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Crank length poll.(15 posts)

Crank length poll.cyclinseth
Aug 8, 2002 7:49 AM
Before I drop the cash I would like to get as much info as possible. I'm 5'8", 30.5" (?) inseam and am using 170 cranks. My cadence range is between 95-110. I'm thinking of going to 172.5.
Will I notice any increase in power due to extra leverage?
Is there any reason I should try 175?
Has anybody else made this change? What were your experiences?

Poll questions:

How tall are you?

What is your inseam?

What crank lenght do you use?

Thank you in advance for your responses.


P.S. Sorry to rehash this beaten-to-death horse.
re: Crank length poll.Steve_0
Aug 8, 2002 7:52 AM
30" Inseam
Never considered changing length.
re: Crank length poll.Matno
Aug 8, 2002 9:09 AM
33" inseam
I just switched from 170 to 172.5 and hardly notice a difference. I also changed gears at the same time though, so that could certainly have more to do with it than the crank length. (I went from 42/52 & 13-26 to 39/53 & 12-27). The only reason I switched was because 172.5 was the cheapest I could find. I have noticed that my cadence is slightly down (from 90 to 85), but that could be a factor of different terrain as well, and I'm working on keeping it up above 90. I've also got 175's on my mountain bike, and don't notice much of a difference there either, although it does tend to make me a little bit "choppier" on the road. If you think about it, there's really so little difference between 170 and 175, most people probably won't notice. I think just adapting your pedaling to whatever cranks you have is most important.
re: Crank length poll.Slowclimber
Aug 8, 2002 10:36 AM
Height: 5'11.5"
Inseam: 31 - 31.5
Crank length: 172.5 but prefer 175's
Cadence: 75-85 rpm
re: Crank length poll.nazgul
Aug 8, 2002 11:30 AM
height 6'0"
inseam 34.25"
cranklenght 175mm
re: Crank length poll.Akirasho
Aug 8, 2002 11:41 AM
a MANLY 175mm... both road and offroad... though over the off season I might experiment with 180's for a TT machine.

We abide.

Remain In Light.
I'm your exact size.Quack
Aug 8, 2002 11:43 AM
5'8" 30.5" inseam. I use 172.5mm cranks on the road. I am unsure of my normal cadence but it is faster than anyone that I ever ride with. I doubt that you will notice a difference by changing.
re: Crank length poll.laffeaux
Aug 8, 2002 11:44 AM
height: 6'0"
inseam: 34.5"
cranks length: 175mm

I have used 172.5 cranks in the past, and can tell no difference.
Isn't 2.5 MM the equivilant of the thickness ........Len J
Aug 8, 2002 11:49 AM
of two credit cards.

Just ride.

Aug 8, 2002 12:57 PM

The concerns about crank length difference seems silly to me.
re: Crank length poll.xcandrew
Aug 8, 2002 1:04 PM
170 road, 175 mountain bike only because it came on the bike. I would definitely prefer 170 on the mountain bike too.

Many people won't notice the difference 2.5 mm makes. I don't know if I would, but I do notice that I hate the 175's. The little bit of extra range of motion that they require disagrees with me. This is not surprising because I am a runner too, and people comment that I have a quick short stride (= less range motion).

There was an article in Velonews a couple of years ago, maybe written by Leonard Zinn, where he did a short study with 4 or 5 riders and a large selection of crank lengths from about 150 to 200 (I'm going from memory). There was no correlation with leg length/height and crank length preference, though the riders did develop individual preferences for a certain length. People usually are not able to try such a variety of crank lengths and some of the short riders were surprised to find that they preferred longer cranks, and some tall riders were surprised to find that they preferred some really short cranks. Also interesting was that the really short cranks were not bad for power or anything like that. Basically, you can't find the optimum crank length for an individual by body measurements alone, and ideally you could try many many different lengths shorter and longer that what you are currently on to figure out what works for you. Or not change at all, since the different common lengths arguably won't affect your power or speed (though long cranks are sometimes associated with knee problems).
one data point..dotkaye
Aug 8, 2002 2:12 PM
6' 2"

used to ride 170, borrowed a bike with 172.5 and liked it better, switched to 172.5 on my bike and noticed immediate and significant increase in speed. The chainrings went from 52/38 to 53/42, so I'd really need to switch back the chainrings and ride for a while to be sure. Also the old cranks were Exage, new are Ultegra, so probably lost about 1/2lb off the bike weight as well.. No way to be sure without a power meter, really. has Sugino 175 cranks for $15, I'm thinking about buying them and trying 175mm, just for grins..
re: Crank length poll.Humma Hah
Aug 8, 2002 2:54 PM
5'11", 34" inseam

I usually run 170 mm.

I have an off-road crankset that's 160 mm to improve ground clearance and I find it works surprisingly well. I adapted easily to it.

I have a 175 mm crankset that I removed and tossed in the junkbin after the Solvang Century last spring, when I developed IT band friction syndrome in my left knee around mile 70. Transitioning from shorter cranks to the 175's produced noticably more knee bending, and felt less efficient to me.

I doubt you would notice an improvement. The extra leverage may be offset my more energy lost squishing body tissue around with the longer travel. You can get more leverage change by shifting one click on the rear der.
I would say save your moneyPODIUMBOUNDdotCA
Aug 8, 2002 3:31 PM
I would recommend saving your money unless your very serious about racing. I race on the track and know of riders who have had multiple sets of cranks to deviate from the 167.5 to other lengths and the differences they have noticed have been minimal. Differences that in a race MAY allow you to push slightly harder up a hill... blah blah blah. But the thing is you also sacrifice some of your spin as you go up to bigger cranks. So its a win lose situation.

Although if your still not convinced perhaps ask to borrow a buddies cranks for the day and take them for a spin. And maybe even set up a few makeshift tt courses and take your times on them to see if there is any difference.

To answer your question I am 5'9 1/3 have an inseam around 31" (?) and use 172.5 on the road and 167.5 on the track. Both standard sizes for the respective types of racing.

Nick Corcoran
5'10" 33 3/4 175mm's(nm)Soultrain
Aug 8, 2002 6:05 PM