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Children's bikesTests

Decathlon bike with a hard fork: Rockrider Expl 900 review

31 May 2026 by Caspar Gebel

Rockrider Expl 900 review: This affordable bike from the outdoor brand is a good choice for kids who tend to prefer the higher-end models in the 9-12 age group. However, even for them, the suspension fork is too stiff.

  • Favorable price.
  • Solid completion
  • Frame geometry is more suitable for taller riders

Rockrider Expl 900: Affordable hardtail with solid components

The French leisure giant Decathlon has long been a major player in the bicycle business, offering its bikes under various brand names. Rockrider represents mountain bikes ranging from carbon full-suspension models costing €9.000 to affordable children's bikes like the Expl 900. What do you get for €400?



  • Travel 50 mm
  • Impeller size 24 "
  • Circuit 9-speed, cassette 11/36 / 32 teeth front
  • frame material Aluminium
  • Weight 11,9 kg
  • Wheel weight 4,6 kg
  • Features Frame shape more suitable for taller riders, fork not sensitive enough.
  • www.decathlon.de
  • Price (RRP) EUR 399,99

 

Private label marketing with a suitable translation range

In terms of components, the Rockrider offers modern standards: The drivetrain with a 32-tooth chainring up front is adequately spaced with an 11-36 nine-speed cassette; the manufacturer relies on its own components bearing the B'Twin logo. At 152 mm, the crank arms are rather long for a bike of this size. The hydraulic disc brakes, equipped with 160 mm rotors, generate strong stopping power.



Stihl jacket bicycle
Rockrider Expl 900
There is nothing to criticize about the fittings.

A suspension fork is also fitted to the bike – a Suntour XCT, boasting 50 mm of travel. At least in theory: with high breakaway torque and a firm setup, our test rider could barely get the fork to compress. Once again, it becomes clear that a rigid fork can be the better choice. At least the Rockrider is affordable enough that one could consider retrofitting an air suspension fork, although the selection isn't extensive.

Rockrider Expl 900
A typical feature of children's mountain bikes is the overly stiff suspension fork.
Rockrider Expl 900
The tires are not very wide, but have a deep tread.


More suitable for older kids

The manufacturer specifies a height range of 135 to 150 cm or an age range of nine to twelve years. However, the frame design seems better suited to the taller children in this group: at 345 mm, the seat tube is a good 4 cm longer than that of other models; the top tube runs straight up to the head tube, where other brands incorporate a bend to reduce standover height. Smaller children might have problems with the Rockrider in this regard.

Rockrider Expl 900
Rockrider uses a solid aluminum patented support.
Rockrider Expl 900
A typical feature of trail mountain bikes is the combination of a short stem and a slack head angle.

At the upper end of the size range, the hardtail impresses with solid performance; however, at just under twelve kilograms, it's not exactly lightweight. Incidentally, fitting the lightest wheelset from the Velomotion test field would save a full 1,8 kilograms.



 

Rockrider Expl 900



Not quite what you're looking for? We've tested a lot of other sporty kids' bikes. You can find an overview here: We tested these 24-inch children's bikes.

Supported by Texlock and Vaude
To ensure that riders and bikes are safe on the road, Vaude and Texlock We equipped our young testers with all the necessary gear. Vaude provided the right clothing for our young test riders, and thanks to the lightweight and secure Texlock locks, we could leave the expensive test bikes unattended without worry when our riders needed a break from the exciting testing.
Texlock
The high-quality Texlock locks utilize an extremely durable steel-fabric tube. This not only protects the bike from theft but also prevents scratches on the frame.


Save €10 on Texlock products now! Use the coupon code velolock10 Are you saving now? EUR 10 on your entire shopping cart when placing your Texlock order.

Up



Conclusion: Rockrider Expl 900

Pro

  • Favorable price.
  • Nine-speed shifting
  • Hydraulic disc brakes

Contrary to

  • quite difficult
  • The frame geometry is more suited to older children.
  • Suspension fork too stiff

Facts

frame materialAluminium
Impeller size24 inch
Travel50 mm
Weight11,85 kg (w.o.p.)
PriceEUR 399
Website www.decathlon.de
Downhilluphill
 
smooth runningAgile
 
The Decathlon bike stands out due to its very low price, for which it offers solid features. Even older children will find the slightly raised standover height manageable. It's a shame that the bike is equipped with a very stiff fork – a rigid fork would almost be better here, especially since it would also make the Rockrider lighter.
Tags:24-inch testfeaturedkids bikesTest

About Caspar Gebel

Caspar Gebel has been on a racing bike for 40 years. The specialist journalist and non-fiction author works for Velomotion and also for the magazines Procycling and Fahrrad News.

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