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Rockrider ST540 Mountain Bike 27.5"

Sale price: $350.00 Regular price: $699.00

Mid-level Sport Trail mountain bike hardtail

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Sale price: $350.00 Regular price: $699.00

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Final Sale: No returns or exchanges

See our return rules for heavy items

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San Francisco, 735 Market St. Options

Select an available color and size to see options.

About this item:

  • Yield: Roll efficiently with 27.5” wheels, 18 speeds, and lightweight tires.
  • Trajectory control: Manage your trajectory: hydraulic disc brakes, tires and wide handlebars.
  • Driving comfort: Enjoy the raised position, adjustable stem, 100mm suspension and hammock saddle.
  • Ease of use: Block the fork with a simple gesture and effortlessly adjust your saddle.
  • Lifetime warranty: ROCKRIDER guarantees the frame, stem and handlebars for life.
Model: 8629914

Product Videos

Product Features

A photo of the Rockrider ST540 Mountain Bike 27.5" in use

Rockrider ST540 Mountain Bike 27.5" | Sport Trail mountain biking

Mid-level Sport Trail mountain bike hardtail

Cycling comfort

100 mm hydraulic fork (smoother). Ergonomic saddle. Height-adjustable stem.


Shimano 2×9 speeds. Lightweight, fast tires. Fork with lockout.

Easy to use

2×9 speeds, hydraulic disc brakes, suspension fork

Questions & Answers

Product Customer Reviews

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2894 Reviews
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Rockrider ST540 Mountain Bike 27.5
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The derailleur is faulty and very dangerous. when you force uphill the chain kicks like if it was unadjusted. I had the bike serviced twice at decathlon and it still does the same thing. Either the mechanic lacks knowledge about repairs or the derailleur is total crap. I like the bike but I will be upgrading the derailleur system.

bin shedding this bike for 3 days and it'sa dream

love the 2x9 drivetrain and hydraulic disc brakes only down side was the xcr suntore fork it was loud and hed no rebound

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Great value

Amazing bike for the money.

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Maximum rider weight?

This is not a rievew but a request for information on the maximum riser weight for this bike?

Good bike

This a very good bike. Just be careful if you purchase in store. As first day of riding this to work right pedal came loose and wobbly. Luckily I stopped straight away so it did not cause to much damage to pedal thread. Got other half to bring me a adjustable spaner and tightened it back up and pedal was fine after that. But after spending 470 pound and some one in store checking bike over then for pedal to come loose I was very very disguted. Ok. I use this bike for about a 8 mile journey to work. And it does a good job gears are nice and smooth breaks work great.. and now pedal is all sorted I'm very happy with the bike.. but like I say after spending that sort of money and for some one instore to check the bike over. You do not expect pedal to come loose. That experience was very very disappointing. The reason I got new bike is because I new it was a 8 mile journey. And on a new bike 2 miles in and the pedal is all loose and wobbly. You can imagine how angry I was. I would recommend this bike. But I would also recommend that check the bike over yourself before setting out on a big journey..

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Hi Derek,

I understand that my colleague, Kyle, from the workshop has been in contact with you this morning regarding your issue.

We are sorry to hear that this has happened. We would like for you to bring the bike back to our store so that we can make sure that the pedal is okay. If there is any problems, we can replace the pedal for you without any further costs as you are still under manufacturing warranty. We will also the rest of the bike to ensure that everything is in working order.

We apologise again that this has happened to you. We hope to hear from you soon.

Kind regards,


Sports Advisor (Customer Service)

Decathlon Wednesbury

Decathlon UK Limited. Company number: 03140144. VAT number: GB679262296.

Registered office: 9 Maritime Street, London, SE16 7FU.

Five star service *****

The member of staff that served us was extremely helpful.

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Did a lot of research on hardtail bikes sub £500 and this ticked all the boxes. I have used this on various trails and it is faultless

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Mountain Bike rockrider

It’s really very good bike..service is awesome

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customer service second to none

I visited the Huyton store at around 5.30 pm on Monday 18th October in the hope of being able to ride out of the store with a ride ready bike. David the bike technician was fantastic. He was due to go on a break but instead showed me the Rockrider ST540 which I could tell was not ride ready as it had been on a display stand. David suggested I go and get a coffee and he would get the bike ready for me and sure enough when I returned the bike was ready and he had even fitted the rear mudguard too. I rode the bike home and to and from work the next day. The ride was great and the gears couldn't have been set up better. This is the second time in 2 years David has set up a bike for me as my last purchase was stolen recently hence the purchase. He is a credit to Decathlon as he always goes the extra mile for his customers and really knows his stuff. I would recommend David and the Huyton Decathlon store to anyone wanting to buy a bike

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Great bike

I was looking for a bike I could take off road, and enjoy when out and about. I absolutely love it, nice easy ride

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Bought through Cycle To Work Scheme

Very impressed with this bike, will help to travel to work now instead of using public transport which has been really bad in the last few months.

Amazing bike

Best bike ever. Only criticism is the handlebars a bit long

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Very faulty product

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Great bike

Renewed bike after riding the same one for 24 yrs. This is a pleasure to ride and very comfy on all surfaces- road,mud,stone tracks and even soft sand. Service at Stockport was brilliant and bike was perfectly set up on collection

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great ride

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Size Guide

Size Guide Visual

Additional Product Information


Frame : 100.0% Aluminum


Entirely designed and developed in France at the B'Twin Village (Lille), this mountain bike is the fruit of the work of an expert team of passionate mountain bikers. Production is done in Suzhou, China by our own factories in order to be as close to the regional Decathlon stores as possible.


Lifetime on frame and fork, 2 years on parts.




California Prop65 WARNING: This product can expose you to chemicals including Lead, which is known by the State of California to cause cancer. For more information, go to

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    Minimal retail footprint

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