144 BCD

A corvette? That bike reminds me more of a slow heavy lincoln Navigator with gold trim.

The drops are like the 4 wheel drive on the navigator: Never used.

The High Flange hubs remind me of offroad tires: Overkill and wretched excess for the street.

poppalurch

This bike doesn't see too much use. That's why it's in a photo studio and not on the street. So, in terms of trying to establish which aspects are "overkill and wretched excess", just keep this in mind:

This bike is like Snoops' 64 impala...it's there to look at (and drool a bit, no?). It's not for doing fixed centuries. I know as Americans we are used to seeing all types of monstrosities (sp?) (SUV's with spinners, or those ugly-ass bmw convertables that look like miata's) on the road, but let's not forget of the imaginative and creative culture of hot-rods and lowriders.

IMHO, I'd much rather see a bunch of dudes poppin' wheelies on their pimped-out colnagos than dudes with hopped-up cars and moto's doing circles in intersections.

phidauex

I'm imagining that the superconducting flywheel would create a magnetic field that could be engaged by one of two electromagnets, one set up to rotate the wheel forward, and the other to rotate it backward. Theoretically, you could continue to hit the brake after you've stopped, and the bike would go backwards. You could probably design a switch lockout to prevent that from happening, but it would be theoretically possible. Since the 'throttle' and 'brake' would activate the coils in the electromagnets, they would just ignore the electric field when disconnected.

The regenerative braking system is like an engine brake, except you are charging your batteries while doing it. Its as if you could resist the pedals on your fixie, and get un-tired. Unfortunately, our metabolism only works one way, unlike electromotive systems which are bidirectional.

My friend's school bus (veggie oil powered) has a magnetic driveline ******er for mountain descents that is a primitive version of the same thing. There are huge magnets on the drive line, and coils of wire around them. When you hit a switch on the steering column, it engages the coils, which get a current flowing through them from the magnets, and create an opposite magnetic field. Its non-friction, so it makes no heat, and you can click it on at a modest level to act as a drag brake on a long descent, and not be afraid of it fading or burning out like a conventional brake. Its very cool. Theoretically, with heavy duty current control circuitry, you could capture that current flow, and use it to charge the batteries on the bus (right now its solar power for the interior lights and other features), but thats an advanced project.

peace,
sam

PS Tyvek would be cool for bags, though it comes in different thicknesses, some of which aren't very strong. One benefit is that I think you can heat-seal it, instead of (or in addition to) sewing it. You may have to experiment a bit, but get yourself an old iron and some tyvek, and try heat sealing it by putting two pieces between some brown paper bag and ironing it. If you can do it, then it would make great waterproof liners, or even entire lightweight bags. Tyvek is pure HDPE (#2) plastic, so it has many of the same properties.

peace,
sam

Terror_in_pink

**** ya, that's a rad poster, i want one!

144 BCD

A lot of fixed gear bikes these days remind me of 64 Impalas with Gold spinners. That's why when I check Ebay these days all these old frames with ancient obsolete tubing and quill stems go for way too much money. They are more collector items and trailer queens than efficeint bicycles for fixed centuries.They were good in their day just like a 64 Impala, but now better fixed gear frames are out there.

Jeez, just look at the "Ben Hur Chariot wheels" on these things? 150 lb kids don't need this kind of stuff: All show, no go.

Poppalurch, I don't think you realize how bad this "look at me on my fixed" epidemic has gotten. It makes me want to hurl.

Terror_in_pink

Dude, everyone who is hating on the colnago is doing so for one or all of the following reasons (deny it as much as you'd like):

1. they can't afford it
2. their bike isn't as nice
3. they cant appreciate GOLD
4. they're insane (because no one should ever hate on a Colnago)

Haters

whoever built that bike, you got my props.

jim-bob

I've been really impressed by the sheer amount of turd-polishing that's been going on lately. If it's lugged, it must be good, right?

I can't wait until I see my first free spirit with a set of phils and those silly aero rims.

jim-bob

I think I fall into 2 and 3. My poor handbuilt frame is only tigged and powdercoated.

Gold? Icky.

To paraphrase my mom, regarding #4 : "that colnago could look so nice if it wasn't wearing those ridiculous clothes!"

karmical

https://www.bikeforums.net/showthread...t=gold+colnago

cicadashell

there must be some ohmic heating, i^2R, but yeah much better then just losing it all to friction. great ideas! keep 'em coming!

i love the way this thread has almost cleanly bifurcated. moving to the other side, that colnago doesn't do a lot for me, but only because gold doesn't do a lot for me. it is certainly a nice build. you know what kills me? those baby-coach wheels people are putting on their escalades and whatnot - the really thin (or, rather, low-profile) ones. talk about a triumph of form over function!

phidauex

This thread is now cleanly sliced into 'geeks discuss futuristic bike technology' and 'purists grouching about those durn kids and their durn shiny bikes'. Which side do YOU want to be on?

Sometimes you just gotta ask yourself, 'what would make me happy?' If people hate biking, it makes ya mad, and now if they like biking, it makes ya mad... The world doesn't know what to do to please you anymore.

And personally, I find personal challenge in polishing turds. How little can I spend to create a bike that might rival a 'nicer' bike in appearance and performance? Its a fun game. And yeah, I actually ride them too.

As to the magnetic brakes, yea, there is some heating from the resistance in the coils, but it is very little, and that heating is only going to raise the resistance a bit, causing the heat to plateau at some safe level as it finds equilibrium. Thats the beauty of room temp super conductors though, no heating! Move as much current as you bloody well please, and it'll just take it.

peace,
sam

144 BCD

Don't get me wrong. I like the challenge of making my own bike for less, but these days old Track frames are not a viable option anymore. The same frame I could buy for a $125 five years ago is now $500+ due to popularity of fixed gear in general.

That leaves you with old road frames with the same obsolete tubing as your foundation to build on.

jim-bob

Well, life imitated whatever the hell it is we've got going on on these forums. As I rode to get some coffee, I almost got mowed down by a massive green and gold Escalade.

bostontrevor

There has to be heating. All energy is eventually dissipated as heat. If there's no heat then you're apparently violating the first law of thermodynamics. I believe that's a ticketable offense.

Otherwise you're merely contributing to the eventual heat death of the universe. Thanks a lot.

sloppy robot

3. i cant appreciate GOLD

phidauex

The great thing about superconductors is that apparent violation of thermodynamics. There is in fact, NO heating. Superconductivity is a phase of matter, just like liquid, solid and gas, where the electrons in the substance pair up, attracted to each other through mutual exchange of photons. These pairs of electrons act in a superfluid state, meaning they can flow without loss of energy. Why? Because the pair, known as a Cooper pair, can only be disrupted by the application of a certain amount of energy, E. If the molecular lattice in the substance possess a latent heat of less than E, then it will be unable to disrupt the paired electrons, and the electrons can move without inhibition.

You'll find that quantum mechanics offers a wide number of possibilities for thermodynamic violation.

Of course, this explains why superconductors have to work in very low temperatures, on the order of 300 or more degrees below 0 fahrenheit, if they warm up, the lattice's latent heat will exceed that of the Cooper pairs disruption energy, and the system will lose superconductivity.

The reason this isn't a complete thermodynamic violation is that in order for this superfluid electron soup to actually DO anything, it needs to interact with a system outside the lattice, which is going to involve some inherent loss. If you have a loop of superconducting material, and you set a current flowing in a circle through it, it will continue to do so forever. Thats not a contradiction though, because the second you attempt to measure the current, you must apply a magnetic field, and that will cause a current drop in the superconductor current. If something's property (in this case, the property of thermodynamic violation) is contingent upon it's non-interaction with the rest of the universe, then it 'doesn't count' as having that property. Molecules can do all sorts of things when no one is looking, and its OK.

For a more in depth discussion of superconductors and their properties and types, I recommend the ever-useful wikipedia: https://en.wikipedia.org/wiki/Superconductivity

peace,
sam

bostontrevor

Right. I actually know that, I was refer to the bus's magnetic braking system whose role is to dissipate kinetic energy as...

phidauex

Well ok then. I thought we had already determined that the bus's braking system does in fact create heat, and that we had moved on to superconductors. I guess it was just the teacher in me, answering questions no one asked. I hope someone liked reading it.

peace,
sam

Terror_in_pink

I knew all that too!

phidauex

Well we are all just a bunch of regular li'l hawkings, aren't we? Why do we waste our talents arguing about hipsters, when we could be using our knowledge to develop mighty weapons of domination, and take over central america?

We may never know..

peace,
sam

bostontrevor

Well it's always nice to have a refresher.

Anyhow, my point is that the bus's magnetic braking system has to generate as much heat as any other braking system as it is dissipating as much energy as any other braking system. The real key questions are a) over what surface area and b) what effect does this heating have on continued braking braking?

Traditional drum or or disc brakes have a pretty small surface area that must shed the heat generated. Further, their performance suffers pretty severely as they continue to heat.

A magnetic brake should have a larger surface area. I would have to sit down and do more math than I want to to consider how the momentum of the bus, the cooling rate of the brake, and the increasing resistance due to heat interact.

How do you know I haven't already?

sohi

hey, I bought my colnago just to make fun of it, strip the paint and wheelie it down curbs. colnago are clown bikes.
here is a fine gentleman that shares your exquisite taste

Terror_in_pink

The Rococo sensibility is sometimes difficult for the bourgeoisie to digest, hence the appropriation and destruction of it.

Riding a Colnago is pretty bourgeoisie anyway, but you won't see me hating.

phidauex

You are correct, the momentum has to go somewhere, in this case to heat. To clarify, the reason you aren't forced to think about the heat as you are with a conventional brake is the surface area, as you mentioned, since the coils are a large amount of material thermally coupled to the frame of the bus over a high surface area, which is more than can be said for a rotor, which is a small amount of material coupled to the thermal mass of the vehicle in a very minute fashion. There is no way to generate enough heat fast enough to melt the copper, so you can basically ignore it. This is clearly different from rotors, rim brakes, or infamous coaster brakes where it is indeed possible to create enough heat in a small enough area to destroy the braking system.

The other factor is how the heat affects the properties of the system. On a hydraulic braking system, you can experience fade as the heat boils the fluid, turning it from incompressible fluid into compressable gas. The friction properties of a brake pad can change as well as they heat up. In the case of the copper coils, the resistance will rise a bit as temperature increases, but its a small amount, and not enough to significantly impact the function of the brake.

So in the beginning, I should have said that the magnetic driveline ******er doesn't produce heat in a way that affects its performance, or causes you to worry about it at all, so can be functionally ignored. And when you are driving a 15 ton vehicle carrying 220 gallons of fuel at 65 miles per hour down a windy mountain pass on the east side of the Sierra Nevadas at 3 in the morning through a cloud of fog, you bless the immortal soul of whoever invented something that slows the thing down without having to worry about it.


Can I come live in your Central American paradise?

peace,
sam

sohi

hate is just a destructive form of love