Motorcycle exhaust pipes form the pathway for exhaust gases from the engine to move out of the motorcycle. Since exhaust gases are always at high temperature, the exhaust pipe should withstand such soaring temperatures and should durable to heat cycles.
So, what are motorcycle exhaust pipes made of? The most commonly used materials for motorcycle exhaust pipes are – stainless steel, mild steel, titanium and ceramic coated steel. In addition, carbon fiber is sometimes used for exterior and aluminium for the muffler.
Let us discuss all these exhaust pipe material in detail in the next few sections.
Materials Used In Motorcycle Exhaust Pipes
For the manufacturing of the exhaust pipes in motorcycles, there are mainly four materials used. These materials are – Steel, Aluminium, and Titanium.
And within steel, we have many types. The commonly used steel types for exhaust pipes are – stainless steel, mild steel, and ceramic coated steel.
Every material has its strengths and weaknesses. The selection of material for exhaust is always a trade-off between weight, heat resistance, durability and ease of manufacture.
Here are the most commonly used materials in the exhaust pipes of motorcycles.
Stainless steel is the most commonly used metal in the exhaust pipes owing to its better performance in resisting heat and corrosion when compared to most materials.
Like its other steel counterparts, stainless steel are easy to manufacture. The easier manufacturability, heat resistance and withstanding corrosion makes it an attractive material for exhaust pipes.
However, the problem is stainless steel does not withstand heat cycles very well. Its more likely to fail at higher temperatures.
Still, stainless steel is a suitable choice of material for exhaust pipes and is used extensively in many motorcycles.
Pros: heat resistance, corrosion resistance, easier manufacturability
Cons: does not withstand heat cycles
Mild Steel exhaust pipes are the least expensive to manufacture. They also perform well to withstand heat cycles. However, their resistance to heat is poor when compared to Stainless Steel.
The inability of mild steel to withstand high temperatures is their biggest drawback since the motorcycle exhaust system sees some extremely high temperatures. Especially when the engine is overheating or the exhaust is backfiring, the exhaust pipe will experience soaring temperatures.
That’s why, the exhaust pipe material needs to withstand such high temperatures and not fail in. If the pipe is unable to withstand high temperatures, the material of the pipe will turn blue or sometimes, even orange and red.
However, despite their drawback of notwithstanding high temperatures, mild steel exhaust pipes are still used given their low cost and moderate durability, Mild Steel are still popular as an exhaust pipe material.
Pros: least expensive to manufacture, low cost, high durability
Cons: poor heat resistance
Ceramic Coated Steel
Ceramic coated steel is nothing but a ceramic layer added to the interior of a Stainless-Steel exhaust pipe. The ceramic coating provides additional insulation properties, making the exhaust withstand higher temperatures and more durable.
Since ceramic coated steel is an improvement on the stainless steel exhaust, the durability and heat resistance is much higher than the stainless steel exhaust pipes. The heat resistance, corrosion resistance, and the durability of ceramic coated steel is extremely good and only titanium exhaust can provide better performance in these parameters.
On the flip side, ceramic coating is difficult to manufacture and as a result are expensive when compared to Stainless Steel and Mild Steel exhausts. The upgrade from stainless steel to ceramic coated steel for exhaust pipes comes at the cost of complex manufacturing and high price.
Pros: heat resistance, corrosion resistance, durability
Cons: complex manufacturing, expensive
Aluminium is one jump up from steel exhaust pipes in terms of cost. Aluminium is very light and hence, low in weight. However, aluminium has low strength. For that reason, aluminium alone is not used in exhaust pipes.
The most common usage of aluminium is only on mufflers and is combined along with steel or titanium for the exhaust pipe.
Aluminium is not the most suitable material for exhaust pipes owing to their low strength. As a result, they are rarely used in exhaust pipes. However, they have their uses in mufflers of certain motorcycles, but are usually combined with a titanium or ceramic coated steel exhaust pipes.
Pros: light material and low weight
Cons: low strength, not the most suitable material for exhaust pipe
Titanium is the most expensive material out of other alternatives owing to its complex manufacturing process and the intensive labor required.
And the high cost is rightfully so, since the advantages the material provide is far superior to its other counterparts. Titanium exhausts are some of the most expensive exhaust systems available out there in the market and at the same time the best performing and superior exhaust systems available.
The high cost of titanium exhaust is compensated with low weight, better resistance to heat and extremely high durability. Titanium has the best strength to weight ratio and are an excellent material of choice for exhaust pipe. The only downside is its high cost.
Pros: low weight, better resistance to heat, extremely high durability
Cons: complex manufacturing process, expensive
Which Exhaust Pipe Material Is Best?
There is no one material fits all approach. As seen in each of these exhaust pipe materials, each come with their own set of pros and cons. The best exhaust pipe material is the one that suits the need of the motorcycle.
As discussed earlier, the choosing of exhaust material is always a trade-off between durability, weight, heat resistance, cost and ease of manufacturing.
If low cost is the main criteria for choosing the exhaust pipe material, then mild steel or stainless steel will be the preferred choice of material for the exhaust pipe.
On the other hand, if high performance and durability is the criteria for choosing irrespective of the cost, then titanium and ceramic coated steel will be the preferred choice of material for the exhaust pipe.
For lower cc engines, which does not soar to very high temperatures in the exhaust system, a high durability to heat cycles and resistance to high temperatures may not be too significant. For these motorcycles, stainless steel exhaust pipes might be more preferable since they low cost, easier to manufacture and provides good heat and corrosion resistance.
For higher cc engines and sports bikes, where the exhaust systems see some really high temperatures, the durability to heat cycles and resistance to such high temperatures become extremely important. That’s why, for these types of motorcycles, titanium and ceramic coated steel as exhaust pipes will be more suitable owing to their high durability and resistance to heat.
Overall, stainless steel is the preferred material if low cost and not durability is the choosing parameter. Titanium and ceramic coated steel are the preferred material if durability and heat resistance is the preferred parameters.