I’ve just purchased a s/h Ti frame for my training/hack bike.
The Chris King headset, SRAM Red chainset and SRAM Red bottom bracket were all an extra bonus.
But I’ve just realized that the cranks are 175. I’ve always run 170s.
What will I experience when I try it Saturday? I’ve never delved into this as I’ve never needed to.

You WILL die.

Saddle 5mm higher, err hang on …5mm lower. And platform SPDs. Oh God, it’s a minefield!

I thought so, just looking at the 175mm sticker made me pass out.

More leverage! Think of it as leg extensions!!

So better top end, less exceleration.

Otherway round.

I tried putting 180’s (replacing 175’s) on my cross bike for a bit of extra leverage but as you have to put the saddle down to keep the same amount of leg extension it of course raised the upstroke by 10mm. Didn’t feel right at all. Got rid.

Dropper post limited to 5mm up or 5mm down?

You actuate it remotely with a thumblever, once every half rev’ of the cranks.

You’d need 1 remote in the drops and 1 on the hoods though …that’s the only issue I can see with this solution.

Plus point is that you get slightly more leverage which makes it “seem” like it’s easier to pedal.

Negative points are that your cadence will drop slightly, your feet are moving further per revolution by approximately 10% yet you’ve only gained roughly 3% extra leverage on the cranks, they’re less kind on the knees and they weigh about all of 5 grammes more! 😉

If you’ve got long legs, you need long cranks for obvious reasons, cos otherwise it’s like riding a kiddies tricycle with your feet barely vibrating up and down. But longer is not always better… Give them a try, see if they suit, but be prepared to want to swap them back. You might not notice any difference, it might be night and day, who knows til you try. And a lot of it is personal preference after all, Bradley Wiggins for instance uses 177.5mm arms on his bikes which is long by anyone’s standards for a road bike…