Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 10-30-07, 07:28 PM   #1
Turd Ferguson
LMLN
Thread Starter
 
Turd Ferguson's Avatar
 
Join Date: Oct 2006
Location: Toronto,On
Bikes: Marin Novato, Argon Krypton, Jamis Aurora, IRO Mark V
Posts: 567
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Wobbling/unbalanced Rear End.

With my new Jamis Aurora touring bike I suspect the rear wheel requires balancing of some sort. When on the bike stand I spin the rear tire at a fast rate and it seems to bounce up and down. At first I suspected the rim might be distorted but it seems fine, perhaps it's not perfect and required wheel truing? Or could it be the crappy stock tires they put on? Upon close examintation the tire does seem a little malformed.

It's a very noticeable vibration, if I hold the bike up from the seat post and spin the tire it's very noticeable...almost too much.

Any ideas what may be causing the problem and how I can remedy it?

Thanks

Last edited by Turd Ferguson; 10-30-07 at 07:34 PM.
Turd Ferguson is offline   Reply With Quote
Old 10-30-07, 07:46 PM   #2
Air
Destroyer of Wheels
 
Air's Avatar
 
Join Date: May 2006
Location: Creating some FA-Qs
Bikes: Nishiki Sport, Downtube IXNS, 1950's MMB3 Russian Folding Bike, MTB
Posts: 3,598
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Does the tire jump up and down or does the rim jump?

If it's the tire it's probably not seated right, you may have to deflate it and make sure the bead around the entire tire is on the rim.

If it's the rim you may either have a flat spot from hitting something or the wheel isn't trued.

The lbs you bought it from should be able to fix either problem under warranty if it is new.
__________________
The Almighty Clyde FAQ || Northeast Index
eTrex Vista References || Road Reference


It's the year of the enema!
Air is offline   Reply With Quote
Old 10-30-07, 07:47 PM   #3
nadimk
Senior Member
 
Join Date: Oct 2007
Bikes:
Posts: 81
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Remove and reseat the tube and tire. Some vertical wobble is always there because of the valve.
nadimk is offline   Reply With Quote
Old 10-30-07, 08:03 PM   #4
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've balanced that vertical wobble out with lead tape on one bike. On the road I'm not sure I could tell the difference.
vpiuva is offline   Reply With Quote
Old 10-30-07, 09:15 PM   #5
Al1943
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Bikes: Trek 5500, Colnago C-50
Posts: 9,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Turn the wheel slowly next to a fixed object with and without the tire to see which is out-of-round.
If the tire is seated properly and the rim is round but the tire is still out-of-round then you may have a defective tire, it's happened to me.

Al
Al1943 is offline   Reply With Quote
Old 10-31-07, 06:51 AM   #6
tellyho
Your mom
 
Join Date: Aug 2006
Bikes:
Posts: 2,541
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would definitely suspect a funky tire rather than an out-of-round rim.
tellyho is offline   Reply With Quote
Old 10-31-07, 09:43 AM   #7
San Rensho 
Senior Member
 
Join Date: Oct 2005
Bikes:
Posts: 5,548
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
If you spin the rear wheel fast of ANY bike in a bike stand, the whole thing will vibrate like crazy. Perfectly normal.

Now, if it vibrates like that on the road, then definitely do the above posted checks.
__________________
Il faut de l'audace, encore de l'audace, toujours de l'audace

1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1
San Rensho is offline   Reply With Quote
Old 10-31-07, 09:48 AM   #8
rmfnla
Senior Member
 
rmfnla's Avatar
 
Join Date: May 2005
Location: La La Land (We love it!)
Bikes: Gilmour road, Curtlo road; both steel (of course)
Posts: 6,049
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 156 Post(s)
Quote:
Originally Posted by San Rensho View Post
If you spin the rear wheel fast of ANY bike in a bike stand, the whole thing will vibrate like crazy. Perfectly normal.

Now, if it vibrates like that on the road, then definitely do the above posted checks.
I was wondering if anyone would catch this; nice one, SR.

BTW, your weight on the bike eliminates this when you are riding.
__________________
Today, I believe my jurisdiction ends here...

Last edited by rmfnla; 10-31-07 at 02:53 PM.
rmfnla is offline   Reply With Quote
Old 10-31-07, 10:55 AM   #9
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by San Rensho View Post
If you spin the rear wheel fast of ANY bike in a bike stand, the whole thing will vibrate like crazy. Perfectly normal.

Now, if it vibrates like that on the road, then definitely do the above posted checks.
On cheap bikes it'll do this yes. Espeically ones with fat tires that don't seat correctly. There's also an important distinction between normal bounce in the stand and bounce because of an improperly seated tire.
operator is offline   Reply With Quote
Old 10-31-07, 06:54 PM   #10
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by San Rensho View Post
If you spin the rear wheel fast of ANY bike in a bike stand, the whole thing will vibrate like crazy.
Not the ones I balanced with lead tape. Spun smooth at any speed. Only took a few grams of tape. But I don't think it made any difference on the road
vpiuva is offline   Reply With Quote
Old 11-01-07, 09:51 AM   #11
rmfnla
Senior Member
 
rmfnla's Avatar
 
Join Date: May 2005
Location: La La Land (We love it!)
Bikes: Gilmour road, Curtlo road; both steel (of course)
Posts: 6,049
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 156 Post(s)
Quote:
Originally Posted by vpiuva View Post
Not the ones I balanced with lead tape. Spun smooth at any speed. Only took a few grams of tape. But I don't think it made any difference on the road
You can also use split-shot (small fishing sinkers) crimped onto the spokes for this.

(See? I'm anal, too!)
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline   Reply With Quote
Old 11-01-07, 09:55 AM   #12
Matt Gaunt
Senior Member
 
Matt Gaunt's Avatar
 
Join Date: Oct 2004
Location: London, UK
Bikes:
Posts: 2,245
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by rmfnla View Post
You can also use split-shot (small fishing sinkers) crimped onto the spokes for this.

(See? I'm anal, too!)
You guys ADD weight? Why would you do that? Why?
__________________
Matt
2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics
Matt Gaunt is offline   Reply With Quote
Old 11-01-07, 11:02 AM   #13
Little Darwin
The Improbable Bulk
 
Little Darwin's Avatar
 
Join Date: Jul 2005
Location: Wilkes-Barre, PA
Bikes: Many
Posts: 8,401
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by Matt Gaunt View Post
You guys ADD weight? Why would you do that? Why?
Yeah! Maybe a better solution is to replace the nipples on the other side of the rim with lighter nipples. Weight weenie savings and satisfy the anal retentive need for perfect balance.
Little Darwin is offline   Reply With Quote
Old 11-01-07, 03:01 PM   #14
San Rensho 
Senior Member
 
Join Date: Oct 2005
Bikes:
Posts: 5,548
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Quote:
Originally Posted by vpiuva View Post
Not the ones I balanced with lead tape. Spun smooth at any speed. Only took a few grams of tape. But I don't think it made any difference on the road
I was going to say, that balacing bicycle wheels is probably overkill from a functional perspective. Even on very fast descents, 50 mph+, I have never had a wheel feel unbalanced. With the low mass of wheels, I think you would have to really get them spinning before you felt any vibration.
__________________
Il faut de l'audace, encore de l'audace, toujours de l'audace

1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1
San Rensho is offline   Reply With Quote
Old 11-02-07, 10:46 AM   #15
rmfnla
Senior Member
 
rmfnla's Avatar
 
Join Date: May 2005
Location: La La Land (We love it!)
Bikes: Gilmour road, Curtlo road; both steel (of course)
Posts: 6,049
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 156 Post(s)
Quote:
Originally Posted by San Rensho View Post
I was going to say, that balacing bicycle wheels is probably overkill from a functional perspective. Even on very fast descents, 50 mph+, I have never had a wheel feel unbalanced. With the low mass of wheels, I think you would have to really get them spinning before you felt any vibration.
Agreed (guess this is your day, SR! ).

My comment about the split shot was kinda in jest although I have seen people do it. I love fast mountain descents (like that last section in the Rosarita-Encinata ride!) and have never noticed a wheel being out of balance.

I don't think there's enough weight variation and/or speed involved for it to matter.
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 10:35 AM.