General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

Rolling Resistance

Old 03-18-16, 12:39 PM
  #1  
one4smoke
Senior Member
Thread Starter
 
Join Date: Jul 2015
Location: Nashville, TN.
Posts: 1,414

Bikes: 2016 Specialized Roubaix SL4 - 2015 Giant Roam 2 Disc

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Liked 13 Times in 9 Posts
Rolling Resistance

A rookie question I know, but should the rolling resistance of the rear wheel be about the same as the front? Should the rear wheel roll just as freely? If it isn't as free, has the locknut just been tightened a bit too much?

Last edited by one4smoke; 03-18-16 at 12:43 PM.
one4smoke is online now  
Old 03-18-16, 12:49 PM
  #2  
elcruxio
Senior Member
 
elcruxio's Avatar
 
Join Date: Jul 2011
Location: Turku, Finland, Europe
Posts: 1,816

Bikes: 2011 Specialized crux comp, 2013 Specialized Rockhopper Pro

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
Originally Posted by one4smoke View Post
A rookie question I know, but should the rolling resistance of the rear wheel be about the same as the front? Should the rear wheel roll just as freely? If it isn't as free, has the locknut just been tightened a bit too much?
Rolling resistance is usually a attribute of the tire, not the wheel. What you are likely talking about is hub drag which can be caused by a host of issues, like too tight bearings, worn bearings, too tight locknuts combined with too tight bearings etc etc.

What setup do you have? what hub? How does it attatch to the bike (threaded axle with nuts or quick release skewer?)
elcruxio is offline  
Old 03-18-16, 12:51 PM
  #3  
BlazingPedals
Senior Member
 
BlazingPedals's Avatar
 
Join Date: Dec 2004
Location: Middle of da Mitten
Posts: 10,894

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

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 882 Post(s)
Liked 12 Times in 10 Posts
"Rolling" or "spinning?" There will obviously be losses by the pawls in the freewheel/hub system, so I would expect the front wheel to take longer to spin down than the rear.
BlazingPedals is offline  
Old 03-18-16, 12:52 PM
  #4  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,401

Bikes: 8

Mentioned: 183 Post(s)
Tagged: 0 Thread(s)
Quoted: 6700 Post(s)
Likes: 0
Liked 119 Times in 100 Posts
If the tires are the same the contribution to rolling resistance will be close, But

[ditto part of above]

actually your Axle Bearing adjustment is probably too tight.

tightening a QR Skewer compresses the axle so what feels OK out of the frame gets too tight when the QR is secured ..
fietsbob is online now  
Old 03-18-16, 01:21 PM
  #5  
one4smoke
Senior Member
Thread Starter
 
Join Date: Jul 2015
Location: Nashville, TN.
Posts: 1,414

Bikes: 2016 Specialized Roubaix SL4 - 2015 Giant Roam 2 Disc

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Liked 13 Times in 9 Posts
Originally Posted by elcruxio View Post
Rolling resistance is usually a attribute of the tire, not the wheel. What you are likely talking about is hub drag which can be caused by a host of issues, like too tight bearings, worn bearings, too tight locknuts combined with too tight bearings etc etc.

What setup do you have? what hub? How does it attatch to the bike (threaded axle with nuts or quick release skewer?)
The specs say "Alloy Disc, 32h"

It has the quick release. The rear wheel spins down and comes to rather an abrupt stop. Compared to the front, which will come to a nice easy stop and will actually roll to the point where the valve stem is on the bottom.

How much could this actually hinder one's cycling effort or slow you?
one4smoke is online now  
Old 03-18-16, 01:43 PM
  #6  
elcruxio
Senior Member
 
elcruxio's Avatar
 
Join Date: Jul 2011
Location: Turku, Finland, Europe
Posts: 1,816

Bikes: 2011 Specialized crux comp, 2013 Specialized Rockhopper Pro

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
Originally Posted by one4smoke View Post
The specs say "Alloy Disc, 32h"

It has the quick release. The rear wheel spins down and comes to rather an abrupt stop. Compared to the front, which will come to a nice easy stop and will actually roll to the point where the valve stem is on the bottom.

How much could this actually hinder one's cycling effort or slow you?
If it spins several revolutions, likely the effect isn't going to be too noticeable in general riding. If it worries you, it might be a good idea to take the wheel to the LBS and let them check it out. They probably have the definite knowledge on how freely a rear wheel should spin. If it's a new wheel I doubt there's a problem, if it's an older wheel it might need servicing.
elcruxio is offline  
Old 03-18-16, 02:20 PM
  #7  
Homebrew01
Super Moderator
 
Homebrew01's Avatar
 
Join Date: Jul 2004
Location: Ffld Cnty Connecticut
Posts: 21,021

Bikes: Old Steelies I made, Old Cannondales

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 785 Post(s)
Likes: 0
Liked 17 Times in 16 Posts
Originally Posted by one4smoke View Post
A rookie question I know, but should the rolling resistance of the rear wheel be about the same as the front? Should the rear wheel roll just as freely? If it isn't as free, has the locknut just been tightened a bit too much?
The rear wheel spins less than the front due to the drive train drag. If you are concerned, you can removed the rear wheel and make sure the axle feels smooth, and any gears spin smoothly too.
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.

FYI: http://www.bikeforums.net/forum-sugg...ad-please.html
Homebrew01 is offline  
Old 03-18-16, 04:46 PM
  #8  
avidone1
Senior Member
 
avidone1's Avatar
 
Join Date: Dec 2014
Location: still above ground
Posts: 1,069

Bikes: 2016 Specialized crosstrail comp disc

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Sometimes I think we sweat the small stuff
avidone1 is offline  
Old 03-18-16, 05:15 PM
  #9  
2manybikes
Dog is my co-pilot
 
2manybikes's Avatar
 
Join Date: Jun 2003
Posts: 17,527

Bikes: 2 many

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 986 Post(s)
Liked 10 Times in 9 Posts
Originally Posted by avidone1 View Post
Sometimes I think we sweat the small stuff
Correct.
2manybikes is online now  
Old 03-18-16, 05:33 PM
  #10  
2manybikes
Dog is my co-pilot
 
2manybikes's Avatar
 
Join Date: Jun 2003
Posts: 17,527

Bikes: 2 many

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 986 Post(s)
Liked 10 Times in 9 Posts
Originally Posted by one4smoke View Post
The specs say "Alloy Disc, 32h"

It has the quick release. The rear wheel spins down and comes to rather an abrupt stop. Compared to the front, which will come to a nice easy stop and will actually roll to the point where the valve stem is on the bottom.

How much could this actually hinder one's cycling effort or slow you?
The "ratchet" mechanism in the back hub allows the wheel to coast when you are not pedaling. Sounds like click click click as the wheel spins and the sprockets and chain do not.

It has drag as the ratchet works. "Free hub" in bicycle slang.
There should be more resistance as you spin the wheel compared to the front wheel.
2manybikes is online now  
Old 03-18-16, 06:29 PM
  #11  
Homebrew01
Super Moderator
 
Homebrew01's Avatar
 
Join Date: Jul 2004
Location: Ffld Cnty Connecticut
Posts: 21,021

Bikes: Old Steelies I made, Old Cannondales

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 785 Post(s)
Likes: 0
Liked 17 Times in 16 Posts
Originally Posted by avidone1 View Post
Sometimes I think we sweat the small stuff
How small do you consider small, and how much sweat, relative to the small stuff ?
Does the small stuff and sweat slow down the bike ?
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.

FYI: http://www.bikeforums.net/forum-sugg...ad-please.html
Homebrew01 is offline  
Old 03-18-16, 06:34 PM
  #12  
BlazingPedals
Senior Member
 
BlazingPedals's Avatar
 
Join Date: Dec 2004
Location: Middle of da Mitten
Posts: 10,894

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

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 882 Post(s)
Liked 12 Times in 10 Posts
Originally Posted by one4smoke View Post
The specs say "Alloy Disc, 32h"

It has the quick release. The rear wheel spins down and comes to rather an abrupt stop. Compared to the front, which will come to a nice easy stop and will actually roll to the point where the valve stem is on the bottom.

How much could this actually hinder one's cycling effort or slow you?
This is a BSO from a department store, isn't it? It's easy to check if the Q/R is too tight - take it off and spin it in your hand. I suspect it's the bearings. They're either mis-adjusted too tight, not enough lube, or just plain bad.
BlazingPedals is offline  
Old 03-18-16, 06:47 PM
  #13  
PaulRivers
Senior Member
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 6,311
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 432 Post(s)
Liked 4 Times in 3 Posts
Usual cause for this for me (if it spins less than 3 times if I pick it off the ground and spin it) is brake pads rubbing. That definitely will slow you down and exhaust you over the course of a ride if you leave it unchecked.
PaulRivers is offline  
Old 03-18-16, 06:51 PM
  #14  
one4smoke
Senior Member
Thread Starter
 
Join Date: Jul 2015
Location: Nashville, TN.
Posts: 1,414

Bikes: 2016 Specialized Roubaix SL4 - 2015 Giant Roam 2 Disc

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Liked 13 Times in 9 Posts
Originally Posted by BlazingPedals View Post
This is a BSO from a department store, isn't it? It's easy to check if the Q/R is too tight - take it off and spin it in your hand. I suspect it's the bearings. They're either mis-adjusted too tight, not enough lube, or just plain bad.
No, it's a Giant Roam.
one4smoke is online now  
Old 03-18-16, 06:52 PM
  #15  
one4smoke
Senior Member
Thread Starter
 
Join Date: Jul 2015
Location: Nashville, TN.
Posts: 1,414

Bikes: 2016 Specialized Roubaix SL4 - 2015 Giant Roam 2 Disc

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Liked 13 Times in 9 Posts
Originally Posted by PaulRivers View Post
Usual cause for this for me (if it spins less than 3 times if I pick it off the ground and spin it) is brake pads rubbing. That definitely will slow you down and exhaust you over the course of a ride if you leave it unchecked.
Have disc brakes, and that's not the culprit.
one4smoke is online now  
Old 03-18-16, 07:00 PM
  #16  
one4smoke
Senior Member
Thread Starter
 
Join Date: Jul 2015
Location: Nashville, TN.
Posts: 1,414

Bikes: 2016 Specialized Roubaix SL4 - 2015 Giant Roam 2 Disc

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Liked 13 Times in 9 Posts
Originally Posted by avidone1 View Post
Sometimes I think we sweat the small stuff
Small? Maybe. Sweating? LOL ...hardly. Nevertheless, nothing wrong with wanting your bike to be running as smoothly as possible.
one4smoke is online now  
Old 03-18-16, 07:08 PM
  #17  
wphamilton
Senior Member
 
wphamilton's Avatar
 
Join Date: Apr 2011
Location: Alpharetta, GA
Posts: 14,438

Bikes: Nashbar Road

Mentioned: 58 Post(s)
Tagged: 0 Thread(s)
Quoted: 2461 Post(s)
Liked 27 Times in 20 Posts
The freewheeling doesn't cause any drag when you're applying power to the pedals. I'd take the wheel off and spin it holding the axle and the problem if any is likely cones too tight.
wphamilton is online now  
Old 03-18-16, 07:37 PM
  #18  
Oldguyonoldbike
Senior Member
 
Oldguyonoldbike's Avatar
 
Join Date: Sep 2014
Location: Norman, OK
Posts: 624

Bikes: Colnago Tecnos, Ciöcc Exige, Black Mountain Cycles Road

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 73 Post(s)
Liked 2 Times in 1 Post
Given the drag of the pawls in the rear hub, it won't spin for as long as the front wheel, but it should not come to an abrupt stop. Since it's a disc hub, I'll assume you have disc brakes. One of your brake pads may be dragging against the rotor. This could be caused by a slightly misaligned wheel, a bent rotor or a pad that needs to be adjusted. Aligning the wheel is no problem, nor is adjusting the brake pads (youtube is your friend). A bent rotor would need to be replaced.
Oldguyonoldbike 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 © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.