hi bro,
me abit blur liao. cant really undestand why it shld be installed in such manner 
There are 2 parts to tire installation. Symetrical/Asymtrical and directional/non-directional.
Very high performance tires are usually directional. They are designed to provide optimum grip when it is turning in a particular direction. For these tires, they cannot be interchanged between left and right. They usually have a marking on the sidewall to show the direction of rotation when fitted. In short, the left and right tires are mirror image.
Alot of assymetrical tires are designed for wet performance to displace the water outwards. Like the RE001, the grooves are designed to displace water outwards so when you see from the front, it looks like the grooves are opposite in direction (one up one down).
However, the tire designer has already designed the grooves such that it does not matter if it is pointing up or down. Only that the correct side of the tire needs to point out.
For asymetrical tires, they can be interchanged left and right. However, care must be taken when fitting to the rims to ensure that the "OUTSIDE" sidewall is facing outside. After that, all 4 tires can change location without removing from the rims.
In short, directional tires have left and right tires and they are mirror images. For assymetrical tires, there are no difference between the left and right tires but because of the way they need to be fitted, they will look like opposites between the left and rights.
Actually, it is nice of bridgestone to make the RE001 non-directional. In that case, the tires can be rotated through all 4 positions for best possible wear.
