172.5mm vs 175mm

[MAVERICK 13]

If I'm used to using 172.5mm cranks, will changing to 175mm make a big difference?

 

I'm roughly 177cm tall

[Zac.A]

If I'm used to using 172.5mm cranks, will changing to 175mm make a big difference?

 

I'm roughly 177cm tall

 

Not sure about the difference, but im 173cm tall and using 170mm cranks...

Why you thinking of changing?

[MAVERICK 13]

I bought a new 172.5mm crank online and it ended up being a 175mm

[rattlesnake]

If I'm used to using 172.5mm cranks, will changing to 175mm make a big difference?

 

I'm roughly 177cm tall

 

 

Yes it most definitely will.

I dont think that you are tall enough for a 175mm crank.

 

If your crank arm is too long you will lose pedal stroke efficiency as the circle that you are having to make is bigger, too big for your height / leg length. This will cause your knees to have to lift higher than what is optimal at the top of the pedal stroke.

 

I know this because I have been through this lengthy process of building up a bike for my wife, with the Specialised Bike Fit technician and getting our tandem optimally sized.

[TuinSlang]

Should not make a huge difference, just remember to adjust your saddle height accordingly.

 

In other words you will need to lower your saddle by 2.5mm

Edited December 19, 2011 by FeltCrazy

[andydude]

I'm 187cm and have always used a 175mm. The size of your legs also makes a difference. I have more skinny legs, but a guy with bigger and stronger legs with my same length could be more happy with a 177.5 or more.

[101SCC]

Yes it most definitely will.

I dont think that you are tall enough for a 175mm crank.

 

If your crank arm is too long you will lose pedal stroke efficiency as the circle that you are having to make is bigger, too big for your height / leg length. This will cause your knees to have to lift higher than what is optimal at the top of the pedal stroke.

 

I know this because I have been through this lengthy process of building up a bike for my wife, with the Specialised Bike Fit technician and getting our tandem optimally sized.

 

Correct, except that Height is one consideration.

If he is 1,77m but massively powerful, he will have sufficient leverage.

If you prefer high cadence cycling / quick bursts of acceleration (Lance) 172.5mm will give you more of what you are looking for. However, a longer crank (with power) can do wonders on a false flat in a 53/13 (Mr Ullrich!)

 

They don't make 180mm cranks for nothing!

[NotSoBigBen]

I have posted this before but here goes again

 

Apparently crank length is of much less consequence than we have been led to believe

 

Myth and Science in Cycling: crank length and Pedaling Technique

 

http://www.plan2peak.com/files/32_article_JMartinCrankLengthPedalingTechnique.pdf

[TheV]

I have posted this before but here goes again

 

Apparently crank length is of much less consequence than we have been led to believe

 

Myth and Science in Cycling: crank length and Pedaling Technique

 

http://www.plan2peak.com/files/32_article_JMartinCrankLengthPedalingTechnique.pdf

 

Well - thank you for taking the time to re-post. Your dedication and time spent on thehub is really appreciated.

 

Thank you for helping us learn more about cycling.

[Christie]

Agree with Ben, crank length does not make a big difference, but you need to set up the saddle height correctly - longer crank = slightly lower. Your body is clever enough to adapt .

[Eldron]

The 175mm crank is only 1.4% longer than the 172.5mm - you will not even notice. In a perfect world you'd spend some cash on a bike set up and they'd probably recommend the 172.5mm crank depending on your thigh length but over here in the real world you smack the longer crank on and forego the 0.0000000000000000000152% power improvement from the correct length crank...

 

Lowering your saddle 2.5mm is the right thing to do.

[Jaco-fiets]

Changing to 175mm cranks def improved my climbing!

[milky4130]

I bought a new 172.5mm crank online and it ended up being a 175mm

Just for interest sake what crank did you get as I can never find 175mm? Thanks.

[MAVERICK 13]

Just for interest sake what crank did you get as I can never find 175mm? Thanks.

 

Dura Ace

[Bat-ass]

You wont notice it... i didnt, i'm 176cm tall and ride 175 cranks. They came on a new road bike and i only realized a couple of weeks after i got the bike. Almost all mtb's come std 175mm cranks.

[splat]

Here goes nothing: I have Dura Ace 7900 cranks with 175mm arms that I have been trying to swap for 172.5mm for ages...

 

(Edit 1: Currently in St Francis)

 

(Edit 2: Would like to keep it Dura Ace)

Edited December 20, 2011 by splat