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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #1 ·
OK, here's the problem...

I'm thinking about Santa Cruz, but it turns out I have a mechanical issue.

My carbon seat post has become frozen into my steel frame and no amount of penetrating oil will loosen it. Do I:
  1. Go all Lennard Zinn on the sucker with a hacksaw?
  2. Try to figure out a way to ship the bike with the seat-post in place? (can you even do that?)
  3. Try to rent or borrow a bike on the left coast?
Inquiring minds want to know...
 

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Festina Lente'
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11,508 Posts
IMO - 1 or 3

Ill have to check today, but I am pretty sure the galvanic couple between Carbon and Steel results in the steel corroding.

Once you Hacksaw it off, then what?
 

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Spicy Dumpling
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9,721 Posts
1: You'll have to do it anyway. A couple of lengthwise cuts with a saw blade should do it.
 

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Lemur-ing
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18,987 Posts
Damn man. That freakin sucks dude.

See, it's always aluminum on steel/ti/carbon or carbon in carbon :)

Why'd you need to take it out? Just rent a bike instead IMO. No need to do it yet at least.
 

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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #5 ·
BentChainring said:
Once you Hacksaw it off, then what?
You cut the post off transversely, and then make two axial cuts through the post to separate a sector like a slice of pie, pry out the sector with a small chisel, and then pry out the rest of the post.

Then if you've done it properly the seat tube is clear and you put a new post in.

OTOH, if the frame is toast, you cry.
 

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corning my own beef
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5,713 Posts
VaughnA said:
1: You'll have to do it anyway. A couple of lengthwise cuts with a saw blade should do it.
+1 (I'm asuming you've exhausted all other options and have decided that the damm thing ain't comin' out, no way, no how).

Go ahead and lop of the seat post an inch or so above the binder, then rig up a keyhole saw that will let you get inside the post and make a vertical cut or two to get the post out. It'll take awhile, but the seat tube will clean up OK.
 

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Just Plain Bitter
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8,602 Posts
Got a heat gun? Try and warm that thing without bubbling your paint, it may loosen it without going all caveman on it. BTW A blow dryer is not the same as a heat gun. If that doesn't work then the hacksaw is looking pretty good.
 

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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #8 ·
rward325 said:
Got a heat gun? Try and warm that thing without bubbling your paint, it may loosen it without going all caveman on it. BTW A blow dryer is not the same as a heat gun. If that doesn't work then the hacksaw is looking pretty good.
I was just thinking the same thing. I have a real heat gun and it makes sense to start with smaller measures.

P.S., returning to Bent's comment, naked carbon definitely produces galvanic corrosion with steel, but the epoxy matrix reduces galvanic current by almost 2 orders of magnitude, so the seat tube may well not be too badly corroded once I get the post out.
 

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Sticky Valentine
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28,404 Posts
Bigger hammer.

Bump for Fred's help. Homeslice may need to bum a 54-56 in Santa Cruz.


joe
 

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Failboat Captian
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6,527 Posts
+1 on the BFH (big F'in hammer) and heat. Heat up the seat tube, and take the BFH to it to try to get it to move (down). What's the worst that could happen? You split the seat post? It was trash anyway.

I'll repeat thr Rule: Force it. If it breaks, it needed replacing anyway.
 

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p != b
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2,303 Posts
Fredke said:
OK, here's the problem...

I'm thinking about Santa Cruz, but it turns out I have a mechanical issue.

My carbon seat post has become frozen into my steel frame and no amount of penetrating oil will loosen it. Do I:
  1. Go all Lennard Zinn on the sucker with a hacksaw?
  2. Try to figure out a way to ship the bike with the seat-post in place? (can you even do that?)
  3. Try to rent or borrow a bike on the left coast?
Inquiring minds want to know...
have you tried the saddle-off-seat-clamp-in-vice-use-frame-as-lever-to-break-post-free-by-rotating trick? That's the only real good way I know to get a good lever on the seatpost to try and twist it.
 

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Beetpull DeLite
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12,756 Posts
Once I had to free a steel post from a steel frame, which probably hadn't been touched since 1975. I can't recall what I ended up doing but I finally got the f'er out.
 

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For president!
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7,802 Posts
Fredke said:
I was just thinking the same thing. I have a real heat gun and it makes sense to start with smaller measures.

P.S., returning to Bent's comment, naked carbon definitely produces galvanic corrosion with steel, but the epoxy matrix reduces galvanic current by almost 2 orders of magnitude, so the seat tube may well not be too badly corroded once I get the post out.
And ice the carbon post at the same time. Some shop mechanic told me a story of covering the seatpost in snow to get it out, but I don't think it was carbon. Will it still work?
 

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Quiet, daddy's drinking
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5,887 Posts
bopApocalypse said:
have you tried the saddle-off-seat-clamp-in-vice-use-frame-as-lever-to-break-post-free-by-rotating trick? That's the only real good way I know to get a good lever on the seatpost to try and twist it.
I was just going to recommend this option.


/Did you take the bottom bracket out and spray the liquid wrench in the frame from the bottom?
 

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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #16 ·
SilasCL said:
And ice the carbon post at the same time. Some shop mechanic told me a story of covering the seatpost in snow to get it out, but I don't think it was carbon. Will it still work?
It would be great for aluminum, but carbon/epoxy has a very small coefficient of expansion (about one tenth that of steel), so it's all in the heat applied to the seat tube.
 

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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #17 ·
Turtleherder said:
/Did you take the bottom bracket out and spray the liquid wrench in the frame from the bottom?
And let it sit overnight. No dice.

I don't have a bench vice, but I took the seat off and clamped a steel rod in the seat clamp to get leverage and no luck torquing the thing free.
 

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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #18 ·
philippec said:
google "ammonia carbon seatpost"
I thought that only worked for aluminum, but I'll try it. Nothing to lose. Thanks.
 

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jaded bitter joy crusher
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19,723 Posts
Discussion Starter · #19 ·
GirchyGirchy said:
Once I had to free a steel post from a steel frame, which probably hadn't been touched since 1975. I can't recall what I ended up doing but I finally got the f'er out.
What a tease you are!
 

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Sticky Valentine
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28,404 Posts
Wait, I think we're all missing the larger issue here....


You only have ONE bike?!?!



joe
 
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