Decathlon B’Twin Rockrider Drowp 9 review

Downhill starter bike

Our rating 
3.0 out of 5 star rating 3.0
GBP £2,171.77 RRP

Our review

It’s a shame the sizing isn’t quite how it should be on the Rockrider – the potential is there, but not quite realised
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Sport store giants Decathlon aren’t new to the bike game. In Europe, they’re one of the biggest sellers of cheaper, low-end bikes. The Drowp 9 is their first foray into the downhill market. Decathlon’s aim was to create a cheap, basic, durable downhill bike that would last a season of downhill racing without a problem.


They must have done something right – summer pre-orders for the Drowp 9 from bike hire outlets in the Alps are already coming in thick and fast. We got our hands on one for an exclusive test.

Ride & handling: Fun, but unstable at high speeds

The sizing of our pre-production sample came up very small compared to other DH bikes we’ve tried. Our medium sample had a top tube length of just 540mm, which made for a pretty upright riding position. 

The 360mm bottom bracket height wasn’t ridiculously high though. The wide 780mm Boobar helped to provide a good stance on the bike, although the shape of the bar is a bit of an acquired taste. 

We had some issues with the stock Kage shock – the compression tune was extremely harsh and rebound painfully slow. It’s something Decathlon need to consider when it comes to production spec. Once we’d bolted on a different shock, the rear end of the Drowp felt good, and was hard to get out of shape. There was a nice amount of rearward axle path movement to eat up square edges. Tracking through the rough stuff is good too, with plenty of rear-end grip.

The Boxxer RC fork is specced with a soft spring, which needed changing to a heavier option before we could even think about pushing the bike hard on serious downhill tracks. It sat low in its travel and bottomed-out with minimal force. 

Although the Boxxer has compression damping adjustment, the soft spring sunk through the travel easily, and the basic compression damper still caused some spiking during harsh high-speed compressions. Any rider who weighs more than about 60kg (132lb) would need to go to at least the medium spring we installed.

As well as a short top tube length, the bike also has a short 1,178mm (46.4in) wheelbase, which makes the bike feel a little unstable at speed. We found we only had a small window in which we could move forwards or backwards on the bike, before it started to feel unbalanced. 

The 442mm chainstay is long considering how short the front-centre of the bike is, and lifting the front wheel is possible, but not as easy as with some bikes. Once both wheels are off the ground, the Drowp’s diminutive stature makes it feel like a dirt jump bike, albeit a heavy one with lots of suspension.

The wheelbase could be increased with the use of angled headset cups. This would greatly improve the bike, because even though the 64-degree head angle is slack, the front-centre measurement is still really short. 

If you’re not travelling at full-throttle speeds, the Rockrider is fun to ride. It feels lively and easy to move about, despite its 18.4kg (40.5lb) weight.

Decathlon b’twin rockrider drowp 9:
Steve Behr/Future Publishing

Frame & equipment: Spec should be durable but spring might need changing

A 6061 aluminium tubeset puts out 210mm (8.3in) of rear wheel travel, with ‘floating shock suspension’ technology. It looks very similar to  a certain World Cup winning frame, except for the fact that the lower pivot is concentric to the bottom bracket shell. 

The 1.5 head tube keeps the front end stiff, and there’s an 83mm bottom bracket and 12x150mm rear-end – these are both usual suspects on a downhill rig. There’s also ISCG 05 chainguide mounting.

Although the Drowp 9 is built with parts that come with a weight penalty, they should last a lifetime. If they do get damaged though, they’ll be relatively cheap to replace. 

A RockShox Boxxer RC fork and Kage R shock are on suspension duties. The brakes – Avid Elixir 5s – come from the same manufacturers, as do the X7 shifter, X9 9-speed mech and the heavy but bombproof Truvativ Hussefelt crankset. 

The chain is kept on by an unbranded chainguide, and a Truvativ bashguard protects it all against any impacts with the ground. Sealed bearing hubs are laced to Sun MX31 rims, which are shod with Maxxis Minion DHF and DHR tyres. A Truvativ 780mm Boobar and unbranded direct mount stem complete the cockpit, while some comfy lock-on grips with flanges provide a nice contact point.


This article was originally published in Mountain Biking UK magazine, available on Apple Newsstand and Zinio.

Product Specifications


Name B'Twin Rockrider Drowp 9 (13)
Brand Decathlon

Weight (lb) 41.5
Headset Type Gravity
Weight (kg) 18.82
Stem Boobar direct mount 50mm
Shifters X7 9-speed
Seatpost Rockrider
Saddle Drowp 9
Rims MTX 31
Rear Shock Kage R
Rear Hub 12x150mm
Rear Derailleur X9 9-speed
Handlebar Boobar 780mm
Available Sizes L M
Grips/Tape Lock-on with flange
Front Tyre Maxxis
Front Hub Sealed bearing 20mm
Frame Material ASTRO AFDHA aluminium, 210mm (8.3in) travel
Fork Boxxer RC, 203mm (8in) travel
Cranks Hussefelt
Chain 9-speed
Cassette SRAM 970DH
Brakes Elixir 5, 200mm rotors
Bottom Bracket (unbranded chainguide)
Spoke Type Black stainless steel