130mm for a 126mm hub frame
03-23-24, 12:03 PM
#101
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It's clear from your posts that you know what you're doing. Both methods work fine. The (admittedly fairly minor) reason I changed from your method to mine was that I liked not having to go back and rebend one or both sides if I could avoid it. Given a frame that starts out straight, I bend one side to 3 mm and then the other, I check the dropouts with the Campy H tool, and I'm done.
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03-23-24, 03:11 PM
#102
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The common methods of spreading rear dropouts (or "fork ends," per Sheldon Brown's strongly expressed preference) were mentioned only once in this thread that I remember (those being the use of 2 x 4's, washers and nuts and a threaded rod. etc.).
Just dropping in to point out that, while the left and right dropouts often move equal distances from the frame's center line when a threaded rod is used, or when the mechanic just grabs and pulls the sides apart, equal movement is not guaranteed.
The advantage of the 2 x 4 method is that, if you begin with a frame whose alignment has been measured to be correct, you can bend one side at a time the correct distance. In the case of a 124-mm OLD being changed to 130 mm, that would be 3 mm per side, obviously.
Once you've moved each side 3 mm, all that's left to do is align the dropouts using the Campy H dropout tool or the Park equivalent and then reconfirm that the frame's alignment is still good.
Just dropping in to point out that, while the left and right dropouts often move equal distances from the frame's center line when a threaded rod is used, or when the mechanic just grabs and pulls the sides apart, equal movement is not guaranteed.
The advantage of the 2 x 4 method is that, if you begin with a frame whose alignment has been measured to be correct, you can bend one side at a time the correct distance. In the case of a 124-mm OLD being changed to 130 mm, that would be 3 mm per side, obviously.
Once you've moved each side 3 mm, all that's left to do is align the dropouts using the Campy H dropout tool or the Park equivalent and then reconfirm that the frame's alignment is still good.
03-23-24, 09:55 PM
#103
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But the discussion got turned around and from "insignificantly small" fractional degree changes in alignment you're now arguing that the gauges we use aren't accurate enough. His Park Tool Frame Alignment Gauge No.2 is fine, it's quicker than my string but that is also fine, and the Campagnolo model H style end alignment gauges are sufficiently accurate and easy to use. Is it within a third of a degree? Who knows, who cares?
You cain't have it both ways. Either the induced change is very small or not. If it is -- and we've discussed ad nauseum how small it is by now -- then adjusting that out with crude tools is extremely difficult, by the very nature of those tools. And if the change is large, the operator did a very sloppy job on the cold set, and/or used poor tools.
And again, if one is concerned about hundredths of a millimeter on the inside dropout face, measuring to the outside of the dropout with that FrameAG-2 is not going to work -- because again, dropouts are not manufactured to sufficient tolerances to make that operation accurate to the desired precision. Of course, a "superlative" mechanic would have known this, but our correspondent here did not.
My original statement was that the angle change introduced by spreading from 126 to 130mm is extremely minor, and that few mechanics are capable of correcting that degree of misalignment with crude hand tools. That remains correct, despite the shenanigans of this alleged superlative mechanic, who first agreed with me, and then apparently out of boredom, decided to undertake a lengthy and nonsensical disagreement.
03-23-24, 10:17 PM
#104
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Grabbing a frame and mauling it with your hands -- as this 'professional' does -- is not SOP, and not "good enough" if we are simultaneously worried about precision to within far less than a degree. Ya cain't have it both ways.
In answer to "Who cares?", the answer is, precisely everyone here who is claiming that dropouts must be aligned to within a couple thin hairs of perfect -- which was quite a bit of the first several pages here.
You cain't have it both ways. Either the induced change is very small or not. If it is -- and we've discussed ad nauseum how small it is by now -- then adjusting that out with crude tools is extremely difficult, by the very nature of those tools. And if the change is large, the operator did a very sloppy job on the cold set, and/or used poor tools.
And again, if one is concerned about hundredths of a millimeter on the inside dropout face, measuring to the outside of the dropout with that FrameAG-2 is not going to work -- because again, dropouts are not manufactured to sufficient tolerances to make that operation accurate to the desired precision. Of course, a "superlative" mechanic would have known this, but our correspondent here did not.
My original statement was that the angle change introduced by spreading from 126 to 130mm is extremely minor, and that few mechanics are capable of correcting that degree of misalignment with crude hand tools. That remains correct, despite the shenanigans of this alleged superlative mechanic, who first agreed with me, and then apparently out of boredom, decided to undertake a lengthy and nonsensical disagreement.
In answer to "Who cares?", the answer is, precisely everyone here who is claiming that dropouts must be aligned to within a couple thin hairs of perfect -- which was quite a bit of the first several pages here.
You cain't have it both ways. Either the induced change is very small or not. If it is -- and we've discussed ad nauseum how small it is by now -- then adjusting that out with crude tools is extremely difficult, by the very nature of those tools. And if the change is large, the operator did a very sloppy job on the cold set, and/or used poor tools.
And again, if one is concerned about hundredths of a millimeter on the inside dropout face, measuring to the outside of the dropout with that FrameAG-2 is not going to work -- because again, dropouts are not manufactured to sufficient tolerances to make that operation accurate to the desired precision. Of course, a "superlative" mechanic would have known this, but our correspondent here did not.
My original statement was that the angle change introduced by spreading from 126 to 130mm is extremely minor, and that few mechanics are capable of correcting that degree of misalignment with crude hand tools. That remains correct, despite the shenanigans of this alleged superlative mechanic, who first agreed with me, and then apparently out of boredom, decided to undertake a lengthy and nonsensical disagreement.
The point I have been making is that the only part of all this that benefits from a degree of high precision are the dropouts to the hub - for the reasons previously stated about how the mechanics of the hub work. The location of the dropouts to the rest of the frame does not need to be very precise, but aren't that hard to be precise because the flats of the dropout where the axle end and QR contact are square to each other, and that's where you measure to with the frame tool.
As several people have pointed out to you, the forces in the frame and what happens when you alter the frame can be complex, which is why it was suggested that your plan to ignore the dropout alignment after spreading the dropouts might not make sense.
03-23-24, 10:22 PM
#105
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But, as I pointed out already, we aren't talking about what I do, but what everyone should do. Whether you use a jig, a lever, your hands, etc - you should check the dropouts with an alignment tool after you check the dropout centering (yes, the alignment tool or a taut string and calipers are sufficiently accurate), because you just applied a bunch of weird forces to complex metal shapes, and they don't always behave predictably.
Steel bikes aren't made of rods, but tubes that don't just bend linearly but twist and interfere with each other. We cold set frames because of concern with putting the tubing under constant tension - but there is really no way to remove all of it because we can't measure how much the final position of the dropout is actually the result of opposing tensions between the seatstay and chainstay.
As for you TC1, I don't think there is a single person on this thread that thinks whatever point you're making is sensible. You are simultaneously saying that all bike techniques are too crude measurement wise, yet insist that something you never measure is fine. Which is why no one agrees with you.
03-23-24, 10:58 PM
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Right -- a superlative mechanic who couldn't figure out what millimeters refer to in this discussion, among other things.
Quote me.
A superlative mechanic can build a tool for under $5 that will prevent the dropouts from being angled while the spread occurs, thereby making a post-operation check unnecessary. Actually, damn near any mechanic can manage that.
To bend the stays, any tool that needs to get the dropout to stop at +2mm, you have to flex the dropouts well past 2mm. If your tool holds the dropout parallel to the frame throughout the arc of the bending, the dropout MUST end up set at the wrong angle. In other words, if you start at 126, you have to go past 130 to maybe 140 or so to get enough plastic deformation to settle back to 130 after the device is removed. There is no chance that the bending the dropout parallel at 140 is going to cause it to settle at parallel also at 130.
So please explain how your $5 tool simultaneously sets two unrelated angles at one time.
It's amusing that you say that after suggesting measuring to the outside of dropouts, when the critical surface is the inside -- without seemingly any concern for resolving the resulting tolerance stack.
You seem to be forgetting what we are measuring and when. I have said that the centering of the dropouts to the frame isn't as important as the dropouts being nicely dimensioned to the hub. The frame alignment tool does not measure dropout width, and I it sounds like you think that it does (because you aren't actually that familiar with what is being discussed). The frame tool is a comparator to find if the dropouts are centered to the frame. This is done after the dropout width is set by measuring the inner distance between them. Then you use the dropout tool to square the dropouts that are already 130mm apart (checked by inner measure) and centered to the frame (checked by alignment too). So there are three separate measures being made with three different tools.
Which sounds suspiciously like you have come back around to agreeing with me, that a few thin human hairs of dropout misalignment are very unlikely to matter, or to be adjusted out.
No, I'm saying that some things need to be more precise than others, but that the forces of bending the stays can produce surprising results at the dropouts. Like when you use a $5 threaded rod tool.
For wildly-varying definitions of "opposing".
Did you read what the frame builder above observed?
So again, as I inquired of you a page or so ago, how many millimeters, or degrees, is close-enough to achieve "a minimum" of asymmetry?
I can align everything so there is an unobservable amount of variation from spec using shop gauges to observe. What's "close enough"? Just putting the 130 wheel in the unaltered 126 frame. But if I'm going to bother to spread a frame, I'm not going to settle for a result that is anything less than spot on for the alignment tools being used.
Luckily for me, physics is not democratic. Neither is mechanics. And, for the record, you originally agreed with me.
Quote me.
A superlative mechanic can build a tool for under $5 that will prevent the dropouts from being angled while the spread occurs, thereby making a post-operation check unnecessary. Actually, damn near any mechanic can manage that.
To bend the stays, any tool that needs to get the dropout to stop at +2mm, you have to flex the dropouts well past 2mm. If your tool holds the dropout parallel to the frame throughout the arc of the bending, the dropout MUST end up set at the wrong angle. In other words, if you start at 126, you have to go past 130 to maybe 140 or so to get enough plastic deformation to settle back to 130 after the device is removed. There is no chance that the bending the dropout parallel at 140 is going to cause it to settle at parallel also at 130.
So please explain how your $5 tool simultaneously sets two unrelated angles at one time.
It's amusing that you say that after suggesting measuring to the outside of dropouts, when the critical surface is the inside -- without seemingly any concern for resolving the resulting tolerance stack.
You seem to be forgetting what we are measuring and when. I have said that the centering of the dropouts to the frame isn't as important as the dropouts being nicely dimensioned to the hub. The frame alignment tool does not measure dropout width, and I it sounds like you think that it does (because you aren't actually that familiar with what is being discussed). The frame tool is a comparator to find if the dropouts are centered to the frame. This is done after the dropout width is set by measuring the inner distance between them. Then you use the dropout tool to square the dropouts that are already 130mm apart (checked by inner measure) and centered to the frame (checked by alignment too). So there are three separate measures being made with three different tools.
Which sounds suspiciously like you have come back around to agreeing with me, that a few thin human hairs of dropout misalignment are very unlikely to matter, or to be adjusted out.
No, I'm saying that some things need to be more precise than others, but that the forces of bending the stays can produce surprising results at the dropouts. Like when you use a $5 threaded rod tool.
For wildly-varying definitions of "opposing".
Did you read what the frame builder above observed?
So again, as I inquired of you a page or so ago, how many millimeters, or degrees, is close-enough to achieve "a minimum" of asymmetry?
I can align everything so there is an unobservable amount of variation from spec using shop gauges to observe. What's "close enough"? Just putting the 130 wheel in the unaltered 126 frame. But if I'm going to bother to spread a frame, I'm not going to settle for a result that is anything less than spot on for the alignment tools being used.
Luckily for me, physics is not democratic. Neither is mechanics. And, for the record, you originally agreed with me.
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03-24-24, 07:10 AM
#107
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You can really tell in this back and forth who has actual experience with cold setting frames and who does not. So much energy to try and refute the experience of anyone who’s actually done this a bunch. 
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03-24-24, 07:12 AM
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Right -- a superlative mechanic who couldn't figure out what millimeters refer to in this discussion, among other things.
A superlative mechanic can build a tool for under $5 that will prevent the dropouts from being angled while the spread occurs, thereby making a post-operation check unnecessary. Actually, damn near any mechanic can manage that.
It's amusing that you say that after suggesting measuring to the outside of dropouts, when the critical surface is the inside -- without seemingly any concern for resolving the resulting tolerance stack.
Which sounds suspiciously like you have come back around to agreeing with me, that a few thin human hairs of dropout misalignment are very unlikely to matter, or to be adjusted out.
For wildly-varying definitions of "opposing".
So again, as I inquired of you a page or so ago, how many millimeters, or degrees, is close-enough to achieve "a minimum" of asymmetry?
Luckily for me, physics is not democratic. Neither is mechanics. And, for the record, you originally agreed with me.
A superlative mechanic can build a tool for under $5 that will prevent the dropouts from being angled while the spread occurs, thereby making a post-operation check unnecessary. Actually, damn near any mechanic can manage that.
It's amusing that you say that after suggesting measuring to the outside of dropouts, when the critical surface is the inside -- without seemingly any concern for resolving the resulting tolerance stack.
Which sounds suspiciously like you have come back around to agreeing with me, that a few thin human hairs of dropout misalignment are very unlikely to matter, or to be adjusted out.
For wildly-varying definitions of "opposing".
So again, as I inquired of you a page or so ago, how many millimeters, or degrees, is close-enough to achieve "a minimum" of asymmetry?
Luckily for me, physics is not democratic. Neither is mechanics. And, for the record, you originally agreed with me.
03-24-24, 06:23 PM
#109
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If you are going to wade into the discussion in the manner that you chose, at least read it first.
03-24-24, 06:26 PM
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03-24-24, 06:34 PM
#111
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Are we done here yet, or are you going to continue to waste everyone's time with your nonsense? At least read your own comments before writing new ones.
And again, we find that it boils down to this "superlative" mechanic eyeballing the frame and calling it 'good'. So we've wasted hours and pages arguing about nothing, because you don't even care about, nor try to achieve, anything that might be called 'precision'.
Which, ironically, was basically my original point -- that the change in dropout angle is sufficiently small that adjusting it out is both typically unnecessary and far from trivial with crude tools and eyeball measurements.
I can align everything so there is an unobservable amount of variation from spec using shop gauges to observe. What's "close enough"? Just putting the 130 wheel in the unaltered 126 frame. But if I'm going to bother to spread a frame, I'm not going to settle for a result that is anything less than spot on for the alignment tools being used.
Which, ironically, was basically my original point -- that the change in dropout angle is sufficiently small that adjusting it out is both typically unnecessary and far from trivial with crude tools and eyeball measurements.
03-24-24, 06:37 PM
#112
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Clearly, you do you.
03-24-24, 06:41 PM
#113
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I’m not “attacking” you, and I don’t think Kontact attacked you, but I think you may be in a little over your head here, and you keep digging. At this point it looks like you’re just arguing for the sake of argument.
03-24-24, 07:53 PM
#114
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Are we done here yet, or are you going to continue to waste everyone's time with your nonsense? At least read your own comments before writing new ones.
And again, we find that it boils down to this "superlative" mechanic eyeballing the frame and calling it 'good'. So we've wasted hours and pages arguing about nothing, because you don't even care about, nor try to achieve, anything that might be called 'precision'.
Which, ironically, was basically my original point -- that the change in dropout angle is sufficiently small that adjusting it out is both typically unnecessary and far from trivial with crude tools and eyeball measurements.
And again, we find that it boils down to this "superlative" mechanic eyeballing the frame and calling it 'good'. So we've wasted hours and pages arguing about nothing, because you don't even care about, nor try to achieve, anything that might be called 'precision'.
Which, ironically, was basically my original point -- that the change in dropout angle is sufficiently small that adjusting it out is both typically unnecessary and far from trivial with crude tools and eyeball measurements.
How is using a measuring tool "eyeballing it"?
And my point has been that your guess that the dropout angle is directly tied to the amount the stay is bent is incorrect. Especially if you are attempting to bend both simultaneously, and one is hard steel and the other mild cast.
03-24-24, 08:03 PM
#115
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You two make my head hurt.
And not in a good way.
And not in a good way.
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03-25-24, 01:23 PM
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But since then you've created various straw men, and persisted in not getting the point, in a way that makes it look like you're out to "win" something, even though it looks from here like you've lost the plot.
03-25-24, 01:57 PM
#117
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I know how to make life easier.
Last edited by Bill Kapaun; 03-26-24 at 06:50 PM.
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03-25-24, 07:08 PM
#118
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03-25-24, 08:09 PM
#119
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03-26-24, 12:29 PM
#120
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By the way, if you don't think these are attacks, you need to try reading again:
"You're an odd fellow. So little experience with actually doing stuff..."
"Hopefully any rational person reading this..."
Amusing to note that, way back up top, when another individual claimed their dropouts became misaligned, your buddy Kontact doubted them:
But when I make the same observation, I am attacked.
Even you agreed with me, a week ago, before getting caught up in the unbridled fun of attacking a person on the interwebz other nothing.
03-26-24, 12:33 PM
#121
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If I'm over my head, what does that make the character who agreed with me initially and then decided to engage in a week-long argument over nothing -- before finally just admitting that they eyeball the frame and then call it 'good'?
By the way, if you don't think these are attacks, you need to try reading again:
"You're an odd fellow. So little experience with actually doing stuff..."
"Hopefully any rational person reading this..."
Amusing to note that, way back up top, when another individual claimed their dropouts became misaligned, your buddy Kontact doubted them:
But when I make the same observation, I am attacked.
Even you agreed with me, a week ago, before getting caught up in the unbridled fun of attacking a person on the interwebz other nothing.
But hey, like I said, you guys do you. If you get your jollies off of arguing over nothing for a week, I don't suppose that I can stop you.
By the way, if you don't think these are attacks, you need to try reading again:
"You're an odd fellow. So little experience with actually doing stuff..."
"Hopefully any rational person reading this..."
Amusing to note that, way back up top, when another individual claimed their dropouts became misaligned, your buddy Kontact doubted them:
But when I make the same observation, I am attacked.
Even you agreed with me, a week ago, before getting caught up in the unbridled fun of attacking a person on the interwebz other nothing.
But hey, like I said, you guys do you. If you get your jollies off of arguing over nothing for a week, I don't suppose that I can stop you.
03-26-24, 12:42 PM
#122
Full Member
A superlative mechanic would recognize that the oft-mentioned dropout alignment tool does not provide a measurement of misalignment, it requires the operator to look at it -- with their eyeballs.
Also, you very recently wrote: "What's "close enough"? Just putting the 130 wheel in the unaltered 126 frame." In which case, you are eyeballing whether the wheel sits appropriately. So apparently, your standard is that anything better than the unaltered 126 frame is just fine.
I've asked, at least twice, for people to take credit for the tolerances which they are able to hold using these crude tools -- but no one has been willing to offer such. The whole point here -- to the degree one exists at all -- has been that you and your acolytes claim dropouts can be aligned to within less than 1/4 degree of perfection with crude hand tools. That's a feat which I would think y'all would want to brag about, but no one seems willing.
Can we just rewind to the part above where you agree with me, and stop wasting further time?
Last edited by TC1; 03-26-24 at 12:59 PM.
03-26-24, 12:44 PM
#123
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What "strawmen" exactly?
And what do you claim this missed point is?
03-26-24, 12:48 PM
#124
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03-26-24, 01:03 PM
#125
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If you read above, you'll find that I made a reasonable and correct statement. Various folks -- yourself included -- agreed with me. Then, for reasons which remain unknown, this Kontact individual started a week-long argument over points which they had previously agreed with and which they are now forced to more-or-less abandon under questioning -- meaning the whole affair was a complete waste of time, except, I suppose, it provided this Kontact individual with something to do for a week. I'd much rather have not wasted the time on this thread, as I have far better things to do.