160 Crank?

Discuss light weight issues concerning road bikes & parts.
wiRIDEfast
Posts: 43
Joined: Fri Oct 19, 2012 4:29 pm

by wiRIDEfast

Previously my wife had a road bike that was just thrown together. She is a good athlete that likes to train and got pretty into it so I decided to re-build the bike into something that was better and more tailored to fitting her. When trying to figure out a crank for her I looked at some of the calculators and found that based on her inseam they recommend 160mm cranks.

I looked around for quite a while for 160mm cranks and found that most cranks ultegra equivalent level and above are not made in 160mm length. Should I just throw her on a 165 and for it to work for her? The only crank I found was a rotor TT crank for $590 which is not really an option.

Any suggestions? Much appreciated!

Brandonnie
Posts: 105
Joined: Sat May 12, 2012 5:48 am

by Brandonnie

Screw the calculator. Just get the 165.

Valbrona
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Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

Think 'Stronglight' or 'TA' or both.

wiRIDEfast
Posts: 43
Joined: Fri Oct 19, 2012 4:29 pm

by wiRIDEfast

according to the stronglight website only their lower end products come in 160mm size. I'll check into the TA specialites models. If not looks like I'll just look for a 165mm and have a few more options.

thisisatest
Shop Owner
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Location: NoVA/DC

by thisisatest

How tall is she? what crank length calculator was this? does it take into account foot size, flexibility, range of motion, core strength, intent, etc?
For the most part, people can ride a wide range of crank lengths with practically no power penalty. There are some more recent studies that have shown secondary benefits for erring slightly smaller, mostly aerodynamic (you can get lower bc your knees aren't going into your gut so far).
In the end, it's not a big deal.

wiRIDEfast
Posts: 43
Joined: Fri Oct 19, 2012 4:29 pm

by wiRIDEfast

Shes 5',0" She has decent flexibility, but great core strength. My original plan was to go with a 165 but then when checking into it today the nettally site, machine head calculator and other things I read were putting her at 158-160. I never really got too into looking at optimal crank size before, I am only a little taller yet have been able to ride 165, 167.5, and 170 cranks once I tinker with the rest of the fit.
I would not typically care so much but she has shown interest in racing this coming summer. She is an exceptional endurance athlete so I wanted to give her the best possible set up without putting several grand into it in case she eventually loses interest. If I go with a 165 I can get something good enough right from the start if she ends up wanting to continue as opposed to going smaller and then making another upgrade or altering the fit by having to go to a 165.

Brandonnie
Posts: 105
Joined: Sat May 12, 2012 5:48 am

by Brandonnie

Is she riding a compact geometry frame?

113245
Posts: 125
Joined: Tue Dec 11, 2012 9:47 am

by 113245

Why does it matter if she's riding a compact frame? It seems to me that crank length would have nothing to do with that unless saddle height is greatly affected, which it's not. Not trying to be cheeky just wondering...

Brandonnie
Posts: 105
Joined: Sat May 12, 2012 5:48 am

by Brandonnie

Cuz if it was she could just lower the seat and use longer crankarms like the much more common 170.

113245
Posts: 125
Joined: Tue Dec 11, 2012 9:47 am

by 113245

Brandonnie wrote:Cuz if it was she could just lower the seat and use longer crankarms like the much more common 170.

Yeah, no... that's not how crank lengths work.

OP: It's hard to assign crank length just based on inseam -- a 165 will probably not be that much different than a 160. If you really wanted to do a 160 you could take a longer one (180 perhaps) and have it cut&thread tapped to a 160.

Ypsylon
Posts: 1403
Joined: Wed May 24, 2006 6:25 pm

by Ypsylon

I believe Bandonnie is saying that if your seatpost is allready all the way down and you can't get your saddle any lower and it's still too high your could solve that with shorter cranks, which I suppose is true.

Of course, if your seat is too high the logical thing is to lower your seat and not raise the pedal. You raise your pedal, when your pedal is too low. :wink:

Telling which one it is can be tricky, but, as it has been stated, crank length is nothing to be overly concerned about and it's usually the seat.
"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.


wiRIDEfast
Posts: 43
Joined: Fri Oct 19, 2012 4:29 pm

by wiRIDEfast

Thanks for the links Louis and all the help everyone else. I had forgotten all about lightning and had no idea Sugino had expanded the products they offered. I thought they were still vintage and single speed, fixed, track based. You learn something every day I guess.

I think I'm going to order a 160 crank from either lightning or sugino and then have her decide which she feels more comfortable with. I appreciate all the help

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maddog 2
Posts: 348
Joined: Wed Feb 25, 2009 7:58 pm
Location: Lancaster, UK

by maddog 2

Mrs Maddog runs a TA Carmina in 160, set up as a compact (you can fit different spiders).

Crank length should be based on leg length, in particular femur length. Many women run longer-than-ideal cranks, just because that's what came with the bike and the main manufacturers don't tend to go any shorter than 170mm.

wiRIDEfast
Posts: 43
Joined: Fri Oct 19, 2012 4:29 pm

by wiRIDEfast

femur length is one of the reasons I wanted to check out a 160. The little leg length she has comes from the tibia or below the knee.

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