How much Force does it take to Pull out a Stuck Seatpost? We Measured it!

[@Shiryas]

Tom, well done! for reaching out with the Load Cell. Phil, another awesome video. Thank you both, cheers.

[@ericcarabetta1161]

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.

[@PhilVandelay]

Yeah it's the "I wasn't asking" kind of solutions that just hit different in terms of satisfaction

[@LifeInJambles]

​@@PhilVandelay "Oh, that's cute. It seems like you got the impression that this was optional."

[@deeranfoxworthy6069]

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!

[@dogbreath6974]

I'd like to see that.

[@PhilVandelay]

The posts definitely do get warm, but since the removal takes a bit there's not too much of a buildup of heat (guessing from touching it, maybe 40-50°) I could see it getting REALLY hot if you pulled one much faster, like with a motorized puller though

[@Plocxmb]

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 😂

[@yetzt]

i could watch this all day long.

[@alandwells]

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.

[@PhilVandelay]

Definitely an interesting theory, but I wonder if the stretching and narrowing wouldn't also apply to the frame itself, potentially cancelling each other out? Actually, one thing I wanted to check and keep forgetting to measure is the elongation of the frames under tension. Because I'm almost certain the seat tubes get longer by a few tenths of a mm at least during the pulling. At the same time we could also measure the diameter of the seatpost and seat tubes before and during the pulling using a micrometer to record even more data and check whether they become thinner to the same percentage. Damn, I guess it's a missed opportunity for this one, but I'll keep this in mind for next time!

[@LifeInJambles]

​@@PhilVandelay I wonder if the seat tube, being steel, may be holding its dimension slightly better? Of course, the post is thicker, so who knows? It'd definitely be interesting to test.

[@EsbenJJensen]

I had a super stuck seatpost in a carbon frame and ended up designing a tool where the tool pulls the seatpost (stretching it and reducing its diameter) and it supported on top of the seat tube, mitigating the effect of constriction of that tube. The problem of putting both seatpost and seattube into tension is akin to a chinese finger trap. According to FEA, the difference in diameter of the tubes at 2000kg was around 0,05mm, iirc. Edit; regarding the elastic limit - as soon as you start applying force to the seatpost, it starts changing diameter. It does not need to reach its elastic limit and yield to achieve this

[@rkan2]

Inb4 making a seat post with a wheatstone bridge (or a few) integrated 😅

[@asm826]

@@PhilVandelay If that is what is happening, then the aluminum seatpost would be more elastic than the steel seat tube.

[@barthanes1]

It's very interesting to know just how stuck they are. Thank you for quantifying it.

[@tobymcnicol922]

how stuck is it on the vanderlay scale of stuckness? 1? 2? 3? Very?

[@just.some.dud3]

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.

[@criggie]

Confirmed - I cut out a bottom bracket cup once, and it took ~2 hours.

[@forgetyourlife]

I had to do this on the stoker end of a Santana tandem. It took days and days with many hacksaw blades. It was a 300mm post. Good thing I got paid by the hour.

[@Neudezign]

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!

[@Tarkov.]

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!

[@alessandromeyer4888]

Saying that he should use penetrating oil is downright insulting, to be honest.

[@PhilVandelay]

I realize it's mostly people blurting out their first thought after 30 seconds of watching, but if a lot of people have that thought I think it's still worth adressing, even if it's not a very informed one. But yeah it's bizarre to assume that anyone would build this without having tried the easiest, most obvious solution first. As for the shims they are definitely a consumable on this. I've only used them a couple times and some of them are beat to hell already

[@nraynaud]

@@PhilVandelay penetrating oil is one of those things that really *feels* like it should work, and absolutely does not work in practice when we need it. Most stubborn objects are not stuck by friction of flat surfaces alone, but by the "shape" of the corrosion.

[@dogbreath6974]

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.

[@NicksStuff]

Yes. But if you *dropped* a Range Rover on it, it would move :D

[@mechadrake]

nono, and two of those tables with range rover. its not that heavy alone :D

[@rmgrabowski507]

Thank you for the very informative video! Inspired me to build one of these machines for our local community bike shop. We get some nice vintage frames with stuck posts on a fairly regular basis. It works! First post was an exciting event. Looking forward to saving many more.

[@NighteeeeeY]

omg you did it! thank you so much!

[@_kostoberina_]

A very helpful experiment. Thank you! So happy I went on directly with the NaOH before throwing tools at it. It took about 30 minutes.

[@salaciouscrumb1747]

these seat post extraction videos are great. keep them coming

[@JockeSelin]

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. 😎👍🏻

[@ПавелАртёменко-п5б]

Смотрю и просто радуюсь. Всё так просто и умело получилось. Разговорная речь очень правильная, четкая и понятливая. Как будто с учителем английского языка общаюсь. Очень интересно ❤

[@williamschultz298]

Good to see you back!

[@joedowling5452]

I’m not bike enthusiast but love your channel. Your processes and the explanation of things is what keep me coming back.

[@LifeInJambles]

That's rad, but have you considered being a bike enthusiast?

[@nraynaud]

thank you for putting a hard number on things, they are astounding, if you had just said "multiple tons" without evidence I would never had bilieved it.

[@morlamweb]

The fact that the puller bent a 12 mm thick steel plate during the extraction process says a lot about the forces involved way before the measurement tool is installed. Awesome work!

[@forgetyourlife]

Most amazing video I have ever seen to take on the scourge of any used bike mechanic.

[@glennpettersson9002]

Gary's projects used a hacksaw to remove a seat post, I like the Vandelay way. If nothing else you and Gary get me greasing my seat posts. 😁

[@pierogies_and_pie]

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.

[@dirkmohrmann8960]

“Hey this guy with a home machine shop spent many hours developing and building a special seat post pulling rig and made a video about it… but you know, I bet he hasn’t heard of penetrating oil” - the thought process of people on the internet, somehow. It boggles my mind.

[@LifeInJambles]

I think half of it is just that anyone with a lot of experience thinks that nothing exists outside that experience. You see it all the time when people start talking about exhaust diameter and a few other topics with cars, too. These people have been told their whole lives that backpressure is necessary for low-end torque or whatever, and they've been working with that information the whole time. You tell them that's not how it works, they don't care about your data or the testing or principles that you cite. They've worked with it and seen that it works in practice more or less how that idea would imply, so it must be right. They don't want to hear about exhaust gas velocity or the timing of negative pressure pulses leading to scavenging effect during valve overlap or anything because they've seen for themselves through experience that smaller tube give better horsepower at lower rpm and they've *known* the whole time that the reason for that is backpressure. It's just one of the downfalls of experience. If you've learned everything you've used to live your life through experience, you don't want to hear that someone might learn something through study that makes your experience less valuable.

[@Heimbasteln]

The HiFi (audio) industry is probably a worthy contender. There are so many people in that industry who don't try to find out if what they are saying is true or even actively ignore the truth. One example is cables for digital signals that claim to improve audio quality.

[@pierogies_and_pie]

​@@LifeInJambles Well put, but a person having experience and a person willing to expand their knowledge in their craft aren't mutually exclusive (or at least they shouldn't be). Anybody devoted to their trade ought to be willing to learn... Unless of course they're just feeling stuck. And bitter. Which always seems to be the case with my exposure to the bike biz.

[@pierogies_and_pie]

@@Heimbasteln Ha, I've heard the weak argument that if you pay more for an audio cable then it just sounds better, as if that cable can magically pass better 1s and 0s lol. But for me bike folk are the worst - Just because you've been assembling bikes out of boxes for 20 years doesn't make you a mechanical/material/structural engineer. Nor does it make you a metallurgist, machinist, artist, or philosopher. Fix my flat and STFU 😂😂😂

[@Mudganon59]

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

[@PhilVandelay]

You summed it up better than I could 👌

[@Mudganon59]

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.

[@tomdahmer7596]

Great work, Phil. Thanks.

[@Metalwolf765]

Awesome video, thanks for getting the science done! Those forces are crazy high.

[@leslieaustin151]

Nothing beats facts! Thanks, good to see facts used to answer those who ‘think they know’.

[@1Curmudgeon]

Yes, I would like to see more experimental videos like this one. It is entertaining to watch your thought process.

[@casefarley5744]

This was awesome! Thanks for adding and sharing more data on this.

[@lbphilroy]

This is so satisfying. when I was young I found a pristine vintage road bike in the trash with this very issue. I tried all of the penetrating oils, and a gas torch, and a large blacksmith vice and sledgehammer, and I never got any progress.

[@antonioduribaik]

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.

[@arielfisher7]

it was so satisfying to watch thank you.

[@JohanLarssonKiruna]

My, that was satisfying seeing all those seatposts surrender. Pure pleasure. Some times when dealing with stubborn seatposts I have been curious about if a cooling/freezing spray would have any effect, since aluminium changes size more than steel as the temperature varies. I suspect it doesn't have any effect in practice, because I don't think the temperature drop would be that high due to the large mass of the frame/seatpost and the problem a spray would have to cool this to a significant degree. But some small amount of curiosity is still there... 😉 Penetrating oil can take a long time to travel into openings and cracks. I've seen many examples of this when traces of oil have appeared at a distance from the point of application after significant time. If using oil on something stuck I will often wait at least over night before attempting to loosen things. For stuck seat posts I have sometimes applied it over a course of many days. As far as I know penetrating oils do not dissolve any noticeable and useful amounts of rust/oxide, but what it does provide is lubrication. In my experience oil can definitely help to remove stuck seatposts in many cases. I usually secure the stuck seat post in a vice, straight down, with the frame pointing upward, up side down. I then apply penetrating oil from above through the bottom bracket and seat tube. I use the whole frame as a lever, turning it back and forth. Can you get the seatpost to move just a little, a degree or even just a fraction of a degree, that movement is enough to most often get oil to penetrate and lubricate the stuck portion of seatpost enough to facilitate and ease the removal. You can often notice that less force is needed to turn the frame compared to previously, if you have let the oil work for some time. When you get the seatpost to turn and wiggle just a little, you apply oil, wiggle, oil it more, wiggle, and so on. Waiting time in between wiggles range from 30 seconds to ten hours... Some times when you get it loose and can remove it this way, large portions of the oxide layer is moist through with oil. Frames can be destroyed using this method though. If the seatpost is really stuck, you can accidently twist and buckle the seat tube of a light bike with thin tubing, even tear the tubing. I believe a seatpost puller like in the video to be much more secure and safer to use, many times over. (As a note, just recently, I discovered that melted wax from a tea light candle was more effective than penetrating oil when it came to loosening rusty bolts on a car exhaust system. I had heard about this method and decided to do a comparison. I heated the rusty parts and bolts with a gas welding torch, and applied the wax to some of the hot bolts and threads. The rest I applied penetrating oil to. I discovered the wax provided much better lubrication and really eased the removal compared to the oil.) Thinking of how many hours I have spent with stuck seatposts it would clearly have been worth it building a device like yours... But I didn't know of anything like it back when I worked with bikes. Steel seat tubes of high quality are often butted in both ends, and are tight only at the top 10, max 15 centimeters before they widen at the middle of the tube. So a long seatpost doesn't mean it will get stuck more or harder than a short one. Cheap frames however have straight gauge tubing of course, and some butted seat tubes are only butted at the BB end.

[@bigmotter001]

Wow I loved this video! A little different and very mechanically interesting! Thanks for posting and take care!

[@PoulHansenDK]

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:

[@PhilVandelay]

Yeah I considered that too, I'll probably try more stuff like that when I get more frames. As for the diameter, I don't think that changes but I wouldn't rule out that the entire seat tube might have gotten longer by a few tenths or so

[@gwogg8209]

Very interesting! Thanks for taking the effort to set up the measurement apparatus

[@mozismobile]

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 :)

[@ArmyofOneandaHalf]

These are so satisfying to watch

[@jarigranroth6873]

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.

[@lefterissidirourgos5414]

Excelent stuff! Congratulations! May I suggest the folowing experiment then. Since we know that the second crack is at least as "heavy" as the first one, try cracking the tool post without any heat or oil, once you hear the first crack, stop, put some oil and heat, and then try again. If for example from 2tons in the first crack you drop down to 1 ton on the second crack after oil and heat, you know it makes a different, if from 2 tons you go up or drop to lets say 1.8tons then you know oil and heat does not help.

[@dudeonbike800]

Excellent video! So cool to see the tension values you're generating. Damn, 6,462.43 lbs of tension!!! Impressive. Thank you and your viewer for doing that! Side note: at the end you use a flimsy wire brush to clean out the seat tube. Not nearly good enough! You need a quality flex hone instead. This will completely remove any corrosion as well as resurface the seat tube perfectly for the next seat post. All without changing the ID. I don't have your beautiful rig, but I DO have a flex hone in the home shop. Not cheap (~$50), but so worth it. I'd love to see you license your design to Park Tool or another company so they could produce it for LBS use. Would be so great to see your rig used around the world saving bicycle frames! Also, there's more investigation to do here. How much "stretching" of the tube his happening? We all know that pulling grips off handlebars is NOT how to remove them. PUSH them off, so they "bunch up" and increase their ID so they slide off easily. Is this happening during your removal process? Conversely, would pushing on the seat post create the same effect? It might, but I'd guess it would be inconsequential. But it would be interesting to test. I think it's time for you to contact some bike makers to send you some out of spec or blemished product so you can indeed create controls. Have 100 defective frames sit for a year in a corrosive environment with installed, un-lubricated seat posts, and THEN do various tests: with & without penetrating oil, differences in pulling vs pushing, and who knows what else! Finally, I cannot wait to see you pull a seat tube or weld apart some day! PS Your name indicated you're Dutch, but your accent says German. Which is it? I'm putting my $ on German.

[@corey_nz]

Fascinating video, some of the forces were higher than I expected. Thanks for making it and editing together so well, it was very easy to follow along. Annoyingly, this wasn't in my feed - I had to see your post on Instagram to know that the video was up 😕

[@PhilVandelay]

I think this is a common bug (or maybe intentional) on KZbins side, not much I can do about if unfortunately. Did you click the bell icon to make sure you get notified?

[@jorgeconcheyro]

Amazing video Phil, thanks for sharing it ;) Cheers from Buenos Aires, George.

[@jbarner13]

I've removed a lot of stuck seatposts over the years, and I think I've used every method possible but this one. I generally used the 'soak & twist' method, using well-respected penetrants, like Kroil, and my very large antique vise. The worse one took an entire winter of weekly attacks before the post came out. Over the course of last year, I was given four frames by our local bike non-profit to free stuck posts. One they had tried to saw out first, an approach that I've never seen work, which becomes exponentially more difficult as the length of the post increases, and almost always results in damage to the inside of the tube. We tried dry ice on two of them, also to no avail. I ended up dissolving all of them out with lye (sodium hydroxide), which is cheaply available as drain cleaner, but which required up to a few weeks to work, depending on a variety of factors, most notably the ease of sealing up one end so the lye would stay in place. While the paint on all four frames survived, at least for the most part, it was visibly scarred in ways that would not rub out. I didn't try reaming posts out, because that would be very tedious, and there's a limit to how far into the tube you can go with an adjustable reamer. Based on the thickness of these posts, you would have to go through the entire range of multiple reamers in a set in order to get the post out, and you would certainly dull whatever one you were using when you started breaking into the oxide layer. One would need a mighty large mill to machine a post out, and would need skills that far exceed mine to setup the bike well enough to go straight down the center of the tube without nicking it. I think the bond between the post and tube is largely mechanical, caused by the expanding layer of aluminum oxide and rust between the two, which is one of the reasons why penetrating oil is ineffective. I wonder if part of the reason why the force to move the post increases is due to the aluminum post expanding from the heat of friction. It would have been interesting to see if this behavior changed at all if you waited several minutes after the first "pop" to reapply force. I love it whenever common sense is shown to more accurately described as common nonsense. Your device is the most elegant and effective approach to removing stuck seatposts that I have seen.

[@mechadrake]

no no, I think your approach to dissolve the offending post is the most elegant solution! :D (oh this works as pun too, perfect!)

[@rhulzinga67]

Very interesting video. Wonderful device. Love it!

[@nordishkiel5985]

I really enjoyed this one. Thank you for sharing!

[@bradnail99]

Great video, thank you so much. I like the gallium approach for one-offs. Seems safer than sodium hydroxide.

[@ChainsawFPV]

As a mechanic, this reminds me of trying to get a trailer hitch out of a receiver when it's been in forever. Even with a frame straightening machine, I have had a couple that would not budge. Any more force would have ripped the vehicle in half.

[@RSOFT92]

Oh Yeah! 😃 LabView and plotting Sensor Data from experiments is always fun!

[@HenningJohansen]

Absolutely fascinating! 😀

[@se9741]

Very informative, thanks Phil!

[@Rubbernecker]

Excellent video!!!

[@RaulMeatFactory1975]

Love this, and yes more experiments please.

[@nunyabusiness3612]

Awesome as always. Vielen Dank 🙏🏾

[@marsrover001]

I just like any bike related content from you.

[@raceace]

Bike verses physics, Seatposts certain a test of character and technical know,. Nice work.

[@raymundzaldivar2748]

Good work! But if the forces goes up to 3T, I suggest you use a Hollow Ram Split Jack to pull it, in place of the nut on top. Also a solid tracktor pin can also be used as a stopper on the bottom bracket. Hope this helps.

[@theorangebaron1595]

On one of my steel hard rock frames, the seat post was so stuck that I ended up shearing the seat post midway thru the seattube, some pretty crazy stuff. Used a giant auger made for steel to ream it out.

[@unionmoon]

Dutchie here. Been riding a bicycle for eh, 55 years by now. Owned maybe a 100 bikes through this time. I never ever had a seatpost stuck actually. Before mounting a seatpost i put acid free vaseline on the seatpost going into the frame. If you have difficulty removing the post, just carefully put a large flathead screw driver where to bolt goes through the collar and wilden the collar and pull the seatpost out.

[@mechadrake]

but thats cheating with preventative maintenance! :D you have to wait years without moving it for aluminum to corrode in real good ;) no greasing or vaselining

[@SolarMillUSA]

@25:30 don’t mean to be pedantic, but in an effort to add to the discussion and accuracy just want to point out that sodium hydroxide is an extremely strong base, not an acid. It’s a very important distinction as accidentally handling or mixing it with other chemicals and not being aware of that can cause serious safety issues. As for the application itself, I can personally confirm that I have used this method many times to selectively dissolve aluminum that has galled up on the surface of a milling bit. It works quite well. But a seat post is a lot more total volume and I could only guess at the amount of time it would take to eat through. Though usually once it starts to get into the interface it’s no longer about breaking it down entirely but just needs to erode enough material to create a clearance. It is a fairly common and easy to get chemical, and is the primary and almost singular ingredient in many common drain cleaners. However, as mentioned in the video it is quite powerful and dangerous to handle if you do not know what you are doing. It can cause severe burns to skin and serious eye damage from splatter. It also can evolve some serious fumes, even before it comes in contact with other materials, but especially when combined with certain other chemicals has potential to create chlorine gas. You really should not handle the stuff unless you know what you are doing or are willing to put some additional effort into learning how to properly handle and dispose of it. Vinegar or another neutralizing acid should be kept on hand in case of an emergency. Always add the powdered chemical to water when creating a solution, never add water to the powder or you can get a violent reaction that throws the caustic base in all directions, like on to you. That said, and I certainly am not recommending that other people do this, but if I were to try it I would start by cutting the seat post off with an inch or two sticking out from the frame. I would degrease the cavity with a light solvent because that’s only going to get in the way. I would rinse water in and out of the cavity several times until it starts to run fairly clear and then fill it one final time then pour the water into a suitable plastic container so I know how much I need to mix, then *slowly* add the sodium hydroxide. I’d then use a funnel to pour this back into the cavity, of course I will have been wearing the proper PPE the entire time (clothes that I do not mind getting bleached if there is any spatter, proper elbow length gloves, ideally a face shield but at the bare minimum at least safety glasses, and preferably a large space with a fan blowing to me first and then a gentle breeze pushing any fumes away from me), would be working in a well ventilated space, and would have the bike frame very well secured so that it does not unexpectedly tip over and spell the contents. Of course I would not have any kids, pets, or clumsy adults in the working area. I would dump the solution back out every hour and check on progress. You could probably use a formula to get the rate of erosion in tenths of a millimeter per hour. But if I had to guess I think it would probably have removed a significant amount within three or four hours. One benefit of this process is that strong bases are *relatively* benign to steels. That is why rebar properly encased in concrete can last for a very long time, the alkaline environment inhibits corrosion. This would only work on an aluminum tube stuck in a steel frame. If the frame is also made of an aluminum or magnesium alloy it’ll simply eat away at both items equally and cause irreparable damage. Anyways, that’s what I would do. But only because I have a reasonable amount of experience handling strong chemicals. It’s not something that I would recommend that other people do.

[@stephensaines7100]

Even before reaching the end of this video, I have to comment as to how incredibly strong brazed lug frames are!

[@phrozenwun]

Since extraction has a (generally) monotonically decreasing max tension, you could add oil part way through the extraction to see if it helps decrease the stiction - if you want to know if it helps. Great stuff, thanks for sharing.

[@johndef5075]

It's amazing how stuck they are. I figured after the initial breaking loose they would come out easier.

[@cthulpiss]

Great one!

[@edwardfletcher7790]

A slide hammer works incredibly well for seat post removal 👍

[@dudeonbike800]

Instantaneous vs static force. Aka "impact" wrench force. Yup. But hard to control. And would you REALLY be able to produce 3 tons worth of force? (Or a little less, since it's impact, but still!)

[@jbarner13]

@@dudeonbike800 It does make one wonder if less pulling force would be require if a hammering action was added, but that would increase complexity significantly, and this rig seems to be effective as it is.

[@edwardfletcher7790]

@@jbarner13 The hammer action is critical on steel frames because corrosion is always the cause for post binding...

[@clovercover5321]

I thought at first this is going to be more force than expected. But almost 3 tons is crazy. Oil and heat brings nothing with posts that stuck. And even if it helps with reducing 100kg it seems nothing in scale to the 3tons. All in all super interesting. Thanks for sharing.

[@alessandromeyer4888]

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.

[@tobymcnicol922]

makes me wonder if a brazed, lugged joint is stronger in tension than a welded, mitred junction. due to greater bonded surface area ..... ?

[@rmvvwls]

@@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.

[@PhilVandelay]

Depending on the frame, I think with some of these we might have gotten close to potentially damaging them. But since those tubes are usually butted, they're thinnest in the center so that might be the most likely place for them to snap if they do. I've definitely seen at least one frame that snapped right in the center of the seat tube using one of these devices so the possibility exists. But yeah the joints themselves rarely brake, if you look at classic broken frame examples, breaking in the HAZ (heat affected zone) right before the weld/joint is the most common, usually at the headtube. The seat tube breaking at the BB shell is not uncommon either though, most likel due to pedaling forces - which also means some frames could have pre-existing fatigue there. There definitely is a bit of a risk with this operation!

[@dangraff8467]

Thanks, i don't feel bad about giving up on the wd and using the cutoff wheel now

[@pippinc7113]

Try soaking the inside the frame with strong ammonia, and you could put a clay dam around the top of the seat tube and put ammonia there to trickle down from the top as well, that should help dissolve the aluminum oxide... But I think your extraction tool is genius and I hope you save lots of frames. Maybe I'll get someone around here to build one.

[@ΚωνσταντίνοςΤσαγκαλίδης-υ1ι]

Your machine works so good, keep up the good job and such a great content. If seat post snap, you can use your machine with some modifications, i drop just an idea, something like split nut you can put it inside the post and expands to pulling it from the bottom, i dont know if that might work its just an idea, Have a great day.

[@catch878able]

If you wanted to try and determine oil penetration and have a frame you're willing to sacrifice, you could cut the frame open after applying heat and oil. That should let you determine actual penetration of the oil.

[@hananas2]

Thanks for providing another reminder to definitely lube every seatpost! I don't know if it was in one of these videos here or on reddit but I saw someone recommend vaseline because it's even better at repelling water and doesn't reduce friction as much as grease. Because of course you still don't want your seatpost to be slipping.

[@dudeonbike800]

Hogwash. There is NO PROBLEM with grease causing "slippage." A properly-sized seat tube mated with the appropriate seat post will NOT slip! This is why so many bikes are built so terribly. "If I grease this part, it will loosen up!" is a very common misconception. The next, which is finally fading into obscurity is "Don't ever grease crank square tapers!" Luckily Jobst Brandt finally ended his debate with his treatise on the issue.

[@hananas2]

@dudeonbike800 I personally haven't had any issues, just something I've picked up from others to be honest. And yes always always always grease square tapers, I live in a rainy wet place where bikes get ridden and stored in the rain (Belgium) and I've had at least 4 second hand bikes where a crank arm was impossible to remove. Only a cheap garbage crank arm will stretch from a greased square taper.

[@EmyrDerfel]

@@dudeonbike800 Luckily, square tapers are banished to the realms of Bike Shaped Objects and the Retrogrouches.

[@dudeonbike800]

@ you've swallowed the bike biz' marketing BS hook, line & sinker! Good little consumer. I bet you're gobbling up electronic shifting and riding ebikes as fast as you can! I'm riding 30 & 40 year old bikes that function perfectly well with square taper designs. And I continue to service bicycles with same. And BTW, Renee Herse, Rivendell, Orange, among other brands are HARDLY constitute "bike-shaped objects." The big box consumer should be so lucky to get square tapers! At least they're not slogging around on one-piece cranks!!! But that wasn't the point at all - pretty funny that you jumped all over it. The point is that waterproof grease, in all its forms is ideal for seat posts and all other metal-metal or carbon contact points. Don't obsess over something so trivial as suggesting petroleum jelly when you already have perfectly suitable grease in the shop.

[@EmyrDerfel]

@@dudeonbike800 rivendell is retrogrouch. Enjoy your vintage technology.

[@uncleenk]

The bond theory comes from when aluminum seat posts are stuck in steel frames. The aluminum seat posts bond over time (The reason is leaving me at the moment) with the steel frames, so often if you get the post moving just a bit, it gets a lot easier to remove it. This is not true all the time though, even on aluminum post/steel frame bikes, because the post might have another issue with it (e.g., in one of my cases, the post was a size up from what the frame could handle, so I had to go in and use a chisel to break off sections of the post from the inside to get some of it out after hack sawing the post in quarters. The post did not survive.). I've heard that people use lye to melt the aluminum seat posts when they are in a steel frame, but I am not confident enough to do that.

[@Nerdifant]

I am seriously impressed of how much force you can apply through your device! Another question would be how you treat the seatposttube on a frame if you decide to reuse it?

[@PhilVandelay]

You can see some of it at the end of the video, running a long wire brush with a power drill through the tube *can* be enough to clean it up but when there was a lot of corrosion, it would genereally be best to run a hand reaming tool through the tube which can really get it clean and smooth again. Problem with those is that you'd need one according to the exact seat post diameter, but there's countless different ones and you'd need a reamer for every size (and they're not cheap). There are adjustable reamers though which might also be an option - so far the wire brush was good enough for me, although it's not ideal. As for the seatpost itself, I'd generally advise people to just get a new seatpost but if you really want to re-use it, they're relatively easy to clean up with a wire brush as well.

[@criggie]

@@PhilVandelay What about a big thrust washer/bearing between the frame and the spinning handle? You're basically making a big vice/vise.

[@AlienLivesMatter]

I suggest cutting the stuck post flush with the frame and fitting a thinner postt with shims if needed

[@chyrt]

you are a legend!

[@KW-ei3pi]

Awesome! Enough said. Regards.

[@mechadrake]

Galium aluminum alloing process next to enbrittle the stuck seatpost in steel frame :D I think it should work. Works on thin walled baseball bats

[@andyzacek9760]

I always imagined that the more you pull, the more the seattube elongates, constricting the diameter, increasing the tightness, requiring more force, and so on like a woven finger trap

[@TimPiggott]

I loved this! ❤

[@classydays43]

I think for my frame, I used a drilled hole, a very large screwdriver, and a hacksaw blade. The old seatpost was definitely destroyed. It took days, but the frame sat out in the rain for several years before I got it.

[@nickdubois8218]

Cool video man.

[@benjaminrefalo216]

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.

[@PhilVandelay]

I am concerned about that, and the flying bolt proves your point. I'll probably at least wear a face shield for these in the future (you can see in the video I started with nothing and ended with earmuffs and safety glasses at least). But yeah setting up some kind of shield around the seatpost would be even better. Actually this would be a good argument for motorizing the device, rather than saving a small amount of time which is irrelevant for me, it would enable you to set up a shield between the operator and the device and also enable one to observe what's happening with the frame/post much better.

[@prfit]

Really interesting, I would love to see more experiments. I'm not a mathematician but I think you could apply the law of large numbers to prove whether using WD40 helps or not if you had enough measurements.

[@iTeerRex]

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 👍

[@Extr400]

Suggest instead of pulling the from the BB you use a collar around the top rim of the seat tube to stop it riding up. That way you keep the seat tube in compression rather than extension where the material deformation will tend to fatten the diameter and reduce extraction force.

[@PhilVandelay]

That's an extremely small amount of surface area to rest 3 tons on, I'm pretty much certain you'd damage the seat tube that way

[@Hurc7495]

I once had an aluminium post stuck in a steel frame, in the end i dissolved it out with sodium hydroxide. it took several weeks and quite a number of changes of liquid!

[@hanselgretel8563]

amazing.

[@624Dudley]

Interesting! 👍

[@lidarman2]

Look at all that powdered sapphire! :D

[@basengelblik5199]

Glad to see you wear ear protection

[@SnootchieBootchies27]

Vandelay industries!

[@TimLPINE]

Bike mechanics (and any other mechanical device) in terms of repair and maintenance are vastly improved when the practitioner has some basic knowledge in the realm of Newtonian physics. Otherwise, as pointed out here by many commenters, you're likely to be repeating erroneous myths or N=1 experiences as the basis for why something works (or doesn't). The scientific method is your friend. Thanks for the measurement and verification to dispel some of these myths.

[@groundcontrolgainesville4841]

Not all heroes wear capes

[@chrismorrison3298]

Does anyone know if electrolysis can be used to dissolve the aluminum oxide or at least weaken it?

[@AntonioGGATX]

I’ve done this on a stuck aluminum seat post on a steel frame. Plug the seat tube at the BB, fill with a basic solution, sacrificial anode that’s insulated from the tubes, and a battery charger. Then just a slide hammer to get it out.

[@VicFroman]

Try using wax as in a crayon, use the heat gun to melt the wax and it will wick down the post. Many mechanics and handyman use this

[@RogerioCosta1.0]

Nice demo! I'm wondering if carbon fiber seat post would not be better for those steel frames. Some people pay a lot for custom cromoly frames, would be nice to not have this problem (or maybe they should start doing cromoly seat post too, I think steel/steel do not stuck so hard like aluminum/steel). RJ, the bike guy has some interesting ideas to stuck seatpost too.

[@PhilVandelay]

Yeah if you want to avoid his it might help to use carbon, but it's generally easy enough to avoid by just doing maintenance. If you remove your post every couple of month and re-grease it, it's very unlikely that you'll ever end up with something like in the video. Also, carbon posts do get stuck as well - you can see one in the previous post pulling video.

[@giggligaggli1]

I removed the very similar destroyed Seatpost from my own tequesta-frame trough infiltrating the Aluminium with liquid gallium.

[@qed9600]

I suspect the need for increasing tension is due to the displaced oxides jamming the gap between post and seat tube. Similar to how corroded threads often jam after breaking free. Reversing direction often clears threads, but doing so to the seatpost is obviously not as easy.