Carbon Fiber Frames and Heat
- Thread starter dsschanze
- Start date
dsschanze said:
You might be surprised in that if it is a 'normal sunny day' and say 90 outside, then it could be as hot as 130-140 in the car. Depending on orientation to the Sun, types of windows and duration of exposure.
Most thing i'd be concerned about would be the tyres exploding.
I wouldn't be planning on exposing a composite frame to super hot car temps too often. While thermosetting epoxies (as most people know them) won't "melt" or deform, they may degrade over time. However this is not a huge issue in 99.999% of cases
The frames are generately "baked" in the first place so the chemical cross bonds are formed. I'm not convinced that excessive exposure to the temps that could be reached in a really really hot car wouldn't be bad for your bike if done too often.
Note I am saying REALLY HOT, and OFTEN. On a 40degC day a car in the sun could get well up over 100deg inside. That could cause excellerated aging of all plastics and rubbers on your bike, less so the frame.
But then when you think about it, the temperature of CF rims can locally get extremely hot also, and they are built to last, so maybe there is no isssue at all for a quality CF frame in a car.
I know in the past people who have left thier tennis raquetes in the rear window of thier car have had reduced durability. Materials may have improved, but when you've spent lots of $$$$ you might as well treat your "investment" nicely!
The frames are generately "baked" in the first place so the chemical cross bonds are formed. I'm not convinced that excessive exposure to the temps that could be reached in a really really hot car wouldn't be bad for your bike if done too often.
Note I am saying REALLY HOT, and OFTEN. On a 40degC day a car in the sun could get well up over 100deg inside. That could cause excellerated aging of all plastics and rubbers on your bike, less so the frame.
But then when you think about it, the temperature of CF rims can locally get extremely hot also, and they are built to last, so maybe there is no isssue at all for a quality CF frame in a car.
I know in the past people who have left thier tennis raquetes in the rear window of thier car have had reduced durability. Materials may have improved, but when you've spent lots of $$$$ you might as well treat your "investment" nicely!
how relevant this is i don't know. but to avoid illustrating my own stupidity, i'm going to say "a friend of mine" taped their tires to cf rims using the tufo extreme tape. well using the tape wasn't the stupid part.
the front tire required a change and trying to pull the tire was overly difficult. so he decided to pull the tire over as far as possible exposing the tape, and gently heating the tape with a heat gun.
he was holding the tire with bare fingers so the heat wasn't extreme. after about 20 seconds '****' a section of rim has all the carbon layers simultaneously delaminate and a very expensive rim is now trashed.
it didn't take much, so i'd say would i expose a frame to hi temperatures for any extended period of time, or regularly? probably better not to.
the front tire required a change and trying to pull the tire was overly difficult. so he decided to pull the tire over as far as possible exposing the tape, and gently heating the tape with a heat gun.
he was holding the tire with bare fingers so the heat wasn't extreme. after about 20 seconds '****' a section of rim has all the carbon layers simultaneously delaminate and a very expensive rim is now trashed.
it didn't take much, so i'd say would i expose a frame to hi temperatures for any extended period of time, or regularly? probably better not to.
sideshow_bob said:
There have been a few cases of that with Tufo Extreme tape, and the problem was a rim manufacturing problem, not a tape or heat problem. Zipp has freely acknowledged that in cases that involved their rims.
Remember, you can get a CF rim hot enough to melt a clincher tire's bead....
but i think you mean in those cases a section of the rim bed delaminated or had a chunk pulled out of it. which i've seen occur.alienator said:
in my case it was the sidewall from the rim bed down. the individual layers all kind of separated. up at the join of the rim bed and the sidewall, there ended up about a 2mm gap. it was definitely heat only that did this.
having said that i'm not going to name the rim manufacturer, but they recently moved production of their rims to china (not that that generally is a bad thing), but since doing it have had all sorts of QC issues. so it may have been a unique combination of events on this rim, heat and a bad layup. who knows.
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