Advice: crank arms less than 165mm

[WETH]

My wife who is 5'3" with a PBH of 74 develops knee pain during rides longer than 10 miles. As she has been easing into cycling over the last year, she rides exclusively in her small chainring (24) on her Sugino XD2 triple 46-36-24 with 165mm crankarms. The pain is in front in her kneecaps. I am going to be raising her seat slightly and pushing her saddle slightly back to see if that helps. I am also considering shorter crank arms given her relatively short legs compared to torso.
Does anyone have experiences with shorter crank arms, especially folks in my wife's height range? Also thoughts on good crank sets with shorter crank arms? I was thinking of trying 155mm crank arms if adjusting seat height didn't alleviate the issue. Can I put non-Sugino crank arms on a Xd2?
Thanks for any insights,
Erl

[Shoji Takahashi]

daVinci Designs has a nice looking crank with 110/74 spider available (i.e., you can transfer your XD2 chainrings to it). IIRC, it's made by White Industries, and some on this list ride it. (Maybe they can chime in?)

It has crank arms from 150mm to 200mm (~$220-- but I'm not sure if I'm reading their site correctly).

http://www.davincitandems.com/comp.html

[Bill Lindsay]

Alex's Cycle in Japan has a lot of <165mm choices.  

http://www.alexscycle.com/cranks/road-1-2-3-4-5-6/

I hope your wife can ride pain-free without you having to spring for a crankset.  I believe that 165 should be able to work.  5'3" is not that short.  

[Jason Cloutier]

Contact Mark Stonich, Bikesmith Design and Fabrication in Minneapolis, MN. at http://www.bikesmithdesign.com.  He modifies cranks to 85mm to 160mm lengths.  His main clients are recumbent riders, but these cranks will also work for upright bicycles.

Here's an information page about short cranks.  http://bikesmithdesign.com/Short_Cranks/crank-questions.html

I'm sure that with Mark's experience he can recommend something suitable for your wife.

Jason Cloutier
Pawtucket, RI

On Tuesday, July 1, 2014 2:47:43 PM UTC-4, WETH wrote:

[Garth]

I'm 6'3" and ride Sugino XD 152's :)  Yes, they make them in 152 ! 

http://www.ebikestop.com/sugino_xd600_78_speed_152mm_243650t_74110mm_crankset_bottom_bracket_not_included-CR1035.php?cat=1042

Sugino also makes the Mighty Mignon, but it's a 110 double , in 140, 145,150 and 155mm . Alex Cycle sells just the arms for about $132 + 20something shipping.

There are also short 110 doubles by Sinz and Origin8 .  I know of no triples shorter than 150, however these guys offer Andel triple black cranks in 110/74. They are the same ones that come with a Surly LHT, only black. He cuts them down as you wish ! 


http://www.bikesmithdesign.com/Short_Cranks/
http://www.bikesmithdesign.com/Short_Cranks/andel.html

On Tuesday, July 1, 2014 2:47:43 PM UTC-4, WETH wrote:

[Eric Platt]

Will second that choice.  Mark is a good guy.  Bias alert - I know Mark and consider him a friend. 

Eric Platt

St. Paul, MN

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[Stan Wasser]

This advice comes from years and years of troubleshooting bicycles, cars, motorcycles etc.  Go with the easiest, cheapest fix first.  Pain in the front of the kneecap is often associated with tight hamstrings.  There are simple, effective stretches for the hamstrings, and they’re a lot cheaper than a new crank set.

 

Stan

[Liesl]

I'm 5'2, 55 years old, have a PBH of 75, am not an athlete, don't have great knees, and use a 165 crank.  The thing that struck me the most is that your wife is riding exclusively on her smallest (24) chainring.  I'm wondering if this might be contributing to the knee pain she feels after 10 miles.  People out here on this list are more knowledgable about these things,  but I'd explore that issue and seat/bar position more before investing in a custom crank as 165 is plenty short.

hope she figures it out!  liesl

[dougP]

My wife is 5'-2" and rides 165 mm cranks.  You don't mention terrain but I'm guessing not too hilly if only going 10 miles?  So how is she able to do this on the 24?  She must be spinning madly.  I'd take a look at how she fits on the bike.  I'm not a big fan of "fit kits" but maybe something basic you can do at home.  The classic "knee over the pedal spindle" with the pedals horizontal and seat height so she gets around 15 degree bend of the knee at the bottom of the stroke may be a place to start.  Some basic stretches could also be helpful. 

dougP

On Tuesday, July 1, 2014 11:47:43 AM UTC-7, WETH wrote:

[Joe Bernard]

I agree with everyone about fit. A standard rule of thumb I read many years ago is "front of the knee pain, too low; behind the knee, too high". I suspect she's bending her knees too much when she pedals.

JB

[WETH]

Thanks everyone for the quick and thoughtful responses. I will definitely be adjusting height of saddle and sliding it back a bit as a first course of action. If that doesn't help, I wanted a plan B which might be the shorter cranks. Stretching more is also good advice that I will pass along. I also will try to get her to experiment with riding a bit more in the middle 36 chainring. She handle the pain well on our 5 day GAP ride of 30 mile days, but I hope I can find a way to eliminate much of her pain. She really enjoys riding. From experience, I know that minor adjustments can bring great comfort or discomfort, so I will start there. It is a challenge to troubleshoot someone else's discomfort.
Thanks again,
Erl

[Steven Frederick]

Maybe just raise the seat and see if that helps rather than moving it back as well.  It will move back a little by moving up anyway, and I've learned the hard way to change just one thing at a time when trying to address this sort of trouble.  I think that crankarm length should be okay--try it with the higher seat before replacing...

My $.02, Steve