Damn, cracked seat tube.

[Kirkspants]

If drilling a hole in the frame is a scary thought, using a flex hone on the seat tube is terrifying. 

Yup! I have never ever done a flex honing of a carbon frame- I could see how it might be approached but I agree- terrifying!

Ooh! Track down your local Campy Guy Who Has All Of The Campy Tools And Will Die With Them and see if he also collected a seat tube ream and just get medieval with it 

THAT would be a terrific page-turner of a post to see how that works out! Mad bike scientist!

[Kirkspants]

FHS, on a serious and hopefully actually helpful note, I highly highly recommend hopping on ebamazon and picking up a digital caliper. The Park tool ones are just fine. (Or get some swanky Mitutoyos like I use at work!)

For its utility, the Park Tool calipers are wonderfully useful for the money.

[FHS]

Oh man, what a bummer.

It's not much and it may not help, but if you want, you can tell Eddy that I'll give him free 30 days of a banner advertisement if he'll replace the frame for you. That might help it make more financial sense for him.

Oh man, I don't even know what to say except a heartfelt thank you and it's definitely worth a try. I certainly don't fault and hold no ill will towards Eddy. He's been great with communication, the transaction was smooth, shipping fast, and communication great. But yeah, bad luck. Thanks again!

[jonnybearback]

It's clearly cracked, not sure why eddy needs the frame to see that.
He would want the frame to see if it's poor machining though or hadn't been through QC at that finishing stage.
Otherwise, wrong size seatpost or the easy out of saying it was ridden/tested with insufficient insertion.

The  way you said installed to mark a cut point  reminded me of a friend who put his seatpost in to mark for the cut. Set his height, marked it, added the "minimum insertion depth" measurement as printed on the bottom of the post. Cut it, reinstalled it, sat on it and snapped the seat tube. Proper brain fart on his part.
Fortunately it was the relative early days of carbon and a 34.9mm seat tube. We epoxied in a shim and he ran a 31.6 post successfully.
With a fixed post, I'd insert it to its bottom out position,  figure how much lower I need it to be which equals how much I want to take off, remove the post then measure up from the end of the post.

I personally would repair that crack at home, but I have all the materials to do it.

[carbonazza]

...I personally would repair that crack at home, but I have all the materials to do it.

Are you using shrink tape or do you have something more sophisticated ?
On top of carbon sheets and epoxy, do you have some must have materials usually overlooked ?

[FHS]

It's clearly cracked, not sure why eddy needs the frame to see that.
He would want the frame to see if it's poor machining though or hadn't been through QC at that finishing stage.
Otherwise, wrong size seatpost or the easy out of saying it was ridden/tested with insufficient insertion.

The  way you said installed to mark a cut point  reminded me of a friend who put his seatpost in to mark for the cut. Set his height, marked it, added the "minimum insertion depth" measurement as printed on the bottom of the post. Cut it, reinstalled it, sat on it and snapped the seat tube. Proper brain fart on his part.
Fortunately it was the relative early days of carbon and a 34.9mm seat tube. We epoxied in a shim and he ran a 31.6 post successfully.
With a fixed post, I'd insert it to its bottom out position,  figure how much lower I need it to be which equals how much I want to take off, remove the post then measure up from the end of the post.

I personally would repair that crack at home, but I have all the materials to do it.

I had issues even inserting deep enough to get to the minimum insertion mark. I ordered a set of digital calipers, as suggested. Just hoping it's the seat post, not the seat tube.

[FHS]

Are you using shrink tape or do you have something more sophisticated ?
On top of carbon sheets and epoxy, do you have some must have materials usually overlooked ?

Looking forward to his reply.

With the irregular surface around the crack, I don't see shrink tape working too well. I won't be able to get a sheet completely wrapped around the area of the crack, like I could on a tube, either way. I think laying sheets will work, and I think I can make a mold that I can wrap shrink tape around to put some good pressure on the layers. I've also seen a video where a guy just wrapped the whole area in foam and tape. I've just never worked with epoxy that has to be squeezed away. If I wrapped everything up tight under foam, or molds, I'm just not sure where the excess epoxy is supposed to go.

[jonnybearback]

Just various thicknesses and types of weaves, epoxy and shrink tape.
I'll make basic forms where necessary like with the carbon skeleton of the Nordic skate  ski boots I fixed last.
I've done some complex repairs at home, chainstay bridges, BB/main pivot area etc..all with shrink tape and electrical tape. The excess epoxy comes out theought the wrap laps with heat under the low amount of tape pressure.

[FHS]

Hi again,

Had a couple of follow up exchanges with Eddie, including the possibility of a new frame. But, in the end, it sounded like everything was going to involve sending the frame back. I decided to just do the repair myself, in stages. My daughter didn't have to be without her bike for any amount of time, and I got the chance to work on new skills.

Here's the repair. Need to clean it up a bit and buff out the new clear coat. Just an Ebay CF repair kit, some sand paper, some mold making clay from Michael's, electrical tape, and some rattle can paint and clear coat.


Edit: Just an fyi... I was able to measure the inner diameter of the seat tube and the outer diameter of the seat post with a set of digital calipers. The inner diameter actually measures slightly larger than the 31.6 mm standard. However, the seat post also measured larger than the 31.6 mm standard, maybe .1 mm smaller than the tube. I only have the one round seat poss and the one round seat tube, but, I'm guessing the seat post is more of an issue than the seat tube.

Does anybody have actual measurements for comparison?