Hot Resetting Rear Triangle

Hot Resetting Rear Triangle

Post by Rick Knowla » Fri, 27 Aug 1999 04:00:00


In discussing my idea to upgrade my old, beloved lugged Reynolds 531d-b
framed bike, a friend suggested today that I consider spreading the rear
triangle to accept 9 speed.  I measured it, and it looks like it is
currently 116 mm. Going to 130 would be a "real stretch".

Since I plan to strip and refinish the frame, does it make sense to have
it "hot reset" by a competent frame builder?  Has anyone tried this?
Comments?

 
 
 

Hot Resetting Rear Triangle

Post by Jobst Bran » Fri, 27 Aug 1999 04:00:00

Quote:
Rick Knowlan writes:
> In discussing my idea to upgrade my old, beloved lugged Reynolds
> 531d-b framed bike, a friend suggested today that I consider
> spreading the rear triangle to accept 9 speed.  I measured it, and
> it looks like it is currently 116 mm. Going to 130 would be a "real
> stretch".
> Since I plan to strip and refinish the frame, does it make sense to
> have it "hot reset" by a competent frame builder?  Has anyone tried
> this?

Don't!  If you knew how much "cold setting" a frame gets anyway when
built and how little it affects the steel for the size of these
deformations, you wouldn't even consider it.  Heating the tube to
visible red is far worse than putting a slight bend in the rear
triangle and then aligning the dropouts.  This is something done
regularly with the tools also found in bike shops.

--



 
 
 

Hot Resetting Rear Triangle

Post by Rick Knowla » Fri, 27 Aug 1999 04:00:00

Quote:

> Rick Knowlan writes:

> > In discussing my idea to upgrade my old, beloved lugged Reynolds
> > 531d-b framed bike, a friend suggested today that I consider
> > spreading the rear triangle to accept 9 speed.  I measured it, and
> > it looks like it is currently 116 mm. Going to 130 would be a "real
> > stretch".

> > Since I plan to strip and refinish the frame, does it make sense to
> > have it "hot reset" by a competent frame builder?  Has anyone tried
> > this?

> Don't!  If you knew how much "cold setting" a frame gets anyway when
> built and how little it affects the steel for the size of these
> deformations, you wouldn't even consider it.  Heating the tube to
> visible red is far worse than putting a slight bend in the rear
> triangle and then aligning the dropouts.  This is something done
> regularly with the tools also found in bike shops.

My apologies for a misleading post that did not accurately state my
question.  Sorry I wasted your time.

When I said "hot resetting", I did not mean heating the tubes and bending
them.  I meant (and should have said) heating the lugs to loosen the
brazing (or is it silver soldering?) and resetting the lugged joints a
fraction.  That would, I imagine, require "longer" bridges, too. Has
anyone tried resetting previously fastened lugs?  Any success?  Would the
heat required change the properties of the tubes?

 
 
 

Hot Resetting Rear Triangle

Post by Jon Isaa » Fri, 27 Aug 1999 04:00:00

Quote:
> That would, I imagine, require "longer" bridges, too. Has
>anyone tried resetting previously fastened lugs?  Any success?  Would the
>heat required change the properties of the tubes?

I think you are worrying yourself over nothing.  Steel frames can take a
serious amount of deformation without damage.  It  is most likely that your
rear triangle is 120 mm.  Cold setting it should be OK, assuming the frame has
not serious fatigue problems.

Trying to reset the lugs just means probably that you will have to coldset the
frame a different amount.   People tend to be afraid of cold setting something,
but this actually makes most materials stronger and is a technique commonly
used to strengthen materials.

Jon Isaacs

Jon Isaacs

Jon Isaacs

 
 
 

Hot Resetting Rear Triangle

Post by John Thomps » Fri, 27 Aug 1999 04:00:00


Quote:
>In discussing my idea to upgrade my old, beloved lugged Reynolds 531d-b
>framed bike, a friend suggested today that I consider spreading the rear
>triangle to accept 9 speed.  I measured it, and it looks like it is
>currently 116 mm. Going to 130 would be a "real stretch".

>Since I plan to strip and refinish the frame, does it make sense to have
>it "hot reset" by a competent frame builder?  Has anyone tried this?
>Comments?

No competent framebuilder will "hot set" a frame.  You'd be
surprised just how much cold-setting steel can take.  Just have
your framebuilder or bike shop cold-set to the proper width and
be happy.


 
 
 

Hot Resetting Rear Triangle

Post by Jobst Bran » Fri, 27 Aug 1999 04:00:00

Quote:
Rick Knowlan writes:
> My apologies for a misleading post that did not accurately state my
> question.  Sorry I wasted your time.
> When I said "hot resetting", I did not mean heating the tubes and
> bending them.  I meant (and should have said) heating the lugs to
> loosen the brazing (or is it silver soldering?) and resetting the
> lugged joints a fraction.  That would, I imagine, require "longer"
> bridges, too. Has anyone tried resetting previously fastened lugs?
> Any success?  Would the heat required change the properties of the
> tubes?

Oops.  Even worse.  That means the position of the lugs needs to be
redone after the frame is widened (without heat).  All this torching
around the dropouts will leave you with lugs that look like an amateur
built the frame, taking forever to get the lugs right with multiple
re-heating and re-brazing.

Who started all this anyway.  I get the feeling that "cold setting =
BAD" is another one of those rumors bike shops started to keep riders
from doing simple frame adjustments themselves.  Such admonitions have
a way of running away on their own, never to be stopped.  It's like
steel frames getting soft, aging tires before use, the curse of
rotating mass, and a slew of other remotely true but factually wrong
concepts.


 
 
 

Hot Resetting Rear Triangle

Post by CV25 » Fri, 27 Aug 1999 04:00:00

So, there is likely no problem cold-setting a frame from 130 to 145mm? My boss
is doing everything possible not to, for fear of damaging a customer's tandem.

I think he's worrying is much-ado about nothing.

Robin Hubert

 
 
 

Hot Resetting Rear Triangle

Post by Rick Knowla » Fri, 27 Aug 1999 04:00:00

Quote:

> Rick Knowlan writes:

> > My apologies for a misleading post that did not accurately state my
> > question.  Sorry I wasted your time.

> > When I said "hot resetting", I did not mean heating the tubes and
> > bending them.  I meant (and should have said) heating the lugs to
> > loosen the brazing (or is it silver soldering?) and resetting the
> > lugged joints a fraction.  That would, I imagine, require "longer"
> > bridges, too. Has anyone tried resetting previously fastened lugs?
> > Any success?  Would the heat required change the properties of the
> > tubes?

> Oops.  Even worse.  That means the position of the lugs needs to be
> redone after the frame is widened (without heat).  All this torching
> around the dropouts will leave you with lugs that look like an amateur
> built the frame, taking forever to get the lugs right with multiple
> re-heating and re-brazing.

> Who started all this anyway.  I get the feeling that "cold setting =
> BAD" is another one of those rumors bike shops started to keep riders
> from doing simple frame adjustments themselves.  Such admonitions have
> a way of running away on their own, never to be stopped.  It's like
> steel frames getting soft, aging tires before use, the curse of
> rotating mass, and a slew of other remotely true but factually wrong
> concepts.

Thanks again for your reply (and to others who have contributed).

Re: your question as to who started all this? A dejanews search uncovered
a thread from a few years ago in which people expressed doubts about the
wisdom of spreading a rear triangle from 120 mm to 130 mm. I could not
find any reference to larger cold deformations.  I'll check with a few
good LBSs on their willingness to give it a go.

 
 
 

Hot Resetting Rear Triangle

Post by si.. » Fri, 27 Aug 1999 04:00:00

[snip]
: Re: your question as to who started all this? A dejanews search uncovered
: a thread from a few years ago in which people expressed doubts about the
: wisdom of spreading a rear triangle from 120 mm to 130 mm.
  Hmmm. Haven't seen this thread, but although adjusting the rear spacing by
~10mm requires a fair bit of muscle-power it's eminently possible. Indeed, I
had one of my old steel frames respaced from 126mm to 135mm not so very long
ago. Providing care is taken to ensure that the dropouts are parallel *after*
the cold-setting has taken place, there should be no subsequent problems - mine
ran sweetly enough until it was replaced by a custom frame.

: I could not find any reference to larger cold deformations. I'll check with
: a few good LBSs on their willingness to give it a go.
  Most should be prepared to do the job for you, and it's not exactly expensive
- I paid the equivalent of about $15 (GBP10) in labour charges. It's one of the
few jobs I'm not prepared to do myself.

Simon

--
Simon Ward, Department of Electronics, University of York, YO10 5DD, UK

Web: http://www.blinkyfish.freeserve.co.uk/   [Observe the Reply-To header]

 
 
 

Hot Resetting Rear Triangle

Post by Troy A. Courtne » Fri, 27 Aug 1999 04:00:00

Quote:

>In discussing my idea to upgrade my old, beloved lugged Reynolds 531d-b
>framed bike, a friend suggested today that I consider spreading the rear
>triangle to accept 9 speed.  I measured it, and it looks like it is
>currently 116 mm. Going to 130 would be a "real stretch".

>Since I plan to strip and refinish the frame, does it make sense to have
>it "hot reset" by a competent frame builder?  Has anyone tried this?
>Comments?

You are basically talking about rebuilding the rear triangle, which is time
consuming and costly.

The good news in terms of cold setting is that many of the older frames have
relatively thicker wall tubing or the tubing is of the stress relieved
variety rather than the specially heat treated thin wall stuff we see today.
The stress relieved thicker wall stay can be easily cold set from 120 out to
130 or 135 with out any real concern except that of seperating a bridge
joint if not properly supported. However, some of the newer tubes just don't
want to give much to cold setting until you are at the ragged edge of it
braking point...if you go a couple mm further and you've just folded the
stay in half.

With all that said, your beloved 531 will not be a problem to cold set. In
my mind, however, it is important to have someone do it that has the tools
and the experience. There have be some in r.b.t. that have suggested putting
a foot on one drop and you hand on the other and yank..."hey it worked for
me"...this is potentially very bad news. It is important that each drop
maintain the same distance from the imaginary center plain of the main
triangle and that the faces of these drop are parallel. Anything less than
that and you can end up with a poor handling or poor shifting (or both)
bike.

Regards,
Troy A. Courtney
________________________________________________
Courtney Custom Cycles
Geneva, IL 60134 USA
630.232.8720

http://www.cccycles.com
________________________________________________

 
 
 

Hot Resetting Rear Triangle

Post by John Thomps » Fri, 27 Aug 1999 04:00:00


Quote:
>When I said "hot resetting", I did not mean heating the tubes and bending
>them.  I meant (and should have said) heating the lugs to loosen the
>brazing (or is it silver soldering?) and resetting the lugged joints a
>fraction.  That would, I imagine, require "longer" bridges, too. Has
>anyone tried resetting previously fastened lugs?  Any success?  Would the
>heat required change the properties of the tubes?

It could be done, but there's really no need.  The biggest issue
you're likely to have after cold setting your frame to 130mm is
cosmetic: a slight bowing of the seat stays at the brake bridge.
This is nothing to worry about; indeed some builders (Basso comes
to mind) had bowed stays as sort of a trademark.


 
 
 

Hot Resetting Rear Triangle

Post by Rick Denn » Sat, 28 Aug 1999 04:00:00

Quote:


>:>With all that said, your beloved 531 will not be a problem to cold set. In
>:>my mind, however, it is important to have someone do it that has the tools
>:>and the experience. There have be some in r.b.t. that have suggested putting
>:>a foot on one drop and you hand on the other and yank..."hey it worked for
>:>me"...this is potentially very bad news. It is important that each drop
>:>maintain the same distance from the imaginary center plain of the main
>:>triangle and that the faces of these drop are parallel. Anything less than
>:>that and you can end up with a poor handling or poor shifting (or both)
>:>bike.

>What kind of spreading tools are used to ensure that the
>spreading is symmetrical? I'm aware of the simple method
>using a pair of nuts on a threaded rod which is claimed to
>do a reasonable job.

Actually, this is not the best method, because it leaves the dropout
not parallel, the bending occurs at the bridge (which may or may not
be a problem) and it doesn't assure symmetry in any case (yielding is
not that predictable). The tools I'd use for a job like this is a
lever bar with a hook in it. A 2x4 works fine. The hook is the
lag-threaded hardware-store variety, with several layers of duct tape
to prevent scratching. The hook is about 45 cm from one end of the
2x4. I hook the hook around the dropout, and then insert a fulcrum
between the 2x4 and the spot where I want the bend to occur. I use a
2x2 of the softest white pine as a fulcrum, and tack it to the 2x4
with a***(from the side so that the***head doesn't dig into
the frame. The softness of the wood has been enough in my case to
prevent dents, though I suppose you can put a thick piece of felt on
it for insurance.

My 2x4 is about four feet long. I put the bike in a stand, and get a
couple of buddies to hole the frame by the seat tube and the head
tube. I hook the lever around the dropout, press the fulcrum at the
bend spot, and apply force. I work both sides, with an alignment
string to maintain symmetry. I work carefully, and so far, I haven't
overshot and had to back up, though I want to overshoot by a mm or two
because realigning the dropouts will soak up some of the new width. I
use a ruler to check spacing.

If the location of the bend is not right at the brake bridge, then you
minimize the risk of popping the bridge's solder joint, which was a
problem mentioned by another poster.

I then realign the dropouts using standard dropout alignment tools.

I don't worry about what the seat stays are doing. I figure they don't
really have to even yield--they are pretty thin, and can just go along
for the ride.

I used to think this was a problem (about 25 years ago, that is). When
I saw Bill Moore bending my fork stays in a form, cold, I realized it
wasn't a problem.

I've widened the rear triangle on three frames using this method,
without even marring the paint.

I'm sure Troy has a more officially acceptable method, but I like
methods that I can do in my ba***t. In general, though, look at the
tools that any good shop will have, and use them as models for your
own homemade tools.

Rick "Forks are harder, just because they are harder to hold onto, but
I've done them, too" Denney

 
 
 

Hot Resetting Rear Triangle

Post by Mike Jacoubowsk » Sat, 28 Aug 1999 04:00:00

Ah yes, as I previously mentioned...the DeRosa method!

--Mike--
Chain Reaction Bicycles
http://SportToday.org/


Quote:


>:>With all that said, your beloved 531 will not be a problem to cold set.
In
>:>my mind, however, it is important to have someone do it that has the
tools
>:>and the experience. There have be some in r.b.t. that have suggested
putting
>:>a foot on one drop and you hand on the other and yank..."hey it worked
for
>:>me"...this is potentially very bad news. It is important that each drop
>:>maintain the same distance from the imaginary center plain of the main
>:>triangle and that the faces of these drop are parallel. Anything less
than
>:>that and you can end up with a poor handling or poor shifting (or both)
>:>bike.

>What kind of spreading tools are used to ensure that the
>spreading is symmetrical? I'm aware of the simple method
>using a pair of nuts on a threaded rod which is claimed to
>do a reasonable job.

Actually, this is not the best method, because it leaves the dropout
not parallel, the bending occurs at the bridge (which may or may not
be a problem) and it doesn't assure symmetry in any case (yielding is
not that predictable). The tools I'd use for a job like this is a
lever bar with a hook in it. A 2x4 works fine. The hook is the
lag-threaded hardware-store variety, with several layers of duct tape
to prevent scratching. The hook is about 45 cm from one end of the
2x4. I hook the hook around the dropout, and then insert a fulcrum
between the 2x4 and the spot where I want the bend to occur. I use a
2x2 of the softest white pine as a fulcrum, and tack it to the 2x4
with a***(from the side so that the***head doesn't dig into
the frame. The softness of the wood has been enough in my case to
prevent dents, though I suppose you can put a thick piece of felt on
it for insurance.

My 2x4 is about four feet long. I put the bike in a stand, and get a
couple of buddies to hole the frame by the seat tube and the head
tube. I hook the lever around the dropout, press the fulcrum at the
bend spot, and apply force. I work both sides, with an alignment
string to maintain symmetry. I work carefully, and so far, I haven't
overshot and had to back up, though I want to overshoot by a mm or two
because realigning the dropouts will soak up some of the new width. I
use a ruler to check spacing.

If the location of the bend is not right at the brake bridge, then you
minimize the risk of popping the bridge's solder joint, which was a
problem mentioned by another poster.

I then realign the dropouts using standard dropout alignment tools.

I don't worry about what the seat stays are doing. I figure they don't
really have to even yield--they are pretty thin, and can just go along
for the ride.

I used to think this was a problem (about 25 years ago, that is). When
I saw Bill Moore bending my fork stays in a form, cold, I realized it
wasn't a problem.

I've widened the rear triangle on three frames using this method,
without even marring the paint.

I'm sure Troy has a more officially acceptable method, but I like
methods that I can do in my ba***t. In general, though, look at the
tools that any good shop will have, and use them as models for your
own homemade tools.

Rick "Forks are harder, just because they are harder to hold onto, but
I've done them, too" Denney

 
 
 

Hot Resetting Rear Triangle

Post by Jobst Bran » Sun, 29 Aug 1999 04:00:00

Quote:
Troy A. Courtney writes:
> What kind of spreading tools are used to ensure that the spreading
> is symmetrical? I'm aware of the simple method using a pair of nuts
> on a threaded rod which is claimed to do a reasonable job.

You'll have to explain that one to me.  What makes the two sides of
the frame spread equilaterally?  The only way I know of without
fixtures is to bend one side at a time, exactly half of the width
required.  This is not so much spreading as bending one side at a time
a desired amount.  After that you use the standard Campagnolo dropout
aligning gauges that are made to be used on cold steel.

Quote:
> Actually, this is not the best method, because it leaves the dropout
> not parallel, the bending occurs at the bridge (which may or may not
> be a problem) and it doesn't assure symmetry in any case (yielding is
> not that predictable).

That is only desirable.  The farther up the bend occurs the smaller
the material deformation and the easier it its to bend.  Symmetry does
not come naturally, there being no two frame sides that are
identically rigid.  You cannot rely on symmetry of the frame to
produce a symmetrical spread,

Quote:
> The tools I'd use for a job like this is a lever bar with a hook in
> it. A 2x4 works fine. The hook is the lag-threaded hardware-store
> variety, with several layers of duct tape to prevent scratching...

The rest of this procedure sounds like bad news to me.  Don't do that!
Are you sure that you are speaking from experience?  This all sound so
theoretical.  How many frames have you done this way?  Ouch!


 
 
 

Hot Resetting Rear Triangle

Post by Dan Goldenber » Sun, 29 Aug 1999 04:00:00

Quote:

> My 2x4 is about four feet long. I put the bike in a stand, and get a
> couple of buddies to hole the frame by the seat tube and the head
> tube.

A good method to hold the bike (I am assuming it is dissasembled) is to
get some used cup and cone bottom bracket cups,***them into the
bottom bracket shell, then clamp the bike in a good vise with the jaws
of the vise against the bottom bracket cups.

Dan Goldenberg
Seattle WA