Crack in seat tube

[milkbaby]

I got lazy and didn't pull an aluminum seatpost from a carbon frame for two years or so. It was tough to get out, and the very last bit of pulling and twisting produced a cracking sound. :eek: Once it was totally out, I could see there was some corrosion of the aluminum seatpost that was keeping it from sliding out easily. Probably galvanic corrosion initially keeping them stuck?

Below the slot in the back of the seat tube there's a bit of cracking of the clear coat for about 1/16 to 1/8 inch. The tap test sound is somewhat dull, so I'm pretty sure I have a teeny crack in the carbon.

I wiped down the post and the inside of the seat tube, liberally greased the post and put it back in with the height marked with tape. I tightened the collar bolts just tight enough that the post doesn't slip, less than the max 5 nm torque printed on the collar.

Since there's a decent amount of post below the bottom of the seat tube and top tube junction (probably 120 mm or more), I should be OK to ride as long as I watch for propagation of the crack, right? Right? I already rode it some and it seems to be holding OK right now. What does the collective paceline wisdom say?

[jmoore]

I say you are ok, esp since there is plenty of post inside the seattube.

[RedRider]

I hope you "liberally greased the post" with carbon paste.

[milkbaby]

I hope you "liberally greased the post" with carbon paste.

That's what I used originally. But I wasn't sure if the carbon grip paste was contributing somewhat to the sticky post, I switched to the Park Tools bike grease on the post.

Should I use the carbon grip paste even if it's not slipping?

[bigboyblue]

Just stuff the post with coffee grounds and no one will find the crack. I do it all the time!

[Black Dog]

I got lazy and didn't pull an aluminum seatpost from a carbon frame for two years or so. It was tough to get out, and the very last bit of pulling and twisting produced a cracking sound. :eek: Once it was totally out, I could see there was some corrosion of the aluminum seatpost that was keeping it from sliding out easily. Probably galvanic corrosion initially keeping them stuck?

Below the slot in the back of the seat tube there's a bit of cracking of the clear coat for about 1/16 to 1/8 inch. The tap test sound is somewhat dull, so I'm pretty sure I have a teeny crack in the carbon.

I wiped down the post and the inside of the seat tube, liberally greased the post and put it back in with the height marked with tape. I tightened the collar bolts just tight enough that the post doesn't slip, less than the max 5 nm torque printed on the collar.

Since there's a decent amount of post below the bottom of the seat tube and top tube junction (probably 120 mm or more), I should be OK to ride as long as I watch for propagation of the crack, right? Right? I already rode it some and it seems to be holding OK right now. What does the collective paceline wisdom say?

Pics would help but you are most likely ok. It was not galvanic corrosion it would have been simple oxidation of the post, unless the post was in direct contact with carbon fibres.

[Titanium]

Coffee grounds????

[fuzzalow]

^ & ^^^

Joke alluding to drug mule smuggling.

OP: unless you really munged up the tube badly, you might walk on this one. A break in the resin up high in the seattube but below the seat cluster is not a highly stressed area in a frame. I'd ride it if I still rode carbon. ;)

[old_fat_and_slow]

Seriously ???

You're asking for an opinion on a frame crack without pictures?

C'mon, take some pictures. Post them, and then we'll see what the cognoscenti think.

[milkbaby]

http://images.tapatalk-cdn.com/15/06/12/05b14f95013dd3ba8477e6c2661dd7de.jpg

Here's the best pic I can get. Now that I'm looking directly at it instead of recalling from memory, the crack in the paint is more like 1/4 inch long.

[jmoore]

Its going to explode when the sun hits it

[Steve in SLO]

Perhaps put a dot at the end of the crack with a Sharpie, ride it some and see if the crack extends past the dot. If it's static, you're probably good to go. If it extends, think about repair.

[old_fat_and_slow]

perhaps put a dot at the end of the crack with a sharpie, ride it some and see if the crack extends past the dot. If it's static, you're probably good to go. If it extends, think about repair.

+1