Sierpiński cranks

http://www.cyclingnews.com/tech.php?id=/photos/2009/tech/news/04-04/Rotor_proto_crankarm_closeup

I kinda like it. Are they generally available?

The report says that it’s a prototype so I’ll guess no.

The novel design uses carefully positioned drill holes to effectively yield a hollow interior.

If by novel design they mean fail* design and by hollow interior they mean shimanos-had-it-for-10-years interior, then yes.

*I’m sure Blakey can explain.

i imagine there are more elegant and stronger ways of achieving a hollow crank then drilling it full of holes. i wonder at their reasoning. something hollow, maybe carbon, with internal ribs or a honeycomb would be stronger and more able to be built light in places and strong in other places?

edit: spud said that while i typed this. need to type quicker.

Eh, not much to say. Cold forged hollowtech is going to be superior and won’t look like a cheese grater, filling up with muck over time.

They’d look the part on your IsoTruss frame though!

Those crazy Spanish dudes at Rotor have been coming up with stuff like this for years.
While it is true that Shimano basically achieved the same thing with their Hollowtech design, this idea goes a step further on the weight reduction.
The problem of course is that a forged part is much stronger than a CNC machined part. I’m sure Blakey can tell us all about how each drilling will increase the probability of stress fractures? :stuck_out_tongue:
But if you’re a pro and want to have the lightest aluminium cranks, then meh, GO ROTOR!

Haven’t read anything on them but I would still wager that 7900 or for that matter 7800 are lighter and stronger.

Rotor have apparently abandoned their eye-catching ‘Swiss cheese’ road crankarm design in favor of a slightly more conventional setup based around their existing Agilis model. The new prototype, tentatively dubbed ‘3D’, features three channels drilled lengthwise through a significantly wider extruded and machined aluminum crankarm, in contrast to the multi-axis drilling of the previous version.

This construction style makes the new crank nominally hollow, stiffer than the existing crank, and presumably also slightly easier to manufacture. More importantly, the latest design passes the stringent European EFBe test standard, which the old one did not.
Cyclingnews

We can close that chapter then eh?

haha they didn’t even pass the product standards test!