[klunky]

http://www.rideon.co.uk/dynamic/?pageId=11&templateId=1

I saw this in Dirt and thought some of you frame building monkeys would be interested or like to chime in. I dont really know much about the process but I imagined it would be heavy (not for any particular reason just my e-speculation)

Clearly there is influence from the honda but I dont think this should turn into one of those threads.

I was just wondering what your thoughts are on a cast frame.
Is it stronger? obviosly a lack of welds is a good thing as thats where the stress normally arrises from but I thought casting made the material fragile/brittle and most manufacturers forged instead of casting if they could afford it.

Please correct me if any of my thoughts are just rubbish!

 

[coma13]

whoa... it's going to be like a toy!

 

[binary visions]

Isn't forging, like, six hundred and fifty gazillion times stronger than casting? Give or take a few gazillion?

 

[klunky]

I did catch a glimpse of an actual frame and it looked like the BB shell etc was solid so pressumably it will be milled out and tapped with a similar thing being done to the head tube.

 

[coma13]

Isn't forging, like, six hundred and fifty gazillion times stronger than casting? Give or take a few gazillion?

no, it's 650 BAzillion times stronger...

 

[Zark]

I hope they got the geometry naile before they made the mold, because that mold must cost a sh*t ton.

 

[skatetokil]

well, casting is used for things like fork legs so it cant be that bad. from what i understand, the air bubble problem can be solved if you pour the metal hot enough.

 

[heikkihall]

well, casting is used for things like fork legs so it cant be that bad. from what i understand, the air bubble problem can be solved if you pour the metal hot enough.

I am no expert but I do not know, nor can I think of any companies that are casting fork lowers. Fork crowns, maybe, and I stress maybe. I do not know of any, but I know that a many motorcycle manufacturers stock forks with cast crowns so It would not suprise me if a few mtb forks had cast crowns. They would be extremely budget oriented forks if there were. Almost all fork lowers are forged as far as I know. Casting is heavy and not nearly as strong as forgings. Seems pretty nuts to make an entirely cast frame.

 

[Slugman]

The last time I did castings was about 15yrs ago... and it was for artifical knees. After seeing the amount of problems that they would get with something the size fo your fist - a frame seems like a BAD idea.

But that was 15 years ago... materials and techniques have come a long way.

 

[ÆX]

i remember a cast magnesium frame in the 90's.

i bet its a ok deal if its light enough, and i doubt it will be.

 

[OGRipper]

I am no expert but I do not know, nor can I think of any companies that are casting fork lowers. Fork crowns, maybe, and I stress maybe. I do not know of any, but I know that a many motorcycle manufacturers stock forks with cast crowns so It would not suprise me if a few mtb forks had cast crowns. They would be extremely budget oriented forks if there were. Almost all fork lowers are forged as far as I know. Casting is heavy and not nearly as strong as forgings. Seems pretty nuts to make an entirely cast frame.

Hmm, then how are lowers made? I really don't know but I would have guessed they are cast. And didn't Marzochhi explain the thin walls/oil leaks on the first 888's as an issue with casting? Can anyone edumacate me here?

 

[heikkihall]

Hmm, then how are lowers made? I really don't know but I would have guessed they are cast. And didn't Marzochhi explain the thin walls/oil leaks on the first 888's as an issue with casting? Can anyone edumacate me here?

Oops yea im sorry. I guess that would make sense how they are made. Temporary brain fart on my end after a long day. I mixed up some information about the manufacting processes.

Still I am not so sure it is a good process for frames.

 

[Biscuit]

I hope they got the geometry naile before they made the mold, because that mold must cost a sh*t ton.

Yea, but once it's done you can manufacture the crap out of them. Completely changes the traditional economies of scale.

You know, thinking about it, if you could get your pieces designed right, a cast bike opens up all kinds of doors.
There are a lot of cool things you can do with plastics these days.
Super strong, super light, and recyclable.

Crazy idea.

 

[skatetokil]

i honestly like the look of it. it seems like they are going to do the intense/cheeta thing with the interchangable seat masts to adjust the size, so they can use exactly the same low standover mainframe for all the bikes.

Somebody get the geo numbers pleease

 

[offtheedge]

i like it. the possabilities of materials and shapes along with the cost effectiveness of casting will surely drive companies to look into this.
that and the cost of raw materials going throught the roof will make this a much cheaper product..........just like anything else being cast.

 

[Biscuit]

it seems like they are going to do the intense/cheeta thing with the interchangable seat masts to adjust the size, so they can use exactly the same low standover mainframe for all the bikes.

I hope not. The most important # in sizing is the horizontal distance from your bb to your bars. Interchangable seat masts don't fix this. I had a Titus that used the same idea, I bought two seat masts for "dh" and for "xc". I could achieve the exact same seat position with both by moving my seatpost up or sliding the seat around.

I agree, it looks cool though.

 

[Westy]

The last time I did castings was about 15yrs ago... and it was for artifical knees. After seeing the amount of problems that they would get with something the size fo your fist - a frame seems like a BAD idea.

But that was 15 years ago... materials and techniques have come a long way.

Casting technology has come a long way. In 15 years companies like Kawasaki and Suzuki have been able to cut almost 100 lbs off of a sportbike mainly through better casting technology.

 

[ChrisKring]

A few random thoughts:

The issue with a large and complex casting is getting the grain structure to align in the direction you want it to. Furthermore, forging doesn't have the porosity issues that casting does.

On the positive side, investment casting tooling is realitively inexpensive compaired to forging tooling.

I don't see a cast bicycle frame ever getting close to the strength/weight ratio of a tube built, hydroformed or carbon frame. With casting, there are minimum wall stock thicknesses required to flow the metal over a distance.

 

[dropmachine]

You guys are dumb. You are missing by far the most important benefit of casting a frame, one that overwhelms any possible negatives.


Think how easy you could add flames.




It boggles the mind, it really does.

 

[SkullCrack]

i remember a cast magnesium frame in the 90's.

i bet its a ok deal if its light enough, and i doubt it will be.

Kirk Precision. I think there was an MTB version too.

 

[MinorThreat]

You know, thinking about it, if you could get your pieces designed right, a cast bike opens up all kinds of doors.
There are a lot of cool things you can do with plastics these days.
Super strong, super light, and recyclable.

Crazy idea.

Think about the possibilities: A Skyway Tuffbike WITH Skyway Tuffwheels.

 

[Kornphlake]

There are actual standards for the aerospace industry that specify what manufacturing processes can be used for different components on airplanes. Wouldn't you know casting has the highest probability of failure for any metal forming process, next time you board an airplane look for something that is rough cast, I'm betting you won't find any. The last plane I was on and paid any attention to, had machined supports for the arm rest on the chairs in coach.

On the other hand there was some investment casting place I went though in college that was casting actions for pistols. I know the automotive industry uses die casting for a lot of engine components and sand casting is still used for a lot of machine bases for precision equipment. Casting can be a great process depending on what the part is supposed to do and which casting process is used.

 

[J5ive]

I dig the dropouts.

 

[PatBranch]

It would takes so long to clean mud out of that.

 

[zedro]

I don't see a cast bicycle frame ever getting close to the strength/weight ratio of a tube built, hydroformed or carbon frame. With casting, there are minimum wall stock thicknesses required to flow the metal over a distance.

have to agree, hollow structures are highly efficient and right now the aluminum alloys used are stronger than that used for castable alloys. They were right about welds being a weak link, but the grain structures between welds and castings are pretty similar and i'm not sure the strength is all that different.

There is a newer type of casting called 'thixoforming' which involves a specific alloy that behaves in a non-Newtonian way (it remains solid until a shear force is applied, turning it into a slush). It's like a cross between casting and forging, where the material is forced into a mold under pressure, netting a low void count and near net shape. It's still not as strong as forged or machined billet parts (claimed to be close), but using casting brings the cost down and allows for shapes otherwise not possible. The transportation industry is looking at this for suspension parts and such (if not using it, i wrote a paper on it years ago).

cool looking design tho

 

[zedro]

There are actual standards for the aerospace industry that specify what manufacturing processes can be used for different components on airplanes. Wouldn't you know casting has the highest probability of failure for any metal forming process, next time you board an airplane look for something that is rough cast, I'm betting you won't find any. The last plane I was on and paid any attention to, had machined supports for the arm rest on the chairs in coach.

and those coach chairs come in at around 60K a seating array, and about double for the fancy 1st class units.

And it's not just about casting properties, it's the alloy used. Most aircraft structure is either 2024 or 7075 for high strength, and these are not castable nor weldable. Just about everything in an airframe and secondary structure is rivetted or bolted together along the shear plane, which has the best strength and fatigue properties (barring composites, but manufacturers are having alot of problems with the large structural units).

it sounds a bit crazy, but i've just started toying with the idea of making a sheet metal and rivet based frame using 2024 and 7075 alloys (basically emulate airframe structure design). Not positive it would be efficient at that scale, but it'd be hella cool next to my Billet bike irate2:

 

[FCLinder]

The design looks nice. I really like the built in Floating Brake Adapter.

 

[ChrisKring]

There are actual standards for the aerospace industry that specify what manufacturing processes can be used for different components on airplanes. Wouldn't you know casting has the highest probability of failure for any metal forming process, next time you board an airplane look for something that is rough cast, I'm betting you won't find any. The last plane I was on and paid any attention to, had machined supports for the arm rest on the chairs in coach.

On the other hand there was some investment casting place I went though in college that was casting actions for pistols. I know the automotive industry uses die casting for a lot of engine components and sand casting is still used for a lot of machine bases for precision equipment. Casting can be a great process depending on what the part is supposed to do and which casting process is used.

Gotcha on this one, the turbine blades in the engine are investment cast titanium. They are either single crystal or di-polar grain structure. I was educated on the manufacturing process of these parts since birth since my dad (now retired) was a engineer developing manufacturing processes and equiptment for 37 years for the major manufacture of turbine blades.

 

[beaverbiker]

thanks zedro, for some solid input. i read a paper about thixoforming in a design class. pretty cool idea.

 

[zedro]

Gotcha on this one, the turbine blades in the engine are investment cast titanium. They are either single crystal or di-polar grain structure.

oooo....how esoteric

 

[MorewoodKid]

The design looks nice. I really like the built in Floating Brake Adapter.

Thats no floating brake adaptor, that is so that the brake caliper will move as you adjust the chainstay length with the sweet-looking moto-styling slotted dropout.

Frame looks good, interesting concept, always good to see the envelope being pushed!

 

[Kornphlake]

Gotcha on this one, the turbine blades in the engine are investment cast titanium. They are either single crystal or di-polar grain structure. I was educated on the manufacturing process of these parts since birth since my dad (now retired) was a engineer developing manufacturing processes and equiptment for 37 years for the major manufacture of turbine blades.

ARRGH, I can't believe I missed that one. I work for a company that makes turbines...

 

[dropmachine]

Idiots!

FLAMES!

 

[OGDMFG]

Do I detect some tension?

 

[w00dy]

Magnet made of Iron,
Lobster made of MEAT!

 

[dw]

thanks zedro, for some solid input. i read a paper about thixoforming in a design class. pretty cool idea.

Cannondale actually used the process for years on dropouts and other parts for the Jeckyll series bikes. I looked into having chainguide parts built using the process but the molds were insane $$. Like 45K for a 2 part mold. Just off the charts. Search around for the term "viscous forging" and you will find some neat stuff.

 

[dw]

Interesting project for sure. Its sure hard to beat a plain old butted tube for a bicycle frame structure.

 

[ChrisKring]

ARRGH, I can't believe I missed that one. I work for a company that makes turbines...

GE or Pratt?

 

[dhmtbman1]

wow that thing has some potential wouldnt buy it cuz its not straight enuf . i like square tubing with hard lines but thats just me

 

[buildyourown]

Wouldn't you know casting has the highest probability of failure for any metal forming process, next time you board an airplane look for something that is rough cast, I'm betting you won't find any.

There is a big difference between investment casting and sand casting. There are many structural airplane parts made with both processes. When I was working as an aerospace machinist, about 1/3 of the components we made started life as a casting.
I'm not saying that it's a superior process. If you look at the newer planes (777) you will see a lot less casting. Many of the parts we made where for 737s and 747s and where designed before 4 and 5 axis CNC machining became common. Back then, casting was the cheapest way to achieve the parts shape and it was "strong enough"

The cast bike looks cool. I'll bet you could make it work with investment casting.