If you change all the parts . . . is it still the same bike?
 

There is a philosophical puzzle called the Ship of Theseus, named after an ancient Greek legend: Theseus goes sailing, and over time he and his crew replace every part of their ship, bit by bit. Is it the same ship?

I bought a beautiful lugged, made in Italy, Bianchi road bike new in 1995, and still have it and ride it today. But over time, I have replaced almost every part of it, such that today, only the seat post, headset, and frameset are original. Even though I did not replace the parts with the exact same things, to me, it is still the same bike.

Have you "Ship-of-Theseus'd" a bike? Do you consider it the same bike, or a different one? At what point does it become a different bike?

are you keeping the original frame? yes, it's the same. no, it's not.

Only thing on my main distance ride, the 36er unicycle, that's original is the steel frame - effectively a simple fork.

Had to replace the seatpost before I could ride it at all since the previous owner was much shorter. Pedals and saddle were preference, added handlebar, brake caliper, cable, and lever. Replaced bearings and cranks, then enough spokes that I ordered new ones and entirely rebuilt the wheel. But I also bought another hub, rim, tube, tire, and cranks and built a second wheel which is the one I'm now riding.

One of these days I'm going to pick up a new frame, as it's the only part short of having two complete setups.

So far actual two wheel bicycles have only minimal parts changed though nephew and I did just rebuild one back up from a cleaning/curiosity teardown replacing only a few things.

is/are they the same bike?

I would also say "the frame" is the tipping point, as a first reaction, but to muddy the waters a bit with a true story: I built up a mountain bike and for the most part was really happy with it. When I discovered that I had cracked the frame, I thought really long and hard about getting exactly the same frame and just moving the parts over to it. I ultimately didn't. But I wonder, if I had, would it have been the same for me?

There was some talk about "forever bikes" a while ago, and the idea of a bike that stays frozen always seemed like a strange idea to me because bikes are so wonderfully mutable. Bike are just begging to be modified yet have a constant distinct character all the same. Maybe I misunderstood the idea, though.

And most likely, there's a serial number somewhere on the frame. Changing the frame changes the serial number which is less trivial than changing wheels or a seatpost.

There's the old joke about the woodsman who brags that he's had the same axe for twenty years. "Yep," he says, "and I've only replaced the head twice and the handle three times."

A similar question arises when we consider the fact that our bodies' cells are completely regenerated every seven years. Are we still the same person ?
It's not really about the referent, the object out there, but rather about the symbolic representation, the memories associated and their emotional responses. If you feel it's the same bike, then it certainly is. If, at one moment, you stopped recognizing that bike, then the reference is broken. The world is constantly changing, whereas our minds are constantly struggling to setup everything in a fragmented, object oriented structure we call reality.

to the original modifier of the unit, that might be acceptable. Should the original modifier decide to transfer the ownership to someone else, it is then not acceptable to be consider the same frame.

My 1998 bike, bought in 1999, is an example of Grant Peterson's "wear something out" philosophy. Upgraded to 9 speeds after a couple years. Frame broke and replaced under warranty, wore out the rear wheel, replaced the front wheel (though I've still got the original), seatpost broke, etc. I even used the fenders that I put on until they broke. The frame and brakes are still original!

Rides the same, though, so I still call it "Fuji Touring."

Yeah, I can relate.

As long as I've gotten a reasonable lifespan from something, I'm okay with things wearing out - chains, tires, cassettes, bearings, wheels, whatever. I buy 'em to ride 'em, and wearing something out feels like accomplishment.

I'd love to write more, but I'm off to have my car serviced: 10.5 yrs old, 147k miles, no plans to get rid of it.

In my mind, it is the frame that determines when it is a new bike.

If I change everything that was never on the bike = it becomes MY bike.
https://cimg4.ibsrv.net/gimg/bikefor...fc5734e56e.jpg
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It's not really a ship of Theseus situation until you have replaced all the parts and also had the frame repaired so many times that nothing is original.

It can go from a schooner to a tugboat - rather quickly.
(how long can a stem go?)
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If you change it from drop bars to condorino - it becomes a horse of a different color.
https://cimg8.ibsrv.net/gimg/bikefor...7b223b173.jpeg

Not to be nit-picky but I'm gonna be, the ship was in dry dock in Athens when everything was replaced a piece at a time.

Yeah? So when is my body get around to it being the knees?

Then I'm getting there. I've got a Giant Perigee, there is nothing original about the bike, the parts were upgraded to shimano 600 including the seatpost, the fork was replaced with a chrome cross fork changing the stem to threadless, a CK headset was installed at the same time, the brake bridge was replaced 20 years ago and when that was done canti tabs were added. After the seat stay failed 10 years ago the bike was repaired and repainted. So even the frame isn't very factory at this point.

The quickest check would have shown that this is a myth.

Some cell types are replaced faster, others aren't replaced period.

All my bikes have been built from the frame up, or built the frame and then added components. None are similar to how they were originally sold. Its pretty easy to say 'its an updated CAAD3' or 'its a modernized 80s road frame'.
No they arent the same bikes as original. Very few bikes are, if they are used. Nobody but collectors care that they arent original and so they are still called by the original name. A bike that is used well for 2 years will have new tires, saddle, tape, pedals, chain, brake pads, and maybe new wheels too(if the user wants). Something that has so many changes just from regular use should still be called what it originally was.

If you start replacing frame tubes than yes it will be a different bike but if you swap components out that doesn't change the actual frame. I have built many of my bikes from the frame up so so long as the frame is original it is the same bike.

Make the bike work for you. Keeping it 100% original is really not sensible unless it works for you or if the bike is super rare and collectible and worth a lot of money but I doubt we are talking that.

At some point in time, all the atoms of your body will be gone and replaced with new ones. Whether some cells die out faster than others is not the point.

My winter/rain/city fix gear. Started life as a UO-8, went single speed and sewups, then fix gear as I started racing. Finished racing, fenders went on year round. Crashed it on a car door and replaced the frame and French parts. Moved up to a Campy track hubbed rear wheel. Bike got stolen but that sweet wheel wasn't on it. Picked up a mediocre Sekine, put on the wheel and kept rolling. Fork failed a few years later and a Miyata slid under the parts. Crashed and shortened it and a Trek slid in to take it's place.

So is that one bike or five? I think of it as one where every piece has been replaced four times. (But I do have the original seatpin. It's been on my Peter Mooney for the past 40 years because its the proper pin for canti cable hanger. 54 years old and in service for 52 of those years.)

The frame is just another part, same as the wheels or handlebars or saddle or cranks or any of a number of bearings. The frame can’t move without the other parts nor is it a “bicycle” without those other parts. If you replace a bearing, isn’t the bike different from the original bike and thus is a different bike?

Lots of parts have serial numbers. Forks, for example, can have them. Some hubs can have them. Some bearings have serial numbers. The “serial number” is a way for manufacturers to keep track of production and inventory or to prevent counterfeiting. If some part has a serial number and you change to a new part, does that mean you have a new bike?

When the amount you spend on the replacement parts exceeds the original purchase price for the bike by such a wide margin, you can no longer justify the sunk costs.

At that point it becomes a resto-mod and and with it the satisfaction that you created a bike superior to the original.

John

The frameset is original. The frameset is the frameset.

But the original bike is not the original design. It's a different bike.

I've seen a vintage Motobécane Grand Record without any Campagnolo on it. Nuovo Record is inherent in the design of the name of the bike. Without it, it's not a Grand Record .

What if I change out the decal that says Peugeot for one that says Rene Herse?