A race inline skate wheel size will be 100mm or higher to give skaters the highest speed with the smoothest roll. Racing inline skates are meant for speed and a larger wheel means longer rotations allowing the skates to reach and maintain a higher speed. As most racing skates are used for marathons, skaters will rely on being able to reach and maintain a high speed for the entirety of the marathon which would make using a standard inline skate not practical.
The cuff on a race inline skate will typically be much shorter than a regular inline skate. A regular inline skate cuff will come up fairly high while a race inline skate cuff ends right above the ankle. A shorter cuff allows for race and marathon skaters to articulate their ankle to ensure a full stride. With a low cuff race inline skate skaters can achieve a double-stride pushing the ankle outwards and then stride back inwards to reach and maintain higher speeds.
Race and marathon inline skates are all going to offer a high performance bearing. Racing skates are all designed for speed and smoothness which is why you won’t find any shotty bearing setups on these skates. Many will offer either an ABEC 9 bearing or a Pro level bearing. Most companies will have their own rating system so an ABEC 9 bearing may be called an ILQ 9 or similar but the rating is the same. A 9 is the highest rating before going into Pro or Swiss bearings which are smoother and offer a better ability at a top speed.
A race inline skate boot is going to fit very close to the foot and will not have a very thick padding. These skates are meant to fit snug and close to the foot to offer the greatest power transfer and ability to fine tune the energy you are putting from your foot to the skates. Many race inline skates are going to offer a heat moldable boot which can be done at a certified skate shop, or the skates will naturally heat mold with the heat from your feet. When the skate’s finally mold to your feet you will have a fit that rivals none other as the skate will hug your foot giving you the ability to really excel while skating.
A race inline skate will offer a very stiff frame which is typically longer than a standard inline skate frame. The reason a race skate’s frame is so stiff is to make sure the frame doesn’t flex when you take your strides giving you the best energy transfer from your legs to the skates. And the race inline skate frame will be longer to give you more speed and to make room for the larger wheels.