not really though. Human body has many joints
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It does though, if you shorten your cranks, the force you have to apply goes up.
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see above re hip angle.
Iām looking at crank length as one variable in a system.
If youāre isolating it, weāre talking about two different things.
You can run whatever crank length your physiology prefers, but if you shorten your cranks and donāt change your gearing your lowest gear is going to feel higher.
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yes, that is true.
it is entailed in the thing Iām thinking about.
gf bike has an xtr 180mm triple bolted to a 15" frame
she hasnāt complained
she also doesnāt know that cranks come in sizes
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I think the idea to have your feet moving at same linear speed with the same force, so itās just proportionate ā x% increase in crank length would go with x% increase in chainteeth. Since 175/5=35, the ā1 tooth per 5mmā rule of thumb would be a perfect match only when you have 35 teeth.
I think short cranks are popular in triathlon, while longer cranks have been more popular for time trial. I think that has to do with muscle groups, tri position emphasizes the quads more, the idea is that wearing out the glutes and hamstrings on the biking leg would just hurt you when it comes to the run. For time trial the idea is more that you use all your muscle groups and they should be all worn out at the end. Longer cranks def do engage the glutes more and I find that can help with posture
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ahh right tri not tt.
Iām thinking about this in part because iāve gotten myself into a very long / low position on my road bikes, and Iām wondering if iām missing muscle recruitment. Iām pretty folded when one foot is at the top of a pedal stroke
guise this is already a very well established ācrank theory about cranksā
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I knew I was keeping this slide rule around for something
It was the simplicity of the suggested chainring size change in the Bikeradar article that got me thinking.
Like ok 150mm cranks would put me much higher with way more open hips. Maybe a nice change? Possibly not.
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The trend towards shorter cranks is 100% tethered to the hip angle at top of the stroke. Thatās it. Hip impingement is the biggest obstacle for many riders (particularly time trialists/triathletes) riding a more aerodynamic position. Iāve watched the reduction of crank length help with this over and over firsthand.
This translates over to drop bar bikes to a certain extent as well and I would make the broad generalization that MOST riders are on cranks that are longer than they need because of some nonsense about āleverageā.
Thatāsreally it.
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This is Lennard Zinnās point, iirc. Longer individual linkages in the postural chain something something. And will wonders never cease, he sells speciality products to address just the problem he identified!
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I love this response because it just kindof ignores that there are lots of other levers in the system.
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yeah, Zinn kind of ignores that humans have lower backs and torsos.
I should try shorter cranks to see if it helps with a pelvic angle thing Iāve been trying to sort out.
I tried 200mm cranks for a while and the increased leverage was really nice and noticeable grinding up hills, but everything else about them was kind of a PITA. Iām back on 175mm after years of 180mm. 
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You guys see this?
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The formulas on that page say I should be riding 187.5mm cranks so I suspect the philosophy doesnāt apply as well to those of us in the tails of the curve.
I think the only way to find out is to try it - just get some cheapo Redline/Sinz/Origin8 BMX 110 BCD cranks and see if things feel better.
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Yeah AppleMan is sort of opposite-Zinn where heās focused on shorter cranks and handwaves the underpinnings once things get long.
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In my experience this is about 80% of bicycle tech lore.
Old geezers complaining because their Garmin canāt receive 2.4ghz signals when the LOS to the sending unit is blocked by carbon fiber because somehow mounting your head unit anywhere but immediately in front of your stem isnāt aero enough. Then they send a photo of their bike and itās got 6" of spacers and a +17 stem. Iām glad you can still ride a bike but I donāt think the position of the Garmin is your primary aero problem.
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