mrwang199432

Hey on my new carbon bike I can see 2 small holes on the frame, is this an issue.

chaadster

That does seem unusual…

Mojo31

Can you stick a needle all the way through, or is it just in the paint?

Koyote

I know this is a crazy idea, but: maybe take it back to the shop and ask them?

leob1

Or contact the manufacturer?

cyclezen

non- branded Frame? use a toothpick to shove as much epoxy as possible into the hole, smooth surface, ride until ... whenever/whatever...
Branded Frame - should be covered by usual Lifetime frame warranty of most bike companies.
Ride On
Yuri

Rolla

I'm not a carbon fiber guy, but I found these:

From a welding/fabrication forum: "Pinholes in vacuum bagged carbon fibre parts are very common."

From German Advanced Composites: "With the standard vacuum resin infusion process the permanent existing vacuum drives the resin out of the laminate into the bleeder fabric and/or resin trap. That leads to voids in the surface caused by pinholes. Pinholes are tiny holes on the surface which are hard to fix and require post treatment, resulting in additional labor costs. This is particularly evident with visible carbon fiber parts. These parts are just clear coated and pinholes affect their post treatment costs tremendously."

Shawn1970

I agree! I've repaired various 93-94 Zipp 440 carbon rims with pin holes this way and they're still going strong.

CliffordK

I wonder if those holes naturally get filled with surface prep. Some of the vintage frames have a layer under the upper finish that is really thick.

couldwheels

Aren't those holes for draining water and bugs that gets inside the frame?

drlogik 

Doesn't seem right to me either. I'd take it back to the shop you bought it from. Maybe call the frame manufacturer and ask them. I can't think of one reason a hole should be on the top side of any tube. Steel frames often have weep holes but I don't think carbon do.

Rolla

On steel frames, they're vents to release expanding air during brazing. Some have drain holes in the bottom of the BB shell, as well. Neither are typical for CF.

couldwheels

I also have them on my aluminum frame. They are useful when it rains. I tilt my bike one side and off the water goes.

On the alu frame, there's big holes inside where the chain and seat stays and top tube meet the seat tube and same goes to the head tube and BB as well. The holes are as big as the diameter of the chain and seat stays and the top tube.

The "nail holes" look and placed exactly the same spots as on a steel frame but I doubt were made for expanding gas because there's big holes in the seat tube and head tube already where these tubes meet.

couldwheels

Are you saying it's impossible for water or mud to get inside a CF frame, dispensing the need for weep holes? I doubt retaining water is good, even for CF frames.

You can ofc, remove the seatpost and drain it upside down but not sure if that's a good thing to do quite often especially if you ride in the rain or wet conditions often.

drlogik 

couldwheels,

Maybe you didn't quite understand what I said:

It was open to correction. Where's the problem?


--

Rolla

I once poured nearly a cup of water out of the seattube of a steel bike after I got caught in a downpour; there's no way it was going to magically escape or evaporate through the tiny holes in the stays.

mrwang199432

I put some water drops on the hole and the hole remained filled which make me believe it's just paint deep.

Either way Giant has a lifetime frame warranty so il just ride until it becomes an issue if at all!

couldwheels

Ahhh, got it!

couldwheels

I actually get the water out by simply raising the front wheel and out it comes from the holes. It works, ofc, some water remains inside. The holes are fairly big in mine, a medium sized nail can fit.

Although it's hot where I live 90 to 100 F common so water evaporates eventually.

Not sure how you deal with such issues in carbon bike, is the frame completely watertight? In that case, you don't need to do anything but I doubt it is watertight.

Rolla

At least it doesn't rust.

couldwheels

Water in the frame can get to the BB. Although BB's are supposed to be sealed and waterproof, the metal parts of BB probably won't tolerate water exposure for long periods and water may eventually get through the seals.

Ofc, you can remove the seatpost, drain the water. But the inside won't dry out completely for at least a few days without the seatpost and if you put the seat post back and there's still moisture inside, that moisture would stay there indefinitely and may affect the BB and headset components with high humidity inside the frame. At least if it had a hole, you can put the seatpost back after you drain the frame, use the bike the next day and the inside will dry out eventually. At least that is my experience with aluminum frame with drain holes. I often ride in the rain, water gets inside the frame, I drain it. The one time I had to tighten the BB after getting lose when I struck a kerb with the crank, I also removed the BB for inspection, it's bone dry inside the frame. Drain holes seem to do their job pretty well.

mrwang199432

It seems to be surface level. I put some drops of water on the hole and the water just sat in the hole which I assume means it's not a full hole?

msu2001la

On the topic of drain holes, my carbon Zipp 303 S wheels have tiny drain holes in the sides of the rims. So, it's definitely a "thing" on some carbon products.

No idea on frames - also I don't think I've ever noticed water being trapped inside any of my bike frames (steel, aluminum or carbon), so I presume there's a hole somewhere that lets it evaporate/weep out?

Mojo31

Since the hole is so small, the surface tension of the drop of water may keep it from going thru the hole. That’s why I suggested using a small needle. If you decide to do that, use gentle pressure just to see if you get resistance.

If you get resistance a few mills down, My guess is that it might just be a paint defect and not a carbon layup defect. Pinholes can form in paint coatings due to entrapped air, solvents, or other materials escaping during the curing process.

If it’s just a paint pinhole, it will likely just be cosmetic.

Kapusta

Drain holes don't work very well when they are on the top.