1st Misleading: Titanium alloy is very light, lighter than aluminum, and almost as light as carbon fiber.
Let’s take a look at the specific gravity of three metal materials commonly used in making bicycles: steel, aluminum and titanium. Titanium is about 57.4% of the weight of steel, and aluminum is about 34.4% of the weight of steel. So aluminum is the lightest. We can see aluminum is 40% lighter than titanium alloy and 65% lighter than steel.
2nd Misleading: Titanium is a rare metal, so it is more expensive.
In fact, it isn’t. The reason why titanium is expensive is not because it is rare, but because of the difficulty of smelting and metal machining process.
3rd Misleading : The thicker the titanium alloy frame is welded, the more the welding points are, the more reliable it is.
Melt welding, as the name implies, is a way to directly heat the workpiece interface to “melted” during the welding process without any pressure; At this time, the heat source heats and melts the interface between the two workpieces to be welded to form a “melt pool”, and the molten pool will move forward with the heat source, and finally cool to form a continuous weld to connect the two workpieces into one.
If the larger the welding area is, the greater the welding heat source is needed. As we know, thermal stress is mechanical stress created by any change in temperature of a material. These stresses can lead to fracturing or plastic deformation.
The heat treatment of titanium is totally different with other metals. When welding is carried out at a high melting point and in a completely oxygen-free state, it is necessary to reduce the heat energy accumulation on the weld junction as much as possible. Only in this way can the metal stress be reduced. So when welding, it is better to make the weld joint better fused, and do not pursue large area welding.
Practice has proved that the more excess weld is, the greater the chance of quality problems. Of course, this is not absolute. Some companies with advanced heat treatment equipment for titanium alloy products will reduce this risk through special heat treatment technology. It should be noted that the grinding of the weld scar (the fish-like bulge on the surface after welding) can not eliminate the stress inside the metal. Too much grinding, especially the welding of titanium alloys, may reduce the welding strength. This must be noted that it is better not to buy the one that has been grinded.
4th Misleading: 6-4ti titanium grade 5 frame is the best titanium frame.
As we know, just like the same steel frame, some are made of carbon steel, some are made of manganese steel, and the prices are also very different. The same is true for titanium frames. There are thousands of titanium frames made by our company in one year. The price difference is still quite large. So it’s not that a frame of a similar material has the same quality. We must talk about it separately and discuss the matter on a case-by-case basis. There was a time when it was rumored that a 6-4 titanium frame was the best titanium frame. However, it is contrary to the facts.
First of all, let us talk about what is going on with the titanium alloy grade 5.
Titanium Grade 5 is alloyed with 6% Aluminum and 4% Vanadium and is commonly known as Ti 6Al-4V. Grad 5 has very high strength but relatively low ductility. If such a material can be used to make a bicycle, it is indeed quite ideal in terms of hardness.
However, in fact, there is no country in the world that can produce a large number of 6-4 titanium alloy seamless pipes. The tubes in some positions, such as the bottom bracket and head tube, can be made into tubes by punching holes in the middle of 6-4 titanium alloy rods.
So why do some people say that their frame is 6-4 titanium alloy? And why are there so many 6-4 titanium alloy frames in Europe and America that several manufacturers stopped production? The reason is simple, the forming process of those tubes is coil welded (seamed tube). How many cases of the so-called 6-4 titanium tube frame cracking, I will not reveal the topic of what manufacturer happened. Everyone knows it. As far as it goes, grade 9 is the best material for bicycle frames.
5th Misleading: Titanium alloy is relatively soft and not wear-resistant.
If you take three sections of 3-2.5 titanium alloy pipe + aluminum alloy pipe + steel pipe with the same wall thickness and cut them with a hacksaw blade for metal cutting, you will know what hardness is. Because of the same saw blade, it is relatively easy to cut the other two metals, but when cut the titanium tube, you will find how the saw teeth are so slippery!
Regarding whether it is wearable or not, let’s we see two examples:
1) Choose a piece of titanium alloy disc used as the front wheel brake in cycle cross bike. I tested it for about half a year. The disc used for the brake is the original G3 oil disc. The collar of the front disc wears out soon. Then we replaced it with a new set. After a few months, I found that the pads of the rear wheel were much more worn. And the disc itself doesn’t show much wear and tear. This is enough to affirm that the wear resistance of titanium alloy is better than that of steel. If you don’t believe me, look at those drill bits that drill holes in metal. Why are titanium-plated drill bits so easy to use and have such a long lifespan.
2) The titanium shaft chain is easier to use than steel chains, and its durability can be seen by the eyes and felt by the body.