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

Shorter crank length as you 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.

Shorter crank length as you age?

Old 08-01-10, 09:16 AM
  #1  
smontanaro 
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Evanston, IL
Posts: 5,860

Bikes: many

Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 1434 Post(s)
Liked 1,363 Times in 747 Posts
Shorter crank length as you age?

I'm curious about crank length for older riders (I'm 56 with one knee surgery under my belt and anticipate another one in the next few years). I read Kriby Palm's pages on crank length but didn't see any discussion of crank length and rider's age. My concern is that as you age and your knees get more creaky longer cranks will be harder on your knees as you try to produce power at the beginning of the power stroke, when your knees are in their maximally flexed position. A shorter crank will not flex your knees as much.

That's my thought/concern anyway. Opinions and advice gratefully appreciated...

Skip Montanaro
smontanaro is offline  
Old 08-01-10, 09:48 AM
  #2  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 642 Times in 363 Posts
I don't know but it's an interesting subject.

I recently was forced to switch over to riding recumbents. Recumbent riders frequently use somewhat shorter cranks than is common on a conventional bike. I've been advised that the 175 mm cranks that I have on my single recumbent bike right now may be hurting my knees. One rider even posted a favorable report after modifying a crank to 130 mm!

I'm wondering how much difference 5 mm can make. I'm probably going to rework my drive train this winter. I'd like to reduce the angular motion of my legs - not because of stress on my knees but because my knees bump the recumbent handlebar. If I were making the decision today I'd probably get 170 mm cranks but a lot of recumbent riders use 165 mm cranks so I might go with that.
Retro Grouch is offline  
Old 08-01-10, 10:02 AM
  #3  
Louis
Senior Member
 
Join Date: Dec 2001
Posts: 4,868
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 10 Times in 4 Posts
I'll be 68 in September; I've noticed my saddle height has needed to come down slightly in the last few years. You may be on to something.
Louis is offline  
Old 08-01-10, 05:58 PM
  #4  
John E
feros ferio
 
John E's Avatar
 
Join Date: Jul 2000
Location: www.ci.encinitas.ca.us
Posts: 21,765

Bikes: 1959 Capo Modell Campagnolo; 1960 Capo Sieger (2); 1962 Carlton Franco Suisse; 1970 Peugeot UO-8; 1982 Bianchi Campione d'Italia; 1988 Schwinn Project KOM-10;

Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 1384 Post(s)
Liked 1,294 Times in 819 Posts
If you knee motion or the efficient portion of it is compromised with age, then shorter cranks make sense. I would change to proportionately lower gears to compensate for the lost leverage. Having said that, I really don't notice any difference between the 165mm cranks on my Peugeot and the 170s on my other bikes.
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
John E is offline  
Old 08-02-10, 09:40 AM
  #5  
HIPCHIP
Lance Legweak
 
HIPCHIP's Avatar
 
Join Date: Apr 2009
Location: Woodland, California, USA
Posts: 867

Bikes: Felt Z-70, GT RTS-2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked 20 Times in 16 Posts
While my studies involved athletes in their teens and twenties, I was taught that a person at any age can improve strength and flexibility, and that proper biomechanics should always be used. While I am not an expert in bicycling, I would say to try and stay using proper technique as long as you can. If due to physical limitations that are age related, then you may need to adjust, but in general, I believe, you would want to keep things as normal as possible. You may need a new bike fit as you may have changed with age. Due to my age and injuries, I've lost over an inch in height, my weight has also gone up due to injuries, so I'm shorter and fatter than I used to be, so this changes how I can do things. Since my back is also shot, I've had to modify the things I can and can't do, so I would think that an increase in age alone wouldn't require a change in crank arm length, but you should get a good fit in relation to your new limitations.
HIPCHIP is offline  
Old 08-02-10, 10:29 AM
  #6  
Pat
Senior Member
 
Join Date: Jan 2002
Location: Orlando, FL
Posts: 2,794

Bikes: litespeed, cannondale

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Hmmm, I think shall refrain about making comments about shorter crank lengths on older riders. That looks like TMI.
Pat is offline  
Old 08-02-10, 04:35 PM
  #7  
maddmaxx 
Boomer
 
maddmaxx's Avatar
 
Join Date: Nov 2003
Posts: 7,214

Bikes: Diamondback Clarity II frame homebuilt.

Mentioned: 106 Post(s)
Tagged: 0 Thread(s)
Quoted: 16098 Post(s)
Liked 1,457 Times in 1,064 Posts
Originally Posted by Pat
Hmmm, I think shall refrain about making comments about shorter crank lengths on older riders. That looks like TMI.
Don't touch this one with a ...... pole.
__________________
maddmaxx is offline  
Old 08-02-10, 11:24 PM
  #8  
Velo Dog
Senior Member
 
Join Date: Jun 2004
Location: Northern Nevada
Posts: 3,811
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I'm 65.5 (today), and I'm still using the same 175s i've ridden for 40 years, mostly because it never occurred to me that i should change them. Still feels OK, though. I have had to lower my seat maybe a centimeter, and I just found out at the doctor last week that i'm 6'3" now, not 6'4". He said most men older than 50 are shorter than they think they are, because they haven't really been measured since college or military service.
The last bike I sold had 170mm cranks, and they felt tiny, like I was going in little bitty circles. But that was six or eight years ago, so who knows?
Velo Dog is offline  
Old 08-02-10, 11:54 PM
  #9  
Wildwood 
Veteran, Pacifist
 
Wildwood's Avatar
 
Join Date: Dec 2004
Location: Seattle area
Posts: 13,304

Bikes: Bikes??? Thought this was social media?!?

Mentioned: 284 Post(s)
Tagged: 0 Thread(s)
Quoted: 3876 Post(s)
Liked 4,781 Times in 2,206 Posts
I can't tell any real difference in 175 or 172.5. Bikes are ridden frequently and interchangably.

I've read some Leonard Zinn articles and have always wanted to try 180s.

59 years and 6'1". No knee issues.
Wildwood is offline  
Old 08-03-10, 01:20 AM
  #10  
Monkey Face
Senior Member
 
Monkey Face's Avatar
 
Join Date: Dec 2009
Location: The Cotswolds, England
Posts: 619

Bikes: Giant Revolt 2. Velo Orange Pass Hunter flat bar

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked 35 Times in 16 Posts
I'd have thought shorter cranks would be harder to turn.... why would a longer lever be harder to turn at the beginning of the power stroke... doesn't make sense. Sorry.
Monkey Face is offline  
Likes For Monkey Face:
Old 08-03-10, 04:43 AM
  #11  
bradtx
Senior Member
 
Join Date: Jun 2010
Location: Pearland, Texas
Posts: 7,579

Bikes: Cannondale, Trek, Raleigh, Santana

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 308 Post(s)
Liked 3 Times in 3 Posts
Skip, Age probably is important primarily as a lifetime of disuse, misuse, wear and tear can rear an ugly head. Aside from some type of physical issue we're pretty adaptable to a range of crankarm lengths. A shorter crankarm is desireable if there is a joint issue with range of motion. Aside from that, a longer crankarm will require less rider effort for a given torque output because of it's mechanical advantage over a shorter crankarm.

Brad
bradtx is offline  
Old 08-03-10, 05:55 AM
  #12  
BlazingPedals
Senior Member
 
BlazingPedals's Avatar
 
Join Date: Dec 2004
Location: Middle of da Mitten
Posts: 12,474

Bikes: Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, Catrike Speed

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1511 Post(s)
Liked 733 Times in 454 Posts
I had a brief experiment with 155mm short cranks. I found that I couldn't spin enough faster to make up for the lost leverage, and it felt like I was pushing harder all the time. I also lost hill-climbing ability, of which I have little enough in the first place. So now I'm back to using 170s.
BlazingPedals is offline  
Old 08-03-10, 06:48 AM
  #13  
chipcom 
Infamous Member
 
chipcom's Avatar
 
Join Date: Sep 2005
Location: Ohio
Posts: 24,360

Bikes: Surly Big Dummy, Fuji World, 80ish Bianchi

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 4 Times in 3 Posts
Originally Posted by maddmaxx
Don't touch this one with a ...... pole.
With over 50 years of usage, one has to expect some wear.
__________________
"Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey
chipcom is offline  
Old 08-04-10, 06:20 PM
  #14  
zonatandem
Senior Member
 
zonatandem's Avatar
 
Join Date: Dec 2003
Location: Tucson, AZ
Posts: 11,016

Bikes: Custom Zona c/f tandem + Scott Plasma single

Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 77 Post(s)
Likes: 0
Liked 19 Times in 11 Posts
Am 77 years old; have bicycled 300,000+ miles. Still using 170mm cranks.
Pedaling 100+ miles a week.
zonatandem is offline  
Likes For zonatandem:
Old 08-04-10, 08:30 PM
  #15  
LAriverRat
Senior Member
 
Join Date: Oct 2009
Location: Downey, Ca
Posts: 910
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 1 Post
I have bio pace on my Trek 1400 and 86 Bianchi as well. Both with 172.5 mm cranks IIRC. No knee problems. When they started to hurt i found the my seat post had slipped down some what. After putting back higher I put a piece of tape as a marker so i can tell if starts to slip again. So far so good.
LAriverRat is offline  
Old 08-05-10, 12:30 AM
  #16  
lhbernhardt
Dharma Dog
 
lhbernhardt's Avatar
 
Join Date: Mar 2006
Location: Vancouver, Canada
Posts: 2,073

Bikes: Rodriguez Shiftless street fixie with S&S couplers, Kuwahara tandem, Trek carbon, Dolan track

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Just to add to the database: I am 59, 6'1", 175 lbs, with 34" inseam. I use 175s on the tandem, but most of my riding is on a fixie using 165s. I really don't notice much difference, but it should definitely be easier to spin the shorter cranks, and in fact I can hit over 60 kmh spinning down an 8% grade. For a given crank rpm (angular velocity), your foot speed is slower the shorter the cranks (linear velocity). When I go up hills on the fixie, I forget all about the crank length. I went up Hurricane Ridge near Port Angeles, WA, last Saturday on 44x16 fixed with the 165s (5200' in 17 miles), no problem, but I've been riding (much of it on the track) for the past 38 years. When I'm on the longer cranks, I've also got gears, which a physics teacher long ago told me was an impedance-matching device.

Bottom line: The gears make a bigger difference than the crank length. If you're on a fixie, then you might be concerned with crank length. On a geared bike, I don't think it makes any difference what crank length you use, but you will probably get a psychological boost going up hills if you have a longer crank, although 5 or 10mm of extra crank length (3 to 6% longer) won't really make a bigger gear any more comfortable or any faster.
lhbernhardt is offline  
Old 08-05-10, 08:53 AM
  #17  
seenoweevil
invisible friend
 
seenoweevil's Avatar
 
Join Date: Jun 2008
Location: Decatur, Alabama
Posts: 956

Bikes: Gary Fisher Tassajara hardtail mtb, '01 Rans Wave, '98 Raleigh R700, Mid-80's Takara Professional, '91 Bianchi Alfana

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I've been struggling with what to do about crank lengths on my bikes lately. My alum. Raleigh has 172.5's and my steel Miyata has 165's. Side by side, the seat, bars, etc. line up very close. Of course they ride a little different, the geometry is a bit more aggressive on the Raleigh, but my knees hurt after riding the Raleigh, even on a shorter ride of 10- 20 miles. I've ridden 40 mile rides the last 3 weekends in a row on the Miyata, no knee pain. I know all other things are not the same, but I'm looking hard for some more 165's right now.Oh, I'm 5'8" now according to the Dr., though I've been 5'9" for years. Darn cheap yardsticks don't measure like they used to!
seenoweevil is offline  
Old 08-05-10, 12:26 PM
  #18  
Metric Man
Old Fart Racing
 
Metric Man's Avatar
 
Join Date: Sep 2006
Location: Draper UT
Posts: 1,347

Bikes: 2015 Trek Domane 6.9 disc D/A Di2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I also have one bike with 170mm and another with 175mm...I can't tell the difference. But it's the subtle things that add up many times. I'd like to hear more on this subject.
Metric Man is offline  
Old 08-05-10, 02:32 PM
  #19  
bobkat
bobkat
 
Join Date: Jan 2006
Location: Bismarck, ND
Posts: 746

Bikes: Modified Burley Koosah, Trek Navigater folding, downtube folding

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
With knee pain developing on my LWB recumbent, I went from the stock 175's down to 152's with appropriate gearing down of the front chain rings.
The knee pain went right away, and I'm as fast (or maybe as slow) as I always was and climb seems unchanged.
I think the shorter cranks make your knees flex and extend less, and while shorter cranks DO result in decreased leverage, with appropriate gearing you won't notice any difference in speed or hill climbing, etc. Unless you are Lance Armstrong or some young jpck or speedster.
I doubt 5 or even 10 mm change would be noticed at all.
When you think of it, we all require different size frames, handlebars, seat heights, so why do we all accept 170 to 175 one size fits all cranks. But most of it is trial and error anyway - if it feels good, do it. What works well for one guy might make the next guy's knees hurt.
bobkat is offline  
Old 08-05-10, 07:28 PM
  #20  
billydonn
Council of the Elders
 
billydonn's Avatar
 
Join Date: Jul 2008
Location: Omaha, NE
Posts: 3,759

Bikes: 1990 Schwinn Crosscut, 5 Lemonds

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 1 Post
I'm 62 and 5'9" with short legs... about 30 inseam. I have no orthopedic issues. I have recently ridden the same exact bike with both 172.5 and 170 cranks ... and I CAN tell the difference. I can ride the 172.5s okay, but prefer the 170s because the longer cranks seem to require a greater bending (more acute angle) of the legs and lower back, especially when riding in the drops. I can also spin the 170s more easily though I am no great fast spinner to begin with.

IMO matching the crank length to one's own body geometry comes first, but the limitations of age and infirmity could come in to play to cause a move to a shorter crank. I can't think of a reason why age would dictate a longer crank but perhaps there is one.
billydonn is offline  
Old 08-05-10, 07:59 PM
  #21  
ahsposo 
Artificial Member
 
ahsposo's Avatar
 
Join Date: Jan 2010
Location: Cyberspace
Posts: 7,163

Bikes: Retrospec Judd, Dahon Boardwalk, Specialized Langster

Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 6731 Post(s)
Liked 5,441 Times in 3,198 Posts
I have a similar build and experience to billydonn.

As a youngster I always had 175 or 172.5 cranks and thats just what they were. Heck, I really didn't care much (and still don't waste a lot of sleep on it) about a couple of millimeters one way or the other anywhere on my bike. I was young, dumn and flexible. Heck, I rode a frame that was too big (way too big) for 25 years.

I bought a SS bike a few years ago for the flatland I was moving into at the time and found my pedal stroke was really nice with this bike. I liked the efficiency and the power I could put through it. Turns out it has 170 cranks. Huh!

Had to replace a frame I loved (my second "good" one but a much better fit than the first) and rode easily 25,000 miles on it and with as nearly an exact duplicate as I could find. Including 172.5 cranks.

What I found was this: Comparing the bikes in the flats (where they were "equal") I liked the shorter cranks better. Better spin. Huh!

So I've replaced the stock 172.5s for 170 and it's good. But I keep thinking the leverage with the longer cranks will be better in the long steeps for me. I like to stand on my pedals going up. So I've got them in reserve. Maybe in the fall I'll get a chance to compare...
__________________
ahsposo is offline  
Old 08-05-10, 08:30 PM
  #22  
bkaapcke
Senior Member
 
Join Date: Jul 2005
Posts: 3,268
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 118 Post(s)
Likes: 0
Liked 50 Times in 25 Posts
Going from 170's to 160's made a big difference to my knees. Changed the angle of the knee bend enough to get some relief. No knee problems? D
don't change crank length. bk
bkaapcke is offline  
Old 08-05-10, 10:28 PM
  #23  
lhbernhardt
Dharma Dog
 
lhbernhardt's Avatar
 
Join Date: Mar 2006
Location: Vancouver, Canada
Posts: 2,073

Bikes: Rodriguez Shiftless street fixie with S&S couplers, Kuwahara tandem, Trek carbon, Dolan track

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
I guess one point no one has mentioned is whether or not they moved the saddle up or down when they swapped cranks. I firmly believe that the saddle needs to be set in relation to the pedal at its lowest point. To set my seat height, I have always used the classic technique:
1. set crank to be in line with the seat tube
2. sit on bike in riding shorts and stocking feet
3. there should be a slight break in the knee with the heel on the low pedal
4. when the saddle is at the correct height, you should just be able to spin the cranks backwards with your heels on the pedals, rocking only slightly

My saddle height using this technique has been corroborated by more sophisticated methods of determining proper saddle height. But the point of my post is this: when I am using 170mm cranks, my saddle is set so that it is 79.0 cm from the middle of the bottom bracket. With 165mm cranks, it goes up to 79.5 cm; with 175's, the saddle goes down to 78.5. Everything is in relation to the pedal at its lowest position. If you keep the saddle at the same height, I think you can wreck your knees with the wrong crank length.

L.
lhbernhardt is offline  
Old 08-06-10, 06:32 AM
  #24  
billydonn
Council of the Elders
 
billydonn's Avatar
 
Join Date: Jul 2008
Location: Omaha, NE
Posts: 3,759

Bikes: 1990 Schwinn Crosscut, 5 Lemonds

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 1 Post
Yes. I forgot to mention it but I did change saddle height in my A/B testing.
billydonn is offline  
Old 08-07-10, 12:01 PM
  #25  
HAMMER MAN
Semper Fidelis
 
Join Date: Apr 2006
Posts: 3,000

Bikes: Tiemeyer Road Bike & Ridley Domicles

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 36 Post(s)
Likes: 0
Liked 1 Time in 1 Post
though i don't ride a recumbent on one of my bikes i recently purchased a felt, i put a compact crank 170- 50/34 and a 11/25 cass.
i have always used 172.5 cranks and 11-23 cass. it is a hell of a lot easier on your joints and for me it helped produce a nicer spin more fluid lie more of a smooth pedal stroke What i personally noticed with the 172.5 cranks there was a lope type affect coming from the dead-spot to the top, with the 170 crank it is far more fluid and constant
HAMMER MAN 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.