Monocoque Bicycle(question)



V

verb

Guest
Has anyone ever heard about a monocoque bicycle and
why they are not mass produced?

ie two halves of pressed metal mig or tig welded
together by a robot.


Wouldn't this be cheaper than handbuilt bikes?
 
V

verb

Guest

> ie two halves of pressed metal mig or tig welded
> together by a robot.


sorry i meant spot welded.
 
2

20cents

Guest
In article <[email protected]>,
"verb" <[email protected]> wrote:

> Has anyone ever heard about a monocoque bicycle and
> why they are not mass produced?
>
> ie two halves of pressed metal mig or tig welded
> together by a robot.
>
>
> Wouldn't this be cheaper than handbuilt bikes?


I thought that CF time trial bikes were monocoque. Yes, no?

cheers,
Darryl
 
V

verb

Guest
"20cents" <[email protected]> wrote in message
news:[email protected]
> In article <[email protected]>,
> "verb" <[email protected]> wrote:
>
>> Has anyone ever heard about a monocoque bicycle and
>> why they are not mass produced?
>>
>> ie two halves of pressed metal mig or tig welded
>> together by a robot.
>>
>>
>> Wouldn't this be cheaper than handbuilt bikes?

>
> I thought that CF time trial bikes were monocoque. Yes, no?
>
> cheers,
> Darryl


Some are, that's true.

CF bikes are still expensive to make though.
I was wondering why metal monocoque bikes are not made,
since it would appear to be a cheap way of making bikes.
 
D

Dorfus Dippintush

Guest
verb wrote:
> "20cents" <[email protected]> wrote in message
> news:[email protected]
>> In article <[email protected]>,
>> "verb" <[email protected]> wrote:
>>
>>> Has anyone ever heard about a monocoque bicycle and
>>> why they are not mass produced?
>>>
>>> ie two halves of pressed metal mig or tig welded
>>> together by a robot.
>>>
>>>
>>> Wouldn't this be cheaper than handbuilt bikes?

>> I thought that CF time trial bikes were monocoque. Yes, no?
>>
>> cheers,
>> Darryl

>
> Some are, that's true.
>
> CF bikes are still expensive to make though.
> I was wondering why metal monocoque bikes are not made,
> since it would appear to be a cheap way of making bikes.
>
>


You would probably find that at some point in time such bikes were made,
however I can't help thinking metal monocoque isn't really suited to
bike frames. Given the cost of materials and labor and the sheer number
of bikes made I'd say that they have settled on the most efficient
design from a manufacturing point of view.

Dorfus
 
J

Joel Mayes

Guest
On 2007-08-21, verb <[email protected]> wrote:
>
> "20cents" <[email protected]> wrote in message
> news:[email protected]
>> In article <[email protected]>,
>> "verb" <[email protected]> wrote:
>>
>>> Has anyone ever heard about a monocoque bicycle and
>>> why they are not mass produced?
>>>
>>> ie two halves of pressed metal mig or tig welded

^^^^^^^^^^^^^^^
>>> together by a robot.
>>>
>>>
>>> Wouldn't this be cheaper than handbuilt bikes?

>>
>> I thought that CF time trial bikes were monocoque. Yes, no?
>>
>> cheers,
>> Darryl

>
> Some are, that's true.
>
> CF bikes are still expensive to make though.
> I was wondering why metal monocoque bikes are not made,
> since it would appear to be a cheap way of making bikes.


Pressed metal is a **** structual material, pop into your local bicycle
reuse/recycle centre and have a look at a set of pressed metal canti's
from a cheap MTB or a kiddies bike.

The side of the canti which holds the solid cable end on most of the
will be distorted out of shape. I once squeezed a brake lever on one of
these hard enough to straigten the hook and pop out the cable.

Even given some unobtainium stuctual grade pressed metal, unless the
join was perfect across the entire length of the bike, particularly the
corners the frame would seperate quite quickly. Have a look at a cheap
pressed and rolled mop handle or curtain rod for an example of this.

For a 56cm frame you would need approximately 7 meters of perfect joins.
Including a lot of very tight corners with poor clearances. I don't know
of any machine which could do this. (there is probably a reason why a
good welder can get employment making high presure vessels)

I think its not done 'cause its not possible to make a cheap and
reliable frame this way

--
Human Powered Cycles | High quality servicing and repairs
[email protected] | Affordable second hand bikes
(03) 9029 6504 | Bicycle reuse centre
www.humanpowered.com.au | Mechanical and on-road training and instruction
 
P

Patrick Turner

Guest
verb wrote:
>
> Has anyone ever heard about a monocoque bicycle and
> why they are not mass produced?
>
> ie two halves of pressed metal mig or tig welded
> together by a robot.
>
> Wouldn't this be cheaper than handbuilt bikes?


Sure its cheaper to make, but you end up with a "POSPITA bike".

Its already been tried of course.

Patrick Turner.
 
T

Terryc

Guest
verb wrote:
> Has anyone ever heard about a monocoque bicycle and
> why they are not mass produced?
>
> ie two halves of pressed metal mig or tig welded
> together by a robot.


I have no recollection of the term monocoque being used like that. Could
by just confused with something else.


> Wouldn't this be cheaper than handbuilt bikes?


That method would involve far too much welding and a great investment in
expensive machinery. Far more economical to employ specialised tradesmen
to do a simple bit of brazing/wlkding from pre-cut components.


Mass pro wheels are machined built however.
 
T

Theo Bekkers

Guest
verb wrote:
> Has anyone ever heard about a monocoque bicycle and
> why they are not mass produced?
>
> ie two halves of pressed metal mig or tig welded
> together by a robot.
>
>
> Wouldn't this be cheaper than handbuilt bikes?


Possibly, but there would be a huge weight increase. Honda made some of
their earlier motorbike frames that way. The Dream and it's derivatives.
their stepthroughs such as the CT90-110 are still made that way I think.

Theo
 
M

Miguel Sanchez

Guest
"Theo Bekkers" <[email protected]> wrote in message
news:[email protected]
> verb wrote:
>> Has anyone ever heard about a monocoque bicycle and
>> why they are not mass produced?
>>
>> ie two halves of pressed metal mig or tig welded
>> together by a robot.
>>
>>
>> Wouldn't this be cheaper than handbuilt bikes?

>
> Possibly, but there would be a huge weight increase. Honda made some of
> their earlier motorbike frames that way. The Dream and it's derivatives.
> their stepthroughs such as the CT90-110 are still made that way I think.
>
> Theo
>



Dang.
 
B

Boostland

Guest
"verb" <[email protected]> wrote in message
news:[email protected]
> Has anyone ever heard about a monocoque bicycle and
> why they are not mass produced?
>
> ie two halves of pressed metal mig or tig welded
> together by a robot.
>
>
> Wouldn't this be cheaper than handbuilt bikes?
>


Here is one if you want to buy it.

<
http://cgi.ebay.com.au/TRIATHLON-WE...oryZ7298QQssPageNameZWDVWQQrdZ1QQcmdZViewItem >

Note: this type of bike is illegal under UCI regulations for competition in
events that go by the UCI regs.