A.Z.KOETSIER
Active Member
This has been debated many times with various outcomes with pros and cons for both lengths.
Well I would like to know your own hands on (feet on) experiences with this matter and then maybe some extra info, here are mine
I have rode cranks from 165mm all the way to custom 1.25kg 200mm monster cranks.
INDOOR
On rollers I managed to get my highest speed with 172.5mm (didn't have shorter cranks at the time) reaching 103km/h. on the same day I only managed 92km/h on 200mm cranks. The limiting factor for both runs was the maximum cadence I could reach. Maybe If i had a big enough gear I would of been able to reach higher speeds on the 200mm as I would of had the leverage to turn it? (see gain ratio http://www.sheldonbrown.com/gain.html )
POLKA DOT
Climbing was my biggest surprise, and also the reason I initially got 200mm cranks using the inseam X 0.216 formula.
I didn't just beat my PR's I absolutely destroyed them. I could stay in a bigger gear for longer. In fact I hardly ever used my small ring.
Is this why Marco Pantani used 180mm cranks when climbing? (The 3 fastest times up Alpe d'Heuz ever) The last person to win the Tour and Giro in the same year.
1. 1995: 36:40 Marco Pantani 22.58 km/h
2. 1997: 36:53 Marco Pantani 22.45 km/h
3. 1994: 37:15 Marco Pantani 22.23 km/h
4. 2004: 37:36 Lance Armstrong 22.02 km/h
CRITERIUMS
In criteriums I hit the 200s so many times that I just stopped pedalling in most bends this made me loose ground and staying at high speed is everything in crits. When i switched back to 172.5mm my cadence did increase and I had to stand on some small inclines to keep the gear turning where previously I could remain seated. never the less I achieved my best results on smaller cranks and possibly also my fastest sprints.
TT
The Race of Truth would seem to be the best place to see which crank to decide on. but this wasn't the case i rode 165 - 200mm with little difference in performance. my main reason for trying out 165s is due to being able to raise my seat an extra 27.5mm and having my knee come up a massive 55mm less, allowing me to get lower on the TT bars, breath better with better aero . a win win win.
I found the 165s really comfortable to ride the diametre path of my foot was so small it felt like I was climbing up a little staircase. But turning a big gear was harder and to make up I had to increase my rpm. And any sort of incline meant the end of days. Since there was no real benefit in my speed with 165 even with all its aero advantages, I returned to bigger cranks to help on undulating terrain.
one thing thats also interesting to note is that my rpm might have dropped a lot on bigger cranks but because i was pedalling in much bigger circles my foot speed didn't really change, and foot speed X foot force = Power .....right?
SUMMARY (for me)
165mm might have been to small for climbs, 200mm might have been to big for crits and high speed sprints,
so maybe i'll look into getting a 180-190mm, which just happens to be the cranks Pantani used to become the greatest climber who ever lived and Indurain used to dominate the sport.
Ride the biggest crank you can spin....?
Well I would like to know your own hands on (feet on) experiences with this matter and then maybe some extra info, here are mine
I have rode cranks from 165mm all the way to custom 1.25kg 200mm monster cranks.
INDOOR
On rollers I managed to get my highest speed with 172.5mm (didn't have shorter cranks at the time) reaching 103km/h. on the same day I only managed 92km/h on 200mm cranks. The limiting factor for both runs was the maximum cadence I could reach. Maybe If i had a big enough gear I would of been able to reach higher speeds on the 200mm as I would of had the leverage to turn it? (see gain ratio http://www.sheldonbrown.com/gain.html )
POLKA DOT
Climbing was my biggest surprise, and also the reason I initially got 200mm cranks using the inseam X 0.216 formula.
I didn't just beat my PR's I absolutely destroyed them. I could stay in a bigger gear for longer. In fact I hardly ever used my small ring.
Is this why Marco Pantani used 180mm cranks when climbing? (The 3 fastest times up Alpe d'Heuz ever) The last person to win the Tour and Giro in the same year.
1. 1995: 36:40 Marco Pantani 22.58 km/h
2. 1997: 36:53 Marco Pantani 22.45 km/h
3. 1994: 37:15 Marco Pantani 22.23 km/h
4. 2004: 37:36 Lance Armstrong 22.02 km/h
CRITERIUMS
In criteriums I hit the 200s so many times that I just stopped pedalling in most bends this made me loose ground and staying at high speed is everything in crits. When i switched back to 172.5mm my cadence did increase and I had to stand on some small inclines to keep the gear turning where previously I could remain seated. never the less I achieved my best results on smaller cranks and possibly also my fastest sprints.
TT
The Race of Truth would seem to be the best place to see which crank to decide on. but this wasn't the case i rode 165 - 200mm with little difference in performance. my main reason for trying out 165s is due to being able to raise my seat an extra 27.5mm and having my knee come up a massive 55mm less, allowing me to get lower on the TT bars, breath better with better aero . a win win win.
I found the 165s really comfortable to ride the diametre path of my foot was so small it felt like I was climbing up a little staircase. But turning a big gear was harder and to make up I had to increase my rpm. And any sort of incline meant the end of days. Since there was no real benefit in my speed with 165 even with all its aero advantages, I returned to bigger cranks to help on undulating terrain.
one thing thats also interesting to note is that my rpm might have dropped a lot on bigger cranks but because i was pedalling in much bigger circles my foot speed didn't really change, and foot speed X foot force = Power .....right?
SUMMARY (for me)
165mm might have been to small for climbs, 200mm might have been to big for crits and high speed sprints,
so maybe i'll look into getting a 180-190mm, which just happens to be the cranks Pantani used to become the greatest climber who ever lived and Indurain used to dominate the sport.
Ride the biggest crank you can spin....?