Received a call the other day on these splines size as compared to the crank recess ID and apparently they are about .009" larger on the diameter, which of course means about .0045" larger on the radius. So it looks like my "likely sub .003"- educated guess" was a smidgin bit off. So now the question lies in how much does this .0045" plus sized spline "etch" into the inner crank hub- as whatever this equates to is all the additional "leverage" that is had post install. FWIW a dollar bill is about .004"- so it is not going to be much "positive grip" regardless.It is pretty clear one solution is actually a true, positive lock, setup. Once done, it is done forever, it will never steer you astray, and is clearly serviceable whenever/wherever needed. The other is a solution that is more so a "vice grip" sort of concept and appears to be a bit gimmicky.
The new splined solution although elegantly thought out and a nice overall part, has been marketed to "just dig deeper" if a spin event where to ever happen. This just is not true, obviously, as our fairly constructive post was moved to the octagon and we were banned from posting in the thread for making these comments... par for the course when there is no real rebuttal.
The meat and potatoes of this comes down to really one thing- how much are the splines digging into to the crank and thus what kind of trace mark are they leaving and is it really enough to be considered a positive lock under all scenarios. One must consider to install the splined hub they are literally pressing it on via threading in the hub bolt, if a dedicated install tool is not eventually provided (ie. using a separate long stud, and a thread on nut/washer); which will limit you on the pressing force that even can be achieved in the first place. The question then lies of what kind of negative clearance is utilized using such a process? This is important as this negative clearance is what actually will allow some groove etching to take place, and is likely sub .003" as it would take a LOT of pressing force to etch these parts as the clearance lessens. Too much pressing force, especially without a pressing tool, the inner crank threads could even be at stake. One must also consider that there will likely be some deviation to the timing relationship as the hub is pressed into position due to the non-straight cut splines, and also consider that the groove may not leave a perfect line for future servicing if needed. Honestly I'd suspect straight cut splines would've been just as effective, hold better position for timing relationships during install, provide a more usable path trace for future servicing, and allow just as much groove etching to attempt to hold the components as one.
Ultimately things like this take many samples, many variables, and much time to see how they are going to pan out. A single vendor using the splined solution successfully for 8+ months could be just as good as another vendor using the OEM setup successfully for 8+ months; or in other words be worth no more than the paper the idea is printed on. As always items like this are best tossed out to a group of guys who truly are pushing the envelope, immediately, and all of the time. Give this group of guys a year+ with it, and if they all have positive feedback along with extreme performance results to back it then that would be some compelling evidence. Until then if you want something that is truly a positive lock and a no-nonsense anti-slip sort of product; the Maximum PSI is going to be the way to go. Sometimes you get what you pay for (whether time or money or both) out there, other times you are simply beta testing.