http://www.webmd.com/alzheimers/news/20120607/coffee-may-help-turn-tide-on-alzheimers-disease
You forgot stroke, breast cancer ...
Quote: Coffee may have other important health benefits as well. Research has shown that it
can reduce the risk of
Parkinson's disease,
stroke,
type 2 diabetes, and
breast cancer.
... and alzheimer's, a form of dementia (memory loss).
In psychology, memory involves both information storage and retrieval. Caffeine probably aids the storage process by improving attention.
They also pose a biological explanation. Caffeine elevates cyclic AMP levels, and cyclic AMP inhibits the production of beta-amyloid. Perhaps this prevents the accumulation of unused beta-amyloid in the brain.
Originally Posted by
Volnix
I just googled for a "FEM analysis of bicycle fork". It just shows that the most stressed part of the fork is near where the brake block is secured with the bolt.
It's probably better to find a brake block that is fastened using a different bolt that fits your fork, or just use another fork for the brake block you are using or something. Making alterations to the fork might weaken it.
Doesnt really matter how much you weigh as long as you are within the design specifications of the bike manufacturer. Some manufactures just require different brake pads for comforming with the quality standards for heavier loads, but:
Basically what happens is that the quality control for bikes, at least here in the EU just requires a bike to go through 100,000 cycles of loads, less then the plastic deformation loads that are needed to provide a catastrophic failure, in order to get an EN-xxxx comformity mark. This is not realistic as this value is kinda the ammount of 2 days cycling.
So the manufacturers can design bikes pretty much as unsafe as they like and still get an EN-xxxx quality certification.
Racing bicycles - Safety requirements and test methods:
http://rousebicycles.com/pdfs/EN14781.pdf
I suspect that something similar is happening with BS standards and the CPSC standards...
If you drill a component, you might or may not weaken it. In fact some hollow circular hollow sections actually have better bending strength over some solid circular sections. But:
If you used a hand held drill then you might have created some tiny cracks that would be the start of a fatigue related catastrophic failure. Aluminium is especially prone to such failures on it's own allready.
Drills on such stuff is usually made when the components are in clamps and usually not by commercial grade drills - drill bits.
So basically in order to summarize it:
THIS IS WHATS GONNA HAPPEN!!!
Quote: Doesnt really matter how much you weigh as long as you are within the design specifications of the bike manufacturer.
On a thread from another forum, the general consensus was that aluminum parts last as long as any other. The worst horror stories came from somebody whose friend of 250 Ibs (103 kg) repeatedly had aluminum bicycles busting in a matter of months. The guy finally settled on a steel bicycle that lasted him years. It's hearsay, but it makes sense. Each part is designed to handle a certain weight range. If you exceed the limit, the parts will bend or snap.
Quote: Basically what happens is that the quality control for bikes, at least here in the EU just requires a bike to go through 100,000 cycles of loads, less then the plastic deformation loads that are needed to provide a catastrophic failure, in order to get an EN-xxxx comformity mark. This is not realistic as this value is kinda the amWhatmount of 2 days cycling.
So the manufacturers can design bikes pretty much as unsafe as they like and still get an EN-xxxx quality certification.
Racing bicycles - Safety requirements and test methods:
http://rousebicycles.com/pdfs/EN14781.pdf
This is an american based company, so this is probably what our parts undergo for testing.
http://www.astm.org/Standards/F2273.htm
Buy the article??? $50!!!! Go to hell! This should be free content!
What is a "plastic deformation load"?
Quote: I suspect that something similar is happening with BS standards and the CPSC standards...
The CPSC is the US Consumer Product Safety Commission, and it regulates bicycle helmets. What's BS?
Maybe the standards are aimed at kiddy bicycles and kiddy helmets.
I'm reading this to get some understanding of stress analysis of bicycle parts.
http://www.wpi.edu/Pubs/E-project/Available/E-project-042910-084057/unrestricted/Fatigue_Analysis_of_a_Bicycle_Fork.pdf
I'm just expanding a hole in the back of the steerer from ~7mm to 7.94mm. The steerer is about 6mm thick.
