Go Back  Bike Forums > The Racer's Forum > Track Cycling: Velodrome Racing and Training Area
Reload this Page >

crank length and bike weight in track sprinting

Notices
Track Cycling: Velodrome Racing and Training Area Looking to enter into the realm of track racing? Want to share your experiences and tactics for riding on a velodrome? The Track Cycling forums is for you! Come in and discuss training/racing, equipment, and current track cycling events.

crank length and bike weight in track sprinting

Old 03-22-16, 07:26 PM
  #1  
spectastic
commu*ist spy
Thread Starter
 
spectastic's Avatar
 
Join Date: Aug 2012
Location: inside my body
Posts: 4,427

Bikes: a few

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Likes: 0
Liked 1 Time in 1 Post
crank length and bike weight in track sprinting

two questions

why do track sprinters generally use shorter crank lengths while road sprinters generally prefer a longer crank length?

my understanding is that track sprinters value aero and stiffness over weight. it's not uncommon for them to weigh 20 lbs, is that right? is weight really that insignificant?
spectastic is offline  
Old 03-22-16, 07:41 PM
  #2  
700wheel
Senior Member
 
Join Date: May 2014
Location: USA
Posts: 570
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 120 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by spectastic View Post
two questions

why do track sprinters generally use shorter crank lengths while road sprinters generally prefer a longer crank length?

..............
My thoughts:
Because track sprinters use one gear that results in a very high cadence. Short cranks facilitate this.
Road sprinters can upshift to a higher gear when they are already at speed so high cadence is less important.
700wheel is offline  
Old 03-22-16, 08:10 PM
  #3  
spectastic
commu*ist spy
Thread Starter
 
spectastic's Avatar
 
Join Date: Aug 2012
Location: inside my body
Posts: 4,427

Bikes: a few

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by 700wheel View Post
My thoughts:
Because track sprinters use one gear that results in a very high cadence. Short cranks facilitate this.
Road sprinters can upshift to a higher gear when they are already at speed so high cadence is less important.
make sense, they're forced to compromise with only one gear, at low and high speeds.

what about bike weight?
spectastic is offline  
Old 03-22-16, 08:13 PM
  #4  
Baby Puke
Senior Member
 
Join Date: Sep 2008
Location: Kanazawa
Posts: 1,490

Bikes: Marin Stelvio, Pogliaghi SL, Panasonic NJS, Dolan DF4, Intense Pro24 BMX

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 254 Post(s)
Liked 4 Times in 3 Posts
There's a lot of research lately that points to better results on shorter cranks regardless of discipline.
Baby Puke is offline  
Old 03-22-16, 08:35 PM
  #5  
spectastic
commu*ist spy
Thread Starter
 
spectastic's Avatar
 
Join Date: Aug 2012
Location: inside my body
Posts: 4,427

Bikes: a few

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Baby Puke View Post
There's a lot of research lately that points to better results on shorter cranks regardless of discipline.
can you point me out to these research? the stuff I read list tradeoffs between longer and shorter cranks.
spectastic is offline  
Old 03-22-16, 08:36 PM
  #6  
grav.digr
Junior Member
 
Join Date: Sep 2015
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
its rather commonplace to see 170mm in the pro ranks these days (on the road)
grav.digr is offline  
Old 03-22-16, 08:47 PM
  #7  
Baby Puke
Senior Member
 
Join Date: Sep 2008
Location: Kanazawa
Posts: 1,490

Bikes: Marin Stelvio, Pogliaghi SL, Panasonic NJS, Dolan DF4, Intense Pro24 BMX

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 254 Post(s)
Liked 4 Times in 3 Posts
Originally Posted by spectastic View Post
can you point me out to these research? the stuff I read list tradeoffs between longer and shorter cranks.
I think this is the article that people have been referencing recently:
Are shorter cranks better? - Cycling Weekly

But it's been known for some time that there is virtually no advantage in power in changing your cranks to anything from the 165mm-175mm range that is typical. The conclusion then, is that shorter is better as it allows you to get a more aerodynamic position on the bike with equivalent hip angle. Or allows you to have the same position with a more open hip angle. Pretty easy. I'd like to try 160's myself.
Baby Puke is offline  
Old 03-22-16, 08:50 PM
  #8  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 7,101

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 94 Post(s)
Tagged: 0 Thread(s)
Quoted: 1736 Post(s)
Likes: 0
Liked 137 Times in 100 Posts
Bike weights matter very little on the track. They never go uphill except to gain height on the banking and much of the reason they do that is to either place themselves where that weight will be used to advantage accelerating as they come off the banking or the rider wants to slow down sharply to force the rider behind to take the lead, again being about to recoup that speed for free coming back down behind the rider he has just forced to pass. Sprinters esp value both stiffness and strength a lot and in general, more of either adds weight. (Track sprinters are the heavyweight wrestlers of the bike world. I've known some whose thighs matched my waist.)

Ben
79pmooney is offline  
Old 03-22-16, 09:00 PM
  #9  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,605
Mentioned: 84 Post(s)
Tagged: 0 Thread(s)
Quoted: 1221 Post(s)
Liked 4 Times in 4 Posts
Originally Posted by spectastic View Post
two questions

why do track sprinters generally use shorter crank lengths while road sprinters generally prefer a longer crank length?

my understanding is that track sprinters value aero and stiffness over weight. it's not uncommon for them to weigh 20 lbs, is that right? is weight really that insignificant?
Several reasons:

Longer crank arms are great for climbing. Roadies climb. There are no hills on the track.

Roadies usually grind at lower RPMs than the cruising cadences that track racers hold. Cruising RPMs in a peloton are like 80-100 RPM. In a track points race, the cruising RPMs are like 100-110 RPM and sprints are 120-130 RPM.

Most importantly:
Roadies have gears, so they shift their way into maintaining the right amount of torque for a given effort as they increase speed. Trackies don't have gears, so they have to regulate speed with cadence. It's easier to regulate cadence (and spin faster) with shorter cranks than longer cranks.

It's not a weight or stiffness thing at all.
carleton is offline  
Old 03-22-16, 09:12 PM
  #10  
spectastic
commu*ist spy
Thread Starter
 
spectastic's Avatar
 
Join Date: Aug 2012
Location: inside my body
Posts: 4,427

Bikes: a few

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by 79pmooney View Post
Bike weights matter very little on the track. They never go uphill except to gain height on the banking and much of the reason they do that is to either place themselves where that weight will be used to advantage accelerating as they come off the banking or the rider wants to slow down sharply to force the rider behind to take the lead, again being about to recoup that speed for free coming back down behind the rider he has just forced to pass. Sprinters esp value both stiffness and strength a lot and in general, more of either adds weight. (Track sprinters are the heavyweight wrestlers of the bike world. I've known some whose thighs matched my waist.)

Ben
yes, there's no climbing, but what about accelerations?
spectastic is offline  
Old 03-22-16, 09:33 PM
  #11  
taras0000
Senior Member
 
taras0000's Avatar
 
Join Date: Dec 2004
Location: 43.2330941,-79.8022037,17
Posts: 1,679
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 308 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
Look at the differences between climbing and acceleration and that will answer your questions.
taras0000 is offline  
Old 03-23-16, 08:22 AM
  #12  
SprintzNKiloz
Senior Member
 
SprintzNKiloz's Avatar
 
Join Date: Nov 2015
Location: Indianapolis, IN
Posts: 97

Bikes: LOOK 675, Dolan DF4, Casati Gold Line, Litespeed Classic, Felt TR2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
My fitter is super into the "shorter cranks = better" for most people. For me it was a matter of lessening deadspots. I am short and have short legs but OLD roadie habits had me riding 172.5s on the road. Once I started racing track w 165s, the differences were noticeable once he got my fit sorted on both bikes. Much earlier engagement in the pedal stroke with shorter cranks for me.
SprintzNKiloz is offline  
Old 03-23-16, 08:27 AM
  #13  
andr0id
Senior Member
 
andr0id's Avatar
 
Join Date: Feb 2009
Posts: 2,522
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1421 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by spectastic View Post
two questions

why do track sprinters generally use shorter crank lengths while road sprinters generally prefer a longer crank length?
You use a short crank arm on a track bike so that so your pedal doesn't hit the upside of the bank when you're riding at a walking pace for a matched sprint.

All the other "reasons" about short cranks making your faster or whatever are speculative hooey.
andr0id is offline  
Old 03-23-16, 08:46 AM
  #14  
queerpunk
aka mattio
 
queerpunk's Avatar
 
Join Date: May 2005
Posts: 6,503
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 304 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by andr0id View Post
You use a short crank arm on a track bike so that so your pedal doesn't hit the upside of the bank when you're riding at a walking pace for a matched sprint.

All the other "reasons" about short cranks making your faster or whatever are speculative hooey.
I've known people who use 172.5s on 43-deg banks and have never pedal struck; and I also know that most tracks are not that steep. So banking can't be a great reason.

And, since shorter cranks can accommodate a more aerodynamic position with a hip angle sufficient to generate power, I don't know if you can call increasing your power:cda relationship 'speculative hooey.'
queerpunk is offline  
Old 03-23-16, 09:00 AM
  #15  
andr0id
Senior Member
 
andr0id's Avatar
 
Join Date: Feb 2009
Posts: 2,522
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1421 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by queerpunk View Post
I've known people who use 172.5s on 43-deg banks and have never pedal struck; and I also know that most tracks are not that steep. So banking can't be a great reason.
Then they have a high BB. My 170's will hit at the Superdrome if I'm going slow enough and it's only 44/45 degrees.
andr0id is offline  
Old 03-23-16, 10:25 AM
  #16  
wens
Senior Member
 
wens's Avatar
 
Join Date: Mar 2010
Location: Northeast Ohio
Posts: 3,215
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by andr0id View Post
Then they have a high BB. My 170's will hit at the Superdrome if I'm going slow enough and it's only 44/45 degrees.
Or they're good at leaning the bike over away from the banking...
wens is offline  
Old 03-23-16, 10:46 AM
  #17  
dunderhi
Registered User
 
Join Date: Nov 2014
Location: 150 miles from Ttown
Posts: 430

Bikes: Little Wing, XTRACK, Electron Pro, SuperCorsa, Paramount, & Thunderdrome

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 65 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by wens View Post
Or they're good at leaning the bike over away from the banking...
I actually think tapping the track with a pedal should be a mandatory drill for newbies. When I rode Giordana last year, I tapped the track with 170's to get a feel for the steepness and felt comfortable with riding 172.5's after that.
dunderhi is offline  
Old 03-23-16, 11:21 AM
  #18  
wens
Senior Member
 
wens's Avatar
 
Join Date: Mar 2010
Location: Northeast Ohio
Posts: 3,215
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
. Maybe certain tracks , but I wouldn't want to be the person getting new riders to tap something as step steep as cleveland , because there's just not much main margin for error . I also don't think you even could do this still drill at a lot of wood tracks , yu slide before you arrive strike .
wens is offline  
Old 03-23-16, 11:40 AM
  #19  
SprintzNKiloz
Senior Member
 
SprintzNKiloz's Avatar
 
Join Date: Nov 2015
Location: Indianapolis, IN
Posts: 97

Bikes: LOOK 675, Dolan DF4, Casati Gold Line, Litespeed Classic, Felt TR2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by dunderhi View Post
I actually think tapping the track with a pedal should be a mandatory drill for newbies. When I rode Giordana last year, I tapped the track with 170's to get a feel for the steepness and felt comfortable with riding 172.5's after that.
I rode Giordana with 165s in March to recon for Nats and had ZERO issues then at Nats I tapped twice in my match sprint rounds. DOH.
SprintzNKiloz is offline  
Old 03-23-16, 11:42 AM
  #20  
SprintzNKiloz
Senior Member
 
SprintzNKiloz's Avatar
 
Join Date: Nov 2015
Location: Indianapolis, IN
Posts: 97

Bikes: LOOK 675, Dolan DF4, Casati Gold Line, Litespeed Classic, Felt TR2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Also RE shorter cranks I will second what QP says as my fitter could quantify to a degree the watt delta between short cranks vs long cranks. Not hooey at all.
SprintzNKiloz is offline  
Old 03-23-16, 12:30 PM
  #21  
spectastic
commu*ist spy
Thread Starter
 
spectastic's Avatar
 
Join Date: Aug 2012
Location: inside my body
Posts: 4,427

Bikes: a few

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by SprintzNKiloz View Post
My fitter is super into the "shorter cranks = better" for most people. For me it was a matter of lessening deadspots. I am short and have short legs but OLD roadie habits had me riding 172.5s on the road. Once I started racing track w 165s, the differences were noticeable once he got my fit sorted on both bikes. Much earlier engagement in the pedal stroke with shorter cranks for me.
yes, I understand shorter cranks are of greater benefit to shorter people, when speaking in the context of 170-175 cranks. may i ask how tall you are and inseam?
spectastic is offline  
Old 03-23-16, 12:32 PM
  #22  
spectastic
commu*ist spy
Thread Starter
 
spectastic's Avatar
 
Join Date: Aug 2012
Location: inside my body
Posts: 4,427

Bikes: a few

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by SprintzNKiloz View Post
Also RE shorter cranks I will second what QP says as my fitter could quantify to a degree the watt delta between short cranks vs long cranks. Not hooey at all.
what was the delta?
spectastic is offline  
Old 03-23-16, 01:47 PM
  #23  
SprintzNKiloz
Senior Member
 
SprintzNKiloz's Avatar
 
Join Date: Nov 2015
Location: Indianapolis, IN
Posts: 97

Bikes: LOOK 675, Dolan DF4, Casati Gold Line, Litespeed Classic, Felt TR2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Nothing massive... 10 watts or so.
SprintzNKiloz is offline  
Old 03-23-16, 01:49 PM
  #24  
SprintzNKiloz
Senior Member
 
SprintzNKiloz's Avatar
 
Join Date: Nov 2015
Location: Indianapolis, IN
Posts: 97

Bikes: LOOK 675, Dolan DF4, Casati Gold Line, Litespeed Classic, Felt TR2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Also, to your other question. Inseam = 28" and height is 5'6" so I for sure fall into the having a lot to gain using shorter cranks perhaps.
SprintzNKiloz is offline  
Old 03-23-16, 01:51 PM
  #25  
Baby Puke
Senior Member
 
Join Date: Sep 2008
Location: Kanazawa
Posts: 1,490

Bikes: Marin Stelvio, Pogliaghi SL, Panasonic NJS, Dolan DF4, Intense Pro24 BMX

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 254 Post(s)
Liked 4 Times in 3 Posts
I have reason to believe the GB sprinters have been using cranks shorter than 165 for some time. And some of them are pretty tall. But as with all this stuff, use what you like. It's just for fun.
Baby Puke is offline  

Thread Tools
Search this Thread

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

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.