# Ladies 5'3" to 5'6" - What's Your Crankarm Length?



## jckid (Dec 13, 2006)

I am 5' 4 1/2" tall, and I'm building up a hardtail mountain bike. I run 170mm crankarms on my road bike, and they work very well for me. I am definitely a spinner and not a masher. I do have knee issues, and I've heard that having your crankarms too long can aggrevate knee conditions. Therefore, I am leaning towards 170's on my mountain bike build. I just think 175's might be too long. I have found an older XTR crankset that is available in 172.5mm, so that might be a possibility as well. 

Anyway, what I would like to see is how many of you in my approximate height range are running 170's vs. 175's.


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## -kelly- (Mar 11, 2004)

I am 5'4" with a 29" inseam. On my road bike I have 165's. Definitely a spinner and not a masher. On my mtn bike, which is a ss I have 170's. On my ss I have no choice but to mash when climbing.


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## Lucky (Jan 12, 2004)

jckid said:


> I am 5' 4 1/2" tall, and I'm building up a hardtail mountain bike. I run 170mm crankarms on my road bike, and they work very well for me. I am definitely a spinner and not a masher. I do have knee issues, and I've heard that having your crankarms too long can aggrevate knee conditions. Therefore, I am leaning towards 170's on my mountain bike build. I just think 175's might be too long. I have found an older XTR crankset that is available in 172.5mm, so that might be a possibility as well.
> 
> Anyway, what I would like to see is how many of you in my approximate height range are running 170's vs. 175's.


Having crank arms too long can aggravate sensitive knees because your feet are traveling in a larger circle, whose bottom is dictated by your extended leg length (regardless of crank length, you'd adjust your seat to be in the same position relative to the bottom of the stroke.) So, a longer crank will force your knee to bend more at the top of the stroke because your foot it higher by 2X the difference in crank length. I wish I could draw a picture. Anyway, on a road bike, it is probably more critical than on an mtbike, because of the steady repetitive nature of pedaling on the road. On an mtbike (at least on technical terrain), you are up and down, standing, sitting, leaning, etc., so the movement is less repetitive. If you are going to ride smoother trails where you will be sitting and pedaling steadily a lot, treat it like a road bike.

For what it's worth, I'm a 5'5" diehard spinner and I run 170's on the road and 175's on the trail. The 172.5's might be a nice compromise for you. Or, try the 175's since there is always a market for 175mm cranks if you don't like them. On the other hand, 170mm mtb cranks are easy to find on sale cheap as last year's leftovers or NOS. (I'm not being very decisive here, am I?) Shorter might be the better way to bet to protect your knees, because there won't be anything you can't ride because your cranks are too short. You'll get just a wee bit less leverage, but not much.

Kathy :^)


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## Lucky (Jan 12, 2004)

stripes said:


> I ride 170mm on my mountain bike. I switched last year, and it made a BIG difference.
> 
> On my BMX cruiser, I have 180s, but it's primarily for sprinting anyway.


How do you like the 180's on the cruiser? Can you spin 'em ok? I'm running 175mm mtb cranks on mine and have thought about trying 180's for more leverage/quicker starts out of the gate. What's your inseam?

Kathy :^)


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## pixy (Nov 8, 2005)

hey jckid- I am 5'3" with 28" inseam. I am a masher and currently run 170 on mtb bike and road bike. I am very comfortable with it. I do have 175 on my SS but only because that was what was available when I started to cobble it together. I do feel like my knees are in my chest when I ride it, and sometimes my knees hurt a tad after major climbing races on the ss. Not sure if that is crank length or just plain abussive mashing that causes it.

I also have run the 172.5 on several older bikes over the years and was fine with that. I don't think they are that easy to find any more, but that is always a nice compromise. 

In my experience, with other female riders that like to spin, is that they prefer 170's. 

Good luck.
pixy


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## Homegirl (Jul 28, 2006)

I'm 5'5" with a 30" inseam and have 170mm. I was told by Santa Cruz that I would want 165 or 170.


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## TheotherH (Jan 21, 2004)

I'm 5" 41/2", inseam 30.5" and more of a spinner. My cranks on all three of my bikes are 175s. I don't have knee or any other issues with this length. Maybe I'll try the 170s next time I buy new cranks.


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## Trajama (4 mo ago)

jckid said:


> I am 5' 4 1/2" tall, and I'm building up a hardtail mountain bike. I run 170mm crankarms on my road bike, and they work very well for me. I am definitely a spinner and not a masher. I do have knee issues, and I've heard that having your crankarms too long can aggrevate knee conditions. Therefore, I am leaning towards 170's on my mountain bike build. I just think 175's might be too long. I have found an older XTR crankset that is available in 172.5mm, so that might be a possibility as well. Anyway, what I would like to see is how many of you in my approximate height range are running 170's vs. 175's.


 I’m 5’5” and started running 165s on all my bikes - so much more comfortable. An added benefit on the mountain bike is fewer pedal strikes - which is always a good thing.


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