Well, i am not a powerful rider, and honestly i cant feel any diference with my previous r7000 crankset. However let's do some solid mechanic with rough numbers.rhs2z wrote: ↑Mon Jun 05, 2023 12:32 amEarlier in this thread, someone reported testing that the Ti axle was significantly less stiff. Can you comment on how this crank feels? What were you using before?
Edit: IIRC, DA 9100 is 490g sans rings. So 100g lighter than the standard 24mm spindle option, but at what compromise with flexiness?
Let's focus on the axle, given that tests made on aluminum axle has been satisfactory we can think that crank arms itself are stiff enough.
on its middle secction elilee axle has an outer diameter of about 22mm. The inner diameter is constant of about 15mm. shear modulus of metals is quite constant, independently of specific chemical composition of the alloy so i will assume a generic shear modulus for titanium of about 45 Gpa.
Shimano r7000 features a constant OD of 24mm and the inner diameter is about 20mm. Steel features about 79Gpa.
Applying the formula of torsional stiffness of a hollow tube for both axles, we can conclude that shimano axle is about 25% stiffer.
Note, however that if elilee would have decided to keep outer diameter constant, and increase de inner diameter in the middle section to 17.8mm, to keep the axle of about the same wiehgt, they would have achieved an axle 20% stiffer than shimano's, and amost 50% sitffer than it's current axle.
i can't tell if this will effectively affect your ride quality or not. i wonder why they decided to machine the outside of the axle instead of the inner part. maybe they had difficulties with tooling needed to make the axle and it would have increase even further the price of the crankset.