Extension Height

Ever had trouble fitting a new stem to a fork only to find that the steerer tube is now too short? The Velobike Steerer Tube Extender raises the height of your steerer by up to 18mm. Precision machined from aluminium, the light weight extender means you no longer have to purchase a new fork for your frameset. 

Note: When using the longer 15mm and 18mm extenders, you may require a longer top cap bolt. Standard bolts are normally around 30mm long.

© The intellectual property for this product is owned by Velobike Innovation Limited. All rights reserved.

Technical Specifications
  • 10mm, 15mm and 18mm extension heights available
  • 50mm deep expansion plug
  • Standard M6 insert thread for stem top caps
  • Suitable for aluminium and carbon steerer tubes
  • Hard anodised black
  • 6061-T6 aluminium
  • Fits 1 ⅛ (1.125” / 28.6mm) external diameter steerer tubes
  • Tighten up to 6N/m<
  • Weight:10mm: 62g15mm: 67g18mm: 71g
Installation Tips

We strongly recommend to epoxy bond the steerer tube extender into your steerer tube for best security.

Frequently Asked Questions

Will this fit any bike?

The extender can be fitted to bikes with a 1 ⅛" external diameter steerer tube. This includes many modern track, road and mountain bikes.

Every steerer tube can be have different internal dimensions — especially carbon ones where the internal dimensions are variable. We have designed the extender to have a tighter tolerance fit into most steerer tubes than your standard headset expansion plug for safety and security. Prior to purchasing, measure the inside diameter of your steerer tube. If it measures any smaller than 22.50mm, you may need to sand some material out. This intersection zone between the steerer tube and extender is only 3mm deep, so not very much material will need to be removed from the inner edge of your steerer tube. If in doubt, ask your local bike shop for assistance.

Is it strong?

Yes. This type of expansion plug system is common for steerer tube and headset assemblies. We have opted for a longer 50mm knurled plug for the extra security and stiffness. Most headset plugs are around 30mm. we recommend the extender to be epoxy bonded into the steerer for best security.

What epoxy do use for install?

A medium/high strength two part epoxy from a hardware store is suitable. Smear a few dabs on each of the three aluminium knurled surfaces before install. This increases the surface friction between the extender and the steerer tube.

If it's glued in, how do I remove it?

If it's required to remove the extender in the future, use the epoxy sparingly. Disassemble the extender, then each of the three blocks can be knocked out without damaging the carbon within the steerer tube.

Can you make the extension longer than 18mm?

In theory, yes. However, for safety reasons we have set the maximum height at 18mm. We suggest you have at least half of your stem clamping around your original steerer tube. 

Velobike steerer tube extender with knurled expansion sleeve

Customers praise this steerer tube extender as a "perfect solution" that solves short steerer tube problems without expensive fork replacements. "Works as expected" and "excellent quality" noted frequently. Most report easy installation, solid construction, and fast global shipping. Two customers experienced fit issues or slipping concerns. "Great for tricky short steerer tubes."

  • 5 stars: 78 (96%)
  • 4 stars: 1 (1%)
  • 3 stars: 0 (0%)
  • 2 stars: 2 (2%)
  • 1 star: 0 (0%)
a
alexandre l.
Quite expensive for what it is + not great engineering

Installed without epoxying at first and it was slipping so I epoxied it and it was still slipping. I though my epoxy job was bad so I thiriughly cleaned it, sanded the inside of the stem and installed it perfectly. It still spins. I ordered a cheap AliExpress oven for 1/10th of the cost which had a metal grove (as per pics. That prevents the extender from spinning. There is nothing preventing it from turning on itself besides some metal on metal friction. The extender slso did not fit square in my fork ( which is ok as per measurements). Kneeling is also quite small and doesn’t « grip » as well as cheaper version. I like that it’s longer.

R
R. J.
The Perfect Solution

I recently built up another bicycle with a very nice used Colnago C50 frame. The previous owner had cut the steering tube shorter than what I prefer. I fabricated an extension solution but felt there had to be a better way. I noodled around the internet looking for a solution I thought was safe and would work and came across the Velobike steer tube extender. I ordered it and a very pleased with it's design, function, and feel it is the best extender on the market. The folks a Velobike are great to work with and I highly recommend them.

J
Jen
10cm Extender

One of my customers needed to raise her stem by 1 cm, and this extender did a fantastic job. It fits well and is great quality.

M
Mark T.
Exactly what was needed

The difference between mild chronic discomfort and an awesome ride height was 10mm... a slightly too short steerer is now the right length with a bit of room for further adjustment. Well made product, quick postage, really nicely presented, stickers and a thank you note to round off a great purchase experience! My Fairlight Strael is now perfect!

W
W
Added stack without buying a new fork

Bought the 10mm expander so I can add another spacer underneath my stem. Bottom half clamps on steerer itself and top half clamps to the expander. Haven’t had any issues and already rode the bike multiple times.

M
Martin
Great product

It's very well designed. Just 25g heavier than the Specialized extender. I've glued it with rather strong epoxy just to be on the safe side. I can swap between 3mm and 10mm. I hope won't make you any troubles, but there is also 3mm version so you can swap it back to the previous height even it's glued. You can ask. After two rides on tarmac, cobbles, and light gravel, I love it. Shipping and taxes to the EU cost as much as the product itself, but it's worth it.

A
ALEX P.
Sorry guys...

Did not fit in my factor ostro. 58 part cost, 67 euro customs(never informed), 30 delivery cost. Sorry but it was the worst transaction I ever did.

Hi Alex, we're sorry to hear about your recent experience with our product. We want to clarify that our steerer tube extenders are designed to fit round 1 1/8' tubes, and unfortunately, they are not suitable for D-shaped steerers like the one pictured on your Factor Ostro. We understand your frustration with the additional customs fees, but please note that we are unable to inform customers of the exact amount as these are collected by the local government of the country the goods are imported into. As stated on our website home page and shipping info page, our prices do not include taxes as we are not able to collect them on behalf of every country. We apologise for any inconvenience this may have caused.

G
Greg -.B.
10mm Extender

This part is everything I hoped it would be. Very high quality, amazing packaging, quick delivery to the other side of the world, and it allowed me to extend my steerer tube a couple of mm above the stem, add a top spacer and eliminate an annoying creaking sound.

B
Brett
Problem solved

Many of the frames I build, like the TIME ADHX, come with short steering tubes. And in the case of the TIME, which is a Allroead bike, I need more stack under the stem. So, I end up mounting the stem at the very top of the steerer, with one clamping screw at the top edge or slightly beyond. The Velobike Steerer Tube Extender is a wonderful piece of engineering, that perfectly solves my problem, allowing the top clamping screw to exert force on the solid extender, rather than the edge of the steerer tube. Thank you, Luke and team, for producing a beautiful, problem solving product like this!

J
Jamie P.
Perfect Solution!

Just installed and impressed! the 50mm insertion Depth seems to add more rigidity to the hollow tube. Well constructed and worth every penny!

Looking good! I'd recomend to lower the stem by another few mm if possible so more surface area of the stem is in contact with the steerer tube. This will further increase the assembly stiffness, security and safety.

I see that your stem is positioned in a negative angled position (pointing downward relative to the axis of the steerer tube). If you flip it pointing upwards you can lower it on the steerer tube while achieving the same (or very similar) handlebar position. This is a win win for further increased front end stiffness, greater aero gains and a safer assembly =)

A
Anonymous
Works as expected

Works as expected! Great for tricky short steerer tubes

J
Jarrod B.

Awesome!

A
Alex F.
Top Shelf Engineering!

Great product. Brilliant service from the crew at Velobike Innovation!

J
Jonathan R.
Excellent quality product

Excellent quality product. Solves my problem with the steerer cut too much

A
Anonymous
Worked perfectly

Worked perfectly

A
Aurelien G.
Easy to install

Easy to install look strong 👍

J
J.C.

Awesome product worked just as described solved my to lower stack height without having to spend a lot of money on a new fork.

A
Aurelien
Sterrer tube extender

Bought the 15mm model. Perfect; seems solid. Good finish.

L
Leo O.
Speedy delivery

I order thursday evening from Sweden and it arrived monday after lunch. Superfast!!

J
Jason

Nice quick service. Product arrived fast

B
Brandon D.
Got my bike fit right

I bought a used Cannondale SystemSix and the steerer was cut too short. This allowed me to get a few extra millimetres of stack height and gave me confidence to know the stem had a solid clamping area.

E
EMMANOUIL G.
Excellent !!!

Good product. Excellent packaging. Fast shipping. Highly recommended !!!

M
M P.
Great solution

Needed a tiny bit more steer tube length. This was the perfect solution. It's a great quality product. Everything from the machining to the packaging is excellent. I wish I'd got a tiny bit shorter one as the bulge underneath my top cap touched the steer tube before engaging my stem but I had a spare top cap that worked and was my own fault for not measuring closer.

K
Kurt K.
18mm extender

The quality of the product is top notch and worked perfectly. The part came very quickly with customer service always being excellent.

M
Marc
High quality

Fit perfectly inside my fork without issues, got the 10mm extender. Fast postage and really high quality product. Thank you team!

P
Paul

Awesome quality product

A
Alex F.
Problem Solved!

Exceptional service. Product engineered beautifully. Personalised hand written thank you was not missed! Hats off all round. Highly recommended.

T
Tymur B.
Fixed my mistake

I made a mistake by cutting the fork steerer tube to fit the correct length. Searching for a solution, I found Velobike and chose their 18mm extender, which compensated for the missing length. I must say, it arrived from New Zealand to Ireland in 5 business days; DHL does their job. I really liked the packaging, and overall, I think the customer service is excellent—description, product quality, FAQ, delivery, packaging. I would recommend the brand to my friends.

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