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

Switching to shorter cranks for road cycling as you get older?

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.

Switching to shorter cranks for road cycling as you get older?

Old 02-16-24, 09:52 PM
  #26  
Senior Member
 
Join Date: Jan 2013
Posts: 2,674

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

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 567 Post(s)
Liked 562 Times in 405 Posts
Originally Posted by 79pmooney
...My knees do not like crank length change at all (chondromalacia patellae) and I have 6 bikes, all riders, so changing crank length is a big deal.
Many years ago I used to race running and cycling and know chondromalacia patellae which in me has now morphed a more dominate osteoarthritis. I would think you might find as I have that the shorter crank lengths and higher RPM are a benefit in reducing the loading on the joint. When you say your knees don't like a changed crank length, was it a minor 5mm you tried or a massive change? Crashes complicate everything so good luck there. As for hips/back it is also complicated, so good luck there as well. I got to where I was seeing a chiropractors monthly for my hip/back pain while extensively traveling internationally and in the US and one finally advised to try a knee pillow and I have not been to a chiropractor in a year and a half. Incidentally, I always enjoy seeing you posts.
easyupbug is offline  
Likes For easyupbug:
Old 02-17-24, 08:57 AM
  #27  
Senior Member
 
OldsCOOL's Avatar
 
Join Date: Jul 2004
Location: northern michigan
Posts: 13,317

Bikes: '77 Colnago Super, '76 Fuji The Finest, '88 Cannondale Criterium, '86 Trek 760, '87 Miyata 712

Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 659 Post(s)
Liked 595 Times in 313 Posts
I’ll be staying with 170. That’s what all my roadbikes and MTB’s have and what I’ve used since 1973. No knee probs which I am thankful for.
OldsCOOL is offline  
Old 02-19-24, 12:45 PM
  #28  
just another gosling
 
Carbonfiberboy's Avatar
 
Join Date: Feb 2007
Location: Everett, WA
Posts: 19,526

Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004

Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 3884 Post(s)
Liked 1,936 Times in 1,382 Posts
By the formulae, I should be on 160s, but my singles are 170 and our tandem captain's cranks are 175. They still work just fine. We hike and backpack, I ski Alpine and XC, and we go the gym twice a week. I think cross training keeps becoming a better and better idea as we age.
__________________
Results matter
Carbonfiberboy is offline  
Old 02-19-24, 01:10 PM
  #29  
Senior Member
 
Trakhak's Avatar
 
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 5,358
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 2477 Post(s)
Liked 2,947 Times in 1,673 Posts
Originally Posted by 79pmooney
My knees do not like crank length change at all (chondromalacia patellae) and I have 6 bikes, all riders, so changing crank length is a big deal.
Not as big a deal as knee surgery, if it were to come to that.

After a year or so of increasingly worrisome discomfort in my left knee, I just last week replaced the 172.5-mm cranks on the bike I use on my smart trainer with 165-mm Sora cranks. So far so good. Maybe a bit of an improvement. I rode 165-mm cracks on various of my track bikes for decades, so at least they don't feel weird to me.

MIght be worth your considering buying a cheap knockoff Hollowtech II crank set in 165 or even 160 to experiment with. I bought a set of cranks, plus a set of chainrings and a Hollowtech II bottom bracket bearing set, for around $60 or so.

Might end up buying Hollowtech II cranks for all my bikes, since I love how absurdly easy they are to work on.
Trakhak is offline  
Old 02-19-24, 04:02 PM
  #30  
Deraill this!
 
Trav1s's Avatar
 
Join Date: Jun 2019
Location: Central Ohio
Posts: 604

Bikes: 18 Cdale Quick 1, 94 S-Works M2, 98 730 Multitrak, and a few others

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 139 Post(s)
Liked 416 Times in 241 Posts
I'm 5'6" with a 29.5" inseam (measured by the book method) and was riding a 170mm crank on my primary bike without much problem. Picked up a vintage MTB with 175mm crank - any ride over 10 mies left me sore in the hips and knees. Meanwhile, I upgraded the primary bike to 165mm crank and found riding to be much easier and more efficient. While my cadence was higher, it was more natural and With the helps of the LBS, the vintage MTB was converted to a 165mm crank and all was well. While 170mm works, 165mm is more comfortable and natural for me...
Trav1s is offline  
Old 02-20-24, 10:52 AM
  #31  
Senior Member
 
Tomm Willians's Avatar
 
Join Date: Mar 2020
Location: Nevada County, California
Posts: 789

Bikes: Subject to change at any given moment but currently is...... Colnago Mapei, Colnago C40, Wilier Triestina Carbon, Wilier Triestina Ramato, Follis 472, Peugeot PX60, Razesa, Orbea Terra, Soma Pescadero and 1/2 owner of a Santana tandem.

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked 782 Times in 264 Posts
I switched from 172.5 to 165 as when using aero bars I felt like I was nearly kneeing myself in the chest. 165ís made it much more comfortable.
Tomm Willians is offline  
Old 02-20-24, 11:56 AM
  #32  
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,080

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3405 Post(s)
Liked 3,535 Times in 1,778 Posts
Originally Posted by Tomm Willians
I switched from 172.5 to 165 as when using aero bars I felt like I was nearly kneeing myself in the chest. 165ís made it much more comfortable.
Did you also move the saddle forward, for a larger hip angle?
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is offline  
Old 02-20-24, 12:31 PM
  #33  
Senior Member
 
Tomm Willians's Avatar
 
Join Date: Mar 2020
Location: Nevada County, California
Posts: 789

Bikes: Subject to change at any given moment but currently is...... Colnago Mapei, Colnago C40, Wilier Triestina Carbon, Wilier Triestina Ramato, Follis 472, Peugeot PX60, Razesa, Orbea Terra, Soma Pescadero and 1/2 owner of a Santana tandem.

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked 782 Times in 264 Posts
Originally Posted by terrymorse
Did you also move the saddle forward, for a larger hip angle?
Unfortunately I have no further adjustment available in that matter.
Tomm Willians is offline  
Old 02-23-24, 02:45 PM
  #34  
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
It is common to see riders of all ages with the saddle too low and this puts a lot more stress on the knees. It may be partly from ignorance and partly from adjusting the seat height before they have warmed up enough to all the muscles to stretch. With a new bike or a new saddle I ride for at least 15 minutes before making saddle position adjustments.

Many mountain bike riders have switched to shorter cranks and believe them to be an improvement although their riding environment on dirt trails is quite different from a road rider on pavement.
Calsun is offline  
Old 02-24-24, 08:23 AM
  #35  
Banned
 
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 9,924

Bikes: RANS Stratus TerraTrike Tour II

Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 3352 Post(s)
Liked 1,056 Times in 635 Posts
IMO as you get older, you are not as strong, and should keep the longer crank arms for the torque they produce.
rydabent is offline  
Old 02-24-24, 08:27 AM
  #36  
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 8,373
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 4384 Post(s)
Liked 4,824 Times in 2,981 Posts
Originally Posted by rydabent
IMO as you get older, you are not as strong, and should keep the longer crank arms for the torque they produce.
Or just ride in a lower gear.
PeteHski is offline  
Likes For PeteHski:
Old 02-24-24, 09:48 AM
  #37  
Deraill this!
 
Trav1s's Avatar
 
Join Date: Jun 2019
Location: Central Ohio
Posts: 604

Bikes: 18 Cdale Quick 1, 94 S-Works M2, 98 730 Multitrak, and a few others

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 139 Post(s)
Liked 416 Times in 241 Posts
Iíve always wondered about the physics, especially load on the joints. This curiosity is informed by my automotive knowledge, especially with engine construction - the debate of shorter vs longer stroke, rod ratios, and piston height/side loads. I wonít bore anyone with details but all impact bearing life in different ways. If you are not familiar with the ideas, think of a Ford 300/jeep 4.0 inline 6 (long stroke) v/s Japanese 4 Cyl and 6 Cyl engines (shorter stroke) - lug it or rev it - your call. Pair with the right set of gears small engines can do large amounts of workÖ

Since the gene pool has gifted me with adequate at best knees, Iím trying to be as kind as possible and make cartilage (natureís bearings) last as long as possible. Shorter crank reduces loads and angles in the knee as well as dwell at the top and bottom of the stroke. The move to shorter cranks has reduced knee and hip pain which allows me to ride longer. YMMV
Trav1s is offline  
Old 02-24-24, 12:07 PM
  #38  
Newbie
 
Join Date: Mar 2008
Posts: 74
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 55 Times in 25 Posts
I mostly ran 172.5 cranks on my bicycles, but when I built my touring bicycle fifteen years ago I used 175 Shimano XT cranks because thatís what I could get. When riding on trails, the pedals sometimes touched bumps or rocks so a few years ago I switched to 165s. I like them very much.
I am through with my 60s and have shrunk from 6í to 5í11Ē. I have long used the Greg LeMond saddle height formula which measures from the top of the seat to the bottom bracket center without regard to crank length so I havenít changed saddle height.
Charles Lathe is offline  
Old 02-24-24, 07:39 PM
  #39  
Full Member
 
Join Date: Jan 2022
Location: Albuquerque NM USA
Posts: 482
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 215 Post(s)
Liked 299 Times in 190 Posts
I have just ordered a 165 crankset for my main road bike. I currently ride 172.5. My reason is some slight knee pain that has developed. The pain is very similar to when I had 175 mm cranks on a road bike (that's the way it came). In that case, the pain was pretty much only when riding out of the saddle. And noticeable at the top of the stroke.

While I'm 6' 2", and thus why a standard bike came with 175 mm cranks, my height is in my back, not my legs. My inseam is a bit under 33" (floor to book in crouch method). The shorter cranks will reduce the range of the angle my knees go through. I'm hoping it will reduce loads on my knees. My pain appears to be the patellar tendon.

As for the crank arm leverage question. Certainly a longer crank has more leverage. But keep in mind that the difference of 175 and 165 mm cranks is about 6% or equal to about half a gear change. And of course, given gears, this is only an issue when in your lowest gear. However, I think this is offset by having a greater range of the power stroke. IN other words, sure you have less peak torque for the same applied force, but you can apply force over a greater range of the pedal stroke, so you don't need to produce the same peak torque to get the same average torque.

I actually look at the pedaling dynamics data I had going from 175 to 172.5 mm cranks, and the power stroke got slightly larger (more degrees of the pedal rotation) and also moved up a little. And by that I mean the bottom of the power stroke stayed the same, but the top started earlier with the shorter cranks. Now, I didn't analyze a bunch of data, so I'm not beating this drum too loudly.
Mtracer is offline  
Old 02-25-24, 04:12 PM
  #40  
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 8,373
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 4384 Post(s)
Liked 4,824 Times in 2,981 Posts
Originally Posted by Mtracer


As for the crank arm leverage question. Certainly a longer crank has more leverage. But keep in mind that the difference of 175 and 165 mm cranks is about 6% or equal to about half a gear change. And of course, given gears, this is only an issue when in your lowest gear. However, I think this is offset by having a greater range of the power stroke. IN other words, sure you have less peak torque for the same applied force, but you can apply force over a greater range of the pedal stroke, so you don't need to produce the same peak torque to get the same average torque.
You can think of it in terms of how fast your feet are moving around the pedal circle. A longer crank has more leverage but you have to move the end of that lever (pedal) through a larger distance per revolution and hence your foot speed is higher for a given cadence. It is literally the same effect as using a lower gear, except you have to bend your knees and hip joints more in the process.

As you rightly state, the longer lever is only a potential advantage when in your lowest gear if you are struggling in that gear. You could compensate for the gearing, but it's usually not worth it unless making a big change to the crank length.
PeteHski is offline  
Likes For PeteHski:
Old 02-25-24, 05:48 PM
  #41  
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,080

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3405 Post(s)
Liked 3,535 Times in 1,778 Posts
Originally Posted by PeteHski
As you rightly state, the longer lever is only a potential advantage when in your lowest gear if you are struggling in that gear. You could compensate for the gearing, but it's usually not worth it unless making a big change to the crank length.
There's something else that the longer lever crank arm produces all the time: a greater range of motion (ROM).

I don't know if that is or isn't a benefit to the cyclist, but strength training studies suggest that exercises with a full ROM produce slightly better outcomes (strength, speed, power, muscle size).

Something to consider, at least.
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is offline  
Likes For terrymorse:
Old 02-25-24, 08:02 PM
  #42  
Version 7.0
 
Hermes's Avatar
 
Join Date: Oct 2006
Location: SoCal
Posts: 13,118

Bikes: Too Many

Mentioned: 297 Post(s)
Tagged: 0 Thread(s)
Quoted: 1338 Post(s)
Liked 2,473 Times in 1,448 Posts
Age 74, 6' with a 34 in inseam. 165 cranks on track bike and 172.5 on TT and road bike. I plan on changing my TT bike to 165. I changed a few years ago from 172.5. 165 cranks are faster as tested on the track against the 172.5.
Hermes is offline  
Likes For Hermes:
Old 02-26-24, 03:53 AM
  #43  
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 8,373
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 4384 Post(s)
Liked 4,824 Times in 2,981 Posts
Originally Posted by terrymorse
There's something else that the longer lever crank arm produces all the time: a greater range of motion (ROM).

I don't know if that is or isn't a benefit to the cyclist, but strength training studies suggest that exercises with a full ROM produce slightly better outcomes (strength, speed, power, muscle size).

Something to consider, at least.
It is usually the greater range of motion that causes problems for some cyclists with longer cranks. As far as generating power, pretty much every study Iíve seen concludes that power is not significantly affected by crank length, even over a wider range than is typically available.
PeteHski is offline  
Old 02-26-24, 10:59 AM
  #44  
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,080

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3405 Post(s)
Liked 3,535 Times in 1,778 Posts
Originally Posted by PeteHski
It is usually the greater range of motion that causes problems for some cyclists with longer cranks. As far as generating power, pretty much every study Iíve seen concludes that power is not significantly affected by crank length, even over a wider range than is typically available.
I wasn't thinking about injury issues or power advantages, but the training effect from exercising with a greater range of motion.

Since studies suggest that full range of motion exercises produce superior results, maybe training with longer cranks make you stronger.

Maybe.

On a personal note, I tried shorter cranks briefly and did not like them one bit. They felt very awkward when climbing out of the saddle.
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is offline  
Old 02-26-24, 03:18 PM
  #45  
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 8,373
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 4384 Post(s)
Liked 4,824 Times in 2,981 Posts
Originally Posted by terrymorse
I wasn't thinking about injury issues or power advantages, but the training effect from exercising with a greater range of motion.

Since studies suggest that full range of motion exercises produce superior results, maybe training with longer cranks make you stronger.

Maybe.

On a personal note, I tried shorter cranks briefly and did not like them one bit. They felt very awkward when climbing out of the saddle.
I guess it depends what your riding objectives are. I doubt that there are any studies showing that longer cranks make you stronger. But there are several studies showing that crank length doesn't significantly affect your power output. Pro riders tend to favour shorter cranks too, because it helps them with their aero fit without affecting power.

Then there's the question of how close to your full range of leg motion do you really want to go when you are potentially riding for many hours with significant fatigue? On a 5 hour ride you might be doing around 25,000 reps!
PeteHski is offline  
Likes For PeteHski:
Old 02-29-24, 05:57 PM
  #46  
aka Tom Reingold
 
noglider's Avatar
 
Join Date: Jan 2009
Location: New York, NY, and High Falls, NY, USA
Posts: 40,495

Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem

Mentioned: 511 Post(s)
Tagged: 0 Thread(s)
Quoted: 7341 Post(s)
Liked 2,441 Times in 1,425 Posts
I'm sure there is some trigonometry that can help explain why small changes in crank length makes for a very different experience. I've ridden 170 most of my life. I remember the first time I rode a bike with 175 mm cranks. It felt wrong, and I kept lowering and raising the seat, and I couldn't get a good position. Then I realized what was happening. I previously didn't believe it was perceptible, but yes, it is. I can sometimes perceive a 2.5 mm change, but not reliably.

@rydabent, what have you read that supports your view that longer is better for old folks? Most of us here are saying the opposite. It's easy to understand that more leverage reduces the amount of force required, but we can do that by shifting down or just slowing down. Age reduces a body's range of motion. Long cranks make me uncomfortable.

An interesting experiment: I put 155 mm cranks on my fixed gear bike. It's a street bike for errands, not a track racing bike. It does feel a little odd, but it's not at all uncomfortable. I've had them there for years, and I have no plans to change them.
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog

ďWhen man invented the bicycle he reached the peak of his attainments.Ē ó Elizabeth West, US author

Please email me rather than PM'ing me. Thanks.

Last edited by noglider; 03-02-24 at 08:45 PM.
noglider is offline  
Old 02-29-24, 11:54 PM
  #47  
climber has-been
 
terrymorse's Avatar
 
Join Date: Dec 2004
Location: Palo Alto, CA
Posts: 7,080

Bikes: Scott Addict R1, Felt Z1

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 3405 Post(s)
Liked 3,535 Times in 1,778 Posts
I donít accept that reduced range of motion is a necessary result of aging. Iím about as flexible as I have ever been, maybe even more so.
__________________
Ride, Rest, Repeat. ROUVY: terrymorse


terrymorse is offline  
Likes For terrymorse:
Old 03-01-24, 05:43 AM
  #48  
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 8,373
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 4384 Post(s)
Liked 4,824 Times in 2,981 Posts
Originally Posted by terrymorse
I donít accept that reduced range of motion is a necessary result of aging. Iím about as flexible as I have ever been, maybe even more so.
Whether you accept it or not, it appears to be pretty common.

Also there is a growing opinion amongst bike fitters that stock crank lengths are already too long for many riders under 6ft tall and especially for riders shorter than average. Fortunately Iím tall enough and long-legged enough not to have any range of motion issues with stock 172.5 or 175mm cranks. But if I was building a bike from scratch I would fit 170 or even 165 cranks. I donít see any downside and they can only be better for endurance.
PeteHski is offline  
Old 03-01-24, 06:21 AM
  #49  
Should Be More Popular
 
datlas's Avatar
 
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 43,027

Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix

Mentioned: 560 Post(s)
Tagged: 2 Thread(s)
Quoted: 22571 Post(s)
Liked 8,918 Times in 4,152 Posts
Originally Posted by SharpByCoop
I'll just share I am 5'6" and have a 30" inseam. MUCH of my riding is on Zwift. Measurable.

Indoor trainer bike: I modified a pair of spare arms from 175mm to 155mm (Drilling and tapping) on the basis of many videos on YT exploring this, and my own realization: I'm SHORT.

I could not be more pleased with the result. I found immediately less rocking butt movement on the seat, and they allowed me to spin in a circle.

For the same given heart rate I was up at least 5 watts average.

I have a gaggle if vintage Schwinns and others; I can't convert them, yet I wish I could. Works for me.

If you have a opportunity to experiment try it. The LH/RH taps are only $15 on Amazon.

Coop
Interesting. I am curious if you raised your saddle by 2 cm to compensate for the effective saddle height change. I am thinking some of the improvement may be from a lower effective saddle height.
__________________
Originally Posted by rjones28
Addiction is all about class.
datlas is offline  
Old 03-01-24, 06:33 AM
  #50  
Should Be More Popular
 
datlas's Avatar
 
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 43,027

Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix

Mentioned: 560 Post(s)
Tagged: 2 Thread(s)
Quoted: 22571 Post(s)
Liked 8,918 Times in 4,152 Posts
Originally Posted by terrymorse
I don’t accept that reduced range of motion is a necessary result of aging. I’m about as flexible as I have ever been, maybe even more so.
Also, height loss with aging usually is in the spine, so leg length should be preserved (maybe a tiny loss at knee joint).
__________________
Originally Posted by rjones28
Addiction is all about class.
datlas is offline  

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.