I think this removal method might be working by reaching an elastic limit of the post, stretching it and thereby narrowing it enough to move by the small amounts we see. Once it's moved and the tension released it returns to its original diameter and reseizes. This would explain the required repeated pulls and slip-stick movement. It may even explain the second pull requiring more force than the first as it's bedding in that oxide layer resulting in even more surface area once it's moved.
Personally i dont think that oil does much of anything, because aluminum oxide is harder that aluminum and steel, and main thing, depending of how crystaline\amorphous oxide is, it can be 1.3 to 10-30 times the volume i think. There is not much heating can do, like with iron oxides, i.e. rust on bolts. Those, when heated with blowtorch in lets say aluminum engine block, break rust nicely more often than not. bolt expands more, than aluminum surrounding it (because of thermal conductivity and large mass of engine block, it dissapates heat quicker that steel bolt, thus while applying enough energy quickly with blowtorch or acetylene torch you can heat up and expand bolt more that aluminum surrounding it and that in theory crushes iron oxide, then bolt cools down and it allows you to unscrew it. When you have stuck seatpost, its not like its stuck, more like it grew in size and you essentially have press-fit now, which no amount of oil and heat will release it, because aluminum have greater coefficient of thermal expansion you essentially have to heat entire seattube while simultaniously cooling seatpost to that to dissasemble with lower amounts of force that not. So yeah pulling is the only logical option it seems
And yeah, indication of that aluminum oxide is quite porous, is that when you remove seatpost there is iron oxide too, and not only white stuff, that means there is enough space for ambient air to get it and corrode steel too. So yeah maybe oil will penetrate nicely, but that wont do much beacause seatpost just grew in size and wedged itself. Steel is a cathode so it woudnt rust normally when in contact with aluminum, my guess is that all the contact points turn to aluminum oxide, moisture from ambient air gets in then steel seattube starts to corrode, thats why you see not only aluminum but steel oxide too. That depends on age of frame i would guess.
It's funny the number of people willing to give advice, when you went out of your way to build a specialized machine. Also, sheesh 12:15 you can see the shims deforming!
This was really cool to see a bit of data tied to what was happening. You definitely put it into perspective with the idea of a SUV hanging from the seat post and it barely budging, that's nuts!
Adding another "wouldn't it be interesting" if you had a heat camera to see how much heat is generated by the friction as it breaks loose would be a cool test! Awesome machine!
You are completely right about the hacksaw blade method, incredible tedious and slow. But for us at the time it was the only method we had. Your device is far superior in every way.
the numbers are really informative, tells those inclined to copy your design what we should expect. So it would be great if you could find one so stuck you break the seatpost by pulling on it :)
I love this machine because it forces stubborn materials into submission and compliance. I know inanimate objects don’t feel pain, but I like to believe they do, and this machine imparts a good amount.
Phil, I have watched your videos for a very long time, and I’ve found them all to be mesmerisingly interesting, and this one was right up there. I love videos where facts are being smashed against old wives tales. Thank you for taking a scientific approach to this. 😎👍🏻
@@tobymcnicol922 Generally joints like this *should* be designed so that the joint is stronger than the parent member. Fillet welds for instance, are usually thicker in the throat of the weld than the tubing, so you'd expect the tube itself to fail first.
Very interesting video, definetly interested in this kind of material. Thanks for sharing this information. I have used a modified bearing puller kit for same kind of case couple of times but not as fine contrition as yours.
cudos to the guy putting out 3 tons of force with a hammer for 30 years. what a beast! this video was pretty interesting, nice job! what would one do to prevent this from happening? i guess, putting a layer of grease would help, but whenever i out grease on my seatpost it will no longer clamp safely for the life of me. others told me, they always grease their posts, but for me at least that is not working.
Ahh the bicycle industry... Never have there been more "professional" people with blah blah blah x amount of decades in the biz talking out of their ass. When you put hard data and hard earned empirical speculation against all their "experience" hopefully all those "pros" can take the hint and STFU. Thanks for showing these idiots.
Very interesting. For testing you could try dry and after the first 2 cracks, apply oil and wait and then see if the friction is lower. In dry runs you had the friction even increasing, so this way could be a reasonable test. Another interesting thing is if the seat tube changes diameter after pulling the post out:
awsome job to put in numbers and do this research to this procedure. its quite interesting and surprising how a frame and seatpost are holding more than a ton of preassure. im surprise also a BB can be damaged with that force.
My idea of heating is to heat fast and high when there is already is some force aplied, because the outher tube will get wider and the oxyde will work as an insulator for a short time.
I think a electric heat gun might Not be the Tool, but a gas burner does the job in my case most of the time and time is also a thing that works with the oil.
Great video, thanks! Aren't you worried that extreme force will create a lethal projectile? Like the breaking bolt you show in the video. Perhaps a plexiglass deflector around the seatpost can prevent this at little cost. As for data demonstrating the ineffectiveness of penetrating oil, you can run a metadata experiment randomly testing seatpost extraction with or without oil and, if you have enough tests, you can compare them to see if there's a difference. This will take hundreds of tests, and you'll have to measure each one... it's totally pointless in my opinion because your arguments are perfectly valid and you've made your point with this video, but I think it's the more scientific approach.
I don't think the heat and oil is really necessary because you're tool is strong enough to pull out the posts but just to find out if you do this again with the load cell pull until it cracks and then oil it. If the second crack is much lower it works if not it doesn't. On many of if not the majority of posts the cracks kept getting harder for a time.
You could use Galluim on that last mangled post, it'll turn the Aluminium to mush and it'll just fall out. Pretty sure it won't do anything to the frame assuming it's steel, just don't let it touch anything else Aluminium on the bike or anywhere else. You'll need to scuff up the post first but once it gets in it spreads incredibly well through the metal.
Hydraulics aren't' for more force, they're for making it so that you can put a pump on it and not have to turn a thing yourself. They can probably also pull the tube out in less time than you too, a person does 400 watts when working more or less, the average American outlet does 1800 all out, a euro 240v line does twice that therefore one quarter or eighth the time to pull the tube. Though putting a big geared motor on a nut on the rod you have would do the same thing. Realistically this is more a concern if you were doing dozens or thousands of these, and were worried about how much you were paying people to turn a screw or injury. Edit Because I forgot: An average 3lb dead blow or other hammer lightly swung, essentially let fall, from the shoulder to the level of the crotch, falls 90cm, assuming the seat post and all the attachment parts are driven 5cm out, we can use the pile driver formula to calculate the average force is 28500 newtons, or about 3 tons. Of course, most of the time nobody delicately drops a hammer on work. The average worker can roughly triple the speed of an appropriately sized swung hammer at impact. Interestingly this limit is actually imposed by muscle contraction speed rather than force, so is consistent until the hammer is 'too large'. Hence the conclusion that if you cannot get a stuck seat out with some multiple of 3 tons of force, you are probably doing something wrong. _*this is also consequently why bubba can break very expensive things you wouldn't believe when he gets out a thirteen pound sledge and hits iron with it_
Do you clean up and re-use the seat posts that you've removed or do you consider them weakened or not worth the effort or unsuitable in some other way?
The forces involved in this make me wish you had some shielding around the device, or around you. I know it's pretty overbuilt and that threaded rod is probably up for it but dang
In electrical applications when aluminum comes into contact with steel, there is a special “grease” commonly known as De-Ox, and cheaply found in the electrical department of any hardware store. To basically prevent this galvanic oxidation from happening. It must be awesome to remove these impossible cases 👍
Weight mostly, steel seatposts are very rare nowadays because they're heavy. In case of aluminum frames, both are the same metal but even those can get stuck (usually not as bad though)
yes its sad, i remember that I searched an eternity for a steep seatpost to prevent binding after a successful removal - and i couldn't find one at all :(... btw the removal I did was cutting it with a metal sawblade lengthwise inside the frame - much easier than I expected, so if you do it less frequently than Phil, it is definitely an option! ;) Good video!
Caustic would work to dissolve the aluminium seat post and do no damage to a steel frame but caustic would also dissolve the inside of an aluminium frame...so safe to use for steel frames but not aluminium ones.
Thanks for the time/effort that went into making this great video. Question; at different points you talked about tapping with a hammer while under tension-what would you think about the effectiveness of introducing a "pulsating hammer" i.e., like that of an impact driver to create the same effect? Just a thought.
Very nice work P.V. Phil do you have a link where I could get some information about your oiler that held your WD-40? I might have asked you about that once before but I was having trouble with You Tube concerning reading the replies.. Phil thx for sharing your skills and bringing us along... P.S. I checked for links on your page but didn't see it...
If you did want to really determine the effect of oil, you could use statistical methods. With a large enough sample size, you could count on the variations between different seatposts canceling each other out, which would give you some reasonable probability that the oil either does or does not have an effect. This is, after all, what we rely on in science to do things like determine the effectiveness of medicines, even in the face of variation between people. The thing I was surprised by is just how small a number N has to be before you can get real statistical significance. In most cases, 30 is more than enough, and even a smaller number can wind up giving you enough confidence to draw a reasonable conclusion. Anyway, perhaps you've already considered this. Either way, always look forward to your videos!
I can't believe how many people really think you went all the way for creating a especialized f*•king machine before trying wd-40 and heat or a hammer 😂
Hypothetically, impact loosening could function by breaking up large structures of corrosion that could be producing large point friction in addition to the area friction of corrosion being present at all. If this were the case what you would actually want is a huge amount of impact, like from an impact drill or air hammer, installed so you can let it run for half an hour or so. The scale of impact you would get from a hammer is basically comparable to the scale of impact this puller sees when the tube slips. As shown, this doesn't eliminate the need for the puller. Maybe aggressive impact loosening could reduce the peak force necessary, or make the peaks more regular, but it doesn't seem like the puller takes all that long
These are basically friction welded together. The corrosion creates pitting, the pitting creates galling, which welds the pieces together. Adding heat actually makes things worse. This very much underscores the need to sand / polish the post and liberally lubricate before installing it.
I think this removal method might be working by reaching an elastic limit of the post, stretching it and thereby narrowing it enough to move by the small amounts we see. Once it's moved and the tension released it returns to its original diameter and reseizes. This would explain the required repeated pulls and slip-stick movement. It may even explain the second pull requiring more force than the first as it's bedding in that oxide layer resulting in even more surface area once it's moved.
It's very interesting to know just how stuck they are. Thank you for quantifying it.
how stuck is it on the vanderlay scale of stuckness?
1? 2? 3? Very?
Personally i dont think that oil does much of anything, because aluminum oxide is harder that aluminum and steel, and main thing, depending of how crystaline\amorphous oxide is, it can be 1.3 to 10-30 times the volume i think.
There is not much heating can do, like with iron oxides, i.e. rust on bolts. Those, when heated with blowtorch in lets say aluminum engine block, break rust nicely more often than not. bolt expands more, than aluminum surrounding it (because of thermal conductivity and large mass of engine block, it dissapates heat quicker that steel bolt, thus while applying enough energy quickly with blowtorch or acetylene torch you can heat up and expand bolt more that aluminum surrounding it and that in theory crushes iron oxide, then bolt cools down and it allows you to unscrew it.
When you have stuck seatpost, its not like its stuck, more like it grew in size and you essentially have press-fit now, which no amount of oil and heat will release it, because aluminum have greater coefficient of thermal expansion you essentially have to heat entire seattube while simultaniously cooling seatpost to that to dissasemble with lower amounts of force that not. So yeah pulling is the only logical option it seems
You summed it up better than I could 👌
And yeah, indication of that aluminum oxide is quite porous, is that when you remove seatpost there is iron oxide too, and not only white stuff, that means there is enough space for ambient air to get it and corrode steel too. So yeah maybe oil will penetrate nicely, but that wont do much beacause seatpost just grew in size and wedged itself.
Steel is a cathode so it woudnt rust normally when in contact with aluminum, my guess is that all the contact points turn to aluminum oxide, moisture from ambient air gets in then steel seattube starts to corrode, thats why you see not only aluminum but steel oxide too. That depends on age of frame i would guess.
It's funny the number of people willing to give advice, when you went out of your way to build a specialized machine.
Also, sheesh 12:15 you can see the shims deforming!
Saying that he should use penetrating oil is downright insulting, to be honest.
i could watch this all day long.
I liked the "you could hang a range rover from it and it wouldn't move" comment, that's some sort of stuck and hard to imagine. Great video.
This was really cool to see a bit of data tied to what was happening. You definitely put it into perspective with the idea of a SUV hanging from the seat post and it barely budging, that's nuts!
Adding another "wouldn't it be interesting" if you had a heat camera to see how much heat is generated by the friction as it breaks loose would be a cool test! Awesome machine!
I'd like to see that.
You are completely right about the hacksaw blade method, incredible tedious and slow. But for us at the time it was the only method we had. Your device is far superior in every way.
the numbers are really informative, tells those inclined to copy your design what we should expect. So it would be great if you could find one so stuck you break the seatpost by pulling on it :)
I love this machine because it forces stubborn materials into submission and compliance. I know inanimate objects don’t feel pain, but I like to believe they do, and this machine imparts a good amount.
Phil, I have watched your videos for a very long time, and I’ve found them all to be mesmerisingly interesting, and this one was right up there. I love videos where facts are being smashed against old wives tales. Thank you for taking a scientific approach to this. 😎👍🏻
What I found similarly interesting in the first video and this one is that the brazed joint from BB-to-Seattube resists so much pull force.
makes me wonder if a brazed, lugged joint is stronger in tension than a welded, mitred junction. due to greater bonded surface area ..... ?
@@tobymcnicol922 Generally joints like this *should* be designed so that the joint is stronger than the parent member. Fillet welds for instance, are usually thicker in the throat of the weld than the tubing, so you'd expect the tube itself to fail first.
Good to see you back!
Very interesting video, definetly interested in this kind of material. Thanks for sharing this information. I have used a modified bearing puller kit for same kind of case couple of times but not as fine contrition as yours.
Great work, Phil. Thanks.
cudos to the guy putting out 3 tons of force with a hammer for 30 years. what a beast!
this video was pretty interesting, nice job!
what would one do to prevent this from happening? i guess, putting a layer of grease would help, but whenever i out grease on my seatpost it will no longer clamp safely for the life of me. others told me, they always grease their posts, but for me at least that is not working.
If grease makes it slip, it could be that your seatpost is too thin. There used to be lot of different sizes by .2mm increments.
Ahh the bicycle industry... Never have there been more "professional" people with blah blah blah x amount of decades in the biz talking out of their ass. When you put hard data and hard earned empirical speculation against all their "experience" hopefully all those "pros" can take the hint and STFU. Thanks for showing these idiots.
Very interesting.
For testing you could try dry and after the first 2 cracks, apply oil and wait and then see if the friction is lower. In dry runs you had the friction even increasing, so this way could be a reasonable test.
Another interesting thing is if the seat tube changes diameter after pulling the post out:
I really enjoyed this one. Thank you for sharing!
Very informative, thanks Phil!
awsome job to put in numbers and do this research to this procedure. its quite interesting and surprising how a frame and seatpost are holding more than a ton of preassure. im surprise also a BB can be damaged with that force.
I don’t think people realize how much are 2 tons. It’s like hanging a mid size car to that seat post. That is amazing.
My idea of heating is to heat fast and high when there is already is some force aplied, because the outher tube will get wider and the oxyde will work as an insulator for a short time.
I think a electric heat gun might Not be the Tool, but a gas burner does the job in my case most of the time and time is also a thing that works with the oil.
With the last post i d use a reamer or put the part into a Na-OH solution which will eat the aluminium but not the steal.
omg you did it! thank you so much!
Great video, thanks! Aren't you worried that extreme force will create a lethal projectile? Like the breaking bolt you show in the video. Perhaps a plexiglass deflector around the seatpost can prevent this at little cost. As for data demonstrating the ineffectiveness of penetrating oil, you can run a metadata experiment randomly testing seatpost extraction with or without oil and, if you have enough tests, you can compare them to see if there's a difference. This will take hundreds of tests, and you'll have to measure each one... it's totally pointless in my opinion because your arguments are perfectly valid and you've made your point with this video, but I think it's the more scientific approach.
Absolutely fascinating! 😀
I don't think the heat and oil is really necessary because you're tool is strong enough to pull out the posts but just to find out if you do this again with the load cell pull until it cracks and then oil it. If the second crack is much lower it works if not it doesn't. On many of if not the majority of posts the cracks kept getting harder for a time.
You could use Galluim on that last mangled post, it'll turn the Aluminium to mush and it'll just fall out. Pretty sure it won't do anything to the frame assuming it's steel, just don't let it touch anything else Aluminium on the bike or anywhere else. You'll need to scuff up the post first but once it gets in it spreads incredibly well through the metal.
Hydraulics aren't' for more force, they're for making it so that you can put a pump on it and not have to turn a thing yourself. They can probably also pull the tube out in less time than you too, a person does 400 watts when working more or less, the average American outlet does 1800 all out, a euro 240v line does twice that therefore one quarter or eighth the time to pull the tube. Though putting a big geared motor on a nut on the rod you have would do the same thing.
Realistically this is more a concern if you were doing dozens or thousands of these, and were worried about how much you were paying people to turn a screw or injury.
Edit Because I forgot:
An average 3lb dead blow or other hammer lightly swung, essentially let fall, from the shoulder to the level of the crotch, falls 90cm, assuming the seat post and all the attachment parts are driven 5cm out, we can use the pile driver formula to calculate the average force is 28500 newtons, or about 3 tons. Of course, most of the time nobody delicately drops a hammer on work. The average worker can roughly triple the speed of an appropriately sized swung hammer at impact. Interestingly this limit is actually imposed by muscle contraction speed rather than force, so is consistent until the hammer is 'too large'. Hence the conclusion that if you cannot get a stuck seat out with some multiple of 3 tons of force, you are probably doing something wrong. _*this is also consequently why bubba can break very expensive things you wouldn't believe when he gets out a thirteen pound sledge and hits iron with it_
Do you clean up and re-use the seat posts that you've removed or do you consider them weakened or not worth the effort or unsuitable in some other way?
Cool video man.
The forces involved in this make me wish you had some shielding around the device, or around you. I know it's pretty overbuilt and that threaded rod is probably up for it but dang
15:30 it's called patina.
Would percusive encouragement help? Perhaps trying different frequencies? This is a great visual, thanks.
In electrical applications when aluminum comes into contact with steel, there is a special “grease” commonly known as De-Ox, and cheaply found in the electrical department of any hardware store. To basically prevent this galvanic oxidation from happening.
It must be awesome to remove these impossible cases 👍
you know that you now have to pull a seat tube to destruction?
we need answers to the questions we didnt know we needed to ask.
They need these at bike shops.
Why aren't both tubes made of the same metal?
Weight mostly, steel seatposts are very rare nowadays because they're heavy. In case of aluminum frames, both are the same metal but even those can get stuck (usually not as bad though)
yes its sad, i remember that I searched an eternity for a steep seatpost to prevent binding after a successful removal - and i couldn't find one at all :(...
btw the removal I did was cutting it with a metal sawblade lengthwise inside the frame - much easier than I expected, so if you do it less frequently than Phil, it is definitely an option! ;)
Good video!
@PhilVandelay were any of the stuck posts carbon ?
How about caustic soda(NaOH)? This could eat away the aluminium oxide. Not sure it if attacks the remaining aluminium tough...
Caustic would work to dissolve the aluminium seat post and do no damage to a steel frame but caustic would also dissolve the inside of an aluminium frame...so safe to use for steel frames but not aluminium ones.
Thank you do you have open source plans for the seatpost puller . So more people can use it .
Nice Video!
Awesome!
Thanks for the time/effort that went into making this great video. Question; at different points you talked about tapping with a hammer while under tension-what would you think about the effectiveness of introducing a "pulsating hammer" i.e., like that of an impact driver to create the same effect? Just a thought.
If the GT frame is made out of steel, then maybe gallium can be used to break down the aluminum? idk.
I had a Carbon Setpost stuck in a CroMo Frame... i shizzeled it out.
That was a verry strong bond.
Very nice work P.V. Phil do you have a link where I could get some information about your oiler that held your WD-40?
I might have asked you about that once before but I was having trouble with You Tube concerning reading the replies..
Phil thx for sharing your skills and bringing us along...
P.S. I checked for links on your page but didn't see it...
Nice 👍🏻
If you did want to really determine the effect of oil, you could use statistical methods. With a large enough sample size, you could count on the variations between different seatposts canceling each other out, which would give you some reasonable probability that the oil either does or does not have an effect. This is, after all, what we rely on in science to do things like determine the effectiveness of medicines, even in the face of variation between people.
The thing I was surprised by is just how small a number N has to be before you can get real statistical significance. In most cases, 30 is more than enough, and even a smaller number can wind up giving you enough confidence to draw a reasonable conclusion.
Anyway, perhaps you've already considered this. Either way, always look forward to your videos!
24:58 the situation is worse because the aluminium oxide expand with liquid. Adding heat is good idea because drying out the oxides
I can't believe how many people really think you went all the way for creating a especialized f*•king machine before trying wd-40 and heat or a hammer 😂
Hypothetically, impact loosening could function by breaking up large structures of corrosion that could be producing large point friction in addition to the area friction of corrosion being present at all. If this were the case what you would actually want is a huge amount of impact, like from an impact drill or air hammer, installed so you can let it run for half an hour or so. The scale of impact you would get from a hammer is basically comparable to the scale of impact this puller sees when the tube slips. As shown, this doesn't eliminate the need for the puller. Maybe aggressive impact loosening could reduce the peak force necessary, or make the peaks more regular, but it doesn't seem like the puller takes all that long
These are basically friction welded together. The corrosion creates pitting, the pitting creates galling, which welds the pieces together. Adding heat actually makes things worse.
This very much underscores the need to sand / polish the post and liberally lubricate before installing it.
Great work and interesting facts of needed force to put into! Where are you from / located, if I may ask?