Tandem hub bearing question

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Dear all,

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.

What sort of hub?

Quoted message said:

I have bought a solid spindle as this will be stronger.

Maybe. The tandem hub I've had with the bent axle was a solid one. The ones
which are up to the job are hollow. (but they are on cassette hubs, ie the
loads are more sensible).

Quoted message said:

My bike shop gave me caged bearings races to replace the loose balls.

There are 7 balls per race and I had 9 loose balls per side originally.

Would I be better off using loose balls? Surely the wear rate is going
to be greater using the caged races?

You're right. Caged are easier to put in, but not as good.

cheers,
clive

Quoted message said:

Dear all,

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.

I have bought a solid spindle as this will be stronger.

My bike shop gave me caged bearings races to replace the loose balls.

There are 7 balls per race and I had 9 loose balls per side
originally.

Would I be better off using loose balls? Surely the wear rate is going
to be greater using the caged races?

Yes, more balls = load spread more evenly. Cages are for convenience only.

I'd also worry about the grade possibly being less than very good with caged
balls - as they tend to be used in cheapo components. (Campag ones
excepted).

~PB

In article <[email hidden]>,

Quoted message said:

Would I be better off using loose balls?

Yes.

In article <[email hidden]>

Quoted message said:

Dear all,

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.

I have bought a solid spindle as this will be stronger.

Not necessarily - it depends on the quality of material used and the way
it has been processed.

Quoted message said:

My bike shop gave me caged bearings races to replace the loose balls.

There are 7 balls per race and I had 9 loose balls per side originally.

Would I be better off using loose balls? Surely the wear rate is going
to be greater using the caged races?

Yes. Caged balls are easier to assemble, but more loose balls will fit
in the same space thus spreading the load on the bearing surfaces.

Quoted message said:

Dear all,

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.

I have bought a solid spindle as this will be stronger.

Not necessarily true at all. Material, design, diameter and overall
quality matter more.

Quoted message said:

My bike shop gave me caged bearings races to replace the loose balls.

Not at all impressed by your bike shop. It's harder to put them in, but
you don't have to do that as often as you want to use the wheel. Not
only are cages the lazy, less effective way to support your axle, but
they are normally lower quality, and worst of all, the cage eventually
breaks up, filling your hub cup with sharp debris that wrecks cup,
cone, balls, the lot.

For best results buy bearings (of the proper size), not 'steel balls'.
You may have to go to a bearing supplier to get the real thing.

Bed the fresh bearings in enough thick grease (I like marine-grade
grease), and they should be fixed well enough to assemble with few
problems.

O.

Thanks everyone for your advice!

The hub is an inexpensive one that came on our Raleigh Duo, I have
since built up a Thorn Voyager using most of the parts. It certainly
doesn't shout about it's brand and has a screw on freewheel.

I just accepted the caged bearings at the time, but have since had time
to think about it. I didn't think they could be as good as loose balls.
I will go back to my LBS, he is very helpful.

I decided to use a solid axle as I had anti theft skewers anyway and
thought it'd be stronger assuming a similar grade of steel.

Thanks again,

Cheers,

Nick

Quoting <[email hidden]>:

Quoted message said:

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.
I have bought a solid spindle as this will be stronger.

Not really, it's the outer part of a hollow tube that does the work.
--
David Damerell <[email hidden]> flcl?
Today is Monday, September.

David Damerell said:

Quoting <[email hidden]>:

Quoted message said:

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.
I have bought a solid spindle as this will be stronger.

Not really, it's the outer part of a hollow tube that does the work.

Please give us the calculations that show that by removing material
from an axle it becomes stronger.

Quoting <[email hidden]>:

Quoted message said:

The hub is an inexpensive one that came on our Raleigh Duo, I have
since built up a Thorn Voyager using most of the parts. It certainly
doesn't shout about it's brand and has a screw on freewheel.

Freewheel hubs are inherently more prone to breaking axles.
--
David Damerell <[email hidden]> flcl?
Today is Monday, September.

Quoting <[email hidden]>:

Quoted message said:

Quoted message said:

Quoting <[email hidden]>:

Quoted message said:

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.
I have bought a solid spindle as this will be stronger.

Not really, it's the outer part of a hollow tube that does the work.

Please give us the calculations that show that by removing material
from an axle it becomes stronger.

I didn't say it becomes stronger. However, against certain types of load
(like the ones a bicycle axle sees) the inner material makes a minimal
contribution to the strength of the part and as such getting a solid
spindle on strength grounds does not make sense.
--
David Damerell <[email hidden]> flcl?
Today is Monday, September.

[email hidden] wrote on 20/09/2006 15:50 +0100:

Quoted message said:

I decided to use a solid axle as I had anti theft skewers anyway and
thought it'd be stronger assuming a similar grade of steel.

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre. In fact hollow axles are usually stronger because they are made
better and of better material. Solid axles tend to be used only on
really cheap bikes so are always made cheaply of cheap materials

--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

In article <[email hidden]>

Quoted message said:

David Damerell said:

Quoting <[email hidden]>:

Quoted message said:

Having snapped our rear hub spindle whilst on a touring holiday, I am
having to repair it.
I have bought a solid spindle as this will be stronger.

Not really, it's the outer part of a hollow tube that does the work.

Please give us the calculations that show that by removing material
from an axle it becomes stronger.

It doesn't, but it makes minimal difference to the strength. Hollow
axles are generally made of harder steel to closer tolerances - that's
why in pre-freehub days the occasional one would break, while solid ones
would often bend.

On Wed, 20 Sep 2006 18:30:09 +0100, Tony Raven <[email hidden]>

Quoted message said:

[email hidden] wrote on 20/09/2006 15:50 +0100:

Quoted message said:

I decided to use a solid axle as I had anti theft skewers anyway and
thought it'd be stronger assuming a similar grade of steel.

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre.

Please tell us where the centre stops and the outer begins.

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Wed, 20 Sep 2006 18:30:09 +0100, Tony Raven <[email hidden]>

Quoted message said:

[email hidden] wrote on 20/09/2006 15:50 +0100:

Quoted message said:

I decided to use a solid axle as I had anti theft skewers anyway and
thought it'd be stronger assuming a similar grade of steel.

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre.

Please tell us where the centre stops and the outer begins.

The resistance to bending is at a maximum at the top and bottom (one in
tension, the other in compression), and diminishes to zero at the dead
center, which is called the "neutral axis." It's a basic principle of
engineering statics. It's also the reason you don't drill holes for wire or
pipe near the top or bottom of a floor joist.

--
Ed Huntress

17 mm steel tube pushed thru rear hub , put 6003 ball bearings
on the frame . Mickey Mouse ?

The hub can now be very stiff ,one
piece , nixs bunches of problems ...

If i make a new hub , it can be lighter , for same load ,
no compromises in the strength for the drive side bearing .
Home made Quick Release is simpler also .

Wait to hear of my brake and shifter handles !!
R lever is for actuating . If you dont shift the left
lever , you get both brakes , but rear is limited to 25% ,
pull Left lever to modulate that % .
pull Left lever first and R lever does shifting . But it ratchets ,
so you may need to double pull the lever to shift another gear .

Quoted message said:

On Wed, 20 Sep 2006 18:30:09 +0100, Tony Raven <[email hidden]>

Quoted message said:

[email hidden] wrote on 20/09/2006 15:50 +0100:

Quoted message said:

I decided to use a solid axle as I had anti theft skewers anyway and
thought it'd be stronger assuming a similar grade of steel.

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre.

Please tell us where the centre stops and the outer begins.

Quoted message said:

Please tell us where the centre stops and the outer begins.

At the edge. Duh.

In article <[email hidden]>

Ed Huntress said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Wed, 20 Sep 2006 18:30:09 +0100, Tony Raven <[email hidden]>

Quoted message said:

[email hidden] wrote on 20/09/2006 15:50 +0100:
>
> I decided to use a solid axle as I had anti theft skewers anyway and
> thought it'd be stronger assuming a similar grade of steel.
>

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre.

Please tell us where the centre stops and the outer begins.

The resistance to bending is at a maximum at the top and bottom (one in
tension, the other in compression), and diminishes to zero at the dead
center, which is called the "neutral axis." It's a basic principle of
engineering statics. It's also the reason you don't drill holes for wire or
pipe near the top or bottom of a floor joist.

And why 'I' beams are the shape they are.

Quoted message said:

On Wed, 20 Sep 2006 18:30:09 +0100, Tony Raven <[email hidden]>

Quoted message said:

[email hidden] wrote on 20/09/2006 15:50 +0100:

Quoted message said:

I decided to use a solid axle as I had anti theft skewers anyway and
thought it'd be stronger assuming a similar grade of steel.

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre.

Please tell us where the centre stops and the outer begins.

Well obviously the "center" is a "line" with, as the mathaticians
would say, has only length. (ie. no diameter) :-)
...lew...

Lew Hartswick said:

Quoted message said:

On Wed, 20 Sep 2006 18:30:09 +0100, Tony Raven <[email hidden]>

Quoted message said:

[email hidden] wrote on 20/09/2006 15:50 +0100:

>I decided to use a solid axle as I had anti theft skewers anyway and
>thought it'd be stronger assuming a similar grade of steel.
>

The centre of a solid axle contributes weight but no strength. The
bending stresses are all in the outer layer of the axle and not in the
centre.

Please tell us where the centre stops and the outer begins.

Well obviously the "center" is a "line" with, as the mathaticians
would say, has only length. (ie. no diameter) :-)
...lew...

Well in that case one would question the phrase "...weight but no
strength...".

It's obvious that the poster has either over-simplified, or does not
understand the mechanics involved.

The original poster was completely correct when stating that he
believed that a solid axle would be stronger, assuming a "...similar
grade of steel" (and of course all other relevant similarities, except
that of solidity).