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

3/16 inch ball bearings in rear hub...heavy-duty enough?

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.

3/16 inch ball bearings in rear hub...heavy-duty enough?

Old 02-03-21, 01:07 AM
  #1  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
3/16 inch ball bearings in rear hub...heavy-duty enough?

Seems like I typically see 1/4in balls in rear hubs and 3/16 in the front.

I assume this is because the rear wheel sees more abuse and thus needs a heavier-duty bearing.

I got to wondering about these rear hubs I have that have a cup and cone, loose ball design and use ten 3/16 inch balls per side. Does the ball size alone tell me that they are an inferior design? Would you avoid the use of a rear hub w/ ten 3/16 inch balls per side?
mrmb is offline  
Old 02-03-21, 01:13 AM
  #2  
Bill Kapaun
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 12,535

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1304 Post(s)
Liked 500 Times in 385 Posts
I would be suspect.
Do you think you can maybe be gracious enough to provide the make & model number so we can better serve you.
GIGO.
Bill Kapaun is online now  
Likes For Bill Kapaun:
Old 02-03-21, 01:18 AM
  #3  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts

Shimano HB M756
mrmb is offline  
Old 02-03-21, 03:01 AM
  #4  
Bill Kapaun
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 12,535

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1304 Post(s)
Liked 500 Times in 385 Posts
Why do you ask questions about a rear hub and then show a front?
You can't even keep your own story straight.
I'm beginning to believe you are just a troll when looks at your other posts.
Bill Kapaun is online now  
Likes For Bill Kapaun:
Old 02-03-21, 03:42 AM
  #5  
HTupolev
Senior Member
 
Join Date: Apr 2015
Location: Seattle
Posts: 3,740
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 1709 Post(s)
Liked 778 Times in 392 Posts
Originally Posted by mrmb View Post

Shimano HB M756
That has 3/16" bearings because it wasn't designed as a rear hub. It's a front disc hub where somebody attached a cog where the disc rotor is designed to go, and also changed out the axle to re-space the hub, so that they could use it as a rear hub.

But the image you posted shows information detailing the process of doing this. It's confusing to me that you'd be using that image to show your hub without already knowing why it is the way that it is.

Last edited by HTupolev; 02-03-21 at 03:46 AM.
HTupolev is offline  
Likes For HTupolev:
Old 02-03-21, 03:52 AM
  #6  
Geepig
Senior Member
 
Geepig's Avatar
 
Join Date: Sep 2020
Location: Eastern Poland
Posts: 558

Bikes: Romet Jubilat x 4, Wigry x 1, Turing x 1

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 158 Post(s)
Liked 133 Times in 104 Posts
Originally Posted by mrmb View Post

Shimano HB M756
So this is a front wheel hub that has been set up to take a motor drive at the rear?

3/16" balls could indeed be to small for such an application, are there no rear hubs that could be used instead?
Geepig is offline  
Old 02-04-21, 03:21 PM
  #7  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by HTupolev View Post
That has 3/16" bearings because it wasn't designed as a rear hub. It's a front disc hub where somebody attached a cog where the disc rotor is designed to go, and also changed out the axle to re-space the hub, so that they could use it as a rear hub.

But the image you posted shows information detailing the process of doing this. It's confusing to me that you'd be using that image to show your hub without already knowing why it is the way that it is.
I am aware of what it is, why it is the way that it is etc.

Thats not what I was asking.

I was asking a generalized question about 3/16 balls being in a hub that is in the rear position.

I am not asking a product specific question, but rather a question about how much load and use a 3/16 ball bearing equiped hub can tolerate when used in the rear. And that, relative to 1/4 inch balls.
mrmb is offline  
Old 02-04-21, 03:28 PM
  #8  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by Geepig View Post
So this is a front wheel hub that has been set up to take a motor drive at the rear?

3/16" balls could indeed be to small for such an application, are there no rear hubs that could be used instead?
There are other hubs that could be used, but thats not really the question. But since you asked...

I selected this hub because it is the best hub that I could find that is suitable for commuting year round, 120mm spacing, fixed gear, 42mm chainline, uses a cog interface that is NOT threaded.....and most importantly....the loose ball bearings are WELL SEALED.

Now that this is out of the way....

What I was getting at is the use of 3/16 balls in the rear and how well they would hold up. I also notice that Formula track hubs, front and rear, use 3/16 balls and Formula hubs are pretty common at the track.
mrmb is offline  
Old 02-04-21, 03:35 PM
  #9  
base2 
Random Internet Person.
 
base2's Avatar
 
Join Date: Jun 2015
Location: Pacific Northwest
Posts: 1,567

Bikes: 5 good ones, and the occasional project.

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 796 Post(s)
Liked 377 Times in 232 Posts
Is there a reason you just couldn't slam a cog on a freehub body & use a bunch of spacers to make up the difference? 120mm freehub.

This has sketchy written all over it.

FWIW: Smaller bearing balls are weaker & will crush into the bearing race much sooner on their way to to becoming tiny oval shaped rocks of crunch. There is a reason rear hubs have 4 (count 'em 1, 2, 3, 4) 6902 bearings & front hubs have only 2. It's because the load on the rear is greater. Both in terms of the mass supported, but also the additional loads involved in propelling the bicycle.

Anecdote time: IME Formula hubs are garbage. My wifes mountain bike got about 6 road rides on it before it got notched & crunchy. My road bike front got about 3000 miles before it seized near solid. The front wheel would spindown in about 5 seconds. Cheap, worthless. Formula is a brand to be avoided.

Track rear hubs are not road front hubs.

Subscribed.


Edit: JBI bike has it. Not in stock. Can be drop shipped. Your bikeshop can probably order it as JBI is one of the largest bike parts distributors in North America SunXCD 1 thru 6 speed free hub 120mm OLN 32 hole.

Last edited by base2; 02-04-21 at 03:58 PM.
base2 is offline  
Old 02-04-21, 03:39 PM
  #10  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by Bill Kapaun View Post
Why do you ask questions about a rear hub and then show a front?
You can't even keep your own story straight.
I'm beginning to believe you are just a troll when looks at your other posts.
Did you notice that the front hub was turned into a rear hub?

Additionally, my query was a general one, not a product specific one. When speaking in general terms about the suitability of 3/16 balls in a hub that is in the rear of a bicycle, it becomes moot to include product specific information as all it does is add confusion and bring the discussion in an unintended direction. This, my friend, is exactly why I did not say what hub I was using. But since you insisted in part numbers to "better serve" a general and rather non-product specific query I kindly provided that info even though I knew it was pointless. It was no different with you in another thread where you insisted on irrelevant information divulgence.
mrmb is offline  
Old 02-04-21, 03:50 PM
  #11  
Iride01
Hits [ENTER] b4 thinking
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 6,358

Bikes: '20 Tarmac Disc Comp '91 Schwinn Paramount '78 Raleigh Competition GS

Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 2477 Post(s)
Liked 1,173 Times in 854 Posts
No matter what size bearings was used by the manufacturer for their hub, there isn't really any assumption you can make about the durability of that design based solely on the bearing size. There are other components that are just as or more important. And the person or team that designed it probably took all the reasonable issues into account when they designed it.

I'd think your only question should be whether a component is appropriate for the use you want to make of it. Just because it's a bicycle hub doesn't mean it's for every bicycle. Particularly if you are talking about E-bikes as the motor adds different forces and dynamics to the issue.
Iride01 is offline  
Old 02-04-21, 03:50 PM
  #12  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by base2 View Post
Is there a reason you just couldn't slam a cog on a cassette & use a bunch of spacers to make up the difference?
Well, call it my religious devotion to riding a fixed gear bicycle.

Originally Posted by base2 View Post
FWIW: Smaller bearing balls are weaker & will crush into the bearing race much sooner on their way to to becoming tiny ovals. There is a reason rear hubs have 4 (count 'em 1, 2, 3, 4) 6902 bearings & front hubs have only 2. It's because the load on the rear is greater. Both in terms of the mass supported, but also the additional loads involved in propelling the bicycle.

Subscribed.
This is the kind of discussion discussion I am looking for. Thank you.

So, in thinking this through, it seems as though this set-up would be less forgiving. I wonder if keeping up on greasing the bearings and keeping water out would ensure a long life. Never letting grease dry out, wear out etc. etc.
mrmb is offline  
Old 02-04-21, 03:57 PM
  #13  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by Iride01 View Post
No matter what size bearings was used by the manufacturer for their hub, there isn't really any assumption you can make about the durability of that design based solely on the bearing size. There are other components that are just as or more important. And the person or team that designed it probably took all the reasonable issues into account when they designed it.
I see your point. Thanks for the comments.

Often times (every time?) the only difference between a front and rear matched hub set, in regards to the axle shaft set up, is the bearings and that why I was focusing on that component in particular.
mrmb is offline  
Old 02-04-21, 04:02 PM
  #14  
base2 
Random Internet Person.
 
base2's Avatar
 
Join Date: Jun 2015
Location: Pacific Northwest
Posts: 1,567

Bikes: 5 good ones, and the occasional project.

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 796 Post(s)
Liked 377 Times in 232 Posts
Originally Posted by mrmb View Post
Well, call it my religious devotion to riding a fixed gear bicycle.



This is the kind of discussion discussion I am looking for. Thank you.

So, in thinking this through, it seems as though this set-up would be less forgiving. I wonder if keeping up on greasing the bearings and keeping water out would ensure a long life. Never letting grease dry out, wear out etc. etc.
Oops, I was caught in an editing moment. No worries that you wanted fixed gear specifically & not single speed. Fair enough.

It's not an issue of grease & contaminants, but of service life & metallurgy/metal fatigue.

Interested in seeing how this turns out.
Base2
base2 is offline  
Old 02-04-21, 04:18 PM
  #15  
Bill Kapaun
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 12,535

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1304 Post(s)
Liked 500 Times in 385 Posts
Originally Posted by mrmb View Post
Seems like I typically see 1/4in balls in rear hubs and 3/16 in the front.

I assume this is because the rear wheel sees more abuse and thus needs a heavier-duty bearing.

I got to wondering about these rear hubs I have that have a cup and cone, loose ball design and use ten 3/16 inch balls per side. Does the ball size alone tell me that they are an inferior design? Would you avoid the use of a rear hub w/ ten 3/16 inch balls per side?
You presumed that was common.
Taking a front hub and using it on the rear isn't going to change the size of the Bearing Balls or make it a rear hub.
It's just a front hub being used for an unintended purpose.
Your premise is simply full of holes.
Ignore list. I have better things to do, even if it's staring off in space.
Bill Kapaun is online now  
Old 02-04-21, 04:45 PM
  #16  
well biked 
biked well
 
well biked's Avatar
 
Join Date: Jul 2005
Posts: 7,351
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 102 Post(s)
Liked 42 Times in 31 Posts
As an aside, after qutie a few years in the bike business, I've only seen something fairly similar to this once. It was a rear, disc brake mountain bike hub flipped around to have the rotor mounting holes on the drive side, so that a six-hole fixed cog could be bolted on (like in the OP's pics), and no rear brake would be used. This was on a mountain bike, I believe it was a Surly Ogre with a rear-opening dropout, to be ridden on technical mountain bike trails. I thought the bike's owner was nuts for having a setup like this for off-road riding, but after knowing him for several years now, I realize that he just likes to try different things on bikes, and he's actually quite good at riding that fixed gear mountain bike on technical trails. We all laughed when he described hopping over logs on the bike, he said the biggest challenge is the position of the pedals at the critical moment. But, he said, "when it does come out right it's an amazing feeling."

My little story has no bearing (pun intended) on the OP's question, however.
well biked is offline  
Old 02-04-21, 06:18 PM
  #17  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by Bill Kapaun View Post
You presumed that was common.
Taking a front hub and using it on the rear isn't going to change the size of the Bearing Balls or make it a rear hub.
It's just a front hub being used for an unintended purpose.
Your premise is simply full of holes.
Ignore list. I have better things to do, even if it's staring off in space.
I said ..."I got to wondering about these rear hubs I have that have a cup and cone, loose ball design and use ten 3/16 inch balls per side"...I never said anything about thinking it was common, in fact I am aware that it is somewhat uncommon. Formula hubs have 3/16 balls in the rear. And Velosolo sells this set-up and swears by it. They sell parts to do this and by the looks of it they sell hundreds of cogs for this very set up. While not unheard of, it is not common.

I totally get that the hub was designed for front duty.

I don't have a "premise" here nor did I ever. I was questioning the use of 3/16 balls in rear hub duty. This is a query........not a premise. If you think I had a premise here, I would love to know what it was.

Have fun with the better things out there...
mrmb is offline  
Old 02-04-21, 08:33 PM
  #18  
ShannonM
Senior Member
 
Join Date: Jul 2020
Location: Humboldt County, CA
Posts: 265
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Likes: 0
Liked 119 Times in 80 Posts
So, what you've got here is an MTB front disc hub hacked into a fixed-gear MTB rear hub, right?

Here's the thing: It's a hack. It's a neat hack, and I like neat hacks, so I get it. (I once converted a 26" 48-hole tandem rear wheel with a Phil Wood freewheel / drum brake hub to a flip-flob singlespeed MTB rear wheel by re-spacing the axle to be centered in the hub and un-dishing the wheel.)

Thing is, all hacks, even the neat ones, have limitations. In this case, the limitation is that the hub is just not going to live as long as a real fixed-gear MTB hub.

Most likely failure mode: Bent axle or pitted races.

Build it up and ride it 'till it dies. (The Bike Hacker's Ethic)

--Shannon
ShannonM is offline  
Old 02-04-21, 10:15 PM
  #19  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by ShannonM View Post
So, what you've got here is an MTB front disc hub hacked into a fixed-gear MTB rear hub, right?

--Shannon
MTB front disc hub hacked into a fixed gear TRACK/ROAD rear hub to be exact. No MTB use intended with the hack.
mrmb is offline  
Old 02-04-21, 10:23 PM
  #20  
Gresp15C
Senior Member
 
Gresp15C's Avatar
 
Join Date: Sep 2014
Posts: 3,536
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 936 Post(s)
Liked 458 Times in 307 Posts
Will the axle be the correct diameter for rear wheel use?
Gresp15C is offline  
Old 02-05-21, 12:28 AM
  #21  
Geepig
Senior Member
 
Geepig's Avatar
 
Join Date: Sep 2020
Location: Eastern Poland
Posts: 558

Bikes: Romet Jubilat x 4, Wigry x 1, Turing x 1

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 158 Post(s)
Liked 133 Times in 104 Posts
Originally Posted by mrmb View Post
There are other hubs that could be used, but thats not really the question. But since you asked...

I selected this hub because it is the best hub that I could find that is suitable for commuting year round, 120mm spacing, fixed gear, 42mm chainline, uses a cog interface that is NOT threaded.....and most importantly....the loose ball bearings are WELL SEALED.

Now that this is out of the way....

What I was getting at is the use of 3/16 balls in the rear and how well they would hold up. I also notice that Formula track hubs, front and rear, use 3/16 balls and Formula hubs are pretty common at the track.
Thanks for answering, as an R&D engineer I get to do a lot of crazy things, but one thing I know is that the better you describe your aims and reasoning the better anyone can help. Sure, some people will always try to discourage you, but stuff is just stuff, and nothing has to be what it is packaged to be.

For me the 3/16" balls in a sealed bearing is a good commuter option, unless you are a hard rider who has to hit those green lights and play with the buses and taxis. I would be careful of making comparisons with performance under other conditions, such as racing - where the equipment used has a lot more engineering work behind it, better materials and is regularly maintained and replaced. The great thing is that even if it does disintegrate you learn something, and before that does or does not happen you have time to more extensively review the options and plan to include any other ideas you might have.
Geepig is offline  
Old 02-05-21, 09:13 AM
  #22  
Ross200
Senior Member
 
Join Date: Feb 2019
Posts: 57
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 16 Post(s)
Liked 7 Times in 7 Posts
FWIW, upper level (XT/Ultegra and above)Shimano rear road and mtb hubs have used 3/16 in balls for some time. Not enough riders were wearing out hubs fast enough to support Shimano's program of planned obsolescence, so changes were in order. In the case of the XT FH-M770, the free hub body shatters prematurely before the bearings fail, so the longevity of the bearings is a moot issue.

Disc brakes put more stress on hubs than many people think.

Depending on your personal power output and the vertical component of your riding, hub shell failure and bent axles are far more likely than bearing failure.

Awaiting test reports-
Ross200 is offline  
Old 02-06-21, 12:21 AM
  #23  
mrmb
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 196
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by Gresp15C View Post
Will the axle be the correct diameter for rear wheel use?
These come with a 10mm axle, same as rears.
mrmb is offline  
Old 02-06-21, 02:05 AM
  #24  
dabac
Senior Member
 
Join Date: Mar 2008
Posts: 8,453
Mentioned: 45 Post(s)
Tagged: 0 Thread(s)
Quoted: 1000 Post(s)
Liked 196 Times in 147 Posts
So buy the spin-on disc brake adapter Iíve posted about earlier. Install on a 120 mm track hub. Install your 6-bolt sprocket to the spin-on adapter. Install on bike. Ride on into the sunset, happily ever after, on a rear hub meant to be a rear hub.
dabac is offline  
Old 02-06-21, 07:40 AM
  #25  
tommymc
Member
 
Join Date: Sep 2012
Location: Central Florida
Posts: 34

Bikes: Many, mostly old & low tech

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Liked 7 Times in 4 Posts
The 9mm axles typically on front hubs may be a little more of a problem than ball size. But a longer solid 10mm axle should be possible to use for this fixed setup. I've done that on two front disk hubs, a Deore and a Formula. I think on the last one I used a 185mm long 10mm leaving plenty of room for spacers and outside nuts. The idea of bolting cogs directly to a disk mount is attractive. Drilled cogs in various sizes are available for less than $20 and are probably easier to change than a thread-on cog with locking ring. Another advantage is the option to set up a double cog (twingle) using small thick washers on the screws as spacers between the cogs.
tommymc is offline  

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.