rear wheel axle and dish



T

Tony Sweeney

Guest
I have a rear wheel with a freewheel based hub (36 swaged spokes into an
MA2 rim, 6 speed block).

I am intending using the wheel in a tandem. It won't be carrying a large
weight - combined weight of about 200 pounds (a child on the back).
Which is why I think this 36 spoked 'normal' wheel should be sufficient.

The tandem has 130mm dropout spacing. Although the original oln of the
hub was 126mm, I can put extra spacers on the non drive side to take it
out to 130mm. This only leaves a few mm each side to engage the
dropouts, but looks to be just enough.

This allows a reduction in the amount of dish on the wheel.

But in spacing the axle out I think I am putting more strain on it by
increasing the distance from the dropout to the bearing on the non-drive
side. Therefore increasing the chances of breaking the axle.

Should this be a concern? If so, is it worth that trade off or am I
better off sticking with 126mm and more dish?

Tony
 
On Mon, 20 Nov 2006 15:54:36 +0000, Tony Sweeney wrote:

> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
> MA2 rim, 6 speed block).
>
> I am intending using the wheel in a tandem. It won't be carrying a large
> weight - combined weight of about 200 pounds (a child on the back).
> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>
> The tandem has 130mm dropout spacing. Although the original oln of the
> hub was 126mm, I can put extra spacers on the non drive side to take it
> out to 130mm. This only leaves a few mm each side to engage the
> dropouts, but looks to be just enough.
>
> This allows a reduction in the amount of dish on the wheel.
>
> But in spacing the axle out I think I am putting more strain on it by
> increasing the distance from the dropout to the bearing on the non-drive
> side. Therefore increasing the chances of breaking the axle.


Your biggest concern about breaking the axle will be on the right side,
not the left, since there is still more distance between the right-side
bearings and the dropout than the left (even spaced out 4mm), plus there
will be more force from pedaling. If the child in back "pulls his/her
weight" in terms of pedaling, this could be a problem.

You can get a 130mm 9-speed Shimano cassette hub for peanuts. Use that
instead. Sure, there is more dish, but the axle design is much stronger.
I use this on the tandem my wife and I ride, with no trouble. Be sure to
also get sturdy rims and nice big tires.

--

David L. Johnson

__o | "It doesn't get any easier, you just go faster." --Greg LeMond
_`\(,_ |
(_)/ (_) |
 
Tony Sweeney wrote:
> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
> MA2 rim, 6 speed block).
>
> I am intending using the wheel in a tandem. It won't be carrying a large
> weight - combined weight of about 200 pounds (a child on the back).
> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>
> The tandem has 130mm dropout spacing. Although the original oln of the
> hub was 126mm, I can put extra spacers on the non drive side to take it
> out to 130mm. This only leaves a few mm each side to engage the
> dropouts, but looks to be just enough.
>
> This allows a reduction in the amount of dish on the wheel.
>
> But in spacing the axle out I think I am putting more strain on it by
> increasing the distance from the dropout to the bearing on the non-drive
> side. Therefore increasing the chances of breaking the axle.
>
> Should this be a concern? If so, is it worth that trade off or am I
> better off sticking with 126mm and more dish?
>
> Tony


It's probably fine (because like David said, the unsupported axle on
the drive side is still the weak link by quite a bit even adding 4mm on
the left side), but I think the quality level of the axle is relevant
here... not all are created equal. People who manage to never bend
axles on freewheel hubs on solos seem to do it by being pretty good at
keeping their weight suspended, which your stoker probably won't be
able to do consistently. Also, lots of people run re-spaced setups like
this with less axle in the dropouts than normal, and it's generally
fine because axle protrusion into the dropout doesn't really matter
much or at all, but OTOH doing this with a tandem is going to put that
theory to the test more than normal, especially if it's ever stoked by
a more powerful rider. All in all, it might make sense to just drop the
$10 for a Wheels Mfg 141mm chromo axle of the right thread, if not a
different hub.
 
Tony Sweeney wrote:
> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
> MA2 rim, 6 speed block).
>
> I am intending using the wheel in a tandem. It won't be carrying a large
> weight - combined weight of about 200 pounds (a child on the back).
> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>
> The tandem has 130mm dropout spacing. Although the original oln of the
> hub was 126mm, I can put extra spacers on the non drive side to take it
> out to 130mm. This only leaves a few mm each side to engage the
> dropouts, but looks to be just enough.
>
> This allows a reduction in the amount of dish on the wheel.
>
> But in spacing the axle out I think I am putting more strain on it by
> increasing the distance from the dropout to the bearing on the non-drive
> side. Therefore increasing the chances of breaking the axle.
>
> Should this be a concern? If so, is it worth that trade off or am I
> better off sticking with 126mm and more dish?
>
> Tony


Put all 4mm on the left side, moving the rim to the right, then raise
the tension of the left side spokes, dishing the wheel..a good thing.
 
In article <[email protected]>,
Tony Sweeney <[email protected]> wrote:

> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
> MA2 rim, 6 speed block).
>
> I am intending using the wheel in a tandem. It won't be carrying a large
> weight - combined weight of about 200 pounds (a child on the back).
> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>
> The tandem has 130mm dropout spacing. Although the original oln of the
> hub was 126mm, I can put extra spacers on the non drive side to take it
> out to 130mm. This only leaves a few mm each side to engage the
> dropouts, but looks to be just enough.
>
> This allows a reduction in the amount of dish on the wheel.
>
> But in spacing the axle out I think I am putting more strain on it by
> increasing the distance from the dropout to the bearing on the non-drive
> side. Therefore increasing the chances of breaking the axle.
>
> Should this be a concern? If so, is it worth that trade off or am I
> better off sticking with 126mm and more dish?


I think it is too risky. That configuration too often
breaks on a 126 mm spacing. 130 mm is asking for
trouble. Too nice a wheel to risk; put it on a bike
that is a match for it.

--
Michael Press
 
Michael Press wrote:
> In article <[email protected]>,
> Tony Sweeney <[email protected]> wrote:
>
> > I have a rear wheel with a freewheel based hub (36 swaged spokes into an
> > MA2 rim, 6 speed block).
> >
> > I am intending using the wheel in a tandem. It won't be carrying a large
> > weight - combined weight of about 200 pounds (a child on the back).
> > Which is why I think this 36 spoked 'normal' wheel should be sufficient.
> >
> > The tandem has 130mm dropout spacing. Although the original oln of the
> > hub was 126mm, I can put extra spacers on the non drive side to take it
> > out to 130mm. This only leaves a few mm each side to engage the
> > dropouts, but looks to be just enough.
> >
> > This allows a reduction in the amount of dish on the wheel.
> >
> > But in spacing the axle out I think I am putting more strain on it by
> > increasing the distance from the dropout to the bearing on the non-drive
> > side. Therefore increasing the chances of breaking the axle.
> >
> > Should this be a concern? If so, is it worth that trade off or am I
> > better off sticking with 126mm and more dish?

>
> I think it is too risky. That configuration too often
> breaks on a 126 mm spacing. 130 mm is asking for
> trouble. Too nice a wheel to risk; put it on a bike
> that is a match for it.
>
> --
> Michael Press


If the ride is really .1 offa ton, no problem. What I do for all my
freewheel wheels is
-make sure the dropouts are aligned
-space it so I have the minimum axle on the right to support the
freewheel stack, no more.

If the gent adds spacers to the left, redishes wheel and checks
dropouts, I think it won't be a problem.
 
Nate Knutson wrote:
> Tony Sweeney wrote:
>> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
>> MA2 rim, 6 speed block).
>>
>> I am intending using the wheel in a tandem. It won't be carrying a large
>> weight - combined weight of about 200 pounds (a child on the back).
>> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>>
>> The tandem has 130mm dropout spacing. Although the original oln of the
>> hub was 126mm, I can put extra spacers on the non drive side to take it
>> out to 130mm. This only leaves a few mm each side to engage the
>> dropouts, but looks to be just enough.
>>
>> This allows a reduction in the amount of dish on the wheel.
>>
>> But in spacing the axle out I think I am putting more strain on it by
>> increasing the distance from the dropout to the bearing on the non-drive
>> side. Therefore increasing the chances of breaking the axle.
>>
>> Should this be a concern? If so, is it worth that trade off or am I
>> better off sticking with 126mm and more dish?
>>
>> Tony

>
> It's probably fine (because like David said, the unsupported axle on
> the drive side is still the weak link by quite a bit even adding 4mm on
> the left side), but I think the quality level of the axle is relevant
> here... not all are created equal. People who manage to never bend


The hub is Dura Ace. Hopefully meaning it has a decent quality axle.
Although I have to say I can't tell by looking if it is any better than
others I have.

> axles on freewheel hubs on solos seem to do it by being pretty good at
> keeping their weight suspended, which your stoker probably won't be
> able to do consistently. Also, lots of people run re-spaced setups like
> this with less axle in the dropouts than normal, and it's generally
> fine because axle protrusion into the dropout doesn't really matter
> much or at all, but OTOH doing this with a tandem is going to put that
> theory to the test more than normal, especially if it's ever stoked by
> a more powerful rider. All in all, it might make sense to just drop the
> $10 for a Wheels Mfg 141mm chromo axle of the right thread, if not a
> different hub.


There's probably about 4mm of axle after the locknut on each side. So
only a couple of mm short of the amount you see on new hubs. Like you
say, I don't see that as a problem.

Thanks for the advice.
Tony
 
On Mon, 20 Nov 2006 15:54:36 +0000, Tony Sweeney
<[email protected]> wrote:

>I have a rear wheel with a freewheel based hub (36 swaged spokes into an
>MA2 rim, 6 speed block).
>
>I am intending using the wheel in a tandem. It won't be carrying a large
>weight - combined weight of about 200 pounds (a child on the back).
>Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>
>The tandem has 130mm dropout spacing. Although the original oln of the
>hub was 126mm, I can put extra spacers on the non drive side to take it
>out to 130mm. This only leaves a few mm each side to engage the
>dropouts, but looks to be just enough.
>
>This allows a reduction in the amount of dish on the wheel.
>
>But in spacing the axle out I think I am putting more strain on it by
>increasing the distance from the dropout to the bearing on the non-drive
>side. Therefore increasing the chances of breaking the axle.
>
>Should this be a concern? If so, is it worth that trade off or am I
>better off sticking with 126mm and more dish?
>
>Tony


I've read the replies thus far posted and at risk of initiating
controversy let me suggest just snapping your current wheel into the
frame.

In a 126 vs. 130 discussion here several years ago Sheldon mentioned
he had done the trig and moving the stays 2mm each results in a
one-third of a degree change in dropout alignments. I'd guess that's
within the tolerance most framebuilders would accept.

See: http://tinyurl.com/ws2rf


jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
 
Tony Sweeney wrote:
> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
> MA2 rim, 6 speed block).
>
> I am intending using the wheel in a tandem. It won't be carrying a large
> weight - combined weight of about 200 pounds (a child on the back).
> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>
> The tandem has 130mm dropout spacing. Although the original oln of the
> hub was 126mm, I can put extra spacers on the non drive side to take it
> out to 130mm. This only leaves a few mm each side to engage the
> dropouts, but looks to be just enough.
>
> This allows a reduction in the amount of dish on the wheel.


Good plan.

> But in spacing the axle out I think I am putting more strain on it by
> increasing the distance from the dropout to the bearing on the non-drive
> side. Therefore increasing the chances of breaking the axle.
>
> Should this be a concern? If so, is it worth that trade off or am I
> better off sticking with 126mm and more dish?


As others have noted, it's the right side of the axle that would fail,
if any. That will still protrude farther, and that's where the chain
is doing its pulling.

Some other posters seem to focussed too much on the word "tandem" and
too little on "combined weight of about 200 pounds (a child on the
back)."

There will actually be substantially less load on the rear wheel than
there would be on a solo bike with a 200 pound rider. You won't have
any trouble with it.

Sheldon "Ride And Enjoy" Brown
 
"Tony Sweeney" <[email protected]> wrote in message
news:[email protected]...
> I have a rear wheel with a freewheel based hub (36 swaged spokes into

an
> MA2 rim, 6 speed block).
>
> I am intending using the wheel in a tandem. It won't be carrying a

large
> weight - combined weight of about 200 pounds (a child on the back).
> Which is why I think this 36 spoked 'normal' wheel should be

sufficient.
>
> The tandem has 130mm dropout spacing. Although the original oln of the
> hub was 126mm, I can put extra spacers on the non drive side to take

it
> out to 130mm. This only leaves a few mm each side to engage the
> dropouts, but looks to be just enough.
>
> This allows a reduction in the amount of dish on the wheel.
>
> But in spacing the axle out I think I am putting more strain on it by
> increasing the distance from the dropout to the bearing on the

non-drive
> side. Therefore increasing the chances of breaking the axle.
>
> Should this be a concern? If so, is it worth that trade off or am I
> better off sticking with 126mm and more dish?
>
> Tony


It's been a long time since I've been on a tandem. Rear wheel strength
was always one of my concerns. The forces on the rear axle are much
higher than on most single bikes.

In the past I assembled or worked on a number of tandems that I was able
to road test. These included everything from one with 120mm wide Campy
NR hubs and Clement Del Mundo sewups to a French touring tandem with
Maxicar hubs and 650b fatties.

If it were me, I would feel more comfortable with a heavy duty rear hub
or I would replace the hollow quick release axle in the rear wheel with
a solid track axle for peace of mind. I've seen too many bent and broken
quick release axles on freewheel style hubs used on singles.

It's easy to change a wheel with good track nuts - 2 small wrenches or
you can get track nuts that have socket heads that you can operate with
a pair of hex keys. With a solid axle you can go to 130mm without any
problems.

The bearings on the freewheel side of your hub are set in from the end
of the axle under the middle of the freewheel. The lack of support for
the outboard part of the axle is going to be magnified with a 130mm wide
setup. Many cassette type hubs have the right side bearings set closer
to the end on the sprocket side giving better support for the axle.

Another point, you mentioned that you have a Shimano hub? Recently I had
the rear quick releases slip on 2 bikes that I just worked on. The bikes
had horizontal dropouts. They both had Shimano hubs in new or almost new
condition. One was a Shimano 600 hub and the other a Shimano Deore XT
MTB hub in a new road wheel. I make sure that my quick releases are
tight before riding.

I was out of the saddle honking up a steep hill both times when the QRs
slipped and the wheels shifted against the left chainstay. The bikes
came to an abrupt stop. I was thrown to the ground once but luckily I
wasn't hurt. I inspected both bikes afterward and switched to Campy
quick releases because the Shimanos didn't seem to have enough bite into
the dropouts. They would probably work fine in vertical dropouts but
once is enough for me.

Good luck

Chas.
 
"Sheldon Brown" <[email protected]> wrote in message
news:[email protected]...
>
> Tony Sweeney wrote:
> > I have a rear wheel with a freewheel based hub (36 swaged spokes

into an
> > MA2 rim, 6 speed block).
> >
> > I am intending using the wheel in a tandem. It won't be carrying a

large
> > weight - combined weight of about 200 pounds (a child on the back).
> > Which is why I think this 36 spoked 'normal' wheel should be

sufficient.
> >
> > The tandem has 130mm dropout spacing. Although the original oln of

the
> > hub was 126mm, I can put extra spacers on the non drive side to take

it
> > out to 130mm. This only leaves a few mm each side to engage the
> > dropouts, but looks to be just enough.
> >
> > This allows a reduction in the amount of dish on the wheel.

>
> Good plan.
>
> > But in spacing the axle out I think I am putting more strain on it

by
> > increasing the distance from the dropout to the bearing on the

non-drive
> > side. Therefore increasing the chances of breaking the axle.
> >
> > Should this be a concern? If so, is it worth that trade off or am I
> > better off sticking with 126mm and more dish?

>
> As others have noted, it's the right side of the axle that would fail,
> if any. That will still protrude farther, and that's where the chain
> is doing its pulling.
>
> Some other posters seem to focussed too much on the word "tandem" and
> too little on "combined weight of about 200 pounds (a child on the
> back)."
>
> There will actually be substantially less load on the rear wheel than
> there would be on a solo bike with a 200 pound rider. You won't have
> any trouble with it.
>
> Sheldon "Ride And Enjoy" Brown
>


But, but Sheldon what happens when the time comes and you want to go
riding with another adult or the child becomes a teenager - Tempus Fugit

Chas. I should have bough the 'Traut tandem on Saturday...
 
On Tue, 21 Nov 2006 20:18:47 -0800, "* * Chas"
<[email protected]> wrote:


>
>It's been a long time since I've been on a tandem. Rear wheel strength
>was always one of my concerns. The forces on the rear axle are much
>higher than on most single bikes.
>
>In the past I assembled or worked on a number of tandems that I was able
>to road test. These included everything from one with 120mm wide Campy
>NR hubs and Clement Del Mundo sewups to a French touring tandem with
>Maxicar hubs and 650b fatties.
>
>If it were me, I would feel more comfortable with a heavy duty rear hub
>or I would replace the hollow quick release axle in the rear wheel with
>a solid track axle for peace of mind. I've seen too many bent and broken
>quick release axles on freewheel style hubs used on singles.
>



Good thinking.

Not only will you gain absolute strength from the additional material,
but you'll lose all the possible stress-risers that can exist from the
internal hole.
 
Sheldon Brown wrote:
> Tony Sweeney wrote:
>> I have a rear wheel with a freewheel based hub (36 swaged spokes into an
>> MA2 rim, 6 speed block).
>>
>> I am intending using the wheel in a tandem. It won't be carrying a large
>> weight - combined weight of about 200 pounds (a child on the back).
>> Which is why I think this 36 spoked 'normal' wheel should be sufficient.
>>
>> The tandem has 130mm dropout spacing. Although the original oln of the
>> hub was 126mm, I can put extra spacers on the non drive side to take it
>> out to 130mm. This only leaves a few mm each side to engage the
>> dropouts, but looks to be just enough.
>>
>> This allows a reduction in the amount of dish on the wheel.

>
> Good plan.
>
>> But in spacing the axle out I think I am putting more strain on it by
>> increasing the distance from the dropout to the bearing on the non-drive
>> side. Therefore increasing the chances of breaking the axle.
>>
>> Should this be a concern? If so, is it worth that trade off or am I
>> better off sticking with 126mm and more dish?

>
> As others have noted, it's the right side of the axle that would fail,
> if any. That will still protrude farther, and that's where the chain
> is doing its pulling.
>
> Some other posters seem to focussed too much on the word "tandem" and
> too little on "combined weight of about 200 pounds (a child on the
> back)."
>
> There will actually be substantially less load on the rear wheel than
> there would be on a solo bike with a 200 pound rider. You won't have
> any trouble with it.


Thanks. Obviously this is what I was hoping to hear :)

I know one or two riders in the 200 pound region who have ridden many
miles on rear wheels with 7 or 8 speed freewheels without axles
breaking. All of these miles would have been on made (paved) roads where
the only bumps would be from potholes which is going to help.

If the main concern is the right side, there will be significantly less
load on the axle on my wheel being spaced for 6 speed.

Apart from the odd shortcut through the park on some gravel paths, I
won't be going off road on the tandem. Based on the advice I've had, I'm
happy to use the wheel as planned.

I re-dished the wheel last night and was surprised at how little dish
there now is and how much tension I could put into the left hand spokes
as a consequence. I have another couple of rear wheels with threaded
hubs that have been spaced and dished for 7 sprockets. I'll be doing the
same with those :)

Thanks for everyone for their advice and thoughts.

Tony
 
----- Original Message -----
From: <[email protected]>
Newsgroups: rec.bicycles.tech
Sent: Wednesday, November 22, 2006 4:42 AM
Subject: Re: rear wheel axle and dish


> On Tue, 21 Nov 2006 20:18:47 -0800, "* * Chas"
> <[email protected]> wrote:
>
>
> >
> >It's been a long time since I've been on a tandem. Rear wheel

strength
> >was always one of my concerns. The forces on the rear axle are much
> >higher than on most single bikes.
> >
> >In the past I assembled or worked on a number of tandems that I was

able
> >to road test. These included everything from one with 120mm wide

Campy
> >NR hubs and Clement Del Mundo sewups to a French touring tandem with
> >Maxicar hubs and 650b fatties.
> >
> >If it were me, I would feel more comfortable with a heavy duty rear

hub
> >or I would replace the hollow quick release axle in the rear wheel

with
> >a solid track axle for peace of mind. I've seen too many bent and

broken
> >quick release axles on freewheel style hubs used on singles.
> >

>
>
> Good thinking.
>
> Not only will you gain absolute strength from the additional material,
> but you'll lose all the possible stress-risers that can exist from the
> internal hole.


We started seriously riding offroad/cyclocross/MTB with modified road
bikes about 30 years ago. I got tired of replacing the bent QR axles in
my Shimano and Campy rear hubs after every ride. I weighed 175-180 Lbs.
at that time with very low body fat.

I replaced the QR axles with solid track axles and never had a problem
after that. I carried 2 shorty 16mm wrenches and was able to quickly
remove the rear wheels when necessary.

We used cyclocross sewups most of the time. We started riding beater
road bikes at first before we built 700c MTB frames with vertical
dropouts. The track axles eliminated the problem of wheels shifting
against the left chainstay when honking up hill in low gear on bikes
with horizontal dropouts.

Chas.