Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

A weighted wheel

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

A weighted wheel

Old 12-26-09, 09:51 PM
  #1  
bbllaakke
Senior Member
Thread Starter
 
bbllaakke's Avatar
 
Join Date: Sep 2008
Location: Michigan
Posts: 193

Bikes: Raleigh Sports, Giant Cadex, Waterford X-11, Specialized Rockhopper Comp FS, Viscount Aerospace Pro, Scwinn Passage

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
A weighted wheel

When a bike is in the stand with a wheel spinning, it shakes the bike, which leads me to believe the wheel has one heavy spot. The wheel is laterally true and slightly out of vertical true. Is this the sign of a poorly built wheel?
bbllaakke is offline  
Old 12-26-09, 09:59 PM
  #2  
Yan 
BeaverTerror
 
Yan's Avatar
 
Join Date: Jan 2006
Location: Shanghai, China
Posts: 2,006

Bikes: 1995 Kestrel 4000; 2013 True North Touring; 1989 Miele Tivoli; 1979 Colnago Sport

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 382 Post(s)
Likes: 0
Liked 1 Time in 1 Post
The weld line in the rim and the valve are both heavier than the rest of wheel. That said, my bike does not shake when I spin the wheel in the stand. I'd make sure the wheel is true before jumping to conclusions.
__________________
Yan
Yan is offline  
Old 12-26-09, 10:05 PM
  #3  
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Posts: 5,466

Bikes: Norco (2), Miyata, Canondale, Soma, Redline

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
No, it's a sign that the valve stem is really heavy. Or far more likely, since as mentioned the weld or joint and the stem are opposite and thus cancel each other to some extent, the tire tread is out of true and has a thicker and heavier zone that is the issue.

It's not a problem though since normal riders don't get anywhere near fast enough to feel anything due to this. And the racers that perhaps could feel it while screaming down a downhill are using tires that are better constructed.
BCRider is offline  
Old 12-26-09, 10:14 PM
  #4  
Kimmo 
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,386

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1361 Post(s)
Liked 592 Times in 417 Posts
I seem to recall sticking my speedo sensor on the back wheel to see when this wobble kicked in and found it starting around 40km/h.

Can't think why else I would've gone to the hassle of balancing my wheels with blobs of electrical solder under the rim tape, unless it was down to a hatred of the pendulum look when a wheel's allowed to spin to a stop...
Kimmo is offline  
Old 12-26-09, 11:33 PM
  #5  
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,561
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 684 Post(s)
Liked 332 Times in 221 Posts
Originally Posted by Kimmo View Post
I seem to recall sticking my speedo sensor on the back wheel to see when this wobble kicked in and found it starting around 40km/h.

Can't think why else I would've gone to the hassle of balancing my wheels with blobs of electrical solder under the rim tape, unless it was down to a hatred of the pendulum look when a wheel's allowed to spin to a stop...
One rider I met wrapped solder around spokes opposite the "heavy" spot. He swore it made a difference, but I'm skeptical. Maybe it was the aluminum-foil beanie he was wearing...
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline  
Old 12-26-09, 11:46 PM
  #6  
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Posts: 12,258

Bikes: Bianchi, Miyata, Dahon, Rossin

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
rim or tire is unbalanced.

let the wheel spin freely and you'll see the heavy spot go to the bottom.
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
https://sanfrancisco.ibtimes.com/arti...ger-photos.htm
AEO is offline  
Old 12-27-09, 12:24 AM
  #7  
urbanknight
Over the hill
 
urbanknight's Avatar
 
Join Date: Mar 2006
Location: Los Angeles, CA
Posts: 22,827

Bikes: Specialized Allez Elite, Raleigh Pursuit tandem

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 142 Post(s)
Liked 166 Times in 104 Posts
The seam is heavy. It's normal and it's not a problem. I've been to 50 mph without issue.
__________________
It's like riding a bicycle
urbanknight is offline  
Old 12-27-09, 04:20 AM
  #8  
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Posts: 11,736
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 108 Post(s)
Liked 6 Times in 4 Posts
As others mentioned, the actual RPMs of a bike's wheel isn't fast enough at the speeds achieved by a bike for the imbalance to be an issue. Also the overall light weight of the wheel makes any minor imbalance appear worse than it really is when it's unloaded. A couple grams of imbalance when weighted down by the rider+bike weight isn't going to be an issue.

I've tested this by adding 5-10gm lead-weights to the opposite side of the wheel to even out the imbalance. No change in high-speed stability of the bike (50mph+). As a confirmation test, I moved the weight to the already-heavy side of the wheel to double the imbalance and no difference there either. A third test with 5x the imbalance weight added to the heavy side of the wheel to really throw off the balance yielded no perceptible difference either.
DannoXYZ is offline  
Old 12-27-09, 05:50 AM
  #9  
Kimmo 
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,386

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1361 Post(s)
Liked 592 Times in 417 Posts
Fair enough... it's only worth doing then if you really can't bear the occasional display of pendulum effect...

Pretty cool though if your wheel takes ages to stop and doesn't roll back and forth to finish : )
Kimmo is offline  
Old 12-27-09, 09:19 AM
  #10  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 32,903

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 1686 Post(s)
Likes: 0
Liked 564 Times in 417 Posts
Originally Posted by Kimmo View Post
Fair enough... it's only worth doing then if you really can't bear the occasional display of pendulum effect...

Pretty cool though if your wheel takes ages to stop and doesn't roll back and forth to finish : )
I like a bit of the pendulum effect. It assures me the bearings are smooth and have minimal friction.

The OP mentioned "...slightly out of vertical true". Depending on how bad the "hop" is, it is more likely the cause of the shake.
HillRider is offline  
Old 12-27-09, 09:35 AM
  #11  
davidad
Senior Member
 
Join Date: Feb 2009
Posts: 6,509
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 525 Post(s)
Likes: 0
Liked 130 Times in 110 Posts
Don't worry about it. Balancing a bike wheel and tire doesn't do any good and is not necessary.
davidad is offline  
Old 12-27-09, 11:27 AM
  #12  
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Posts: 5,466

Bikes: Norco (2), Miyata, Canondale, Soma, Redline

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by Kimmo View Post
.......unless it was down to a hatred of the pendulum look when a wheel's allowed to spin to a stop...

That made me smile. But it was a smile of comradeship.... I suspect that enthusiasts such as found on this forum all obsess over some small matter that makes no noticable difference at some time or other. For me it was mixing oil with the bearing grease until it almost wouldn't run just so the bearings on my old classic Campy hubs would have the absolute minimum resistance while still being "greased" instead of "just oiled"....
BCRider is offline  
Old 12-27-09, 11:36 AM
  #13  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 32,903

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 1686 Post(s)
Likes: 0
Liked 564 Times in 417 Posts
Originally Posted by BCRider View Post
For me it was mixing oil with the bearing grease until it almost wouldn't run just so the bearings on my old classic Campy hubs would have the absolute minimum resistance while still being "greased" instead of "just oiled"....
Thread drift alert!

Weren't older Campy hubs fitted with oil-ports that would allow you to add oil to the bearings without having to disassemble the hub? For truly minimum friction all you had to do was add a few drops of oil before every ride. John Forester in his book "Effective Cycling" recommends oil for hub bearings and even gives directions on how to add oil ports to hubs that didn't come with them.
HillRider is offline  
Old 12-27-09, 03:39 PM
  #14  
freako
Banned
 
Join Date: Feb 2006
Posts: 497
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
If it doesn't vibrate on the road then don't worry about it. If it vibrates all the time on road at any speed then the issue is the wheel. If it only vibrates at a certain range of speed like between 20 and 25 then it's a harmonic problem meaning the wheel and/or tire is incorrectly balance. In this case check to make sure the speed sensor is directly opposite of the valve stem (the valve cap is not an issue since it weighs about 1 gram). Then do the pendulum effect thing another poster mentioned to find the heavy side, but do it several times to make sure it's not a randam chance. Sometimes the tire may be slightly heaver on one side and simply moving the tire 1/4th a turn on the rim will even it out, if not move it another 1/4th a turn till the pendulum effect is no longer favoring one side.
freako is offline  
Old 12-27-09, 04:21 PM
  #15  
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,561
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 684 Post(s)
Liked 332 Times in 221 Posts
Originally Posted by HillRider View Post
Thread drift alert!

Weren't older Campy hubs fitted with oil-ports that would allow you to add oil to the bearings without having to disassemble the hub? For truly minimum friction all you had to do was add a few drops of oil before every ride. John Forester in his book "Effective Cycling" recommends oil for hub bearings and even gives directions on how to add oil ports to hubs that didn't come with them.

Just drifting in here... you could put oil in hub bearings if you wanted in various hubs up until the late '80's or so. The advantage was a tiny bit less bearing drag. The disadvantage was that the oil needed to be added every couple rides or so, and it would flow out and collect on the outside of the hub and spray on the rim if you were over-enthusiastic.

Here's an early-'80's set of Shimano 600EX cassette hubs with oil holes:

__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline  
Old 12-27-09, 05:57 PM
  #16  
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Posts: 11,736
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 108 Post(s)
Liked 6 Times in 4 Posts
I use Mobil-1 85-90wt tranny oil in the hubs of my track bike, reaaallly smooth! The wheels spin forever, although they do pendulum at the very end. Only problem is the oil only lasts about 1-2 days max. Perhaps I can experiment with mixing in a little grease...
DannoXYZ is offline  
Old 12-27-09, 06:37 PM
  #17  
Kimmo 
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,386

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1361 Post(s)
Liked 592 Times in 417 Posts
Heh... proposed forum subsection: The Anal Corner ; )

...Where you can discuss such matters as the perfect length of ally bolt to secure your BB cable guide and so forth...
Kimmo is offline  
Old 12-27-09, 07:03 PM
  #18  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 32,903

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 1686 Post(s)
Likes: 0
Liked 564 Times in 417 Posts
Originally Posted by Kimmo View Post
Heh... proposed forum subsection: The Anal Corner ; )

...Where you can discuss such matters as the perfect length of ally bolt to secure your BB cable guide and so forth...
You are too late. That forum is already well established. Read any thread here for details.
HillRider is offline  
Old 12-27-09, 07:05 PM
  #19  
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Posts: 28,353

Bikes: 1987 Bianchi Campione

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Likes: 0
Liked 23 Times in 17 Posts
Wheel balancing comes into play when the rider starts doing high speed descents.
operator is offline  
Old 12-27-09, 07:09 PM
  #20  
Kimmo 
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,386

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1361 Post(s)
Liked 592 Times in 417 Posts
Yeah, given the amount an upside-down bike can wobble around when the back wheel's cranked as fast as it will go, I wouldn't be surprised if you could feel it >100km/h.
Kimmo is offline  
Old 12-28-09, 01:46 AM
  #21  
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Posts: 11,736
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 108 Post(s)
Liked 6 Times in 4 Posts
Originally Posted by Kimmo View Post
Yeah, given the amount an upside-down bike can wobble around when the back wheel's cranked as fast as it will go, I wouldn't be surprised if you could feel it >100km/h.
Add 150lbs of lead-weights to the bottom of the saddle on the upside-down bike and see how much wobble you get.
DannoXYZ is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
oneidabow1
Bicycle Mechanics
8
01-10-16 08:05 AM
Deontologist
Bicycle Mechanics
21
10-28-15 12:47 PM
Pukeskywalker
Bicycle Mechanics
18
03-14-13 05:10 PM
adlai
Bicycle Mechanics
6
04-28-10 06:07 AM
tspek
Road Cycling
33
02-24-10 04:49 PM

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 - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.