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Rockrider ST900, Mountain Biking Bib Shorts, Men's

Sale price: $39.99 Regular price:

A bib to wick perspiration away: shorts with mesh straps. The pre-formed pad is comfortable and breathable. Stay well supported by the straps and the thicker hems.

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Sale price: $39.99 Regular price:

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San Francisco, 735 Market St. Options

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Model: 8530068

Product Features

A photo of the Rockrider ST900, Mountain Biking Bib Shorts, Men's in use

Rockrider ST900, Mountain Biking Bib Shorts, Men's | Our team of mountain bikers has designed these bib shorts for mountain bike rides of 3 to 4 hours in warm weather.

A bib to wick perspiration away: shorts with mesh straps. The pre-formed pad is comfortable and breathable. Stay well supported by the straps and the thicker hems.

Seat comfort

Ride comfortably for up to 4 hours with the ergonomic, pre-formed foam pad.

Moisture wicking

E "mesh" fabric on the straps and the main fabric wick away perspiration.


The straps and the bottoms of the legs keep everything in place.

Irritation reduction

The pad sticks well to your body and is ventilated.

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Rockrider ST900, Mountain Biking Bib Shorts, Men's,black

Product Customer Reviews

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Rockrider ST900, Mountain Biking Bib Shorts, Men's,black
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The pluses. Good pad. Very comfy and I could barely feel my saddle under them. The negatives. The pad. Very wide. Very wide indeed. Too the point that I could feel my inside leg chafing as I rode. The fit. Who designs these things? The first pair I bought were a medium. Got home and tried them on. The legs were tight and very long. Over the knee long. The second pair having returned the first were in a small size. The legs. OMG! An anorexic stick insect would struggle to put these on. But at least the length wasn't stupidly long. But the torso was short and as such the straps were digging into my shoulders. Unfortunately I hate clothing tags and chopped them off so I can't return them. Decathlon, please hire new designers so that clothes fit normal people. Buyers, go on a severe diet if you want to fit into these.

Good quality at great price

Great looking equipment at great prices

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Decent first bib shorts

As a reluctant bib shorts wearer I was more than pleasantly surprised with these. They were very comfortable thorughout a 40 mile ride - only worn them once to date so hardly an in-depth review. My disappointment is with the other version of bib shorts in the store; I tried on two pairs, nominally the same size, and I couldn't get the others over my knees.

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Bib shorts comfier than expected

I was after a pair of bib shorts to see out the last warm weather rides of these year before moving onto full leg bib tights. For the price I was expecting thinner material and just enough padding. These are well made comfortable and the padding would easily see a 4 hr plus ride. Will definitely be purchasing more

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Sizing wrong poor quality

According to size guide I need a small,went for medium and the legs had pulled at the seam and holes in the inner thigh.lycra seems not to be as good quality as before

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I'm sorry to read that you have had issues with the fabric. Please return it for an exchange or a refund. Could you also reply to me with your clothing size as I wish to compare it with the size charge on the website.
Peter Lazarus, National Cycling Manager, DECATHLON
Good for coomute

They cover my back, and they dry fast. Excelent overall

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Really nice set of shorts

Well priced quality very good can't fault them

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Decathlon 500 Bib shorts

If you want a pair of bib shorts that are comfortable and nice to ride in. Do not buy these. Whilst riding and also using Chamois cream, I have completed a 100 mile ride and have never before, whilst using any other bib shorts experienced the pain from sores that I am in now. These shorts and the padded seat in the shorts offer no protection on long rides. I will now think twice before buying any clothing such as this from decathlon.

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Thank you for taking the time to give us a review of these bib shorts.
I would agree with you that for rides of such distances that this short may not be suitable. We recommend that the 500 series is for rides of a few hour or so. The 900 series range with a gel chamois is more suitable for such distances. But irrespective of which shorts you buy, we would also recommend bedding in new shorts before a long ride just to be sure that they're suitable as they can be a personal thing, the same as bike saddles I guess.
If you are not happy with the shorts, you are of course more than welcome to return them to your local store who will happily exchange them for you.
Peter Lazarus UK Cycling Market Manager DECATHLON
Padding too much?

Just bought a pair in Medium but the padding seems to be far too big compared to other bib shorts I have. Is it supposed to be this big or can you select a smaller size pad?

Bib shorts 500

Shorts fitted very well and comfy for a couple of hours in the saddle

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Great bib would recommend

Very comfortable and so much padding would recommend these to anybody

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1st class

Sized as it says on the tin, fit is good , comfy. does the job very well, will buy again.

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Cracking bib shorts

Great quality shorts, very comfortable after 50 miles riding and a great price

Hello Grant,
Thank you for posting a review of your bib shorts. I'm pleased to read that you find them so comfortable. If you like the padding then you may be interested to read that we use the same one (orange colour) on our winter cycling tights as well.
Peter Lazarus UK Cycling Market Manager DECATHLON
bib shorts

not very impressed . no leg grippers . and the seat doesnt really cover your front groin area . first time i used decathlon and last . poor bib shorts

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Dear Sir,
I'm sorry to read that you are having issues with the pad on these shorts.
I see that you have bought a "Small" size, it may be worth trying a "Medium" or "Large" as from my own experience the sizes dome come up on the small size. The larger size may well provide a better fit in terms of the saddle position. I use shorts and tights with this pad myself and have ridden extensively with them for the last 10 months, I am of average build (5'11 and 32" inside leg) and the Large was spot on for me. Rides of up to 90 miles have not caused discomfort.
Bring them back to us and try a larger size as we have a 365 returns policy meaning that if you are not happy you can return them to us for a refund too.
Peter Lazarus UK Cycling Market Manager DECATHLON
Okay so far

Ordered the XL as I usually do in Decathlon ranges but needed to exchange for the 2XL. Material is really sheer and I worry for it's longevity but they were stupidly cheap. Like them more than the shirt I ordered with it which is inferior to previous year's offerings. If I'd have seen in store I probably would have thought twice. Same criticisms of transfer logos.

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Size Guide

Size Guide Visual

Additional Product Information


Main fabric

  • 80% Polyamide
  • 20% Spandex


  • 100% Polyester cationic

Padding - Inner fabric

  • 100% Polyester cationic

Padding - Outer fabric

  • 80% Polyamide
  • 20% Spandex

Do you wear them with or without underwear?

And yes, undershorts are worn without underwear. With underwear, you are more subject to chafing and shearing... All combined with perspiration (heat + humidity): this is quite the recipe for infections.

What is a "mesh" fabric?

Mesh fabric is thinner, lighter, and airier than cotton or polyester fabric. This breathable fabric wicks away perspiration more quickly. The fabric doesn't leave a damp feeling on your skin (which can give you chills while cycling), making the bib shorts more comfortable to wear (feels like a "second skin").



Product testing

Our engineers have all of our products tested by mountain bikers in real conditions. These tests complement the tests we do in the lab and mean that we can approve our products before they go on sale.

Superior quality. Unbeatable prices.

For 40 years, Decathlon has delivered the best value in the retail sports industry by offering high-quality, sustainable and cost-effective products.

Decathlon makes the difference
  1. product-research

    Research and development

    delivers high-quality cost-effective products

  2. State-of-the-art production processes

    minimize manufacturing costs

  3. Optimized supply chain

    reduces retail prices

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    Minimal retail footprint

    lowers overhead and indirect costs


Size Guide Visual