Seat tube cracks - trouble?

[Blue Jays]

Definitely would not take it on a road ride until it is repaired.
Better to get ahead of it and get it fixed before a really big failure.

[FR8CAR]

The post fits pretty well - snug even - without the collar but seems like a professional should take a look. That said I’m pretty confident the original owner wouldn’t have tolerated a bodge job.

Any ideas for a carbon repair spot in the DC area?

Thanks, all.

[David Kirk]

IMO - if you continue to ride the bike the crack will grow and it will fail and things could get ugly.

I would send it to a pro carbon fixer and have it taken care of before it lets go.

After having the frame repaired I'd install a stout aluminum seat post in place of the carbon post. Some carbon posts compress a shocking amount when clamped on and this could easily lead to the top of the seat tube to necking down. Some carbon posts are also very flexible and your weight bouncing on the saddle causes the post to flex at the top of the frame....which in turn causes the top of the seat tube to flex along with it which puts the front of the seat tube in tension and compression. Not good.

Good luck.

dave

[ultraman6970]

What Mr kirk says.... plus...

Remove paint 1st to check that out all the way down to the carbon.

IMO the repair doesnt look like super complicated, either way all the time to add carbon paste to a seatpost even if its aluminum is a good idea. The torque requirements will go down for a lot.

[jemdet]

What material? Carbon?

If so, you could always epoxy a sleeve on the inside and run a smaller diameter seatpost. Would require a constant-ID seat tube for the length of the shim for me to feel safe. DP420 with an aluminum shim.

Even with an epoxied shim, I'd be fully prepared to take a cab home on any ride. But, hey, that area of the frame is typically well-supported and I can't see a failure knocking you on your ass (or face). That's my NON-EXPERT opinion, of course. Especially since I have no idea how the lay-up on that particular frame would react to a failure.

If you are really attached to the frame, I bet that carbon-repair / Calfee / Ruckus could fix it for ya.

[speedevil]

How far down into the seat tube does the seatpost go? I would expect that type of crack if the bike was ridden with a seatpost above the minimum insertion.

it seems unlikely but since you're not the first owner, the history might be hard to come by.

+1 on looking inside the seat tube before removing any paint on the outside.

[FR8CAR]

Appreciate the assistance - I will inspect more based on the above and report back.

[R3awak3n]

yeah, just remove a tiny bit of paint. This will tell you if yes its cracked or just the paint in seconds. Sure you will have paint missing but better to know.

[rst72]

I had the same issue but on a steel frame. Think the ST was hogged out a little too much. A Coke can was just think enough to make a shim that made it flush and stopped the crack.

***Not suggesting to do the same with a carbon frame.

[Joxster]

Is it a legit Pina? or bought off eBay at a bargin price?

[VC Slim]

Originally Posted by FR8CAR

The post fits pretty well - snug even - without the collar but seems like a professional should take a look. That said I’m pretty confident the original owner wouldn’t have tolerated a bodge job.

Any ideas for a carbon repair spot in the DC area?

Thanks, all.

If you are unable to find a local carbon repairer I can recommend someone in Austin, Tx.

[FR8CAR]

Originally Posted by Joxster

Is it a legit Pina? or bought off eBay at a bargin price?

I didn’t buy it off of eBay and I trust the seller.

[charliedid]

Originally Posted by VC Slim

If you are unable to find a local carbon repairer I can recommend someone in Austin, Tx.

Like

[FR8CAR]

Looks like there’s no need to scrape paint as the cracks are evident on the inside. There also is a smaller crack in the same spot on the back side slot but it may just be in the paint.

[R3awak3n]

Definitely looks like from overnighting the clamp. Did you use a torque wrench?