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ST 900 Mountain Bike Shorts - Black

Sale price: 18.000 KD Regular price:
Color: Choose a color
Size: Select a size
Sale price: 18.000 KD Regular price:
Model: 8381758

Product Features

A photo of the ST 900 Mountain Bike Shorts - Black in use

ST 900 Mountain Bike Shorts - Black : These durable mountain biking shorts have been designed for rides in warm weather lasting over 4 hours. Undershorts sold separately.

Ride through the undergrowth with no worries this summer. The stretch fabric provides freedom of movement. 2 flat secure pockets. The little extra: 2 adjustment rip-tabs at the waist.

Abrasion resistance

Experience a brush with nature! Fabric withstands friction and snags.

Freedom of movement

Made from stretchy fabric, with 2 rip-tabs on the waistband to adjust the size.


The fabric and loose fit wick away perspiration.


2 flat pockets with zips to keep items safe.


260 g in size L.

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Product Reviews

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851 reviews

ST 900 Mountain Bike Shorts - Black
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Great shorts terrible sizing

After reading previous comments about the sizing being small I checked to make sure i measured my hips not waist and ordered the correct size for me going by the size chart. Even double checked with customer service as i needed them for this weekend ... They arrived today I should be smack bang in the medium size range.. so ordered a medium as I was advised by decathlon which as it turned out was way to small. Sent back and not happy. Quality wise they seemed great

Good quality, price could be better

Comfortable and hard wearing. Ideal for my commute to work. Price a little steep.

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Sizes way too small

Unfortunately I won't be able to wear these shorts as the size is way too small. Always been wearing M sized bib shorts, these ones are so tight I almost could not put them on. Not sure I can return it since I've detached the two pieces. Disappointed.

I'm deeply sorry to read that the sizing guide was not clear enough. The measurements are for the hips and not the waist. This can cause confusion.
Please return them to us for a refund or an exchange.
Peter, Cycling Manager, DECATHLON

Bought for my son and he loves them would definitely buy them again

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best ever

As usual Decathlon came up with the goods. Some MTB shorts are so expensive and they needn't be- these are very well designed (by bikers, obviously), fit great, have useful features (zipped pockets away from the hips, a high waist at the back, etc) and are really stretchy. I wear them off-road, on-road and when I am camping too. I've cycled 1000's of miles in them. And they're so cheap I'm about to buy a second pair right now!

Ideal touring shorts

I had struggled to find a good fit pair of shorts for 3 season cycling/cyclotouring and these fit the bill perfectly. Well made, comfortable using a padded liner and durable. They are well designed and a quality product.

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Great shorts very robust

Great pair of shorts sturdy with good side pockets

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Good shorts

Excellent shorts that fit well and do a good job.

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Poor fit

Tried these on today and they look great, loads of features. To get the very well cut bum into a comfortable position, you have to hoist the waistband really high and I ended up with the crotch cutting me in half. This also meant that trying to get into any sort of cycling position would have meant the waistband would also have cut me across my belly button. Not comfortable. Shame really because I swear by the road gear. The mtb gear just doesn't stack up.

MTB Shorts

these shorts feel good & look good.

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Brill Product

This is my second pair of these shorts. They are exactly what I wanted to enable me to cycle to work. They aren`t too tight as to cling when wet and they are a lovely length, (being 6ft tall) in both the leg and body. They quickly dry and dont need need ironing but still look tidy.

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exellent fit

excellent fit perfect price

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Fantastic MTB Shorts

I bought the 700 padded undershorts a while ago and had been using them to ride under some old cargo shorts. Last week I saw these on offer for £14.99 and decided it was time to try some proper MTB shorts. The first thing that strikes you is the quality. These are well made and you can see why they are normally £30. The material is super lightweight and stretchy and there are 2 zip pockets should you need to use them. The hooks for the undershorts are great and I would say for a proper "experience" with these shorts you should get the undershorts. Sizing is a little tight, I would normally take a medium but had to step up to a large for both the undershorts and these shorts, but they are a perfect fit. I've not seen the 500 or 300 version of this short in the flesh so to speak but for £14.99 you might as well get these.

MTB shorts

Ideal entry level plain shorts, not padded but ok for me. Zipped pockets are a bonus for holding keys and phones secure.

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Fantasic trail shorts

Purchased these shorts as a replacement for my old royal racing shorts. First thing that grabs you is the quality of the construction and the vibrant colour. They are a very comfortable and well though out pair of shorts. Stretchy in all the right places, not restrictive at all. Very light, drys quickly and breathable fabric. My favourite shorts, at a great price. Going to get a black pair now. I ride mainly surrey hils trails and XC

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Additional Product informations


Main fabric

  • 15% Elasthane
  • 85% Polyamide

Our tip: wear undershorts for added comfort!

At Rockrider, we recommend adding undershorts with a pad under your 900 mountain bike shorts. The undershorts fit discreetly under your shorts We must say: it is certainly more comfortable with a pad.The 500 and 900 mountain bike undershorts are compatible with the 900 mountain bike shorts.

Product tests

Our team of product designers based at the B'Twin Village in Lille is continuously working to make cycling more comfortable for our users.Our obsession is to create products that meet the specific cycling needs of our users and eliminate things that get in the way of their rides.

Product tests

Our team of product designers based at the B'Twin Village in Lille is continuously working to make cycling more comfortable for our users.Our obsession is to create products that meet the specific cycling needs of our users and eliminate hindrances to a good cycling experience.We then test our products in the field, as we are convinced that only by subjecting them to real world conditions, like the ones you experience on your bike, can we continuously improve our products.

A rating to compare products' environmental impact

A product's environmental impact is calculated for its entire life cycle using various indicators. An overall rating (ABCDE) is given, allowing you to easily identify products with the best environmental performance by comparing similar products to each other (T-shirts, trousers, backpacks etc.).Decathlon openly displays the environmental ratings of its products.To find out more:

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Size Guide Visual