We are not psychologists but we can think of 3 reasons immediately. Firstly, if you had just paid several hundred dollars for a set of bearings, you too would "believe" that they were better than what you had bought previously for around $30.00 to $40.00. Secondly, and somewhat similarly, if you really believe that something will make you faster, it probably will (it's all in the mind). Thirdly, how do you seriously compare the speed at which your new [ABEC 9 bearings] allow you to travel against the speed that your old ABEC 1 bearings allowed you to travel several months ago when they were also new ? More likely you would be comparing against the speed at which the old ABEC 1 bearings allowed you to travel after they had worn considerably. Try this in reverse. Take out the old ABEC 9 bearings after several months and replace them with new ABEC 1 bearings and you will get a similar increase in speed.

Stainless Steel bearings are usually marginally softer than Chrome Steel bearings, but this should not matter unless you are an aggressive skater. Stainless Steel bearings are advantageous if you are skating in wet conditions or close to the sea. They will rust (they are a high carbon content stainless steel), but they won't rust as quickly as Chrome Steel bearings.

Both of the above standards are exactly the same for 4 of the 7 major elements used in Chrome Steel. Of the remaining 3 elements the specifications overlap, meaning that an SUJ2 bearing steel is also in many cases conforming to SAE52100 and vice versa. That is not to say that all batches of one will also conform to the other, but the differences are minimal anyway. Don't let anyone tell you that one is better than the other.

A skates wheels can easily get up to 2-3 times the RPM (revolutions per minute) of an Indy Car wheels. We will bet that what you read did not mention that this is still well under the capabilities of the 608 bearing (see point 6 above). Speed is not one of the problems faced by skate bearings - lack of lubrication, contamination, moisture and the unavoidable shock loads associated with skating are the biggest problems. Be very wary of anyone trying to tell you that Skating is a high speed application.

In relation to the formula supplied, the basic formula is incorrect as it shows forward momentum being the product of the Radius of the Wheel and RPM. It only takes a little logic to realise that one turn of a wheel does not move the wheel forward by the distance of its radius but rather by its Circumference. However, using this incorrect formula in the above analogy will still get you the same result as to the relationship of the skate wheels fag bearings speed to that of the Indy Car. Whilst the formula used is incorrect, the analogy is still correct - albeit irrelevant.

The jury is still out on this one. The Nylon Retainer (Cage) is usually used in high speed bearing applications, so its use in skating applications would normally not be necessary. The Nylon Retainer may have some slight advantages over the Steel Retainer in that it could possibly help to dampen the shock loads associated with skating, and it may assist in holding the lubricant in. More testing would be required, however unless somebody comes up iko bearings with an inexpensive version of this type of retainer, the steel retainer would probably still be the most economical type over a period of time.