Lubrication
If you think your cube is not turning smoothly, and you really want to improve your speed, one thing you can do is to lubricate it. There are mainly two types of lubricants: petroleum-based and silicon-based. All you need to do is disassemble it and apply the lubricant.
From my own experience as well as what I've heard from others, WD-40 will damage your cube and is therefore not a good choice.
I've also tried using vaseline before, and it did make the cube easier to turn. However, after some time, it 'ate up' the inside of the cube.
Therefore, petroleum-based lubricants are usually not recommended. But I do believe that it may work well on some cubes. I've heard of successful cases before, in which the cubes turn really well after lubrication, but are not damaged at all.
So it's totally your own choice to decide whether to use petroleum-based lubricants, silicon-based lubricants, or to simply buy a new one that is easier to turn. You can also buy DIY cubes or those which you can adjust the tension yourself. Look for cubes at online stores here.
I've also tried using vaseline before, and it did make the cube easier to turn. However, after some time, it 'ate up' the inside of the cube.
Therefore, petroleum-based lubricants are usually not recommended. But I do believe that it may work well on some cubes. I've heard of successful cases before, in which the cubes turn really well after lubrication, but are not damaged at all.
So it's totally your own choice to decide whether to use petroleum-based lubricants, silicon-based lubricants, or to simply buy a new one that is easier to turn. You can also buy DIY cubes or those which you can adjust the tension yourself. Look for cubes at online stores here.