Go Back  Bike Forums > Bike Forums > Fifty Plus (50+)
Reload this Page >

crank length & saddle height with age

Notices
Fifty Plus (50+) Share the victories, challenges, successes and special concerns of bicyclists 50 and older. Especially useful for those entering or reentering bicycling.

crank length & saddle height with age

Old 02-23-23, 11:14 AM
  #26  
Iride01 
I'm good to go!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 14,810

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 50 Post(s)
Tagged: 0 Thread(s)
Quoted: 6100 Post(s)
Liked 4,732 Times in 3,262 Posts
Originally Posted by big john
So when he said "keeping the saddle height the same" he meant in relation to the pedal. I guess that's why you get paid the big bucks.
That's the way I took it since that's the way saddle height was defined later in the post.

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!
Iride01 is offline  
Likes For Iride01:
Old 02-23-23, 11:42 AM
  #27  
smontanaro 
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Evanston, IL
Posts: 5,859

Bikes: many

Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 1434 Post(s)
Liked 1,362 Times in 747 Posts
Originally Posted by big john
Don't forget that longer crank arms will have the pedal further away from the saddle at the bottom. It's generally suggested to lower the saddle when installing longer cranks.
Understood, but my knee will also be in greater flexion at the top of the pedal rotation. There is probably a happy middle somewhere.
__________________
Monti Special
smontanaro is offline  
Likes For smontanaro:
Old 02-23-23, 11:46 AM
  #28  
smontanaro 
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Evanston, IL
Posts: 5,859

Bikes: many

Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 1434 Post(s)
Liked 1,362 Times in 747 Posts
Originally Posted by big john
Me too. Therefore, longer crankarm=lower saddle. Or am I losing it?
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.
__________________
Monti Special
smontanaro is offline  
Old 02-23-23, 12:09 PM
  #29  
big john
Senior Member
 
big john's Avatar
 
Join Date: Sep 2005
Location: In the foothills of Los Angeles County
Posts: 25,105
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 8189 Post(s)
Liked 8,848 Times in 4,395 Posts
Originally Posted by smontanaro
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 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.
big john is online now  
Old 02-26-23, 03:45 AM
  #30  
hsea17
Junior Member
 
Join Date: Jan 2017
Posts: 104

Bikes: Giant SCR / Felt FR5 / Trek Emonda ALR 6 / Trek Domane AL2

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Liked 17 Times in 12 Posts
Originally Posted by big john
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've just ordered crank arms on 170mm from my bicycle dealer. Going from 172.5mm and when get them dealer told me to set up the saddle with 2.5mm . I want to try due to arthritis in one knee, second knee have started show similar symptoms I was diagnosed with arthritis some 12-13 years ago but "knock on wood" as you I have been fortunate to keep going even with some slow run /jogging using Kinesio taping now on both knee. However will be interesting to see if shorter cranks will make any difference when cycling.
hsea17

Last edited by hsea17; 02-27-23 at 04:24 AM.
hsea17 is offline  
Likes For hsea17:
Old 03-25-23, 09:38 AM
  #31  
Road Fan
Senior Member
 
Road Fan's Avatar
 
Join Date: Apr 2005
Location: Ann Arbor, MI
Posts: 16,853

Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8

Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1851 Post(s)
Liked 654 Times in 498 Posts
Originally Posted by smontanaro
Understood, but my knee will also be in greater flexion at the top of the pedal rotation. There is probably a happy middle somewhere.
Skip, it looks like you face a trade off between "tighter" knee closure angle due to higher TDC foot position with the longer crank arm, and more rocking of your hips on the seat as your leg stretches down an extra few mm to reach the pedal and finish a good power stroke. I doubt there's a generic solution to that dilemma. In my self-fitting I strive for ust enough pedal extenstion that I'm not driving my foot into the pedal at BDC. Usually this results in low hip rocking with 172.5s or 170s. I find 170s a little more comfortable overall.

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.
Road Fan is offline  
Old 03-26-23, 08:10 AM
  #32  
bruce19
Senior Member
 
bruce19's Avatar
 
Join Date: Jul 2006
Location: Lebanon (Liberty Hill), CT
Posts: 8,456

Bikes: CAAD 12, MASI Gran Criterium S, Colnago World Cup CX & Guru steel

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 1722 Post(s)
Liked 1,272 Times in 734 Posts
Originally Posted by Carbonfiberboy
I'm 77. Haven't changed anything in 25 years. I don't have any musculoskeletal problems.
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.
bruce19 is offline  
Old 03-28-23, 09:54 PM
  #33  
Road Fan
Senior Member
 
Road Fan's Avatar
 
Join Date: Apr 2005
Location: Ann Arbor, MI
Posts: 16,853

Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8

Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1851 Post(s)
Liked 654 Times in 498 Posts
Originally Posted by bruce19
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.
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."
Road Fan is offline  
Old 03-29-23, 04:05 AM
  #34  
bruce19
Senior Member
 
bruce19's Avatar
 
Join Date: Jul 2006
Location: Lebanon (Liberty Hill), CT
Posts: 8,456

Bikes: CAAD 12, MASI Gran Criterium S, Colnago World Cup CX & Guru steel

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 1722 Post(s)
Liked 1,272 Times in 734 Posts
Originally Posted by Road Fan
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."
Only if crank arm length remains the same.
bruce19 is offline  
Old 03-29-23, 08:50 AM
  #35  
Road Fan
Senior Member
 
Road Fan's Avatar
 
Join Date: Apr 2005
Location: Ann Arbor, MI
Posts: 16,853

Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8

Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1851 Post(s)
Liked 654 Times in 498 Posts
Originally Posted by bruce19
Only if crank arm length remains the same.
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.
Road Fan is offline  
Old 03-29-23, 08:58 AM
  #36  
bruce19
Senior Member
 
bruce19's Avatar
 
Join Date: Jul 2006
Location: Lebanon (Liberty Hill), CT
Posts: 8,456

Bikes: CAAD 12, MASI Gran Criterium S, Colnago World Cup CX & Guru steel

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 1722 Post(s)
Liked 1,272 Times in 734 Posts
Originally Posted by Road Fan
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.
Maybe I'm the one who was unclear. I'm saying that if you measure saddle height from BB axis to saddle top your fit will change if you change crank arm length. FWIW that's what bike fitters have told me as well.
bruce19 is offline  
Old 03-29-23, 09:11 AM
  #37  
Road Fan
Senior Member
 
Road Fan's Avatar
 
Join Date: Apr 2005
Location: Ann Arbor, MI
Posts: 16,853

Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8

Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1851 Post(s)
Liked 654 Times in 498 Posts
Originally Posted by bruce19
Maybe I'm the one who was unclear. I'm saying that if you measure saddle height from BB axis to saddle top your fit will change if you change crank arm length. FWIW that's what bike fitters have told me as well.
That is certainly true. I've changed from 170 to 172.5 and backwards several times, and I do adjust my saddle height to compensate. Once when I forgot to reset the height I had a lot of pain until I figured it out - the saddle was effectively higher than my butt wanted it to be.
Road Fan is offline  
Likes For Road Fan:
Old 03-29-23, 09:13 AM
  #38  
Trakhak
Senior Member
 
Trakhak's Avatar
 
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 5,338
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 2429 Post(s)
Liked 2,885 Times in 1,646 Posts
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.
Trakhak is offline  
Old 03-30-23, 01:19 PM
  #39  
bruce19
Senior Member
 
bruce19's Avatar
 
Join Date: Jul 2006
Location: Lebanon (Liberty Hill), CT
Posts: 8,456

Bikes: CAAD 12, MASI Gran Criterium S, Colnago World Cup CX & Guru steel

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 1722 Post(s)
Liked 1,272 Times in 734 Posts
Originally Posted by Trakhak
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.
I think I was the one who posted that. When I was a college QB I was measured at about 5'10 1/2". My inseam was 32.5". Now at age 77 I am 5'8 1/2" but still have a 32.5" inseam. Why? Well age, of course. But, I also have had some spine issues and in 2013 I crashed my bike and broke my neck. This a fusion of C1 & C2 and the loss of height. So, in my case, yes it's about upper spine.
bruce19 is offline  
Old 04-02-23, 09:56 PM
  #40  
hsea17
Junior Member
 
Join Date: Jan 2017
Posts: 104

Bikes: Giant SCR / Felt FR5 / Trek Emonda ALR 6 / Trek Domane AL2

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Liked 17 Times in 12 Posts
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
hsea17 is offline  
Old 04-11-23, 01:04 PM
  #41  
Calsun
Banned
 
Join Date: Mar 2021
Posts: 1,280
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 608 Post(s)
Liked 382 Times in 288 Posts
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.
Calsun is offline  
Old 04-11-23, 11:22 PM
  #42  
terrymorse 
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,006

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3339 Post(s)
Liked 3,436 Times in 1,737 Posts
Originally Posted by Calsun
The trend is toward shorter cranks on bikes with owners replacing 165mm with 155mm cranks.
And as with many of the bike fashion trends, there is little to no data to suggest a benefit from using shorter cranks.

There is one caution to heed: if you do switch to shorter cranks, you will need to install lower gearing.
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is online now  
Likes For terrymorse:
Old 04-12-23, 07:13 AM
  #43  
easyupbug 
Senior Member
 
Join Date: Jan 2013
Posts: 2,652

Bikes: too many sparkly Italians, some sweet Americans and a couple interesting Japanese

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 560 Post(s)
Liked 546 Times in 396 Posts
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.
easyupbug is offline  
Old 04-13-23, 09:23 AM
  #44  
terrymorse 
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,006

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3339 Post(s)
Liked 3,436 Times in 1,737 Posts
Originally Posted by easyupbug
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.
How does a shorter crank help your arthritic knees?
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is online now  
Old 04-13-23, 10:13 AM
  #45  
easyupbug 
Senior Member
 
Join Date: Jan 2013
Posts: 2,652

Bikes: too many sparkly Italians, some sweet Americans and a couple interesting Japanese

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 560 Post(s)
Liked 546 Times in 396 Posts
Originally Posted by terrymorse
How does a shorter crank help your arthritic knees?
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.
easyupbug is offline  
Likes For easyupbug:
Old 04-13-23, 12:11 PM
  #46  
terrymorse 
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,006

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3339 Post(s)
Liked 3,436 Times in 1,737 Posts
Originally Posted by easyupbug
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.
Thanks, that makes sense. The medical/physiology folks would call that "reduced knee flexion", I think.
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is online now  
Old 04-13-23, 02:06 PM
  #47  
smontanaro 
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Evanston, IL
Posts: 5,859

Bikes: many

Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 1434 Post(s)
Liked 1,362 Times in 747 Posts
Originally Posted by easyupbug
[My orthopedist] believes that at my fit recommended saddle height (set at the bottom of the pedal stroke) the relief I get is that at the top of the pedal stroke my leg is not as bent....
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.
__________________
Monti Special
smontanaro is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.