Hi both are ISO interface , both can be used with 75 cranks ??

You'll probably get an answer faster in SSFG or Bike Mechanics.

Sugino 75 cranks are rare on the track these days. Other NJS cranks even more rare.

Dude I totally use Sugino 75's! They are fantastic cranks! I believe the Hatta will work just as well having the same taper and length. I think they are something of an upgrade (maybe?) to the regular 75 BB, but they have been offering the "super lap" version for a long time now so I see the Hatta less over here.

I had Sugino 75s a couple of years ago. They are great. I was just commenting that they are uncommon.

Hi. Why 75,s are uncommon on track at this time? thank,s

Square taper is old tech. Shimano Octalink track cranks are an upgrade in almost every area (stiffness, maintenance, cleanliness, tuning, installation...).

Even Octalink is old tech, but no one's made anything significantly better for track.

Still very common among non-professional track riders in Japan, home court advantage I guess. I like square taper. It lasts forever. Modern solutions are far more fragile. I've been using the same BB for over 10 years now, and it's not quitting anytime soon.

Edit: Carleton is right, non-square taper BB's are probably stiffer. But how strong are you? Can you flex one of these? I sure can't.

I honestly think it's for the same reasons that loose and caged-ball bearings are rare on wheel hubs: Maintenance.

Setting (and resetting) the tension and cleaning are a pleasure for some people and a P.I.T.A. for others. Properly cleaned, oiled, and tensioned loose ball bearings are a joy to experience. But, they usually don't stay like that for long. And in my experience, most riders/racers don't nerd-out on bike maintenance.

Sealed bearings aren't buttery smooth, but they are smooth enough...especially when they don't require cleaning or a special tool to tension.

EDIT:

Yes, I imagine that it comes easy for a lot of folks, but a lot of people either don't know how to or don't like to do it. Removing cranks and bottom bracket, cleaning all of the dirty muck, de-greasing everything, re-greasing and packing, and reinstalling is a fair amount of work.

Full disclosure: I'm a former BMW technician, so I enjoy taking care of stuff. And I may have more skill with it than some, but basically I re-pack my BB and hubs (DA large flange on training wheels) once a year, and I normally don't need to touch them for another 365 days. But as Carleton said, your milage may vary, and may depend on interest/skill/temperament.

But yeah, I'll admit-- properly set up loose ball bearings are a thing of beauty to me. I also just love the longevity of these pieces and the fact that they've been around for so many years, unchanged. That is getting extremely rare in this world.