crank length & saddle height with age
#26
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Now I need something to go with my coffee. I think the muffins my wife bought are a little stale. Thanks for the chit chat!

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Understood, but my knee will also be in greater flexion at the top of the pedal rotation. There is probably a happy middle somewhere.
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No, however... If I'm going from a common 170mm crank length to 175, leaving the distance from the saddle to the pedal the same means that my foot will be 1cm higher at the top of the pedal circle. I will probably compromise a bit to start, raising my saddle a tad, then listening to see if my knees tell me I've got it wrong.
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No, however... If I'm going from a common 170mm crank length to 175, leaving the distance from the saddle to the pedal the same means that my foot will be 1cm higher at the top of the pedal circle. I will probably compromise a bit to start, raising my saddle a tad, then listening to see if my knees tell me I've got it wrong.
I do move around on the saddle when riding which changes the relative position a bit, I'm sure. Like when on a flat section, I will slide back and try to get aero (which isn't very aero). Or I move around when climbing.
Good luck with the knee issue! I've been very fortunate with my knees and I attribute at least part of that to spinning instead of mashing years ago.
#30
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I can't really help with that. I've relied on the saddle to pedal at the bottom and never considered where it ends up at the top. I've also never changed crank length and I'm almost 69.
I do move around on the saddle when riding which changes the relative position a bit, I'm sure. Like when on a flat section, I will slide back and try to get aero (which isn't very aero). Or I move around when climbing.
Good luck with the knee issue! I've been very fortunate with my knees and I attribute at least part of that to spinning instead of mashing years ago.
I do move around on the saddle when riding which changes the relative position a bit, I'm sure. Like when on a flat section, I will slide back and try to get aero (which isn't very aero). Or I move around when climbing.
Good luck with the knee issue! I've been very fortunate with my knees and I attribute at least part of that to spinning instead of mashing years ago.


hsea17
Last edited by hsea17; 02-27-23 at 04:24 AM.
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#31
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Another question is, which choice makes it easier to pull your foot back at bottom, and to (perhaps more affected) push your foot over the top for a little earlier start at the power stroke. I could see the longer arm and tightened knee angle affecting how the start of the downstroke works.
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I will be 77 on Juneteentth. I also have not changed anything since I began riding in my early 30's. FWIW people should be advised that you measure seat height from pedal spindle not BB.
#33
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Actually one can do it either way, but you hav to be careful to make corrections wo there isn't a 17 cm problem built in to you r new bike "fit."
#35
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Maybe I'm not clear on what we are talking about. You can set and adjust saddle height on a given bike based on measuring from any fixed point on that bike. As long as you do the numbers consistently, it will work. If the crank is changed, one needs to think about how to compensate so your leg extension remains the same.
But I don't see how it can be true that measuring from the BB axis to the saddle top is the only valid way to address saddle height.
But I don't see how it can be true that measuring from the BB axis to the saddle top is the only valid way to address saddle height.
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Maybe I'm not clear on what we are talking about. You can set and adjust saddle height on a given bike based on measuring from any fixed point on that bike. As long as you do the numbers consistently, it will work. If the crank is changed, one needs to think about how to compensate so your leg extension remains the same.
But I don't see how it can be true that measuring from the BB axis to the saddle top is the only valid way to address saddle height.
But I don't see how it can be true that measuring from the BB axis to the saddle top is the only valid way to address saddle height.
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Earlier in the thread I mentioned that I've dropped my saddle height as I aged from my 60s into my 70s. Someone responded that his height has changed but not his leg length.
Did a search. He was right. Evidently the majority of people lose height in the spine but not the legs. Now my saddles are feeling as though they're too low.
Did a search. He was right. Evidently the majority of people lose height in the spine but not the legs. Now my saddles are feeling as though they're too low.
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Earlier in the thread I mentioned that I've dropped my saddle height as I aged from my 60s into my 70s. Someone responded that his height has changed but not his leg length.
Did a search. He was right. Evidently the majority of people lose height in the spine but not the legs. Now my saddles are feeling as though they're too low.
Did a search. He was right. Evidently the majority of people lose height in the spine but not the legs. Now my saddles are feeling as though they're too low.
#40
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Well, at least I'm not the only one who shrinks.
In military service as a 20-year-old I was measured at 5'77 now plus 40 years later I'm barely 5'65.
Btw, I've clearly been measuring seat height wrong my whole life, measuring from BB to the center of the saddle
hsea17

Btw, I've clearly been measuring seat height wrong my whole life, measuring from BB to the center of the saddle

hsea17

#41
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The trend is toward shorter cranks on bikes with owners replacing 165mm with 155mm cranks. With adjustments of seat height I always take a tool and ride for at least 20 minutes before making an adjustment. I need to give my body time to warm up and my tendons and ligaments and muscles to stretch out.
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There is one caution to heed: if you do switch to shorter cranks, you will need to install lower gearing.
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Living with arthritis my knees give me all the data I need to stay on my bikes, my 165mm is not a fashion trend but a necessity.
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May not apply to anyone else as I am in my 70s but after experimenting with a couple of my bikes the results had me ask my Orthopedist. She believes that at my fit recommended saddle height (set at the bottom of the pedal stroke) the releaf I get is that at the top of the pedal stroke my leg is not as bent so my knees arenot seeing as much compression of the knee cap or the knee moving to the outside with the 7.2mm shorter crankset.
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May not apply to anyone else as I am in my 70s but after experimenting with a couple of my bikes the results had me ask my Orthopedist. She believes that at my fit recommended saddle height (set at the bottom of the pedal stroke) the releaf I get is that at the top of the pedal stroke my leg is not as bent so my knees arenot seeing as much compression of the knee cap or the knee moving to the outside with the 7.2mm shorter crankset.
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That was my thinking when I originally started the thread. While fuller range of motion would be preferable, our knees will tell us what works.
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