Butted tubing for rollcages

I'm building a rollcage with some friends for an off-road buggy. Being
a cyclist, the first thought that came into my mind was butted
chromoly tubing to save weight. I see that a lot of people don't use
this stuff for rollcages and I have wondered why. Is it really that
much of a pain to weld the tubes or is it a cost consideration? I can
definitely see butted tubing being pricier than the standard tubes
from your corner metal supermarket.

Anyone know of bicyling outlets (online would be nice) which sell 1"
and 1.25" OD butted tubes at competitive prices? I already checked
with a Reynolds tubing supplier and he told me that they only sell
standard OD's and lengths for bicycles alone. What else should I
consider before using butted tubes for this buggy?

bicycle_disciple wrote:
I'm building a rollcage with some friends for an off-road buggy. Being
a cyclist, the first thought that came into my mind was butted
chromoly tubing to save weight. I see that a lot of people don't use
this stuff for rollcages and I have wondered why. Is it really that
much of a pain to weld the tubes or is it a cost consideration? I can
definitely see butted tubing being pricier than the standard tubes
from your corner metal supermarket.

Anyone know of bicyling outlets (online would be nice) which sell 1"
and 1.25" OD butted tubes at competitive prices? I already checked
with a Reynolds tubing supplier and he told me that they only sell
standard OD's and lengths for bicycles alone. What else should I
consider before using butted tubes for this buggy?

I wouldn't for a roll cage. Using larger diameter mild steel
tube you can get the shapes curved on exhaust pipe machines
and finish with a welder. Plus, bicycle tubes top out at
630~650mm length. With a thicker tube, your interface to the
common 1/4 inch plates for mounting is straightforward.

_Could_ you use fillet brazed butted frame tubes? Sure, but
it hardly seems worth the other necessary design changes.

Bike tube has favorable ratios of torsional resistance to
weight but isn't maybe the best choice bashed sideways with
a head below the cage.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Oct 18, 3:08*pm, bicycle_disciple
wrote:
I'm building a rollcage with some friends for an off-road buggy. Being
a cyclist, the first thought that came into my mind was butted
chromoly tubing to save weight. I see that a lot of people don't use
this stuff for rollcages and I have wondered why. Is it really that
much of a pain to weld the tubes or is it a cost consideration? I can
definitely see butted tubing being pricier than the standard tubes
from your corner metal supermarket.

Anyone know of bicyling outlets (online would be nice) which sell 1"
and 1.25" OD butted tubes at competitive prices? I already checked
with a Reynolds tubing supplier and he told me that they only sell
standard OD's and lengths for bicycles alone. What else should I
consider before using butted tubes for this buggy?

Tubing meant for bikes really isn't the right choice for a roll cage.
A butted tube isn't designed to be mashed in the soft middle bits.
What you need is negatively butted tubing.

On Oct 18, 4:08*pm, bicycle_disciple
wrote:
I'm building a rollcage with some friends for an off-road buggy. Being
a cyclist, the first thought that came into my mind was butted
chromoly tubing to save weight. I see that a lot of people don't use
this stuff for rollcages and I have wondered why. Is it really that
much of a pain to weld the tubes or is it a cost consideration? I can
definitely see butted tubing being pricier than the standard tubes
from your corner metal supermarket.

Anyone know of bicyling outlets (online would be nice) which sell 1"
and 1.25" OD butted tubes at competitive prices? I already checked
with a Reynolds tubing supplier and he told me that they only sell
standard OD's and lengths for bicycles alone. What else should I
consider before using butted tubes for this buggy?

I'm not sure if you want a roll cage that's only good at
bearing loads on the ends of the tubes.

bicycle_disciple wrote:
:I'm building a rollcage with some friends for an off-road buggy. Being
:a cyclist, the first thought that came into my mind was butted
:chromoly tubing to save weight. I see that a lot of people don't use
:this stuff for rollcages and I have wondered why. Is it really that
:much of a pain to weld the tubes or is it a cost consideration? I can
:definitely see butted tubing being pricier than the standard tubes
:from your corner metal supermarket.

:Anyone know of bicyling outlets (online would be nice) which sell 1"
:and 1.25" OD butted tubes at competitive prices? I already checked
:with a Reynolds tubing supplier and he told me that they only sell
:standard OD's and lengths for bicycles alone. What else should I
:consider before using butted tubes for this buggy?

Whether you want to survive the roll over or not? If yo udon't , save
time and money, and skip the cage. If you do, build a proper cage. Racing
organizations publish standards for roll cages. I realize you're
probably not racing, but find the closest classto what your building,
and read up on it. Typically, they're built of 1.5 inch, 0.120 wall
thickness DOM 4130 (some rules let you use 1020, which is easier to
work with) for main tubes, with suplimental tubes madeo f 1.5 0.095
DOM.

--
sig 22

David Scheidt wrote:
bicycle_disciple wrote:
:I'm building a rollcage with some friends for an off-road buggy. Being
:a cyclist, the first thought that came into my mind was butted
:chromoly tubing to save weight. I see that a lot of people don't use
:this stuff for rollcages and I have wondered why. Is it really that
:much of a pain to weld the tubes or is it a cost consideration? I can
:definitely see butted tubing being pricier than the standard tubes
:from your corner metal supermarket.

:Anyone know of bicyling outlets (online would be nice) which sell 1"
:and 1.25" OD butted tubes at competitive prices? I already checked
:with a Reynolds tubing supplier and he told me that they only sell
:standard OD's and lengths for bicycles alone. What else should I
:consider before using butted tubes for this buggy?

Whether you want to survive the roll over or not? If yo udon't , save
time and money, and skip the cage. If you do, build a proper cage. Racing
organizations publish standards for roll cages. I realize you're
probably not racing, but find the closest classto what your building,
and read up on it. Typically, they're built of 1.5 inch, 0.120 wall
thickness DOM 4130 (some rules let you use 1020, which is easier to
work with) for main tubes, with suplimental tubes madeo f 1.5 0.095
DOM.


What he said.

And note that's a hefty 0.12 inches (0.3+mm )not 1.2mm (mere
touring bike tube). Those of us who have rolled cars view
this problem in a different light.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Mon, 18 Oct 2010 13:08:34 -0700 (PDT), bicycle_disciple
wrote:

I'm building a rollcage with some friends for an off-road buggy. Being
a cyclist, the first thought that came into my mind was butted
chromoly tubing to save weight. I see that a lot of people don't use
this stuff for rollcages and I have wondered why. Is it really that
much of a pain to weld the tubes or is it a cost consideration? I can
definitely see butted tubing being pricier than the standard tubes
from your corner metal supermarket.

Anyone know of bicyling outlets (online would be nice) which sell 1"
and 1.25" OD butted tubes at competitive prices? I already checked
with a Reynolds tubing supplier and he told me that they only sell
standard OD's and lengths for bicycles alone. What else should I
consider before using butted tubes for this buggy?


Stop and consider for a moment. If tube is butted, i.e., thicker on
the ends, then the manufacturer must have had an idea where the ends
are to be when the tubing was made.

Difficult to do with random lengths, or if you were to shorten the
tube significantly

Cheers,

John D. Slocomb
(jdslocombatgmail)

On 18 Oct, 21:08, bicycle_disciple wrote:
I'm building a rollcage with some friends for an off-road buggy. Being
a cyclist, the first thought that came into my mind was butted
chromoly tubing to save weight. I see that a lot of people don't use
this stuff for rollcages and I have wondered why. Is it really that
much of a pain to weld the tubes or is it a cost consideration? I can
definitely see butted tubing being pricier than the standard tubes
from your corner metal supermarket.

Don't do it, not that you could get the required lengths. To save
weight, design the buggy frame around the roll over cage.



Anyone know of bicyling outlets (online would be nice) which sell 1"
and 1.25" OD butted tubes at competitive prices? I already checked
with a Reynolds tubing supplier and he told me that they only sell
standard OD's and lengths for bicycles alone. What else should I
consider before using butted tubes for this buggy?

"AMuzi" wrote in message
...
David Scheidt wrote:
bicycle_disciple wrote:
:I'm building a rollcage with some friends for an off-road buggy. Being
:a cyclist, the first thought that came into my mind was butted
:chromoly tubing to save weight. I see that a lot of people don't use
:this stuff for rollcages and I have wondered why. Is it really that
:much of a pain to weld the tubes or is it a cost consideration? I can
:definitely see butted tubing being pricier than the standard tubes
:from your corner metal supermarket.

:Anyone know of bicyling outlets (online would be nice) which sell 1"
:and 1.25" OD butted tubes at competitive prices? I already checked
:with a Reynolds tubing supplier and he told me that they only sell
:standard OD's and lengths for bicycles alone. What else should I
:consider before using butted tubes for this buggy?

Whether you want to survive the roll over or not? If yo udon't , save
time and money, and skip the cage. If you do, build a proper cage.
Racing
organizations publish standards for roll cages. I realize you're
probably not racing, but find the closest classto what your building,
and read up on it. Typically, they're built of 1.5 inch, 0.120 wall
thickness DOM 4130 (some rules let you use 1020, which is easier to
work with) for main tubes, with suplimental tubes madeo f 1.5 0.095
DOM.

What he said.

And note that's a hefty 0.12 inches (0.3+mm )not 1.2mm (mere touring bike
tube). Those of us who have rolled cars view this problem in a different
light.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Andy meant 3.0mm. Like everyone else says; don't do it.
Kerry

On 18/10/10 05:52 PM, AMuzi wrote:
Those of us who have rolled cars view this problem in a different light.

I'm a member of that group.

A good case can be made for a decent restraint system and a helmet too.

Hitting one's head on tubing is strangely similar to being hit on the
head with a pipe.

A poorly designed roll bar or cage can be a death trap.

As has been previously said various race sanctioning bodies can provide
invaluable information on cage design.


Marcus