bicycle project (committee)

[The_Matrix]

My joke was about the fact that we often get lost in the fact that aluminum has a lower density.
as you rightly point out, y/rho of steel and aluminum look like, so, so much so as not to get down in details, if you do aluminum, put three times a material that weighs a third, and therefore you have the same weight.

But there's a but. steel is calculated more easily, has a fatigue limit, behaviors under various types of stress are known. is more weldable, admits smaller welding cords. Therefore, always to simplify the overwhelming, with aluminum you have to use a bigger safety factor than with steel.

This is demonstrated that aluminum is heavier than steel.

Of course, a design made by aluminum experts (aerobic case) allows to rosicare where with steel is not possible. and here is also the rare cases mentioned above.

the problem is exquisitely marketing... a steel mtb doesn't buy you...

 

[Fulvio Romano]

the problem is exquisitely marketing... a steel mtb doesn't buy you...

then brushing steel can be a solution? Who do you want me to try with the magnet? :biggrin:
Similarly to how plastic pieces are made with "simil carbon" finish, or, worse still, boats with bridges in epowood (plastic!) in "simil teak".

bleah:36_1_10:

 

[MBT]

then brushing steel can be a solution? Who do you want me to try with the magnet? :biggrin:
Similarly to how plastic pieces are made with "simil carbon" finish, or, worse still, boats with bridges in epowood (plastic!) in "simil teak".

bleah:36_1_10:

I go to memory, so forgive me any inaccuracies
years ago, a motorcycle house, the mas, produced a model called "alpine star"
had a "innovative" cooling system, as the air was sucked and passed first on the headboard and then into the cylinder
so the hottest area was hit by the fresh aspirated air and the cylinder (less hot) worked with already heated air. everything worked egregiously and allowed a "lixical" cover of the cylinder, a kind of tube for air passage.
commercially it was a failure. people saw that cylinder smooth and didn't understand the hidden efficiency... .

Need comments?

 

[Fabrizio M]

the problem is exquisitely marketing... a steel mtb doesn't buy you...

a myb in steel doesn't buy you because with the hydroforming on the allumino you can get forms impossible to do with the steel ... the real problem is marketing and the brain of those who buy the mtb, there are people who control the beauty of the decals almost if they care about the brakes or the mechanical parts.
I personally look at the essence, I fuck with the appearance.

 

[The_Matrix]

then brushing steel can be a solution? Who do you want me to try with the magnet? :biggrin:
Similarly to how plastic pieces are made with "simil carbon" finish, or, worse still, boats with bridges in epowood (plastic!) in "simil teak".

bleah:36_1_10:

:finger:
The problem is that you have to use the "tuboni". .

 

[The_Matrix]

a myb in steel doesn't buy you because with the hydroforming on the allumino you can get forms impossible to do with the steel ... the real problem is marketing and the brain of those who buy the mtb, there are people who control the beauty of the decals almost if they care about the brakes or the mechanical parts.
I personally look at the essence, I fuck with the appearance.

not by chance I went from:
- marin eldridge grade steel
a
- specialized fsr
a
- cannon f4000sl

... and the next will be (maybe) carbon... o (maybe) again in aluminum.. .

 

[Fulvio Romano]

Need comments?

margaritas ante porcos!

 

[MBT]

not by chance I went from:
- marin eldridge grade steel
a
- specialized fsra
- Cannon f4000sl... and the next will be (maybe) carbon... o (maybe) again in aluminum.. .

fsr and f4000sl are the grades of steel used to build them??? ?

:tongue::

 

[MBT]

margaritas ante porcos!

You're right.
note the air outlets on the tested cover

 

[M_free]

the problem is exquisitely marketing... a steel mtb doesn't buy you...

fake steel bikes are on sale and are regularly purchased....:biggrinon-one, scapin, chromag... .

 

[The_Matrix]

fake steel bikes are on sale and are regularly purchased....:biggrinon-one, scapin, chromag... .

on 100 mtb for sale now, more or less:
- 80 am in al
- 15 are carbon.
- 5 are steel
... of course we exclude those for sale at the coop...

 

[M_free]

on 100 mtb for sale now, more or less:
- 80 am in al
- 15 are carbon.
- 5 are steel
... of course we exclude those for sale at the coop...

the percentages I do not know them, but there are fields in the world of the bike where the steel frame (almost alloy steels 4130) is what is asked by the customers (see bmx and currently in Italy is taking field the bike from communting where those who own those "original" know that I am snapped fixed with steel frame).

 

[Er Presidente]

Matteo said right.
I add that if you are truly convinced and stra-convinced of the goodness of the idea try to make some drawings and file a patent.
the world of bicycles (in which I work) is made of children of good women ready to steal ideas at all times.



we call e/rho (module of young fract density) the specific stiffness:
for steel (example aisi630) is worth 200/7.85=25.48 [GPa/g/cm^3]for aluminium (example 7075t6) is 71.7/2.81=25.6 [GPa/g/cm^3]for titanium (example 6al4v) is 113.8/4.43=25.69 [GPa/g/cm^3]for carbon (preg fabric) is, in the plane, 68/1.55=43.87 [GPa/g/cm^3]Steel, aluminum and titanium look like specific stiffness. The carbon turns out. a similar reasoning could be done with the specific resistance (breaking rig or fract density yield), and still wins carbon.
carbon is, however, a "brupt beast", a carbon artifact is difficult to do and what a sproposito.
so much aluminum is used, because obviously not all parts of a structure are equally stressed, and therefore in other parts is worth the brute force of lightness (rho=2.7-2.8g/cm^3)

If the steel was the lightest I think the planes would do it with this material. . :wink:

I feel called into question!
the planes would also make them "de fero", the problem is that the sheets of the coating sheet would have a particularly reduced thickness, so much so as not to be able to maintain the shape, that on the monoguous structures is everything.
until the structures were "a traliccio" after the wood came "iron" and defended well, until the "monoguscio".
then there was also flexibility and steel lost the primacy "ideological".

 

[Antosacca]

if you may still be interested, after this exhausting discharging on materials. would I also like the realization of the tricycle, if I have understood as the one attached? contact me... .
Hello, Antonio.

 

[The_Matrix]

the percentages I do not know them, but there are fields in the world of the bike where the steel frame (almost alloy steels 4130) is what is asked by the customers (see bmx and currently in Italy is taking field the bike from communting where those who own those "original" know that I am snapped fixed with steel frame).

It is a...
not commuting or bmx
:finger:

 

[render54]

I have not read all the posts, but a bike with 2 wheels in front there is already, I have seen a 50 new ones in an osio shed over bg,ss 625 de brembo, the owner of the sheds that has a repair shop car, made them conjure and sometimes I see it also coming home in the evening, passing in front of my office, pedaling cheerfully on one of these.
the two front wheels are not fixed but have a pantograph that makes them bend in the curve, as in the bike.

 

[Antosacca]

I have not read all the posts, but a bike with 2 wheels in front there is already, I have seen a 50 new ones in an osio shed over bg,ss 625 de brembo, the owner of the sheds that has a repair shop car, made them conjure and sometimes I see it also coming home in the evening, passing in front of my office, pedaling cheerfully on one of these.
the two front wheels are not fixed but have a pantograph that makes them bend in the curve, as in the bike.

in northern Europe is the most used city transport, especially in Denmark, where there are more tricycles than pedestrians. the cities have a kilometre stretch of cycle paths above the road length. if known, applied to the rear wheel is the energy recuperator of the "powered" called "ruota copenhagen". there is a complete mechanical project. for this I allowed myself, to publish the image and to ask if to someone interested; also because, from us, you are building many cycle paths and to respect the environment and live more healthy is the only "track" to follow.

 

[New Rider]

since I come from the competitive world of mtb I can specify some info given here.
- as already blinded by you does not exist in absolute the best frame since every variable and editable over the years.
- bikes make it with many materials and prices.. Usually you choose the type of material based on how you will use the bike. e.g. for 300 km long distances and more you tend to use carbon bike with a high elastic coefficient (modifying the plots) precisely to give comfort to the cyclist. Inverse speech happens when we have relatively short circuit races where there are continuous raises and speed variations here then the use of aluminum or steel. I personally saw steel bike cost more than some carbon.
In any case carbon is a very elastic material is the difference you feel immediately from the first pedals.
then what to say.. Currently world production is pushing to build carbon downhill bikes.. . http://www.youtube.com/watch?v=d7cmm-xzvc4... to strengthen that carbon can be a material like an alu if not adirittura the best. only flaw is that if you fall and break a 99 out of 100 plot you don't notice with the risk of finding yourself in the air with a two-piece frame. .http://www.triridemtb.com/evil-carbon-rottura-a-la-bresse/then what to say.. Maybe if the speech goes on I can make a practical contribution as well. It is in fact that I have a 3 wheeled carbon bike would not make sense perhaps racing since the uci categories for these bikes are not there and therefore it would not make sense to employ forces/demands to create super performing models.

Bye.

 

[Antosacca]

http://www.triridemtb.com/evil-carbon-rottura-a-la-bresse/then what to say.. Maybe if the speech goes on I can make a practical contribution as well. It is in fact that I have a 3 wheeled carbon bike would not make sense perhaps racing since the uci categories for these bikes are not there and therefore it would not make sense to employ forces/demands to create super performing models.

Bye.

You're right, mine was just a non-sports business speech. passing through the Nordic countries I was surprised by the large number of tricycles in the city, I found the great utility of these means. are used to bring children to school, to make expenses, to go to the park, they are used in every activity carried out in the city. they have installations that allow to use them when it rains and when it is cold. if even in Italy, given the energy and environmental problems, it takes on (see electric bike) the thing is probably worth being considered, always from the commercial point of view.
Bye.

 

[New Rider]

It will be that I am pessimistic but all the beautiful things that happen in other European countries here will be just mirages. as the incentives of bicycles of a few years ago.. practically instead of encouraging the use of these to profane users of the bike (see for example. places, communal places, mothers and children, small trips to the city) have been used by people already sailed in this sport to buy high quality bikes (costose) with a greater discount. the classic Italian egoism. I think of me and my wallet and you arrange. Then boom, I'm miraculously gone. classic Italian maneuver? I think it's a bit like photovoltaic. ...