Why does Shimano still use old octalink on Dura Ace track group?

I thought the outer bearing / through axel design resulted in a stiffer and lighter crank set up, no? Surely this would be better than the old splined octalink?

Why do they continue to use 90's technology on the track group but not the road groups? Am I missing something? Is it UCI sanctions?

http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/road/Dura-Ace_Track.image.-groupTextImage-Single-image.dash.jpeg

Possibly NJS/JKA sanctions rather than UCI as (so far as I know) Omnomnoms and Rotors are UCI legal.

I'd suspect the Octalink design is just as stiff as the 24mm outboard design but a bit porkier. I also suspect its bearings run with less drag out of the box than the 24mm design, it has a lower q-factor (or more heal clearance) and as weight doesn't really matter to track folks it's still a viable proposition.

Or Shimano just can't be bothered to produce a 24mm bearing cup that doesn't have any weather sealing

Also: adjustable chainline.

Awaits Tester

newest 9000 dura-ace crank+bb weights almost the same as the classic track version mentioned here. I think it might be something about stiffness or bearing thing.

Don't forget the external bearings make the bottom bracket slightly wider than 107-109 mm which is most popular in track bikes. And that might cause a problem with chain line. Maybe it's something about the distance between crank and frame? But I don't think that this problem in not to be overcame, especially for Shimano.

Other theories?

Given the axle is shorter than the 24mm design and nearly as large at 22mm and supported by both cartridge and needle bearings I suspect it may actually be stiffer.

Or betterer. Or something.

I wouldnt think there's enough of a market to R&D a new track group, especially when it's still world champ level.

I'm still saying that its coz in the world of NJS, Octalink is high tech and that will make it the group/crankset of choice for many keirin racers.

The cost and time of creating a HT2 track crankset might be negligible but there'd probably be a large cost in getting it NJS approved and Shimano possibly see the keirin market as a good earner.

Also, is anyone (that matters - ie national teams) really buying external bearing cranksets as an upgrade to DA anyway or is the only real upgrade a move to a proprietary system like the Looks use?

Hoy would have been on 7710s at the last Olympics, that must sell a shit load of cranks and if you're still churning out cranks that you did all the design and R&D for, what, 14(?) years ago, why invest a penny in a replacement?