I have no clue on how to inspect CF for cracks other than visually. Can you use a dye penetrate? I worked in the power industry and all metal fab/welding was thoroughly inspected using many methods. One was dye penetrate, which is a very simple process. I've always wondered if a similar method could be applied to CF inspection, one specifically made for CF if it doesn't exist already.

This was my first thought - something not newsworthy being offered up as provocative.

boy, makes me want to stay away from carbon even more. buying new is kinda too much money in my opinion for any really good carbon bike properly outfitted.

How dare the owner of the shop do what he/she feels is best for the business! Shame on him/her!




Said sarcastically.

A customer of ours that is an attorney was the victim of the unseen crack and he was gracious enough to be satisfied with a new frame. He advised us to turn down any frame inspections of this nature. Frames involved in wrecks, as he put it, puts "undue liability" upon the shop should we inspect them, making us directly liable for injury or harm if one fails. Be it aluminum, steel, titanium, or carbon, off to the manufacturer it goes for inspection.
For what it is worth, he did let us know that regardless of who inspects it, should someone decide to sue due to a wreck from a frame failure, the shop will most assuredly be involved in it.

As for the ugly responses in this thread, put all your assets on the line and do frame inspections for people. I'm sure they will appreciate it.

If a frame is suspected of damage, why would the dealer put themselves in the middle of the inspection sequence? Dealers are not necessarily pros at inspection of frames. Send it to the manufacturer where the expertise and responsibility belongs. IMO.

So do you do no mechanical work either? Because there is always an implicit liability potential with the "test ride" following work done. I don't know of any shops that do official frame checks, they all will look something over and point out anything obvious and tell you that its up to you to determine if its safe to ride

I was Trek's warranty inspector back when they made lugged steel and bonded aluminum frames. Rust under the paint is obvious from the bubbling, and not a warranty issue. Even rusty steel frames seldom fail suddenly or catastrophically, and other steel failures e.g. from insufficient braze penetration or overheating of joints also typically exhibit slow failure modes. Our most common steel frame failure was broken rear dropouts; Shimano in particular had a run of problematic UF dropouts that necessitated mid-production substitution of Campagnolo dropouts. Aluminum has a very different failure progress than steel, and can go from an initial crack to complete failure surprisingly quickly. We replaced a significant fraction of the initial production run of bonded aluminum frames when cracks appeared at the tube/lug junction. destructive analysis of these frames eventually showed that this was not a joint failure, but an artifact of the paint being less flexible than the epoxy holding the joint together, with the result that the paint would crack but the underlying joint remained completely intact. Reformulation of the paint addressed this issue.

It comes down to personal choice.
If you rarely crash it isn't a problem.
If you do and don't like the unknown aspect of whether the frame is sound ride something else.
Or don't ride something that costs more than you are comfortable with to replace if the unexpected happens.

I raced used frames. This was pre carbon frame area. You could get used frames for pretty cheap, from somebody who went all in on the equipment and then realized it wasn’t for them.

I think you need to clarify a bit. There's nothing wrong, and it may prove helpful and/or life-saving, with a bike shop inspecting a frame for damage -- eg. while performing other service functions. The problem comes about when the bike shop sells that as a service offering unto itself.

There is an increased liability anytime you offer your opinion in a professional capacity.

Yup, all cracks in steel are so easy to detect that engineers have developed specialized machines (magnaflux, etc) to detect cracks that are not visible to the naked eye.

Free!

But you get what you pay for.

I'm a bit confused though. The inspections that you WERE doing...were they with x-ray/ultrasound/etc, or just a visual inspection in the shop?

If you don't have imaging equipment...then yes, I would say without reservation that performing carbon inspections for people is a terrible idea. Unless you're actively and repeatedly telling people that the inspection are non-comprehensive at best, meaningless at worst. But then...what's the value in the inspection anyway at that point?

So yea, I think the only prudent response to an inspection request is just to state that carbon inspections require imaging equipment, which we don't have.

Well yeah.. so if in the course of servicing a bike, and the shop does not see any cracks or other frame damage, they would be kinda stoopid to tell the customer they looked it over on their own initiative and btw the frame is safe and fine to ride. OTOH, if they come across what appears to be a crack or damage, I can't imagine an increase in liability from telling the customer that they found such and that they advise having an expert check it out further before riding.

the exact same way as you or i would obvioulsly.

you see a line, then try to make the line wider.. does it get wider with force? yeah, then its cracked.
maybe push your finger into the "line" and see if there is some kind of movement there.

I sometimes wonder if the whole of humanity suddenly went completely nuts.

If you were to present this "problem" to people living in the 50ies, in the US. I'm fairly certain they would have solved it in like 1 minute. just like me. carbon is no different to other frame materials when searching for suspected cracks imo.

But people are afraid of carbon. they don't want to touch the holy carbon, made by the taiwan mass production buddhas.

I'd say if anyone human can make it then anyone human can inspect and determine if its shot. easy as that. and it actually is easy as that.

I am not singling out carbon frames, but am making a statement about all frames regardless of material. When questioned about how we inspected the frame be it metal or resin, and they ask what imaging equipment we used, and we come back with a dumb answer, we are screwed. We have torque wrenches, but imaging equipment? Nope.

you dont need imaging equipment. you need common sense.

they had no "imaging equipment" building the first 50 nuclear/hydrogen bombs. and even if they had it would have been toast. yet they still managed to produce more efficient stuff all the time.

This! Had a guy a while back wanted me to check his car for tracking devices and bugs. Claimed he thought someone was following him...Uhh, you need to go see the police. If someone is following you around, I want no part of this. If they aren't, I want no part of your crazy delusion.

Nuclear bombs and tracking devices....

It's scary out there.


-Tim-

You might want to join the 21st century, at least with respect to your vocabulary.

he probably wanted you to sweep his car for cop bugs!

this is very easy to do. actually tracking/proving hf transmitters are there is very easy. you can do it with a dynamic microphone and a micamp. its a very sensitive system (usually above 60dB) and even the most faint electomagnetic devices will sound like f-ing beacons when you plug in headphones to listen. basically all electronic stuff makes a signature. and if you find a signature/sound/disturbance where there should be none then you know there is something weird going on.

I can record my shielded computer psu electronic airborne noise from about 0,5m with full amplitude.

Most if not everything will show up way above 20khz. though. and as we all know humans can only hear up to 20khz. but the devicec will either am or fm or pulse modulate at way lower freq than this. so its very audible.

The reason i know this is that i heard a quite loud HF/noise sound when playing music at full blast in my stereo.

And i simply investigated. built an antenna. hooked sh1t up. and listened to all my all my electronics. In my case the stationary computer psu was the offending part. and you could see it far far away on the spectrum analyzer in my daw!!

i once read a book about electronics. once.

Dont think so. I meant what i wrote there. and you all know what i wrote is true.

You could make your point w/o being offensive.