I hope that Alan will be able to respond to you. It’s very unfortunate that it got stolen, I feel sorry for you. Good luck!

     • Gareth,

       We want to keep them as spares ourselves for when we start doing longer rides.

       Sorry.

       Alan

10. Hi I’ve just ordered the est520 from decathlon I couldn’t get the large size because they are always out of stock So I ordered the medium I’m a bit worried that it might be the wrong size so is there much difference between the large and the medium ?
    Thanks bob

    • Hi Bob,

      I shouldn’t be to worried about this. The sizes decathlon sells are actually quite similar. The M size will give you a slightly more up right posture, which is great for most people. But the difference between the M and L is slim. You can always add an adjustable stem adapter, this way you can probably make it fit perfectly. I always use them on all my bikes, I think that it is a great upgrade, that’s inexpensive as well.

      Adjustable riser like this: https://s.click.aliexpress.com/e/_dVEwoBJ

    • I have the medium. I’ve changed the seat and the stem to suit me (short legs, long body) and I find it really comfortable. As I said in another post, the difference in size between S & M is only 1 inch, so I think you will be fine.

11. Hi there, I’m away to purchase an e-st520. I am 177cm in height, I have read in various reviews that Rockrider bikes are quite large. Would you recommend the medium or large size…?

    Cheers 🙂🙂🙂

    • Hi Stine,

      The best thing to do, is to actually test the sizes at a Decathlon shop if you can. For your size, I would recommend a large size though. I have converted a lot of bikes of decathlon (same frame sizes). For people of your size, the large frame was always the best.

      • So, if I’m 185cm height, you recommend XL size?
        Thanks for your review!

        • Hi Trupo,

          I am also about that height. Both the L and XL are fine for me. If you want to sit more upright, go for L. If you want a more sportier stance, go for the XL.

12. Does the E-ST520 have a USB port.. I know there was one on the first version of the E-ST500 model however that was removed in V2.

    • Hi Kenneth,

      To my knowledge it doesn’t have one. I can’t see it anywhere and it also isn’t listed in the description of the product. If an ebike has one though, it often is limited to 500mA charging. Which makes it a quite slow method of charging.

      • Hi Giel

        I have the rockrider 520 mtb in Australia. Would like to put in an electric motor onto it. What model would you recommend

        • Hi Amith,

          Because this is a really popular MTB, I made a complete build video on how to convert this bike (Rockrider ST 520). You can find all the necessary components in the description of my video: https://www.youtube.com/watch?v=lxSx33Ps_RQ&ab_channel=Edrivenet

          This conversion uses a Bafang BBS02 system: https://s.click.aliexpress.com/e/_dYOcBOC

          You can find the links to the other components you need in the video description.

    • no USB on the E-ST520

13. Hi Giel,

    Great review, the E-ST 900 has 90Nm and the E-ST 520 has 70Nm from the same motor, if I used the controller from the E-ST 900 unit would I be able to get 90Nm from the E-ST 520 motor?

    Cheers in advance

    • Hi Andrew,

      The E-ST 900 and E-ST 520 both use the exact same Brose motor. They therefore also both have the same torque figure: 70Nm.

      So it’s not correct that the E-ST 900 has 90 Nm torque, it has 70 Nm as well. This is stated in my review and on the Decathlon spec sheet as well.

      So swapping controllers wouldn’t change the performance.

14. I have the e-st 520 since 2 weeks, I have traveled with this bike 130 km almost all trails with beautiful climbs and downhills and I must say that I am satisfied with it. Silent and powerful Brose engine, the battery as it is written, allows about two and a half hours of fun, obviously depends on a thousand factors. Unfortunately I made a stupid fall on a trail and I broke after a while a spoke of the rear wheel but this is part of the game. However, the limit is me and not the bike.
    Obviously particularly extreme downhills are not ideal, for extreme use it’s better to orient yourself perhaps on a full suspended e-bike like the Stilus but for medium difficulty routes the e-st 520 defends itself very well.

    • Thanks for sharing!

      • Here is a small update: I have traveled more than 600 km and the e-st 520 is confirmed as good.
        I fell down again during a downhill (24,5% slope!!!) but everything was ok! 🙂
        I put tannus armor on the tires to avoid annoying tire punctures. However, I have never punctured.
        The only thing that needs to be replaced are the pedals, because in my opinion they are not suitable if one does trail or little downhill. Better to take better performing pedals with steel pins and not plastic, so as to have more grip (I’ll take the HT components PA12A pedals neon yellow). The Brose engine is fine as well as the battery life which for the tours I do never let me down. A friend of mine recommended the drop seatpost for safer downhill riding (at the moment I don’t change the seatpost) and ergonomic bar grips (soon I’ll take the Ergon GA3 bar grips).

        • Hi Trix

          That’s awesome! I am glad you didn’t got hurt in your accident. Thanks for sharing your experience with the E-ST 520, really helpful for others interested to buy this e-bike.

          • HI Giel,

            Any recommendations for s good quality kick stand for this ebike ?

          • Hi,

            I personally think this stand from Decathlon works great:

            https://www.decathlon.co.uk/p/chainstay-stand-500/_/R-p-12228

15. I just ordered one, it will arrive in 10 days. Reviews look amazing.
    My usage will be mainly commuting on roads and some parks during covid, nothing too rough.
    I had a Carrera Comp hybrid bike before and reeeeally missed a front suspension even to just go up/down small pathways steps and felt the thin wheels unsafe in particular when the road was wet.

    A couple of questions:
    -any upgrade or accessory you would recommend?
    -I couldn’t find on the website a replacement battery ( in case I wanted a second spare one) what are the options there? (I imagine the one for e-st 500, is there any other/better one?)

    Great review btw and thank you in advance 🙂

    • Nice that you bought one! Absolutely great ebikes for the money, you will definitely like it!

      Having front suspension is always nice indeed, I also find it a must have. Even if you only use it on road.

      The big tires provide a lot of confidence even in wet circumstances indeed, I also like this about mountainbikes in general.

      For commuting I can always recommend mud guards and possibly also a luggage carrier. Decathlon sells these as well. An bike stand is also a must have in my opinion. Having the ability of the bike to stand on its own is really convenient.

      You should be able to buy a replacement or spare battery at Decathlon workshop. They provide almost all parts separately. If you can’t find them, I would contact Decathlon about this. I think they should be able to provide them.

      The E-ST 900 has a slightly bigger battery, so buying such a battery could be an upgrade. I am not sure if they are backwards compatible though, would have to ask Decathlon about this.

      Have fun riding your new e-st 520!

      • great news, Decathlon confirmed the bigger battery would fit.

        • Good to know, thanks for sharing! That’s really convenient.

16. Excellent review. I appreciate the comparison between the 900 and 520 versions. I have two questions that apply to both of these central motor eMTBs. (1) How do the bicycles perform in zero assist? Does the presence of the actuator add significant resistance due to backdriving it, and how does this compare to (Decathlon’s) hub driven eMTBs? (2) Does the 70Nm torque limit refer to the applied torque on the pedals or the resulting torque on the rear wheel (in the lowest gear)? If the former, the maximum resulting torque (lowest gear) on the wheel would be 70*42/34=86Nm, more than twice the torque limit of Decathlon’s hub driven eMTBs (42Nm)!

    • Hi Sep,

      Thanks, an ebike with a mid-drive motor generally rides better in zero assist mode than a hub motor ebike. Ofcourse an ebike will always have more resistance when pedaling along without any assistance. But with a mid-drive motor, it still is relatively comfortable in zero assist mode, you don’t feel the actuator that much. It will have a lot less resistance than hub motor ebikes (especially gearless type hub motors, Decathlon sells geared hub motors, fortunately). So I would say that with a mid-drive motor you can still pedal along with relative ease in zero assistance mode, but even a little assist will increase the comfortability ofcourse.

      The 70Nm torque of the mid-drive applies to the output shaft of the mid-drive motor. So it indeed will be the torque on the front chainring (pedals). You therefore can increase the wheel torque by selecting a lower gear indeed. With hub motors, the specified torque figure, is already the wheel torque. This is the case because the hub motor is part of the wheel and therefore the ratio can’t be altered.

      So yes, in the lowest gear, the mid-drive motor will have more than twice the wheel torque as the hub driven ebike. It, therefore, is a lot more suitable for climbing steep hills.

17. Hello There,
    I will be doing mild offroading and commuting in the countryside with an emtb, would you recommend this or a Cube acid one 400? Any other bikes you would recommend. I am looking to spend up to 1600,
    Thank you so much for your time.
    Joe

    • Hi Jo,

      I think the rockrider e-st 520 is the better deal over the cube acid one 400 because: It’s cheaper, has a slightly bigger battery, has slightly more torque and uses higher quality (more expensive) gear, like the suspension for example. The E-ST 520 will be an capable off-roading bike, mild offroading will therefore be no problem. You will also be able to commute nicely with this bike. So, for a 1600 budget, the e-st 520 is pretty much the best deal out there.

      • Hello,
        Sorry for so many questions, but I am just wondering how reliable the bike is.

        • Hi Joe,

          No problem, you can ask as many questions as you like! That’s the purpose of the comment section 🙂

          It’s always hard to tell something about reliability. This model hasn’t been around for that long, so there are not any long term customer reviews yet.

          I however don’t see any problem with the reliability of this bike. I think it’s a very sturdy build e-bike, that won’t easily break. Everything is assembled nicely and integrated into the frame. So, I would say that reliability of this e-bike will be excellent as well. The Brose e-bike motors also have good reputation, so I don’t expect any reliability issues there.

          So if your thinking of purchasing it, I wouldn’t be scared about the reliability. There are no obvious signs that shows that the reliability will be bad. And even if problems would occur, Decathlon has amazing customer support.

18. Been weighing up options between the e st520 and the Carrera Vulcan e bike I would primarily be using for a mix of commuting and countryside trails rides etc Which do you recommend

    • Hi Neil,

      I would definitely recommend the E-ST 520 over the Carrera Vulcan ebike because of the following reasons:

      The E-ST 520 has a great Brose hub motor with a lot more torque and power than the hub motor of the Carrera. A mid-drive system in general is just better: more torque, more adjustability, better weight distribution. So only for this reason alone, I would go for the E-ST 520 with its premium Brose mid-drive system.

      I think the frame of the E-ST 520 looks better, more durable and better build than the Carrera Vulcan. The Carrera Vulcan doesn’t appear to be designed as an ebike from the ground up. So no special frame design like the E-ST 520.

      Because the E-ST 520 is from Decathlon, servicing it will be really easy when problems should occur. You can just go to one of their stores, to get it fixed. With the Carrera Vulcan problem fixing will be much more tideous.

      These are the three main reasons that I would go for the E-ST 520 instead. Hope this helped.

19. Thank you for this nice review! Should i buy this 520 electric bike or a full hardtrail (fox or rockshox judy suspension, drop seatpost , 1×12 speed with 11 50)?
    I need a bike for climbing mountains and a little bit of downhill.

    • Hi Daniel,

      I think that this 520 e-bike is perfect for your purpose. Having this nice Brose mid-drive motor with a lot of torque will make climbing hills a breeze. The 520 is also capable enough for some downhill mountainbiking. If you however want to do some extreme downhilling (high speeds, rough terrain) then you will really need to go for a full suspension alternative. But for some conservative downhilling, it will do just fine! So if you want to have a great ebike for uphill mountain biking and medium/light downhill mountainbiking the 520 will not disappoint!

      • Thank you so much!

        • Good afternoon! Excuse me for asking so much, but you are very helpful. What would you choose between this 520 Electrical and the Merida one forty 400 2020?

          • Hi Daniel,

            I think this really depends on if you want electric assist or not, since the Merida one forty 400 isn’t an ebike. The Meride one forty 400 is a way higher quality mountainbike, with high quality suspension, brakes, etc. So if you want to take on the serious mountainbiking sport, this is an excellent mountainbike. But if you want electric assist, than the 520 is about the best you can get at this price point. So I think you should decide if you really care about the electric features of the 520, if not, the Merida one forty 400 will be the better mountainbike in that case.

20. Nice review but it has only been compared to the e-st900, but I am in doubt between the e-st520 and the e-st500 v2 which costs 1200 euros. I saw that the biggest differences are the brakes and the engine. What do you recommend to a biker for use on the wood trails that are not too difficult, at the first ebike experience (i have an old Rockrider 5.2)?

    • Hi Trix,

      In your case I would go for the e-st520 instead of the e-st500 v2. The Brose motor gives the bike a complete different ride to the e-st500 v2. The mid-drive motor will provide a lot more torque and overall stability. The components used are also of higher quality (suspension, brakes, rims). You state that you actually want to use the mountainbike to do some off-roading. The 500 v2 will also suffice for light off-roading, what you are planning, but it will provide a significantly less pleasent ride. You will just have a lot more fun and capabilities with the 520. It also gives you room to do some more hardcore off-roading if you want to do that later on. In my opinion it’s worth the extra money, you will have an absolutely great electric mountainbike, with a lot of high quality features for its price. You won’t regret it! I hope this helped you. Thanks for your comment 🙂

      • Thank you so much for your opinion! The 520 is a new bike. surely decathlon has added the missing piece between 500 and 900. My use is 80% offroad even if I don’t go every day.

        • It’s indeed the missing piece between the 500 and 900! If you use it 80% offroad, I would definitely go for the 520. I hope you can still find one in stock in these covid-19 times!

          • Actually here in Italy it’s a problem to find bikes in stock in every decathlon shop and also online. I hope that the situation improves for everyone.

      • I’ve had my E-ST520 for nearly a week now and I absolutely love it. Cracking bike for the money, looks good, feels good, and so powerful. You will not be disappointed 👍

        • Thanks for the review. Very detailed and informative 👍🏻.
          I have ordered one based on this and am just counting the days until delivery. It took 2 and a half frustrating weeks trying to order one but got there in the end!

          • That’s great! Getting your hands on an ebike these days can indeed be hard. I am glad you still could order one!

21. I’d love to buy one but there never seems to be any in stock 😫

    • That’s indeed a big problem at the moment. Due to the covid-19 situation pretty much all bikes are sold out at Decathlon. Hope that they can get their supplies back to normal soon.

22. If you have any questions about this ebike, please leave a comment below. I will try to answer your question within 24 hours. If you own this ebike yourself and you want to share your experience, please do so as well.