Sharpening Style

ROH vs FBV® Sharpening

Radius of Hollow (ROH) is the conventional and "old" way of sharpening skates. It is the size in inches of the circular pattern applied to the bottom of the ice skate blades to provide two distinct edges. The ROH (r) is also referred to as a groove, a hollow grind or a ground radius.

The selection of a ROH has a direct effect on a skater's bite angle and therefore performance. A 1/2” or 5/8" ROH is considered standard. However, lower and higher ROH are also used. Higher ROH results in lower bite angles and conversely, lower ROH’s result in higher bite angles.
The Flat Bottom V is a new way of sharpening skates. This inovation from Blackstone Sports provides more advantages in comparison to the ROH.

FBV Pro's
Better gliding and turning abilities
• Smoother and more dynamic actions
Less fatique
Excellent performance in combination with contouring
Runners last longer (less material removed per sharpening)
• Faster skating than with ROH sharpening (less drag)
Ideal for young players (easier to stop, better use of edges)

FBV Con's
Some skaters say, "it feels like skating on ball bearings!"
FBV needs straight blades in order to get even sharp edges along the blade
• FBV sharpening requires more skills than ROH sharpening (Type of grinding wheel, honing,
finishing, dressing, skateholder adjustments and contouring knowledge is more
important than for a ROH sharpening. It is also more time consuming for sharpeners)

When asking for a FBV®, a skater will ask for a 90/75 or a 100/75, etc. The first number is the width of the flat part 'd' of the blade. The second number is the height 'h' between the edges of the blade and the flat area of the blade.

We offer ROH and FBV as shown (R equiv = ROH equivalent):

The BFD, or also called FBC (Flat Bottom Circular Arc), sharpening is not identical to the Flat Bottom V. Some shops offer FBV but deliver actually an FBC/BFD sharpening. This sharpening style is different in geometry and delivers limited options only. Try the real FBV from Blackstone.