Stunt Scooter Materials
Although two scooters look identical, it is possible that the two are of completely different quality. The quality depends on several factors: production quality, materials, pre-treatment of materials, etc. All of these aspects are practically invisible when looking at a city scooter, an adult scooter or especially a freestyle scooter. Yet they play a major role in the quality of the product.
As a result, a product that looks the same can sometimes cost three times as much, because the manufacturing quality is simply better. Many entry-level brands of scooters often invest more money in the image and appearance of their parts than in the actual technical development that determines the lifetime of the components in our scooter.
In this little guide you will see what to look for so that you know what you are buying.
The Different Metals
The most interesting materials in the freestyle scooter industry are aluminum, steel, and titanium. Each metal has different properties, advantages and disadvantages. Some are lighter but less stable, others are very stable but also heavier. In all cases, the ratio between strength and weight is relatively the same for these materials.
To make it easier for you, we will examine the different characteristics of these materials. However, we will only deal with the subject briefly, as it is of course a little more complicated in reality.
Aluminium is the lightest of the three metals, but with a density of 2.7 to 2.8 g / cm3, it is also the least stable.
The big advantage of aluminium is that it is very easy to work with, and it is also very cheap to build moulds to shape it. This makes it much easier to create more complex shapes. In addition, it can be forged, which makes the manufactured products more stable by forging at extremely high pressure.
Nevertheless, aluminium is quite rigid, and after the welding process, additional heat must be applied so that the welds do not break. This extra heat can be found in the description of the article under the name "Heat-treated", or "Heat-treated".
There are different aluminium alloys. Pure aluminium is very unstable with an elasticity of less than 60MPa. To make it more stable, aluminum is mixed with other chemical elements.
1XXX = pure aluminium
2XXX = aluminium + copper
3XXX = aluminium + manganese
4XXX = aluminium + silicone
5XXX = aluminium + magnesium
6XXX = aluminium + magnesium + silicon
7XXX = aluminium + zinc
8XXX = aluminium + other elements
In addition, other elements must be mixed to produce the final aluminum. Depending on the distribution of the individual elements, the name of the alloy changes.
Alloys 6061, 6082, 7075 are very often used for handlebars, decks, clamps, forks or pegs. Thus, only alloys of the 6XXX and 7XXX series are useful for parts for freestyle scooters or even city scooters. Not only for their stability, but also because they can be heat treated.
Heat treatment is a bit like "baking" the metal for a certain time, but at a very precise temperature level. It makes the internal stresses and welds homogeneous (i.e. transforms them into a single structure) to make them more resistant to breakage. The material gains a doubling of stability through this procedure.
For 6XXX aluminium, the part is first placed in a special furnace for 2 hours and then immediately cooled in a water-oil bath. This is known as the T4 treatment. After this treatment, it can happen that the workpiece is deformed and has to be straightened. For example, an 82.5° handlebar becomes an 80° handlebar.
The part is then treated again for 8 hours at a lower temperature and then slowly cooled down. This is called the T6 treatment.
At 700h, the process is a little different. The heat treatment must be carried out with much higher precision, otherwise the theoretically desired stability is not achieved.
6063 T6: 240 MPa
This is the entry level of the 6XXX series aluminum and is often used on entry-level scooters. Often it is not mentioned big, as it is a very cheap alloy.
For example, the first District chainrings (V1) were made from this aluminium and were unfortunately not very strong. The following versions of these decks were made from 6061 aluminium, and were much more stable and are still one of the best selling decks on the market today.
6061 T6: 310 MPa: This is the most used aluminium on the best scooters, but it is still an inexpensive material compared to other types.
6082 T6: 340 MPa: Represents the best alloy in the 6XXX series.
7005 T6: 350 MPa: The only aluminum in the 7XXX series that can be welded. It is very similar to 6082 aluminum.
7075 T6: 580 MPa: It could be called the Rolls Royce of aluminum alloys. Three times more expensive than 6061. Because of its high density, it is very difficult to machine or forge. It is unfortunately impossible to weld 7075 Alu. There will never be a deck or handlebar made of this aluminium. The 7075 Alu must be machined with a CNC machine. Therefore you will only find forks or pegs made of this material.
Unfortunately, some brands do not necessarily tell you the truth about the alloy they use. Sometimes, the characteristics of the aluminium used are also misinformed by the factories.
This is why Riders brands are very useful to you because they really strive to improve the quality of the products.
Steel is much more difficult to machine than aluminium. The material itself is also much cheaper than aluminium.
Unfortunately, it is much heavier than aluminium with a density of 9.8 g / cm3. But it can also be used with a thinner / thinner material to produce a stable part, so that you can end up with a similar weight.
In the BMX industry, steel has long since replaced aluminum because of its flexible properties. The flexibility of steel helps to balance the high forces that occur in the extreme figures of our sport and that need to be absorbed.
Steel doesn't really need heat treatment, but if it does, it can make it 40% more stable. Unfortunately, heat treatment is more expensive than aluminum.
Normally, steel has a thickness of 250 MPa, but it can be much higher for different alloys.
The most common alloy is chromoly 4130, known in Europe as 25CD4. It is an alloy consisting of steel, iron and carbon containing 1% chromium (Cr) and 1% molybdenum (Mo). The strength of this system is about 700 MPa. After heat treatment, stability can increase up to 1100 MPa, but only on real high-end handlebars, which we will probably never see on freestyle scooters because of their exorbitant price.
The main characteristic of titanium is its elasticity, almost twice that of steel and eight times that of aluminium.
However, contrary to many opinions, titanium is not more stable than steel, it is slightly less, but it can also be made more stable with the right treatment. It is also very light with a density of 4.5 g / cm3. Although still a little heavier than ALU but only half of the steel has almost the same stability as mentioned. This allows us to use more material than steel, but still makes it lighter and more stable.
The problem with titanium, however, is that it is very expensive and hard to find and the processing is complicated.
As with aluminium and steel, there are different alloys, which are divided into "degrees". According to their characteristics. There are a total of 38 degrees.
Pure titanium has a thickness of 350 MPa.
The "Grade" 5 Titanium, also called 6AL-4V, is mainly used in the aerospace sector. It is also used in most other titanium components. It can reach up to 1050 MPa (hardness) after heat treatment and can also be welded.
We hope to see more and more titanium parts, maybe even a deck, but your wallet would start to cry ;o)).