Carbon diagnosis

[rbtmcardle]

Any thoughts on whether this is a cracked tube or simply paint damage.

The frame was new and built once with di2 by a qualified and trusted mechanic at my lbs.

Meivici seat tube.

http://i1242.photobucket.com/albums/gg526/Rbtmcardle/Mobile%20Uploads/F118A284-A588-456E-9CEB-7BF8D32BE35C_zpszp2pd1ns.jpg (http://s1242.photobucket.com/user/Rbtmcardle/media/Mobile%20Uploads/F118A284-A588-456E-9CEB-7BF8D32BE35C_zpszp2pd1ns.jpg.html)

[gone]

Hard to tell but looks cracked to me. If the derailleur clamp was tightened enough to compress the paint, which is what appears to have happened judging from the picture, it was pretty darned tight.

[Lionel]

You need to remove the paint to find out.

[RedRider]

There was a good amount of paint on those MeiVici frames and that location has some of the thickest tubing. The torque from an electric FD is greater than mechanical. Campy Record FD clamps were particularly sharp and Parlee carbon ones worse.
Hope it's just the paint...

[texbike]

I have a friend that has a carbon Serotta that ended up being cracked in that same area from over-tightening the derailleur clamp.

Texbike

[Louis]

I'm guessing that's more likely to be a structural issue than just a cosmetic paint issue. The fact that the whole area is showing signs of distortion does not bode well.

Take some tape and mask off the area, sand it down (carefully) and see what's going on.

Good Luck

[Peter P.]

Here's one way to tell if it's cracked-

Take a small, clean, white rag and stuff it down the seat tube with a coat hanger. You should be able to retrieve it later by putting a barb or hook on the end of the coat hanger.

If you're lucky, that area of the seat tube is accessible from the bottom bracket.

Anyway, after stuffing the rag down the seat tube to the location of the clamp,
lay the frame so the seat tube is horizontal and spray the outside of the area with a colored fluid like Liquid Wrench or machinist's layout dye. Spray it several times so you're sure the area is saturated. Let it sit for a couple hours.

Remove the rag and see if there are any telltale signs the fluid penetrated the crack and reached the rag.

I used a similar method to unearth a crack on my steel frame.

Edit: If you DO have access to the seat tube from the bottom bracket, then lay the frame so the seat tube is horizontal. Place a piece of cellophane tape on the outside of the tube over the suspected crack. Then flow a puddle of Liquid Wrench or whatever into the seat tube and let it sit for an hour. If the crack is real, the liquid will migrate through the tube and stick to the tape.

[gone]

Great idea Peter P! I'm going to have to remember that one. Much less destructive than sanding.

[RedRider]

I have a friend that has a carbon Serotta that ended up being cracked in that same area from over-tightening the derailleur clamp.

Texbike

Yes, that's a problem caused by lack of the correct torque wrench setting. I can attest to the Serotta staff taking details like these very seriously. Every dealer had a list of recommended torque settings for everything on a frame. Customer Service also had the list so if anyone called with a torque question it could be answered immediately.
If a Meivici seat tube cracked from over tightening the FD someone really had to muscle it.
Unfortunately, there's no good remedy to a damaged Meivici carbon tube. The only safe solution would be to replace it but those tubes are no longer available. Patching a repair would not be an option I recommend.

[rbtmcardle]

Thanks all for the insight.. the irony is that I received this frame new from serotta after I sent mine back to be repainted... when they received it (original) back I was told my "old" frame was cracked at this same spot.. so this may be the second frame with the same issue. I gave up wrenching on my own a few years ago.. and I really trust the mechanic.. very frustrating.. I will try the soak the area trick and move forward from there.. at the very least get a parlee clamp.

[Dead Man]

I had a carbon steerer that looked a lot like that, from an over-tightened stem, but worse.. the carbon itself was obviously crushed. No paint to offer doubt. Looked perfectly clean on the inside- plug slid in and out with no hangup, couldn't feel anything with your finger. I doubt liquid would have soaked all the way through, as I suspect only the top layers of laminate were crushed.

You'd never know until your face was bouncing off the busted jagged edge of broken steerer, or you just happened to be replacing your stem (this case).

[nicrump]

read this thread. it applies more to your situation than the steerer.

http://forums.thepaceline.net/showthread.php?t=156418&highlight=creep

[Louis]

read this thread. it applies more to your situation than the steerer.

If it is creep, might this location be less critical than on a steerer tube, given that an F-der probably doesn't apply huge loads to that area?

I'd think that if it's just due to deformation of the composite and isn't an actual failure, then at that location it might be OK to ride.

[ultraman6970]

The bike creaks?? a crack in that area should creak IMO.

[nicrump]

if it were before me i'd do a tap test. if it had tonal change(even loose paint can cause this) i'd sand away the finish and tap again. if tonal changes, pass it on to a pro to fix.

the crux of it is the damage site, if you wanna continue a band clamp fd then the fix should maintain round and correct O.D. all while actually fixing the problem. not impossible.

[rbtmcardle]

Thanks again for the insight. I stripped the components off this frame which is how I found the damage/crease, i tap just about everything as a normal course of daily life, the sound of the tubes is consistent throughout. Or perhaps better stated there is no change in tone in this tube vs the other similarly sized tubes.

The bike rode incredibly nice like it's supposed to with no creak or unusual noises nor did it misbehave in shifting.

I don't have any real plans for it, was just going to mothball it for awhile until I have more time to ride.

Thanks again and I will update with any further development as I will examine it a bit closer with a magnifying glass etc.

Bob

[cfox]

When I had a Meivici a ways back, I was told by Serotta 2 nm tightening torque for the FD clamp! The thing was barely hanging on, but it worked. I've always thought carbon bikes should have braze (riveted) on FDs.

That looks cracked to me; the crimp + the crack looks like a bad combo. I know this is the equivalent of an IT guy telling you to reboot your computer, but you should send it to Calfee.

[Bruce K]

Disagree on lost cause if cracked

Ruckus Composites has done done pretty amazing repairs

BK

[David Kirk]

I would hesitate to spray any oil based liquid in the area to see if it's a crack at that stuff will be very tough to get out should you want to have it repaired.

dave

[nicrump]

I would hesitate to spray any oil based liquid in the area to see if it's a crack at that stuff will be very tough to get out should you want to have it repaired.

dave

spot on!

[RedRider]

In my opinion, repairing cracked/broken carbon is a very questionable practice.
You have to remember that your carbon frame is not like a fiberglass car body. You can't just fill it in, sand and paint.
I do know of some repairs that have been successful; without immediate failure. Some have lasted years and have no sign of further damage but that doesn't give me peace of mind nor would I recommend it.
The important thing to know is that while a small crack might appear on the surface there is no way of knowing what stress damage might have occurred internally.
There are some carbon experts out there that can help evaluate damage but I would only trust the original builder with a repair.

[bart998]

Cracked. I bet Craig Calfee could repair it and maybe include a FD mount.

[notsew]

Or perhaps better stated there is no change in tone in this tube vs the other similarly sized tubes.


If the sound is the same in that area as everywhere else, I'd be shocked if there was any structural damage. Composite can't really break without some delamination.

Out of curiosity, has anyone ever experienced a break that didn't produce a change in tone at the area?

[Bruce K]

Visit the Ruckus website

They do not do "band aid" repairs

They are 3D modeling and (after careful analysis) bonding in whole segments of carbon tube (some with internal reinforcement.

Repairs are generally hard to detect without prior knowledge and their paint work is top notch

I know several others, besides me, who are very happy with their work and they are usually much less than Calfee

BK

[Black Dog]

^This^ If you decide to scrap the frame without trying a repair solution there are many folks here who would help you dispose of it by taking it off of your hands...:)

[rbtmcardle]

Thanks. I have reached out to Ruckus and I'll let them decide what's appropriate. I certainly don't want to ruin a great riding frame, I suspect it's superficial but the little riding I've been able to fit in has been on the Kirk.

[hockeybike]

Ruckus has great customer service, give em a ring for sure. Also, see about getting the shop to absorb some of the cost--they should take respobsibility if they did the wrenching.

[jds108]

If the diagnosis is that it's OK, I'd just suggest using a FD clamp that has the crimp area of the clamp on a different part of the tube. I'd also be looking for one that spread the load out over a larger area. Neither of these things may in fact matter, but they're certainly not going to hurt.

[nicrump]

If the sound is the same in that area as everywhere else, I'd be shocked if there was any structural damage. Composite can't really break without some delamination.

Out of curiosity, has anyone ever experienced a break that didn't produce a change in tone at the area?

never happened. but there is no accounting for ones opinion of "tonal change" vs. anothers.

[kgreene10]

In my opinion, repairing cracked/broken carbon is a very questionable practice.

I've trained and raced two years so far on a repaired chainstay with no hint of trouble. You clearly need to have faith in the skills of the repairer. Mine told me - and I believe him - that the repaired area is stronger than anywhere else on the frame. My experience could be exceptional of course or the thing could fail tomorrow but it still seems quite solid.

[Keith A]

One thing I've wondered about with a carbon frame that is been repaired is how the ride is affected by the repair. With many of the manufactures talking about how their frames are tuned using different carbon thicknesses, layups, shapes and etc -- it seems like a repair would modify these parameters and therefore ride differently than before :confused:

[rbtmcardle]

I am bringing the frame down to my lbs where it was built, I've spoken with the mechanic, whom I trust more than anyone to work on my bikes, this shop is a former serotta dealer and been around for 40 plus years. He assures me that the fd was tightened to the shimano spec of 5-6nm. I'm not certain what the serotta recommended torque was but I can't imagine it would be designed to be less than the standard torque of a fd. Regardless I understand this is a first world problem and more than anything just love the frame and hope to keep it on the road.

Thoughts on the Parlee clamp? Is there something else that works better?

Thanks for all the knowledge.

[Keith A]

...
Thoughts on the Parlee clamp? Is there something else that works better?

Thanks for all the knowledge.

Did you see this input on the Parlee clamp?

There was a good amount of paint on those MeiVici frames and that location has some of the thickest tubing. The torque from an electric FD is greater than mechanical. Campy Record FD clamps were particularly sharp and Parlee carbon ones worse.
Hope it's just the paint...

[Matthew]

I am using a Parlee clamp on my Meivici without any issue. Parlee specifically makes these to help avoid clamping issues. The band is much wider to distribute the load over a greater area. I guess you could say the edges are sharp but I don't think they are a problem and don't think they will cut into your frame at all. They are pricey and I have read where others have had slipping issues but I have not experienced that at all. Check with forum member Maverick1, I think he uses them on all of his bikes and his collection of rides is second to none. Hope this helps. Matthew

[kgreene10]

One thing I've wondered about with a carbon frame that is been repaired is how the ride is affected by the repair. With many of the manufactures talking about how their frames are tuned using different carbon thicknesses, layups, shapes and etc -- it seems like a repair would modify these parameters and therefore ride differently than before :confused:

I wondered that too. In my case, I don't notice the repaired chain stay at all. Perhaps repairing a different tube or replacing one entirely with a different layup would make a noticeable difference. It also could be that my Fisher Cronus simply isn't as finely tuned as a Meivici or other custom bike so that any repair has less impact.

[rbtmcardle]

Did you see this input on the Parlee clamp?


Keith. Thanks, I had missed that.

Don't see how this can be so difficult, though I still don't "know" that its a damaged tube.

[RedRider]

Did you see this input on the Parlee clamp?

To clarify, the Parlee clamp does have a greater surface area holding the frame so there is less pressure on any individual point. It's thin and the edges can be sharp which did "dig in" to the thicker paint applications. This was not structural but often caused concern when removed.

[Shiversolitude]

if I had any question of carbon being cracked or not I would probably take it somewhere to have it professionally inspected.

Once carbon cracks it will really go... so you dont wany to be riding and have one of your tubes break. I had a Giant MCM top tube break on me once and I had to ride about 10 miles with the broken tube. The whole ride the frame was wiggling around like wet spaghetti... not good.