RockRider 340 Review (Decathlon, B’twin MTB bicycle)

This bicycle is one of the cheapest models that have front suspensions and can have a light mtb use, from Decathlon (B’twin).

I say light use because the RockRider 340 is using basic v-brake brakes and has single simple rims.

To escalade obstacles and for downhill, you will want to have double enforced rims and disk brakes, in order to not risk your life.

As I said, the brakes are basic, they have some sort of variation, meaning that if you lightly press them (front – back), they will brake slowly. For dangerous situations, if you press the levers stronger, the bicycle will brake much faster.


The good thing about the brakes is that the levers can be pulled with two fingers, they move very smooth and feel very comfortable.

The suspension

Is just a standard SunTour fork. It looks and feels very durable. Since I just ride inside a city, I set the suspension to the hardest level, I don’t really need suspension. However, there is a big difference riding this bike and one that doesn’t have a front suspension. This one is much more comfortable since the front suspension will attenuate the shocks.



The frame

Is made of aluminum, fells very strong. It has a square shape, very different than the usual frames. Some people that don’t know much about bicycles will think that you ride a top bike made of carbon.

It also helps that the paint is matte, giving a very aggressive look. Beware of scratching the frame. Don’t use frame bags with zippers as they will easily scratch the frame.


Talking about aggression, the top bar of the frame has an interesting position, it is lifted from the handlebars to the saddle part of the frame, giving the impression that while riding, you are always climbing a hill. Very interesting feeling. It might sound funny but I think just because of this detail about the frame, the bicycle is just encouraging the rider and tells him that he’s doing a good job.


The shifters/gear system are Shimano/Sram, nothing bad to say about them. To change a gear, stop pedaling and use the shifter, then start pedaling slowly. The gears are getting changed smoothly, nothing really to complain. If the last gear, 7th has issues, there is a small plastic that can be rotated (near the derailleur). Rotate it slowly and try to change the gear. If you really don’t know what you’re doing, avoid this.


Also a good thing about this bicycle is that it makes almost no sound while running. Is one of the things I like on a bicycle, to be silent.

The bad parts about the RockRider 340

The pedals are made of plastic and they look and feel very cheap. You definitely want to change them with some better pedals, wider, made of aluminum.

The saddle is also really bad. It is very uncomfortable. You can just replace it. There are cheap models that will do the job just fine, but not the standard one that comes equiped.

What you see in the pictures are replaced pedals and saddle from the stock ones.
The pedals here are made of aluminum (they were like 10 euro and the saddle is from Lidl (supermarket in Europe), called Crivit, around 6-7 euro).
Also, the bottle and the bottle cage are not included.

These parts need to be replaced. Other than that, the rest of the parts will work great, the tires, shifters, brakes etc.
After a year or two, replace the rear tire as you will get a lot of punctures. The stock one is really thin and it will wear out fast.

Besides getting new pedals and saddle, you also really need a kickstand because this bicycle doesn’t come equipped with one. When you buy the bicycle, you can also get a basic kickstand also from Decathlon. Almost any middle frame kickstands will work. You will need two pieces of basic rubber when installing the kickstand. Just place the two pieces of rubber between the kickstand metal parts to protect the frame.

Speed and gears


You can get a decent speed with this bicycle. On straight road, the highest speed I got was 30 km/h.

For cruising, you can use the biggest front gear and the last back gear (7). For riding it in the city, you usually want to use the 6th back gear and second front gear (middle). For climbing, you can switch to the 5th rear gear. You don’t really need the other smaller gears.

It depends how fit and trained you are but this bicycle can be used without much effort.

Overall, I love this bike, it is just great for its price. It is a great choice if you don’t need double enforced rims and disk brakes. If you just need a comfortable bicycle for city offroad (if the roads are not very smooth in your country, like in mine, which is Romania).

After 2 years of using it

After 2 years of using it, around 3-4k km, the bicycle still works with no issues. I’ve changed the rear tire and the front brake pads. The gear and the chain are still in good condition. The frame and other metal parts are still in perfect condition.

You can ask me anything about the bicycle in the comments.


  • lakshmanprakash says:20.06.2016

    Pls suggest .. whether I can use this bike in normal on-road .It will feel difficult???

  • admin says:20.06.2016

    I use it almost everyday and I think it’s fine. Has a decent speed.

  • Gerry fernandez says:07.08.2016

    Hello. I have some questions about this model. I bought one recently and i cant shift to the 3rd change in the front. It is stucked in the shift before the 3rd. What can i do? Also, theres a way to change the wheels/tires for lighter and narrower ones?

    Thanks !

  • admin says:08.08.2016

    @Gerry fernandez, you probably need to adjust the front shifter, better get the bicycle to a service, I think it will be cheap to just adjust the shifter.

    There should be tires with no textures (for city roads), without those bumbers from the default tires.

  • Abhishek Banerjee says:24.08.2016

    Is it good enough for commute to college. Total distance ~ 20 kma.
    Also, can I add disc Brakes later on?
    Should I buy Rockrider 340 or Cosmic Trium?

  • admin says:24.08.2016

    @Abhishek Banerjee, it’s fine for that distance. I use it because I have rough roads where I live (city). If you have better roads, rather get a city bicycle which should be lighter. RR 340 has around 16kg.
    But it’s fine anyway.

    As far as I know, you can’t add disk brakes.

    I don’t know the specs for Cosmic Trium.

  • admin says:01.09.2016

    @Abhishek Banerjee forgot about you. You should get the cosmic one, has double enforced rims, 27.5 wheels. The frame is probably worse than the one from Rockrider. I would go for the Cosmic one.

  • Alex Shep says:01.11.2016

    does the fork have any lockout mechanism?

  • admin says:03.11.2016

    @Alex Shep, it doesn’t have. You can set it to minimum but I’ve noticed when on the bike that the suspension is slightly used. But depends on your weight, I’m 86kg.

  • Himanshu says:07.11.2016

    Which one is better rock rider 340 or road racer 700c(unirox)

  • Neil Darlington says:06.12.2016

    Couple of questions: could I upgrade this bike with Disc Brakes ? (front, rear or both)

    Is the front wheel quick release ? if not could I upgrade to quick release easily.

  • admin says:06.12.2016

    @Neil Darlington from what I know you can upgrade only the front one with disk brakes.
    Front wheel has quick release, rear doesn’t.

  • Deepak Gupta says:31.03.2017

    I’m 5’8″ with 83 kg weight. I wish to cycle to loose weight and stay fit.

    The Rockrider 340 looks good but I’m little confused between arm twist gears and thumb shifters. So pls help.

    Also, I checked out Firefox Swiss military series and liked the cycle.

    Deepak Gupta

  • admin says:31.03.2017

    @Deepak Gupta, I’ve used the bicycle for quite a while (the twist gear shifter) and they are fine. I’m using only the 7th (rarely when the road is flat), 6th (most of the time) and 5th when climbing (rarely). So the shifter don’t matter that much.
    I don’t think Rorkrider 340 comes with thumb shifters unless you ask them at the store to upgrade. In that case, you could go with thumb shifters but like I said, it doesn’t matter that much. Check this video.

  • M says:13.05.2017

    Is there any Tipps to Maintain this bike ?
    Should I go tubeless ?

  • Balaji says:22.02.2019

    I am planning to go for a long ride nearly a 500 km .so what all the update have to do for mtb 340.and since this is my first long drive .please guide me further

  • admin says:22.02.2019

    @Balaji Definitely get tons of inner tubes in case you get punctures along the way. And tools.
    Replace the saddle with one that is comfortable, like the one from my pictures.
    Replace the pedals with flat aluminum ones.
    That’s it.

    I sold mine and bought the RR520 version.

  • Cooker says:08.05.2019

    Sure cool bike,more like above the average
    Looks light when lifting it,howerver in the road you can’t understimate its speed when pushing shift to 7 ,really dangerous especially in hills ,the disc won’t stop you when rooling becauwe of its weight…
    Well not a really for racer but rather leaping mountains

  • Rafael Belliard says:18.05.2019

    I am a complete newbie and just bought this bike. I also plan to use it for commuting about 9km at a time and 18km a day. When you say that you set the suspension to the hardest to almost disable them, what is that you do? Is it increase the “weight adjuster” to the max or to its min weight? Thank you!

  • admin says:18.05.2019

    @Rafael, you can screw that adjuster clockwise, that way you can reduce the suspension travel as much as possible so you get more speed if you ride on a flat road with no bumps.