Ya, they are great. Make sure to over build it. Our first two versions were not strong enough and bent. First one bent up top where the nut for the threaded rod sits and second time it bent the axle going through the bottom bracket.
Looks like this works. At free bikes for kids, we use a big honken pipe wrench and a cheater bar, one person holds the bike while another twist the wrench on the seatpost, usually works. I have talked to Park tool on this with the idea that a big 1/2" super hard socket with 2 slots that would fit over a hardened pin that fits through that hole in the seat post and simple use a impact wrench to loosen. Every shop should have an impact wrench. I've seen BB cups and even one freewheel that were impossible to yank off. Doesn't happen often but when you need it, it comes in handy. Take care!
I've had good luck with using ammonia and heat, on the seat tube, with a pipe wrench. Ammonia acts on the aluminum corrosion better than penetrating oil.
Heat the ammonia in a microwave, pour it into seat tube thru empty bb, enough to fill seatpost's hollow cavity and pool above post end inside seat tube. Occasionally heating exposed post with a hair dryer or heat gun helps break corrosion and encourage penetration from differential expansion of steel & alu. Never had one take more than a few hours.
@@slowerandolder This sounds really toxic! Better do it outside AND wear a full face chemical respirator. Better yet, just google "Ammonia inhalation injury".
I like the design of your simple machine, it is very robust and thought out. I'm wondering if building one with a screw type jack mechanism would increase leverage, and therefore make turning the screw easier.
Awesome. For those unable to come up with a similar contraption : Industrial ammonia will get an alloy post out of a steel frame without any difficulty. Dyeline printers use that strength ammonia. Protect your lungs !
That's interesting and a lot more appealing than the gallium trick that people talk about. Invert frame and fill seat-post tube through BB shell? How much do you recommend? And how long to get results? Thanks!
Cool puller! Curious: why not spray the penetrating oil down the seat tube and then flip the frame to flow the fluid around the inside of the frame… hopefully between the post and frame! Maybe you already did?
Thanks, we sprayed the frame and let it soak with penetrating oil multiple times for about a month before hand both from the top and bottom. It’s amazing how stuck they can still be.
@@GringineerCycles Amazing how stuck the seatpost was/is! Like: how was it ever inserted?! I know: bimetal corrosion is a thing, but that seatpost was anodized and I didn’t note any corrosion. Any observations or theories on what caused this stuck?
Was it corrosion? The seatpost didn't look discolored or anything. I wonder if it was an incorrect seatpost size, since some sizings are within 0.2mm of each other.
Seatpost was right size, it was galvanic corrosion which happens between aluminum and steel. It was hard to see in the video because of the angle and all of the penetrating oil but the post and the inside of the seattube showed signs of galvanic corrosion which leaves like a crusty white material behind.
These pullers are amazing. It seems they can rescue almost any frame. I will have to build one.
Ya, they are great. Make sure to over build it. Our first two versions were not strong enough and bent. First one bent up top where the nut for the threaded rod sits and second time it bent the axle going through the bottom bracket.
Looks like this works. At free bikes for kids, we use a big honken pipe wrench and a cheater bar, one person holds the bike while another twist the wrench on the seatpost, usually works. I have talked to Park tool on this with the idea that a big 1/2" super hard socket with 2 slots that would fit over a hardened pin that fits through that hole in the seat post and simple use a impact wrench to loosen. Every shop should have an impact wrench. I've seen BB cups and even one freewheel that were impossible to yank off. Doesn't happen often but when you need it, it comes in handy. Take care!
I've had good luck with using ammonia and heat, on the seat tube, with a pipe wrench. Ammonia acts on the aluminum corrosion better than penetrating oil.
I haven’t tried ammonia before I’ll give that a test on the next stuck aluminum post.
Heat the ammonia in a microwave, pour it into seat tube thru empty bb, enough to fill seatpost's hollow cavity and pool above post end inside seat tube. Occasionally heating exposed post with a hair dryer or heat gun helps break corrosion and encourage penetration from differential expansion of steel & alu. Never had one take more than a few hours.
@@slowerandolder This sounds really toxic! Better do it outside AND wear a full face chemical respirator. Better yet, just google "Ammonia inhalation injury".
Worked great! Without the puller you made that frame would have been junk! Thanks for another great video!
Thanks!
Great work! Sick bike too!
Thanks!
Great work 👌🏻
Thanks!
I like the design of your simple machine, it is very robust and thought out. I'm wondering if building one with a screw type jack mechanism would increase leverage, and therefore make turning the screw easier.
I live by the keep it simple mantra, That might work Ill have to look into that idea.
Park Tool, get on that!
Awesome. For those unable to come up with a similar contraption : Industrial ammonia will get an alloy post out of a steel frame without any difficulty. Dyeline printers use that strength ammonia. Protect your lungs !
That's interesting and a lot more appealing than the gallium trick that people talk about. Invert frame and fill seat-post tube through BB shell? How much do you recommend? And how long to get results? Thanks!
Sodium Hydroxide, which is also Lye mixed w/ some water will eat the aluminum out. It's messy and time-consuming but will do it.
Cool puller! Curious: why not spray the penetrating oil down the seat tube and then flip the frame to flow the fluid around the inside of the frame… hopefully between the post and frame! Maybe you already did?
Thanks, we sprayed the frame and let it soak with penetrating oil multiple times for about a month before hand both from the top and bottom. It’s amazing how stuck they can still be.
@@GringineerCycles Amazing how stuck the seatpost was/is! Like: how was it ever inserted?! I know: bimetal corrosion is a thing, but that seatpost was anodized and I didn’t note any corrosion. Any observations or theories on what caused this stuck?
I wonder if anyone makes a giant ultrasonic cleaner. If they do, the price is likely out of reach for most people.
Was it corrosion? The seatpost didn't look discolored or anything. I wonder if it was an incorrect seatpost size, since some sizings are within 0.2mm of each other.
Seatpost was right size, it was galvanic corrosion which happens between aluminum and steel. It was hard to see in the video because of the angle and all of the penetrating oil but the post and the inside of the seattube showed signs of galvanic corrosion which leaves like a crusty white material behind.