ZaMis
Not only is my freakish melon wide it is tall. So when I try on even the largest helmet it rides up so high on my head that it doesn't provide much protection and looks ridiculous. Is there a manufacturer that specializes i hard to fit heads? How about a shop in the Twin Cities?
Answer
Try a skateboard or BMX helmet. Just Google skateboard and your zip code.
Try a skateboard or BMX helmet. Just Google skateboard and your zip code.
How does a bike helmet help reduce the impact of a crash?
Grant
Using equations if possible, thanks. I know that it spreads the force across a larger area of your head, but what about absorbing?
Answer
A helmet reduces the impact of a crash using two methods: distributing the force over a large area and slowing down the impact.
Using the basic equation of force, Force = mass * acceleration, we can look at how these two methods reduce impact.
Force can be measured simply as total force (e.g. 100 Newtons) or quantified by force over area (e.g. Newtons per square centimeter). As a bicycle helmet spreads the force for one point to a larger area, the force/area measure is decreased. This reduces the force applied to a single area, however, the overall force applied is still the same.
Acceleration is the other part of the equation that a helmet works to minimize. Acceleration is often measured as length over time-squared (e.g. meters/second-squared). Upon impact, the helmet is designed to crush, and this process of crushing extends the amount of time involved for the head to come to a stop (or before it bounces). This increases the time value in the measure, and since the time measure is a squared value, the effects of increasing the time involved has a big impact on reducing the overall acceleration and subsequent force.
To represent the two methods used by bicycle helmets to reduce impact, it is better to rewrite the original equation of Force = mass * acceleration as force/area = mass * (distance/time^2). Now you easily see where the added area for absorbing impact, and the increased time for the impact have big impacts on the trauma experienced by the head. The mass is slightly increased by the helmet, but nowhere near makes up for the distribution of force and slower acceleration (deceleration).
A helmet reduces the impact of a crash using two methods: distributing the force over a large area and slowing down the impact.
Using the basic equation of force, Force = mass * acceleration, we can look at how these two methods reduce impact.
Force can be measured simply as total force (e.g. 100 Newtons) or quantified by force over area (e.g. Newtons per square centimeter). As a bicycle helmet spreads the force for one point to a larger area, the force/area measure is decreased. This reduces the force applied to a single area, however, the overall force applied is still the same.
Acceleration is the other part of the equation that a helmet works to minimize. Acceleration is often measured as length over time-squared (e.g. meters/second-squared). Upon impact, the helmet is designed to crush, and this process of crushing extends the amount of time involved for the head to come to a stop (or before it bounces). This increases the time value in the measure, and since the time measure is a squared value, the effects of increasing the time involved has a big impact on reducing the overall acceleration and subsequent force.
To represent the two methods used by bicycle helmets to reduce impact, it is better to rewrite the original equation of Force = mass * acceleration as force/area = mass * (distance/time^2). Now you easily see where the added area for absorbing impact, and the increased time for the impact have big impacts on the trauma experienced by the head. The mass is slightly increased by the helmet, but nowhere near makes up for the distribution of force and slower acceleration (deceleration).
Powered by Yahoo! Answers
Title Post: Where can I get a bike helmet to fit my large head?
Rating: 100% based on 9998 ratings. 5 user reviews.
Author: Unknown
Thanks For Coming To My Blog
Rating: 100% based on 9998 ratings. 5 user reviews.
Author: Unknown
Thanks For Coming To My Blog
Tidak ada komentar:
Posting Komentar