Condensed answer: It’s possible to install a BMX stem on an MTB if the handlebars have a 22.2mm clamp-on diameter.
Requirements for Installing a BMX Stem On an MTB
A BMX stem would fit on an MTB when the following criteria are met:
1. The bar-clamp of the stem should match the diameter of the handlebars.
The average BMX stem has a 22.2 bar clamp. As a result, it’s too small for common MTB handlebars which have а 31.8mm clamp-on diameter.
Therefore, only MTB bars with a 22.2mm clamp area would fit on a classic BMX stem.
The common MTB handlebars sizes are different, however.
25,4mm, 31.8mm, and 35mm bars dominate the market. As a result, the available 22.2mm options are limited.
It’s also worth noting that most 22.2mm MTB bars are made of Chromoly steel which greatly increases the weight of the bar.
An average 22.2mm steel MTB bar weighs between 500 and 700 grams whereas a 31.8mm aluminum one is 300-400 grams.
22.2mm MTB bars are made out of steel because the diameter is too small to produce a strong bar out of aluminum.
Aluminum isn’t as dense as steel and requires more volume to match the strength of a steel component. Hence why aluminum frames have much larger tubes than steel ones.
Below is a list of 22.2mm bars that would work with a BMX stem:
|NS District||Chromoly Steel||No||550 grams|
|DMR Wingbar||Chromoly Steel||Yes||700 grams|
|Nemesis Project||Chromoly Steel||No||655 grams|
|Gusset 3″ Open Prison 750 Bars||Chromoly Steel||No||580 grams|
|Gusset 2″ Open Prison 750 Bars||Chromoly Steel||No||560 grams|
|CTN Eastwood Bar||Chromoly Steel||No||590 grams|
|Atomlab GI Riser Bar||Chromoly Steel||No||590 grams|
|Renthal Jump Bar||7010 T6 Aluminium Alloy||No||380 grams|
|Black Market Molly Hatchet Bars||Chromoly Steel||No||455 grams|
|Dartmoor Toxic v.2||Chromoly Steel||No||415 grams|
|Fireeye FIRE BAR||Chromoly Steel||Yes||790 grams|
|Surly Sunrise||Chromoly Steel||Yes||778 grams|
|Norther Cycles Custom Steel Sweepy Riser Bar||Chromoly Steel||No||485 grams|
|Fairdale MX 28″ Handlebar||Chromoly Steel||Yes||453 grams|
|Dobermann Bikes||Chromoly Steel||No||645 grams|
|Average:||575 grams||20.28 oz|
2. The fork-clamp diameter should match the diameter of the fork’s steerer tube.
Most MTB bikes have suspension forks with a steerer that’s either 1 1/8″ from top to bottom or tapers from 1 1/8″ to 1 1/2″.
In both cases, a standard BMX stem would work because it has a fork clamp diameter of 1 1/8″.
What Are The Benefits Of Using a BMX Stem On an MTB
The primary motivation for installing a BMX stem on an MTB is appearance rather than function. Many people like the design of BMX stems and install them on their MTBs for style points.
What Are The Downsides Of Using a BMX Stem On an MTB
1. Limited Bar Choice
A BMX stem restricts you to bars with a 22.2mm clamp area. And while there’s a decent number of them on the market, the volume is nowhere near close to that of dedicated 25.4mm and 31.8mm MTB bars.
2. Heavy Bars
Most 22.2mm are made of Chromoly and some have a crossbar/brace for extra support.
Thе combo results in bars that are substantially heavier than MTB models made out of aluminum.
Conversely, larger clamp areas (25.4mm, 31.8mm and 35mm) allow designers to use hollower tubing and lighter materials such as aluminum while still achieving a satisfactory level of strength.
The larger the tube, the hollower it can be without losing strength because most of a pipe/tube’s strength comes from its outer layers.
For that reason, a pipe is stronger than a solid rod of equal mass when both are made of the same material.
Bicycle engineers have been relying on this phenomenon to produce components with excellent strength to weight ratio.
The most obvious example would be bike frames – they’re all composed of tubes.
The table below contains the weight of popular MTB bars with common diameters:
|Renthal Fatbar® 35||305g|
|LEVELNINE Team 35||326g|
|Truvativ Hussefelt Comp||347g|
|Race Face Atlas 35||320g|
|SQlab 3OX MTB 31.8||325g|
|PRO FRS 31.8 40 mm Riser||345g|
|Spank Spike 800 Race||330g|
|Chromag Fubars FU40||330g|
|Ritchey Trail 2X 31.8||276g|
|Ritchey Comp Kyote||355g|
Conclusion: The average weight of regular MTB bars is 325g. Meanwhile, the average weight of 22.2mm MTB bars is 575g (table 1).
The difference amounts to 250grams – a lot of weight in the world cycling.
Short MTB stems are notably lighter than BMX models because the MTB design requires less material.
The tables below compare the average weight of BMX and MTB stems:
|Fit High Top V2||344g|
|Animal Inverse Stem||382g|
|Fly Volcano 2||281g|
|Thomson Elite X4 Stem||165g|
|Renthal Apex Stem||146g|
|NEWMEN Evolution 318.4||167g|
|LEVELNINE Team AM Stealth 35 Stem||135g|
|Hope FR/AM 31.8||134g|
|Race Face Chester 35 Stem||170g|
|Race Face Turbine 35||150g|
|Chromag HIFI V2||200g|
|Chromag BZA 35 Stem||165g|
Conclusion: On average, MTB stems are two times lighter (323.9g vs 152.9g).
Are BMX Stems Stronger?
It depends on the model. In general, both MTB and BMX stems are plenty strong to handle a lot of abuse as long as the production quality is good.
What You Need to Know
A BMX stem can be installed on an MTB only when the handlebars have a 22.2mm clamp area.
22.2mm MTB bars are made out of steel and are heavier than standard MTB bars.
On average, BMX stems are heavier than MTB models.
A classic MTB stem is plenty strong and allows you to choose between more handlebar models that are also a lot lighter than the 22.2mm options.
The only incentives to use a BMX stem on an MTB are looks or the absence of alternatives.