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As per my last post, I'm learning how to use clipless shoes. First 3 days of practice went fine, but on the 4th I came to a stop and couldn't get my foot out in time -- in truth, I got one foot out, but the bike fell the other way. So I and the bike tipped over to my left -- I caught myself with my hands, but the bike clattered to the ground with me astride it.

It's a carbon-frame Giant Revolt. I see no visible damage to the frame, and I'll take it by the bike shop tomorrow, but since there's no visible damage I believe they'll say "it's fine". Which hopefully it is. But how worried should I be with this kind of crash? I've read that when you crash a carbon frame, you should get it inspected professionally. Does tipping over like this count as a crash?

I know that no-one knows the state of the frame, and without X-raying it -- which seems a lot to do -- there's no way to know for sure. But then again "probably alright" doesn't feel very safe.

If every time I tip over while learning clipless means I could break the frame, this seems a possibly terribly expensive proposition.

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    I've had several low speed crashes on my bike with a carbon fork. When claiming waranty on the most-likely improperly bonded dropouts they did not care about the obvious marks of crashes on the shifters - the bike is to be ridden. Small crashes like that should not break it.
    – Vladimir F Героям слава
    Commented May 2, 2021 at 20:22
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    Unless you fell on the frame sideways with your whole body weight and quite some momentum I wouldn’t worry. Carbon is strong, it’s hard to damage the fibers without scratching or breaking the paint (and even when the paint is damaged the fibers are usually fine).
    – Michael
    Commented May 2, 2021 at 20:41
  • @Michael. Thanks. That makes sense and is what a lot of people say. How do I reconcile that with the other group of people who say that any impact could lead to internal damage that could lead to catastrophic failure? Sometimes it's hard to make sense of it, as a carbon frame newbie...
    – Cerulean
    Commented May 3, 2021 at 9:43
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    If it makes you feel better: this was probably the last time you crashed like this!
    – user2705196
    Commented May 3, 2021 at 12:38
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    @Cerulean In the vast majority of cases, the threshold for damage is higher than what you experienced.
    – MaplePanda
    Commented May 3, 2021 at 14:34

3 Answers 3

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In practice, there is one thing I've seen enough to call it a pattern: aero/teardrop carbon seatstays and chainstays cracking near the joints after being flexed excessively during a crash. Some of these combine very light construction with a very flat joint in the side to side direction. Some frames like this you could probably break by falling over at low speed enough times. I'm mostly talking about the kind of tubes you'd see on a tri bike.

Most carbon bikes have nothing like the above vulnerability and, falling over at low speeds, realistically would only get damaged in a major single point impact to a tube. You could probably get that to happen if you fell on the wrong thing.

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  • This is the bike -- images.giant-bicycles.com/b_white,c_pad,h_650,q_80/… -- is this the kind of frame you're talking about? I assume not...
    – Cerulean
    Commented May 2, 2021 at 17:48
  • @Cerulean Not really, but it's also a spectrum. A lot of manufacturers have converged around somewhat dainty seatstays. There's upside there in ride quality and weight, but good at being overloaded from the sides they are not.
    – Nathan Knutson
    Commented May 2, 2021 at 18:54
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Any lightweight road frame of any material can be dented very easily. As long as you don’t see a mark on the frame indicating that it touched the ground, there’s nothing to worry about.

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  • Thanks. What about "invisible damage" that Juhist mentions below. That's the exact thing I'm concerned about. Is it a realistic possibility if I see no scratches or dents? I know the bike shop has said to me in the past "no scratches, no damage", but I'm not sure how through they're being.
    – Cerulean
    Commented May 2, 2021 at 17:23
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    @Cerulean An alu alloy frame is more likely to get damaged than a carbon fiber one. However, in a simple fall it absolutely should not happen to either of them, it takes much more to break a frame. Of course if you fix the tube at both ends and start jumping on the centre, you might crack it without scratching it, but that is quite artifficial. And you will be surprised how much force is necessary.
    – Vladimir F Героям слава
    Commented May 2, 2021 at 20:13
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    @Cerulean Did you hear any fibers breaking or anything? Seeing as this is a gravel bike and not some 700g hill climb frame, it should be strong enough. I've seen a video somewhere of a carbon frame surviving being run over by a pickup truck.
    – MaplePanda
    Commented May 2, 2021 at 21:13
  • @MaplePanda no, I don't recall hearing anything but to be honest I was involved in trying to catch myself (which I did, on my hands, so I didn't go face first into the pavement!). The pedal itself hit with a large sound. I don't recall anything else, but, again, my attention was elsewhere.
    – Cerulean
    Commented May 3, 2021 at 9:46
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    @Cerulean It's quite a distinct sound similar to wood splintering. If you didn't notice it, it almost certainly didn't happen. The sound of hundreds/thousands of dollars worth of bike frame breaking is very distinctive :)
    – MaplePanda
    Commented May 3, 2021 at 19:36
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If every time I tip over while learning clipless means I could break the frame, this seems a possibly terribly expensive proposition.

I agree, it is. There are few solutions:

  • Use a frame with a metallic frame and fork. Metals can only get damaged by bending, immediate cracking, or delayed fatigue cracking. The first two can be immediately observed and the third can be inspected on a dense schedule after a crash which you will end after you are satisfied that there will be no delayed fatigue cracks. This is different from carbon fiber which can get damaged in invisible ways and then suddenly fail "just riding along" due to the damage which would be visible only to either destructive testing or some kind of X ray machine.

  • Use a different bicycle for learning how to use clipless pedals. Preferably a bicycle that is as cheap as possible so you won't regret damaging the bicycle.

However, I find it strange that a clipless learner would crash. I have never crashed due to learning clipless pedals, yet have crashed few times due to other reasons. It is not a law of nature that every clipless learner has to crash. Several ways that could avoid crashing are:

  • If you are using clipless pedals with tension adjustment, set it to the lowest tension, but you'll probably want to adjust the tension up after your practicing is done
  • If you are using SPD pedals, use the multi-release cleat for practicing and when your practice is over and you can reliably unclip, only then switch to the proper single-release cleats
  • Try few times without moving how to clip and unclip. If you aren't moving, you probably won't crash. Only when you have learned the unclipping motion will you unclip in motion.
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    This is wrong on both accounts. The carbon scare is mostly misplaced, and applicable rather to excessively lightweight parts rather than carbon per se (carbon enduro MTBs can take a lot of beating – mine dropped off a, like, 5m cliff once with no issues). Excessively light aluminium is just as dangerous (if not more, because it can fatigue and then suddenly fail without ever having crashed at all). ...
    – leftaroundabout
    Commented May 3, 2021 at 10:01
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    ...And, good on you for having learned clipless without any crashes – but that's just not representative, most riders will crash at least once when using them in the real world because of some unexpected situation. I certainly did.
    – leftaroundabout
    Commented May 3, 2021 at 10:01
  • I think it's worth pointing out that the right of passage isn't to crash but instead to just awkwardly fall over after stopping. In virtually all situations the major risk is embarrassment, whereas crash implies risk of significant injury.
    – whatsisname
    Commented May 5, 2021 at 4:53

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