BlazingPedals

Calling that rotor "safe" is like calling a tire with a huge gash in it "safe" because the boot seems to be holding. Safe or not, I think we can all agree that the rotor is pretty much at the end of its useful life. I for one would want to replace it before the next ride.

TimothyH

I would frame that rotor along with the photos in this thread. Hang it right in my living room.

Who is the rider? I want to follow him on Strava.


-Tim-

balut bandit

u235

My grip is a little torn, am I safe?
In the big scheme of things, is downhill singletrack riding a relatively 'safe' activity anyway? Riding a bike and more so off road and even more so in a down-hill is a VERY dynamic event based on feedback and experience. Everything is changing multiple times a second all the time, don't you just accept it and move long with what you are given? People are capable of adjusting to changing risk and adversity during the ride. If one of my brakes failed during a ride, it would take me 2 seconds to realize it, a moment to look at it and assess the carnage and impact and then adapt and decide if i can move on. No different than if you hit a section of wet leaves, ride a bike down hill with cantilever brakes in the wet, loose rocks, random rogue sticks that wedge themselves in moving parts, a tree down, a stream running across the path and so on.
I think this whole thing is way blown out of proportion and actually strange.
Three out of ten car accidents occur within one mile of your home. I park at the shopping center and ride my bike home from there. I am 30% safer!

Kapusta

veganbikes

Holy using the wrong meme, Batman. The point that was made was quite apt for your situation

Stuff isn't safe because it magically hasn't totally failed stuff is safe because it is working at or near 100% and is not damaged or broken in anyway. The cord to my toaster is frayed and wires are sticking out but it is safe because my house hasn't burned down yet!

balut bandit

It's refreshing that you remain so utterly confused (and fearful). Comparing a working rotor on a mountain bike to a working tire on a car is a false equivalence due to the differences in potential failure modes, potential consequences, speeds, weight, etc.

While I am not surprised that you can't understand the difference, it is sad that you remain mired in such a confused state.

I truly hope that you get better some time.

BlazingPedals

Let's see... In both cases of booted tire and that rotor, the structure is compromised. It's only luck that is holding things together - and that may be good enough if you're limping back to the trailhead. If the booted tire fails, the rider will probably crash. If the brake pad catches on the structurally-compromised rotor, the rider will probably crash -- AND the frame will probably be ruined.

So yeah, I see how they are completely different examples. I guess you're saying that your friend felt no need to replace the rotor anytime soon, since it was still "safe" to him. Heck, removing the extra metal probably saved a few ounces. Maybe he can patent the design.

balut bandit

I have had many MTB tires fail over the decades. Sometimes catastrophically. Even a double pinch flat at mach schnell one time. The tire failures did not cause me to crash. It is rare that a tire failure results in a crash. Your assumption is flawed.

You need to go back and read my post above explaining why this would not happen. The brake pad did engage the "structurally-compromised rotor," repeatedly, for over an hour. The brake continued to work, the brake pad did not catch, and the rider didn't crash.

Also, even assuming your fantasy is possible, let alone probable (again, it's not), I am amazed that you imagine that a locked rear tire = rider probably crashing. It seems that you have never ridden a mountain bike off-road.

A frame would be ruined because a rear wheel locked and a rider crashed? Seriously? Again, it seems that you have never ridden a mountain bike off-road.

Bill in VA

Just like cars by and large. Metallics stop way better, but ONLY when hot, have a harder pedal, and wear out the rotor. Semi metallics sort of split the difference, but are dusty and noisier. I remember images and videos of the Porsche 935 Turbo race car brakes glowing through the wheel slots after the famed long Mulsanne straight at LeMans due to heavy braking for the corner in the late 1970s.

That said, what are most bikes (not pure race machines, but MTB, road, and gravel) currently being sold with as OEM - organic or other? Are any ceramic?

Kedosto

Bill in VA

Thanks. Good to know.

daoswald

I'm not buying that this is due to typical rotor wear and tear. There had to be something else at play here; an impact.

balut bandit

u235

I've had some misalignment that the whole rotor would deflect to one side when applied. I have no desire to analyze it at a metallurgical level in a repeatable manner to see if that really matters or not or how critical that is to rotor life and stress. I adjust to avoid rubbing and eyeball it but no doubt there is some angular error still there in some plane. I have seen some pad wear patterns that the top and bottom of the pad are uneven and the opposite pattern on the other side before and assume that is the cause and the pad eventually mitigates the difference. Pad wear differences from leading to trailing edge would be the same thing with a twist. As the rotor wears and gets thinner, those twisting or bending forces become a larger factor. Not implying that is the case here, just a general comment.

veganbikes

Have never been less confused in my life. A broken rotor is not safe and won't magically become safe because someone got lucky. You are beyond confused and living in such a magical dream world it is almost beyond belief. I have never seen someone so delusional that they believe something that shattered and is now broken and you can hold pieces of it in their hand, is safe. That must be some good crack that you have smoked, it is not my thing and I don't really support it but if it helps get you through life, go for it.

Siu Blue Wind

Really? How did you even come up with this? Is this really necessary? Come on.

veganbikes

Fair enough but this dude has been denying heavily that the broken rotor is safe to the point it is getting beyond ridiculous.

DrIsotope

I've been following this one for awhile, and I really don't get the whole kerfuffle. Perhaps I missed it-- the owner of the bike in the OP-- at the conclusion of the ride, he removed the damaged rotor and replaced it, yes? If that is the case, what's the big deal? Parts fail all the time, particularly on MTBs. A failed brake rotor is hardly the end of the world-- especially as it was the rear rotor.

I've finished rides with screws stuck in the tire, broken spokes, and bent rims. All of which I would reckon potentially more dangerous than a damaged rotor, because the wheel could just fold up and put me on the ground.

Homebrew01

Crazy Idea Everyone..... Post about the topic, not other people....Let's give it a try.

Canker

I guess the real question here is WHAT WOULD YOU HAVE DONE? I already mentioned my 6 mile ride out of the wood with NO REAR ROTOR so I would have just kept riding. I would have taken it a bit easy but I really wouldn't have worried about it. I certainly wouldn't have walked my bike out of the woods. The way those ice tech rotors are made the strength of the rotor wasn't really compromised, it was just the braking surface that peeled off.

tagaproject6

BlazingPedals

Yeah, I guess to the OP, "safe" means "OK to continue using for now." To me, "safe" means it doesn't need replacing. In his place, I would have done the same thing, though: finish out the ride, perhaps holding back on the 'gonzo' maneuvers.

In fact, I did almost exactly the same thing when I hit a rock and partially broke the weld on my front rim. I was almost at the farthest point of an evening ride; so the alternatives were either walk 15 miles, make the 'call of shame' or gingerly finish the ride. I made it home and immediately retired the wheel. I was taking a small chance riding on it, but holding my speed down limited the potential for damage.