Bike Seat Post seized- attempt to free with ammonia
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- เผยแพร่เมื่อ 5 เม.ย. 2012
- This video documents an experiment to free a seized aluminum seat post in a steel frame. It is said that ammonia can help free such parts, but in fact it does nothing to assist.
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Time to build a tool specifically for freeing seized aluminum seat posts in a steel frames.
I have a couple more ideas. Instead of just pouring the ammonia once and letting it sit overnight, dump out and refill the seat tube with fresh ammonia every 30 to 60 minutes and tap firmly on the seat tube with a rubber mallet every 15 to 20 minutes to try to break up the corrosion inside so the ammonia can penetrate between the post and tube. Also, if you clamp the post in a vice and the post spins in the bench vice, have a second person put a pipe wrench on the post if you have enough room so that you have more grip on the post. I just used this same method less than an hour ago to free a post that was stuck just as bad if not worse than the one shown in this video. The post will be badly scarred but you will have a much better chance of getting it out in one piece
You guys should create a slide hammer attachment that can go down the inside of the seatpost and hook the bottom so the seatpost can be pulled out. Basically a slide hammer hook that already exists but with a shaft long and thin enough to go the full length of a seatpost.
Ill glady buy one so I can restore my mint Kona A'ha (the green one).
Had this same problem with a bike that my friend brought to me. He wanted me to adjust the seatpost, yea, no can do. Now it's sitting on NaOH bath and melting away.
+Park Tool Calvin You spelled experiment wrong. Also if I can make any recommendation, park tool should make its own 18 inch Plumbers wrench, believe me it's gotten me out of a lot of binds on bike. Just a thought.
I tried loads of things on a seized post, and the only one that worked was to drill a 12mm hole in centre/bottom of the BB shell to allow straight access to seat tube, drill a hole across the seat post and bolt an old hub axle through it, and then (with frame upside down) drop in a section of straight 10mm rebar (ask at a demolition site).The rebar rest against the old axle, and you can beat it out with a lump hammer. Support the frame carefully on wood to prevent deformation. The hole in the BB shell doesn't matter if you fit a cassette BB unit afterwards.
Interesting method @type17 this would definitely be a last resort as removing material from a frame can weaken the frame and make the safety questionable. cheers!
Yes, it was definitely a last resort after weeks of on-off trying of other methods, but it was a 90's Raleigh beach cruiser, so not a bike like to see high-energy usage. However, I did keep the hole as small as possible by using rebar (thin but still strong). It's also the one place you can probably get away with drilling a hole in any frame - similar to the weight-saving cut-outs in gorgeous Italian race frames.
PS: Love the content of this channel, Hi to Calvin and all the gang. I'm still using my Park Tools every day, some of which are 25 years old.
@@type17 there's another TH-cam video of someone using a 10lb slide hammer to remove a seatpost. it looked effective in a similar way, but did not require any frame modification
Had seatpost powder coated in 40 year old Dave Moulton frame. Took a gamble I got it right in my prime!
Next time try Janitorial Strength Ammonia (10%). Nasty smelling stuff but gives you a better chance of getting it free.
Hi Calvin, did you make a video of the hacksawing you resorted to? If so could you share a link to it please?
Hi Kevin, that is a "jab saw" and we do not have a video on this.-Calvin
Hi again Calvin, thanks for the reply, as there's no video can you briefly describe how you attempted to remove the post with the jab saw and say whether it was successful? Failing this method have you guys ever tried the caustic soda dissolving method? Thanks In advance.
The jab saw was successful, it usually is, but takes a long time. The saw cuts vertically inside the post. You make several cuts, at least 3, but more is better. The chemical treats often don't work but sometimes you have nothing to loose so give it a good. There is often a pressure from the built up material and corrosion. - Calvin
Hi, calvin ,can you do video with vinegar 20 percent; more concentrated than household vinegar;sold at home depot; chemistry wise,,, vinegar attaches to the corrosion between aluminum and steel seatposts. thx ben stanski;would love souvenir if you make video;
I have a Specialized carbon hybrid frame, do I need to put lubricant on the aluminum seat post to prevent it getting stuck?
Yes you need Park Tool SAC-2 or super Carbon Alloy Compound this will help from the post getting seized.
And the part 2???
I could give that bi-plane fork a good home. ;-)
Ya need a park tool for this. Try and engineer that and you'll win invention of the century. But if people would just maintain their bikes this would never happen. Or maybe never put aluminum seat posts into steel frames
Calvin, are you sure that the ammonia did not leak out before it could do it's thing?
Anyway, I tried this method and it did not work.......
The ammonia was still inside when I checked. It did nothing to eat the corrosion. There are cases where the post has bonded to the frame. This frame required a hacksaw.
-Calvin
Amonia worked for RJ the Bike Guy(!)
Caustic soda would work better
Production values in the old school Park Tool videos were quaint weren’t they?
This is from back when Calvin *was* the Park Tool video department. I believe this is a GoPro Hero 2 on a chest mount, probably edited in iMovie.
Did anyone here ever try to combine amonia while heating the seat tube.?
DO NOT MIX HEAT AND AMMONIA. Again, Do not mix ammonia and heat. That is highly dangerous and will produce a toxic gas.
Park Tool Thx a lot for the warning
360p video resolution, really?
Back in 2012 (when this was posted) that was not bad. Current videos are in 4k.
@@parktool that makes a lot of sense
fail