Product Colors and Sizes

  • Black Friday product
  • New Deal product
  • Cyber Monday product
  • Clearance product
  • Deal product
  • Best Seller product
  • Ecodesign product
  • New product
  • Staff Pick product
  • In The News product
  • Innovation product
  • product

Btwin, Adjustable Oversize Stem Aheadset

Sale price: $29.99 Regular price:

Adjustable stem with oversize diameter (1.25"/31.8 mm) for added comfort.

Color: Select a color
Size: Select a size
Sale price: $29.99 Regular price:

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.

Model: 8272094

Product Videos

Product Features

A photo of the Btwin, Adjustable Oversize Stem Aheadset in use

Btwin, Adjustable Oversize Stem Aheadset | precisely adjusting the height of your riding position without changing the handlebar. Handlebar diameter: 31.8 mm.

Adjustable stem with oversize diameter (1.25"/31.8 mm) for added comfort.


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

Skip to reviews
770 Reviews
Write a Review 

Btwin, Adjustable Oversize Stem Aheadset,base color
Filtered by reviews Loading reviews…
Adjustable Aheadset Oversize Stem

Give the rider choice in regard to a more upright riding position. Most appreciated as you get older

icon-circle-checkmark verified purchase
Adjustable MTB oversized stem

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.

icon-circle-checkmark verified purchase
Does the job

Does the job

icon-circle-checkmark verified purchase
Makes riding more comfortable

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.

Cycle parts

Good selection of parts in stock

icon-circle-checkmark verified purchase
Adjustable Stem.

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.

icon-circle-checkmark verified purchase
Works well :-)

Easy to fit and does exactly what I need

icon-circle-checkmark verified purchase

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.

icon-circle-checkmark verified purchase
Well made and easy to install

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!

Not good feels unsecure

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.

Hello Mark,

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
handlebar extension stem

Great product and fitted by a courteous and proficient assistant.

icon-circle-checkmark verified purchase
Useful, quality item.

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.

icon-circle-checkmark verified purchase
Great price and sturdy

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

excellent product and easy to set up

Simple to use and gives a good range of adjustment

icon-circle-checkmark verified purchase


icon-circle-checkmark verified purchase
Skip to reviews

Additional Product Information



  • 100% Aluminium 6061


  • 100% Steel



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

  4. laptop-checkout

    Minimal retail footprint

    lowers overhead and indirect costs


Size Guide Visual