Bike fit / correct riding position

anyway crank length .. I found that 170mm was more comfortable (even with higher saddle to bar drop) and faster than 172.5mm for me, why is that? I am 170cm with 81cm in seam.

Femur length?

ah yes, makes sense, I should try 165mm buyaboat.jpg

I got mine done by Matt at the specialized concept store in Covent garden, highly recommended

How did you test this? With a Wattbike or something?

Yes, crank length don't make that much of a difference unless you're shorter than the average where it's become fairly notiable.

Plus I'm impressed you can tell a 2.5mm difference.

Euph?

powermeter is on 170mm, non PM are 172.5 all I do is change post height; strava said 170 was faster plus it felt more comfortable i.e. less fatigue after long ride. Can digg watts if I can be bothered ..

Erm, changing post height is not the same as changing crank length as far as I know, they are two different measures in regards of your position and body angles on the bike. I can be wrong of course, I'm still a newbie about these things.

changing post height is not the same as changing crank length as far as I know

And no-one suggested it was: if you change the length of your crank, you will need to adjust the height of your seatpost.

strava said...

#badscience

Better than no science though I guess.

I was referring to amey posts, he is simulating crank length changes moving the post, but I might have misunderstood

Or maybe it's because of you were unfit when you rode the 172.5?

2 days apart

Or because it was too darn cold in winter.

You can't possibly test whether a 2.5mm difference in crank length is faster, at least not on a road bike. Possible an argument on a TT bike, but then I reckon you'd need at least a 10mm change to see anything.

2 days apart.

You weren't in form 2 days ago.

Also strava is not a metric

A static bike, measured power at heartrate... uploaded to Strava?

lolz

You weren't in form 2 days ago.

LOLZ

Isn't 170cm shorter than average (I'm not certain I'm still in imperial for height)?

I can tell the difference between 2.5mm when one was too big and the other just right :)

(Frankly 5mm was really obvious when both within size, so I wouldn't be that surprised if some could tell the diff)...

plus it felt more comfortable

Ignoring whether strava makes a difference, if it felt better that's probably a pretty good indicator!

Isn't 170cm shorter than average (I'm not certain I'm still in imperial for height)?

54cm road bicycle usually have them although mine have 172.5mm length which mean according to amey's calculation, that'll be why I did well on my Richmond Park lap today.

it's amazing how 2.5mm make such a difference.

#172dot5mm4lyfe

170cm is 5'5"/5'6"

I spent some time today with Nichola (Velophysio) and found it one of the most interesting and useful hours I have spent with anyone talking about me on my bike. Would utterly recommend.