Carbon bikes - environmental disaster?

fat and old
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Re: Carbon bikes - environmental disaster?

Postby fat and old » Thu Dec 07, 2017 3:17 pm

RonK wrote:
fat and old wrote:
RonK wrote:
The image of the village blacksmith in Upper Volta or Outer Mongolia trying to weld a bike frame made of tubing with less than one millimetre wall thickness with a blow torch or a couple of car batteries and electrode immediately comes to mind.



Are the bike frames used by those tourers that go for those sort of tours really less than a millimeter thick? I would have thought they'd be tougher?

Yes - in fact it's difficult to find tube sets with a wall thickness greater than 0.9mm at the butts. Most touring bikes are made from butted 4130 chromoly tubes with a wall thickness of .9/.6/.9


Dead set? I would have thought they'd be thicker/tougher/insert correct word here. Learned something new. Thanks :)

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Re: Carbon bikes - environmental disaster?

Postby human909 » Thu Dec 07, 2017 4:17 pm

fat and old wrote:
RonK wrote:Yes - in fact it's difficult to find tube sets with a wall thickness greater than 0.9mm at the butts. Most touring bikes are made from butted 4130 chromoly tubes with a wall thickness of .9/.6/.9


Dead set? I would have thought they'd be thicker/tougher/insert correct word here. Learned something new. Thanks :)


Here are the specs Surly, copy and pasted from elsewhere.

LHT.
TT=.8x.5x.8 at 31.8mm
DT=.9x.6x.9 at 31.8mm
ST= 1.2x.6x.9 at 29.8mm at the seat tube and 28.6mm at the bottom
bracket
Stays= .9mm
Fork blades= 1.1mm to 1.4mm tapered

Check.
Top Tube - 28.6mm dia 0.9 - 0.6 - 0.9mm thickness
Down Tube - 31.8mm dia 0.9 - 0.6 - 0.9mm thickness
Seat Tube - 29.8 dia at seat collar, 28.6mm dia at bb 1.2 - 0.6 -
0.9mm thickness
Stays - 0.9mm thickness
Fork - 1.2 - 0.9 - 0.7 thickness

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P!N20
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Re: Carbon bikes - environmental disaster?

Postby P!N20 » Thu Dec 07, 2017 4:26 pm

fat and old wrote:Dead set? I would have thought they'd be thicker/tougher/insert correct word here. Learned something new. Thanks :)


Not strictly touring, but a Columbus MAX top tube is 0.7, 0.4, 0.7.

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RonK
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Re: Carbon bikes - environmental disaster?

Postby RonK » Thu Dec 07, 2017 5:46 pm

fat and old wrote:
RonK wrote:
fat and old wrote:
Are the bike frames used by those tourers that go for those sort of tours really less than a millimeter thick? I would have thought they'd be tougher?

Yes - in fact it's difficult to find tube sets with a wall thickness greater than 0.9mm at the butts. Most touring bikes are made from butted 4130 chromoly tubes with a wall thickness of .9/.6/.9


Dead set? I would have thought they'd be thicker/tougher/insert correct word here. Learned something new. Thanks :)


Well, your thinking is correct. Touring bikes are made from heavier tubes. But, this tubing is at the heavy end of the scale.

This what makes the assertion that steel frames can be welded "anywhere" so laughable. It takes considerable skill and the right equipment to weld such thin-walled tubes, and you don't find those just "anywhere".
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1Rowdy1
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Re: Carbon bikes - environmental disaster?

Postby 1Rowdy1 » Thu Dec 07, 2017 6:30 pm

I see people restoring 30 / 40 year old steel bikes. In 40 years time will people be restoring 40 year old carbon bikes?
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silentC
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Re: Carbon bikes - environmental disaster?

Postby silentC » Thu Dec 07, 2017 7:02 pm

This what makes the assertion that steel frames can be welded "anywhere" so laughable. It takes considerable skill and the right equipment to weld such thin-walled tubes, and you don't find those just "anywhere".

Parts of my house are made with 1.6mm steel sections and that stuff is quite difficult to weld without blowing holes in it. DAMHIK.

In 40 years time will people be restoring 40 year old carbon bikes?

This begs the question "why would anyone want to?" Steel has a certain nostalgia attached to it. Carbon is a different aesthetic. More of a means to an end than an object to be admired, although I know people who do admire them as objects. But who knows what the future retros will be into?
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Re: Carbon bikes - environmental disaster?

Postby human909 » Fri Dec 08, 2017 2:07 am

RonK wrote:This what makes the assertion that steel frames can be welded "anywhere" so laughable. It takes considerable skill and the right equipment to weld such thin-walled tubes, and you don't find those just "anywhere".


If we are talking about low skill environments the you are quite correct. But if you don't have considerable skill it can also be repaired with appropriate gussets or plates to get the job done. All with materials and equipment that is common throughout the world...

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Re: Carbon bikes - environmental disaster?

Postby Comedian » Fri Dec 08, 2017 7:27 am

silentC wrote:
This what makes the assertion that steel frames can be welded "anywhere" so laughable. It takes considerable skill and the right equipment to weld such thin-walled tubes, and you don't find those just "anywhere".

Parts of my house are made with 1.6mm steel sections and that stuff is quite difficult to weld without blowing holes in it. DAMHIK.

In 40 years time will people be restoring 40 year old carbon bikes?

This begs the question "why would anyone want to?" Steel has a certain nostalgia attached to it. Carbon is a different aesthetic. More of a means to an end than an object to be admired, although I know people who do admire them as objects. But who knows what the future retros will be into?


This lovely old bike tells a story about legendary frame builder XXXXX. He raced in the 30's and went to war in Europe. When he returned to Australia he set up a workshop building bikes in Fitzroy, where his business became an iconic feature of the area. He made frames for several Australian Olympic and Commonwealth games medalists.... and even a TDF winner.. This particular frame was made for a well known local cyclist who preferred ... He typically built 2 frames a week and got them painted by local painter who could often be found in the local pub with XXXX...

OR.

This lovely bike was the brainchild of an American marketing graduate from Yale who worked for Gullible Bikes. He identified a niche in the market where he thought he could sell enough product at a sufficient margin that he could put that on his resume and get a bigger bonus. He workshopped that and got approval from the board who handed it to the engineering team. The team ran it through their finite analysis programs and produced a CAD Diagram. They then contracted this out to a mold maker. Once done they organised a contractor to build a prototype in each size. These were painted, and they were workshopped to see if they were appealing to their demographic.

With minor changes to the colour scheme a tender was put out to a number of known contract frame manufacturers in China. Zing Gong Shen agreed to build 75,000 at $15.42 USD a unit. This price was accepted and they agreed to deliver in the August of 2019. In the meantime the marketing team at Gullible Bikes swung into action, and took many photos of extras from the modelling agency that looked like studious engineers talking to attractive local cyclists from Instagram that the receptionist had stalked with the prototypes for 5000 likes.

The frames were sold online worldwide and it's unclear if any were used in competition.. or even at all. The return warranty rate of 28% was considered acceptable for this type and this project was considered a commercial success. It's unclear whether any of the designers or marketing team continued to work in the industry as the company had a high turnover at the time due to their stockmarket float. Zing Gong Shen bicycle manufacturing shut down due to patent infringement charges, but it's believed many of the company staff went on to work with several other contract frame makers in the area. It's unclear whether the women and children who worked laying up the frames in the hazardous environment even knew what they were making, or indeed whether they suffered long term health effects.

They are quite different narratives aren't they? :shock:

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silentC
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Re: Carbon bikes - environmental disaster?

Postby silentC » Fri Dec 08, 2017 7:43 am

Yes in my other pastime people get all sentimental about old tools and make much the same arguments about old hand tools versus new power tools as their justification for why they prefer one over the other. At the end of the day it is neither here nor there when discussing the end results. But the landfill argument is valid.
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1Rowdy1
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Re: Carbon bikes - environmental disaster?

Postby 1Rowdy1 » Fri Dec 08, 2017 9:15 am

My 40 year comment was more about will a carbon frame last 40 years, not really about why anyone would want to.
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P!N20
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Re: Carbon bikes - environmental disaster?

Postby P!N20 » Fri Dec 08, 2017 9:20 am

Comedian wrote:He typically built 2 frames a week and got them painted by local painter who could often be found in the local pub with XXXX...


Rubbish. Nobody drinks XXXX in Fitzroy.

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Re: Carbon bikes - environmental disaster?

Postby human909 » Fri Dec 08, 2017 9:32 am

P!N20 wrote:Rubbish. Nobody drinks XXXX in Fitzroy.


I have to giggle at that..... :D

But hey he may have meant:
https://en.wikipedia.org/wiki/Shire_of_Fitzroy

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Re: Carbon bikes - environmental disaster?

Postby P!N20 » Fri Dec 08, 2017 9:36 am

^ Ah. My bad.

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Re: Carbon bikes - environmental disaster?

Postby silentC » Fri Dec 08, 2017 10:03 am

1Rowdy1 wrote:My 40 year comment was more about will a carbon frame last 40 years, not really about why anyone would want to.

I think if you looked at how many 40 year old steel framed bicycles have been restored by retro enthusiasts versus the number that have been crushed or left to rust away in someone's garden, it would be a very small percentage. No reason to think there won't be some mad carbon retro guys around using techniques yet to be developed to restore old carbon frames in 40 years. That is if they haven't all been recycled for wind turbine blades by then. I think carbon fibre will become a much more reusable material than it is now in time to come. In fact I think steel bicycles of any age will become increasingly rare in the next couple of decades.
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Re: Carbon bikes - environmental disaster?

Postby duncanm » Fri Dec 08, 2017 10:11 am

1Rowdy1 wrote:My 40 year comment was more about will a carbon frame last 40 years, not really about why anyone would want to.


the only things that will destroy a carbon frame are physical damage and excessive sunlight (UV).

The failure points (excluding crash and other damage) will be things like aluminium and steel components bonded or in contact with the frame corroding, and possibly damaging the frame in the process.

I've got a 25yo carbon (composite) frame going just fine. I can easily see it going another 15.

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Re: Carbon bikes - environmental disaster?

Postby P!N20 » Fri Dec 08, 2017 10:22 am

silentC wrote:No reason to think there won't be some mad carbon retro guys around using techniques yet to be developed to restore old carbon frames in 40 years.


It's already started! viewtopic.php?f=23&t=95451&p=1417770#p1417770

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Re: Carbon bikes - environmental disaster?

Postby silentC » Fri Dec 08, 2017 10:30 am

I knew they'd be around :) Not quite 40 years old but getting there!
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Re: Carbon bikes - environmental disaster?

Postby RonK » Fri Dec 08, 2017 10:55 am

Comedian wrote:They are quite different narratives aren't they? :shock:

Yes, and how very contrived to pitch bike A so romantically.

Hand-built bikes with that sort of provenance will always be of interest to collectors. As will bikes which were raced by accomplished racers, no matter what they are made of - steel, aluminium, carbon fibre.

Mass-produced and mass-marketed bikes will never attract the same level of interest.
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Re: Carbon bikes - environmental disaster?

Postby silentC » Fri Dec 08, 2017 11:00 am

At the risk of sounding like Popular Mechanics circa 1950, I would not be surprised if within the next 40 years most mass-produced bicycle frames will be 3D printed using some polymer or other homogeneous man-made material. When it wears out, you throw it in the vat and print a new one.
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RonK
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Re: Carbon bikes - environmental disaster?

Postby RonK » Fri Dec 08, 2017 11:01 am

silentC wrote:I knew they'd be around :) Not quite 40 years old but getting there!

Alan Bikes have been making carbon fibre bikes since 1976. They are very collectable.
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silentC
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Re: Carbon bikes - environmental disaster?

Postby silentC » Fri Dec 08, 2017 11:13 am

OK, I was referring to the one in the post, I think it is late 90's? But I didn't know CF had been around that long. The first CF I ever saw was a Giant Allegre with a CF top tube in Clarence Street Cyclery around 1993.
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Re: Carbon bikes - environmental disaster?

Postby Duck! » Fri Dec 08, 2017 11:49 am

The earliest CF frames date back to around 1984.
I had a thought, but it got run over as it crossed my mind.

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kb
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Re: Carbon bikes - environmental disaster?

Postby kb » Fri Dec 08, 2017 12:57 pm

P!N20 wrote:
silentC wrote:No reason to think there won't be some mad carbon retro guys around using techniques yet to be developed to restore old carbon frames in 40 years.


It's already started! http://bicycles.net.au/forums/viewtopic ... 0#p1417770

Haha. I was about say QV:-)
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fat and old
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Re: Carbon bikes - environmental disaster?

Postby fat and old » Fri Dec 08, 2017 1:01 pm

Assos C/F track bike. 1976

http://www.velonews.com/2010/09/gallery ... ike_140221

No idea if it's the first C/F as claimed, maybe this?

http://www.classicrendezvous.com/USA/Graftek.htm

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Re: Carbon bikes - environmental disaster?

Postby Calvin27 » Fri Dec 08, 2017 1:37 pm

Comedian wrote:
Calvin27 wrote:I also mentioned a few pages back that it has no theoretical fatigue limit. That is you can keep stressing it over and over and it shouldn't ever develop cracks provided the specimen doesn't have flaws to begin with. Steels do have a fatigue limit and aluminium is even lower than steel (i.e. lss cycles before it develops cracks). For bicycles with high cyclical loading this is a pretty important property.


Sorry. That's incorrect. Steel and titanium do not have fatigue limits, as long as they are bent less than youngs modulus. Good frame builders will ensure that steel and titanium frames do not bend in normal use beyond this point - giving them indefinite life.

https://en.wikipedia.org/wiki/Young's_modulus

Aluminium on the other hand doesn't have this property. Each time it bends is one less time it can bend before it breaks. Good frame designers ensure that high stress aluminium parts don't bend so as to get around this.


Endurance limits are usually half of the tensile strength. No idea why you referenced young's modulus. Young's is stress/strain relationship, not fatigue.

This is what you should have referred to.

https://en.wikipedia.org/wiki/Fatigue_limit

Technically steel does have an endurance limit (i.e. a theoretical threshold where at a given stress, the material will not fatigue). However this does not really happen in practice, due to one of two things usually:
1. The material will usually exceed the endurance limit at high stress regions.
2. The specimen is always imperfect -especially around welds (notice how lots of failures happen around welds?)

Carbon on the other hand has a much generally has a endurance limit much closer to the tensile strength as opposed to steels which are about half and alus which don't have one at all (or very low stress endurance limit).
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