FUNN Nixie 40 mm Grey – short 31.8 mm MTB stem
The grey FUNN Nixie 40 mm mountain bike stem has a light, silvery tone that looks almost like raw aluminium on the bike. Underneath is a 3D forged AL6061 body weighing 120 g, with 0° rise and a split four-bolt 31.8 mm bar clamp. The short 40 mm length speeds up steering response in tight sections. It suits trail bikes where you want contrast against a black cockpit without a saturated colour.
Key benefits
- 40 mm length, 0° rise: The front wheel changes direction with smaller hand inputs, which pays off in tight corners and roots. The bar stays low and you fine-tune its height with spacers.
- 3D forged AL6061 aluminium (120 g): A forged body is denser and stronger than a casting and adds just 120 g to the cockpit.
- Split bar clamp (dual clamp, 4 bolts): Two separate clamps with two bolts each grip the bar in two places rather than one narrow band.
- 31.8 mm bar clamp, 1-1/8" steerer: Fits 31.8 mm bars with at least 50 mm of straight centre section and forks with straight or tapered steerers.
- 6 Nm torque marked on the clamp: The value is printed right on the faceplate, so you do not have to look it up when fitting.
- Excellent value for money: A forged AL6061 body, split four-bolt clamp and 120 g for under 900 CZK.
Short stem, quicker steering
Stem length sets how far in front of the steering axis the bar sits. At 40 mm that lever is short: a smaller hand movement turns the front wheel. In a tight corner or in roots, that means faster line corrections. The shorter reach also puts you further over the rear wheel, so on steep descents you are pushed less over the bar. On trail bikes a short stem pairs with wide 780–800 mm bars, which calm the steering down.
What do 0° rise and a 40 mm stack height mean?
A 0° rise means the stem sits square to the fork steerer and neither raises nor lowers the bar. You set bar height with spacers under the stem or with a higher-rise bar. The 40 mm stack is the height of the steerer clamp. The steerer should end about 3–5 mm below the top of the stem so the headset top cap has room to preload.
3D forged AL6061 aluminium body
The Nixie body is made by 3D forging: an aluminium blank is pressed into a die under high pressure, where it takes its final shape. Forged material is denser than a casting and the metal grain follows the shape of the part. That is why it takes more load at the same wall thickness. AL6061 alloy is widely used for stems and bars, machines well and resists corrosion. The result is 120 g at 40 mm length. The surface is sandblasted with contrasting polished areas.
Split bar clamp and correct fitting
The faceplate is split into two separate parts (dual clamp), each with two bolts. The clamping force acts in two places set apart from each other. That is why the stem needs a bar with at least 50 mm of straight centre section: on bent or tapered parts the clamps would not sit flush. Tighten the bolts gradually in a cross pattern and keep the gap equal above and below the bar. The final torque is 6 Nm. A torque wrench is worth it, since an overtightened bolt strips aluminium threads and a loose one lets the bar rotate. The box contains the stem itself with its bolts.
A grey stem – silvery tone without shine
The grey on the Nixie is light and close to silver, with a sandblasted matte surface. It goes well with raw, brushed aluminium or grey painted frames and with forks that have silver stanchions. It stands apart from a black bar without overpowering the frame colour. The contrasting NIXIE lettering and the 40 on the side stay easy to read.
You will find the full technical details in the Specification tab of the product.
Frequently asked questions (FAQ)
Does the FUNN Nixie stem fit 35 mm handlebars?
No. The Nixie is made with a 31.8 mm clamp only and there is no 35 mm version. There are no shims from 35 mm down to a smaller diameter, so a 35 mm bar will not go into a 31.8 mm clamp. You need a 31.8 mm bar with at least 50 mm of straight centre section.
Will the Nixie fit a fork with a tapered steerer?
Yes. A tapered steerer widens to 1.5" towards the crown, but at the top, where the stem mounts, it measures 1-1/8". The Nixie steerer clamp is 1-1/8". It will not fit older forks with a 1" steerer without a shim.
What is the difference between the Nixie 40 mm and 50 mm?
Only the length. The 50 mm version moves the bar 10 mm further forward, steering is slightly calmer and the bike more stable at speed. The 40 mm version reacts faster and puts you more over the rear wheel. The 31.8 mm clamp, 0° rise and 40 mm stack height are the same on both.
What torque do the Nixie stem bolts need?
The manufacturer specifies 6 Nm and has the value printed on the clamp. Tighten the four faceplate bolts gradually in a cross pattern so the gap is equal above and below the bar. Set the headset preload with the top cap before tightening the steerer bolts.
