Does ROH affect time between sharpenings?

[Christy]

I always thought blades would hold a sharpening for a certain period of time regardless of ROH so if I changed the ROH on my blades the hours between sharpening would be the same, however some friends are saying that their blades need sharpening after about 10 hours because of the ROH. I know some people prefer to have skates sharpened frequently so there isn't much of a transition but 10 hours seems very short. Also, is having blades sharpened so frequently a good idea?

[Bill_S]

My first thought was "yes, it will". A smaller ROH has a deeper center, and the edges are thinner - wearing faster. Also, power sharpening could possibly remove the temper from the steel at the very tip of a narrow edge, leaving soft steel. There's not as much steel behind an edge with a small ROH to absorb heat from unlubricated power grinding.

Then I drew the blade's hollow to scale comparing a very aggressive 3/8" ROH to a gentle 1/2" ROH. They don't look nearly as different as I would have expected...



Having seen that, I now expect that outside variables would matter much more - hard vs soft ice, deep edges vs upright skating, clean skate guards vs. not, etc. I predict that it's a case of the theoretical being swamped by larger environmental factors.

10 hours between sharpenings seems like an aggressive schedule, and will reduce the life of the blades. At typical metal removal rates of .005" per sharpening (power sharpening), you'd remove a whopping 1/4" in one year skating @ 10 hours/week. However sharpening frequency is a personal preference. I'd just do what feels OK, so when you start sliding a bit more than usual, get them sharpened.

[Christy]

Wow - I'm amazed at how similar they look. Like you I would have expected a greater difference.

I track my skating hours and usually plan to get my blades sharpened every 25-30 hours based on how they are feeling. That's why I was so surprised with the 10 hours.