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Btwin, Adjustable Oversize Stem Aheadset
Adjustable stem with oversize diameter (1.25"/31.8 mm) for added comfort.
Free shipping over $35
See our return rules
Free pickup
San Francisco, 735 Market St. Options
Select an available color and size to see options.
Product Videos
Product Features

Compatibility
28.6 mm (1 1/8") headset and OVERSIZE 31.8 mm (1 1/4") handlebar.
Optimized posture
60° adjustment possible for an individually adapted position.
Product Customer Reviews

Give the rider choice in regard to a more upright riding position. Most appreciated as you get older
Good durable stem.Plenty of adjustment and so far has held up well including mountain bike specific trails.Before buying it, consider whether the length of your existing brake and gear cables can handle the change in angle.
Does the job
I bought my bike when it was still very hard to find bikes due to covid. I ended up having to settle for a bike that was too small for my height. This product allowed me to have my seat at the correct height and have my back less bent over reaching for the handle bars.
Good selection of parts in stock
I bought this as I was changing my handlebars and it gives a much wider range of adjustment for comfort and positioning. A pretty descent standard of finish and quality.
Easy to fit and does exactly what I need
After suffering with backache due to the handlebars being too low I invested in a adjustable aheadset and have been reaping the benefit since. It has made a huge difference to my riding comfort and enjoyment without having to lengthen brake and gear cables.
Very simple to install onto a RockRider 560. I used a 5mm hex bit and an electric screwdriver to screw to the correct torque. Well made and works great!
i have had nothing but problems with this stem i have torqued all the bolts to the required level but there's still a lot of movement in the stem that feels unsafe tried different angles etc but no joy so have had to take off the bike.
Sorry to hear that your experience with this product hasn't been as you'd expected. I've fitted a few of these and not had any play within the stem. I'd suggest you take the item back for a return.
Rob Basnett b'Twin Product Expert DECATHLON
Great product and fitted by a courteous and proficient assistant.
I bought this adjustable stem because I've been having trouble getting down on the drops on my road bike, hardly ever used them because I find it uncomfortable, (I'm getting old!!), solved the problem with this stem, raised the bars enough to make using the drops comfortable again. Very useful item, would recommend to anyone who struggles using their drop bars.
I am a time trial cyclist. Getting in position is a pain the butt. Buy one of these stems and you can mess with your position until you've got what you want. Then you can buy what suits.... Word
Simple to use and gives a good range of adjustment
happy
Additional Product Information
Composition
Bottle/Body
- 100% Aluminium 6061
Screws
- 100% Steel
Origin
Imported
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
-
Research and development
delivers high-quality cost-effective products
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State-of-the-art production processes
minimize manufacturing costs
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Optimized supply chain
reduces retail prices
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Minimal retail footprint
lowers overhead and indirect costs

Btwin, Adjustable Oversize Stem Aheadset
Your location: City, ST
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Heavy products return policy
If you return a product you will receive a refund for the purchase price plus any applicable sales taxes, less any non-refundable charges.
Decathlon will cover all shipping costs associated with your return except for items excluded from our return policy such as bikes, basketball hoops, snowboards, surfboards, tents, and other larger / heavier items.
Return costs for heavy products:
Weight Thresholds | Shipping within California | Shipping outside of California |
---|---|---|
> 9 lbs | $20.00 | $25.00 |
> 30 lbs | $50.00 | $65.00 |
> 100 lbs | $100.00 | $125.00 |
> 200 lbs | $200.00 | $230.00 |
If you return a product at any of our store locations, we will gladly help you find the best alternative product or refund you on the spot.
