Issues regarding the handling of the T-64 family of tanks (including the T-72, T-80, T-84 and T-90) were raised from time to time by critics of Soviet armor technology and others. There is really no need to ask this question – because we can't get a definitive answer. However, one of the T-64 family of tanks has already been eliminated. The production of the T-64 was discontinued in 1987, and some conspiracy theorists looked for conspiracy theories in it. Actually, there is a conspiracy, but it is very mundane......
The star of that era
The T-64 became the first tank in the world to use composite armor. This is its main achievement and what worries NATO countries. NATO countries "hurriedly" accelerated the tank development program. MBT-70 and XM803, MBT-80, Leopard 2K and XM1...... The task of all these projects was to develop a unified tank that would be able to compete with the T-64 and T-72, preferably surpass them.
NATO was developing a similar product of the Soviet composite armor, but it used spaced armor inside the hull of the combat vehicle. It was a very logical idea, and most interestingly, it corresponded to the challenges of the time. In the 50s and 60s, the main threat to all tanks was shaped charges. Grenades, rocket-propelled grenades, missiles, bombs...... There was everything back then. Moreover, it was difficult to protect the tank from a shaped charge. Its destructive power does not depend on attack range and speed. The most coping with shaped jets is heterogeneous armor, a technology adopted in the USSR, while the "West" is working on spaced armor structures.
T-64B and T-80
Of course, the T-64 was not only revolutionary in armor. When it came out, the T-64 used the world's largest ammunition-loading loading mechanism, and its engine was extremely small in size but incredibly powerful. In addition, there are gearboxes that minimize power losses from the engine to the drive wheels. Its gun caliber is also very revolutionary - 125 mm. At that time, there were only a few tanks that could exceed this caliber, and those such as the M551 Sheridan and M60A2 Starships were mainly missile tanks, while the T-64 was capable of firing tank shells typical of the 60s and 70s, and in 1976 it was also equipped with a weapon control system (КУВ).
Why did the USSR abandon the T-64?
There are several reasons for this. If one recalls the initial technical assignment of the T-64, it had to have the same protection and firepower as a heavy tank (which was still in service with the countries of the world in the early 60s) up to 35 tons, as well as the mobility of a medium tank. To understand this, the T-10M weighs 50 tons, and the T-64 must have an equal level of protection and firepower at a mobility level not lower than that of the T-55 or T-62 (weighing 36 and 37 tons, respectively).
Project 430
A pre-production prototype of the T-64 appeared in 1963 with a composite armored front of the hull, a cast homogeneous turret and a 115 mm gun, adapted to a rotary loader. Due to the peculiarities of the reloading mechanism, the ammunition was designed to be charged in parts, and not as in the case of the T-62. It is understood that Project 430 (the earliest prototype of the T-64) weighed a little more than 35 tons. Project 432, which weighed 36 tons when it reached pre-production, while the production version of Project 434 (better known as the T-64A) weighed 38 tons.
The increase in weight was due to the change of gun caliber from 115 mm to 125 mm, changes in the structure of the turret (now with a stuffing chamber) and improvements in the armor of the frontal part of the hull. Due to the change in the caliber of the gun, adjustments to the reloading mechanism had to be made. All these changes did not change the suspension system of the tank.
219 SP1 project
The "first swallow" of the suspension problem was the development of Project 219 (that is, the future T-80). The T-64's load-bearing wheels could not withstand the impact of high-speed off-road driving, so the T-80 adopted load-bearing wheels of a larger diameter and covered with rubber. In addition, the modernization potential of the T-72 was "limited" due to the weakness of the suspension system (compared to the T-72 and T-80). The same T-72 has increased in weight since 1973 (from 40 to 46 tons), and its suspension is capable of withstanding increased loads, while the T-64BM "Blatter", weighing 46 tons, has problems with the reliability of the running gear. Because of this, further production of "Blatter" was abandoned and replaced by the T-2017BV of the 64 model.
The issue of production is also worth mentioning. From 1963 to 1987, about 8,000 tanks were produced. In comparison, all models of the T-80 produced a total of about 10,000 units, while the total number of T-72 units is estimated at 30,000 units. The T-64 could only be produced at the plant in Kharkov, so the T-72 appeared as a simplified version of the T-64 and was unified with the T-62 in some components (engine and load wheels), and later attempts were made to carry out a deep modernization of the T-64 with a gas turbine engine. So there was the T-80......
T-64BM "Blatter"
summary
The USSR abandoned the T-64 not because of the ability to foresee the future and "revive the empire". The question of the T-64 is more mundane...... The initial technical requirements greatly limited the engineers, so a series of groundbreaking technical decisions were made. These requirements contributed to a revolution in tank building, but at the cost of a number of problems with the T-64 - "early" problems with the suspension system, engines, as well as problems with production. These problems prompted the USSR to abandon the T-64 in favor of the T-80U and UD.