This might be a fun project for any age...

http://www.chopzone.com/cd-chopthis.htm



Amazing what can be done with electrical conduit. Not just for wires
anymore!


Cheers.

Buzz Saw wrote:

http://www.chopzone.com/cd-chopthis.htm

In case you think that Reynolds' 502 was designer labelling with no
more technical use than thin mild steel rolled from washing machine
scrap and stolen manhole covers:
Bicycle frames take a great deal of strain and anyone putting tension
on a road vehicle with the mechanical abilities of solder, is likely to
end up in hospital for a very long time.

Bike frames might look fairly thin at the ends of their respective
tubes but the section thickens toward the middle. Lengths of it are
available from specialist suppliers. It is made to specific engineering
standards that control the dimensions of every piece sold.

It certainly sounds a recipe for disaster....................I always
understood the tubing was thicker at the ends rather than the middle in good
quality tubing. The suggestion that a novice could pick up an arc welder and
satisfactorily weld thin tubes together seems a bit
optimistic............... I've been trying for years and still can't do it!
Geoff
"Weatherlawyer" wrote in message
oups.com...

Buzz Saw wrote:

http://www.chopzone.com/cd-chopthis.htm

In case you think that Reynolds' 502 was designer labelling with no
more technical use than thin mild steel rolled from washing machine
scrap and stolen manhole covers:
Bicycle frames take a great deal of strain and anyone putting tension
on a road vehicle with the mechanical abilities of solder, is likely to
end up in hospital for a very long time.

Bike frames might look fairly thin at the ends of their respective
tubes but the section thickens toward the middle. Lengths of it are
available from specialist suppliers. It is made to specific engineering
standards that control the dimensions of every piece sold.

"Geoff Norfolk" wrote in
:

It certainly sounds a recipe for disaster....................I always
understood the tubing was thicker at the ends rather than the middle
in good quality tubing.

Me too, maybe it was a typo.

IIRC it was to withstand brazing- not, as remember it, welding, at the
joints

mike

In article ,
"Geoff Norfolk" writes:
It certainly sounds a recipe for disaster....................I always
understood the tubing was thicker at the ends rather than the middle in good
quality tubing. The suggestion that a novice could pick up an arc welder and
satisfactorily weld thin tubes together seems a bit
optimistic............... I've been trying for years and still can't do it!
Geoff

Having seen the effects on a friend of mine when his very expensive
bicycle snapped whilst cycling through Watford, I can say you really
don't want that to happen to you...

--
Andrew Gabriel

In article ,
says...
"Geoff Norfolk" wrote in
:

It certainly sounds a recipe for disaster....................I always
understood the tubing was thicker at the ends rather than the middle
in good quality tubing.

Indeed.

Me too, maybe it was a typo.

IIRC it was to withstand brazing- not, as remember it, welding, at the
joints

Welding and/or brazing - it depends on the alloy and heat treatment used
for the tube. Arc welding is quicker and hotter/more localised than
gas welding/brazing, so the thermal considerations of the joint design
are different. Reynolds 753 was silver-soldered and you had to pass a
test (solder tubes and stays into a bottom-bracket, which Reynolds would
then pull apart) to make sure you were getting enough heat into the
joint to flow the solder properly, without heating the tubes enough to
weaken them significantly.
Cheap crap steel frames use thick heavy soft steel, so arc welding isn't
the problem that it can be with cold-drawn (and thus work-hardened)
tubes in exotic alloys (which are often heat-treated). Properly welded
crappo frames will usually bend gradually rather than failing
catastrophically - Pashley used to get away with this in their tandem
and trike frames, which are pretty highly stressed.