Go Back  Bike Forums > Bike Forums > General Cycling Discussion
Reload this Page >

Ball bearing size and quantity query

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!

Ball bearing size and quantity query

Old 03-21-16, 01:34 PM
  #1  
miracle914
Newbie
Thread Starter
 
Join Date: Mar 2016
Location: Florida
Posts: 1

Bikes: Giant

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Ball bearing size and quantity query

Hi Guys,

I recently got a Giant Sedona 2012 but found some play in the rear wheel bearings.
I took it apart and I found that one side looked good but the drive side contained 9 x 1/4 in balls with a large gap. Inside the axle there was a tenth ball which I thought must fit in the gap. No way, it was just slightly too big to fit.
I took the wheel to a bike shop and they just refitted the shaft with the original 9 bearings which they said was OK.
My question is should there be any gap in the bearings (almost a 1/4 inch in total) or should there have been maybe 10 or 11 smaller bearings which would fit snuggly?
Also not sure if it is a Giant back wheel as it is heavier duty than the front and is not marked "Giant"

Trying to learn fast
miracle914 is offline  
Old 03-21-16, 01:48 PM
  #2  
J.C. Koto
apocryphal sobriquet
 
Join Date: May 2008
Location: Star City, NE
Posts: 1,076

Bikes: 2008 Surly Long Haul Trucker "The Truckerino"

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked 0 Times in 0 Posts
9 x 1/4-inch ball bearings per side sounds right for a normal rear hub. It's not supposed to be a tight fit so a gap is normal.

Also, Sheldon Brown's site is an excellent resource of knowledge for people just learning or anybody else for that matter. If you like, you can start reading from the beginner's page.

Last edited by J.C. Koto; 03-21-16 at 01:51 PM.
J.C. Koto is offline  
Old 03-21-16, 02:10 PM
  #3  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 36,049

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 121 Post(s)
Tagged: 1 Thread(s)
Quoted: 4339 Post(s)
Likes: 0
Liked 1 Time in 1 Post
A gap, typically less than what one ball would fit is both normal, and necessary to the function of a ball bearing.

A properly built, and/or adjusted will have all balls in contact and under a slight load at all times. The overall bearing load from the weight on the axle is added to the load at the bottom, but unless the bearing is overloaded, doesn't change the other loads.

As such the force on the balls is purely radial, and happenstance and the lube's hydraulic pressure will cause the balls to spread themselves out somewhat equally. If the balls were overcrowded and made contact with each other it would prevent that natural spreading and cause friction as the adjacent ball surfaces rubbed past each other.

By the same token, a no gap design would make bearing construction nearly impossible, because ball to ball contact would prevent the radial contact necessary. By the same token, if the gap is too large the load might force the axle down slightly between the lowest balls, spreading them apart, and increasing both wear and vibration.

As for your 10th ball, odds are that it came from the other side, though on some hubs there's a recess behind the cup where an extra ball that was dropped during assembly could hide harmlessly until discovered by the first person to look.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Old 03-21-16, 02:32 PM
  #4  
VegasTriker
Senior Member
 
Join Date: Feb 2006
Location: Sin City, Nevada
Posts: 2,101

Bikes: Catrike 700, Greenspeed GTO trike, , Linear LWB recumbent, Haluzak Horizon SWB recumbent, Balance 450 MTB, Cannondale SM800 Beast of the East

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 297 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
I just picked up a used Specialized Hardrock bike to refurbish and have the rear hub apart. There are 18 1/4" balls - 9 on each side.
VegasTriker 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.