Are Boron Cantilevers Becoming Extinct?
- Thread starter Mister Pig
- Start date
Cyclists would beg to differ.
The frame on the bike upgrade I'm looking at is stiff where it needs to be, and unlike an aluminum frame, it does not "flex" when you stand on the pedals to launch. The bike is much more responsive and wastes less of the cyclist's energy, not to mention being lighter in weight. Yet it also has some inserts in the fork and the tail that allow the frame to partly act as a suspension to cushion the ride a little (without sapping energy like many shock systems do). The thing with carbon fiber is that the fibers have to be oriented properly. You can align the fibers so that the tube is completely rigid in one direction, yet can flex in another. In a larger frame tube used on a bicycle, I can see this being easy to accomplish. But on a cantilever, being as tiny as it is, I can see why it it is an issue--the fibers would have to be extraordinarily fine to orient in the right directions, and even then it would be hard to use a lot of fibers to sufficiently layer them do it right (without adding a lot of mass). It could be that a cantilever is just too tiny of a piece to successfully make out of carbon fiber.
Pio1980
AK Member
Bicycles was what I was thinking comparative rigidity, which frames deliver the harshest ride should indicate greatest rigidity. CF has an advantage for fiber grain orientation, the hardness of the adhesive component could be varied to affect rigidity.Cyclists would beg to differ.
The thing with carbon fiber is that the fibers have to be oriented properly. You can align the fibers so that the tube is completely rigid in one direction, yet can flex in another. In a larger frame tube used on a bicycle, I can see this being easy to accomplish. But on a cantilever, being as tiny as it is, I can see why it it is an issue--the fibers would have to be extraordinarily fine to orient in the right directions, and even then it would be hard to use a lot of fibers to sufficiently layer them do it right (without adding a lot of mass). It could be that a cantilever is just too tiny of a piece to successfully make out of carbon fiber.
Ultimately, there would be an upper limit.
ripblade
Addicted Member
I had the opportunity to take a brief sprint on an all CF road bike a couple of years ago....even the cranks, brakes, shifters, etc were CF....only metal bits amounted to not much more than bearing races, axles and a few nuts and bolts. While the bike accelerated very quickly, my overall impression was that I was riding a piece of plastic as compared to my CrMo frame, making it feel cheap beneath me despite the fact it was many, many times more expensive.
Anyway, bikes and cantilevers are not the same thing, and any means of evaluating them is completely different based on the end usage. Just by listening, the CF cantilevers have good tone but don't handle high energy levels as well, which suggests to me that they flex more, but I have no way of proving that to be the case.
Pio1980
AK Member
Nor beryllium, nor monocrystal gemstone.
Titanium, yes.
808_state
Super Member
So anyone care to weigh in on titanium cantilevers? The Technics EPC series mc carts apparently used Ti cantilevers. Would cost these days be too much of a factor?
ripblade
Addicted Member
I can't imagine so....if anything it's probably cheaper now than before. Compared to Al there may not be enough gain to justify the cost difference. Titanium boride looks more promising, but I have no idea if it will ever make a comeback either.
JP
7480 74111110101115
Only the 300MC, IIRC. 305MC, 305MCMK2, 310MC, and 310MC2 are all boron pipe.