i am new to the WW world and am hoping you all, since you were already on the topic, could answer a crankset question for a 2016 Cannondale SuperSix Evo Hi-Mod. i just picked one up on close-out and am planning to strip it of its ultregra bits and replace it with SRAM Red 22 mechanical. i had originally planned to keep the 8-arm Cannondale Hollowgram Si crank, but am now considering switching it over to a SRAM Red BB30 crank... do you all have any experience running a SRAM Red BB30 crank on the new SS Evo HM? i am curious about: 1.) installation, 2.) shifting comparisons between the Hollowgram and the SRAM Red and 3.) weight comparison.
Saw your other post about considering a Wheels Mfg BB. I did that too. I replaced the stock BB on my 2016 HM (running eTap) with the Wheels Mfg PF30
(I have the ceramic bearing option). It fits great and works with both the stock Si crankset on the Ultegra model and the Red BB30 crank which I have since installed. Wheel Mfg PF30 thread together was 104 grams.
RE: Si to RED BB30 installation:
It's pretty straight forward although you will need a cannondale tool to remove the Si crank arms (cannondale tool KT013). You may also want cannondale tool KT011 to knock out the old BB with the plastic cups, but you could also do it without. Once you've got your Si crank off, the SRAM BB30 installation was smooth. FWIW, I used the stock cannondale dust caps on my Wheels Mfg BB. the crank installation went pretty smoothly. I did not use the little grey plastic collar, just the spacer shims and a wave washer.
I'm using the SRAM RED BB30 crank with eTap, not the Red Mechanical you're considering, but FWIW, the shifting is better with the SRAM RED BB30 cranks.
As for the cranks, IIRC the stock Si crank (arms, spiderring, spindle) was around 630 grams with the Si spiderring. I replaced mine with an SiSL2 spider ring and it was still 579 grams. When I went to a SRAM RED BB30 crank, that was only 515 grams with the 50/34 stock rings.