Helmet vs. Bar
Helmet Mount – The advantage of a helmet
mount is the light is higher off the ground and has a better angle
of attack to the ground. This better angle of attack puts more viewable
light on the ground. None of the light’s output is wasted
by shooting it into space. You can aim the light by just moving
your head up and down or looking around. This allows you to inspect
technical descents more closely or look down the line through quick
“S” turns. For fast turning single track helmet lights
are a must. The downside of helmet lights are they don’t work
very well in dusty conditions. Some people feel they lack contrast.
That the light washes out on smaller obstacles. This is caused by
the lights angle of attack. It illuminates both sides of the obstacle.
They also don’t work well in drizzly rain or fog. The light
will reflect back into your eyes off of the water droplets.
Handle Bar Mount – The main advantage of
this type of system is the light cast shadows on the ground. It
is these shadows that many people feel give them the contrast that
allows them to ride at full speed. Bar lights work better than helmet
lights in dusty, drizzly rain, and foggy conditions because the
light does not reflect back into your eyes. But the reality is,
in these conditions your really just measuring degrees of better
in crummy conditions.
The downside of bars lights are they don’t work well in twisting
turning single track because the light quite often is aimed the
wrong way. Since the light is relatively parallel to the ground
you waste a fair amount of your light output by shooting it into
space.
6v vs. 13v
Both the 6v and 13v system use the same internal battery cells.
The 6v system is comprised of 5 cells and the 13v system contains
11 cells. The key advantage of the extra voltage is run time. By
doubling the voltage and maintaining the same relative wattage of
output you can more than double your run time. The 13v lamps run
hotter. This makes them more efficient, increasing run time, and
the higher temperature is produces more light output. The 13v 12w
lamp shoots further down range and has a slightly wider beam than
the 6v 15w lamp. The downside to the 13v system is the battery is
twice as heavy because it has twice and many cells.
A general rule of thumb to go by when trying to decide between
a 6v and 13v systems is:
- Buy a 6v when size and weight is your main buying motivation.
- Buy 13v systems when run time and brightness is your main buying
motivation.
Smart switching
Smart switching is a great add on to any lighting system. These microprocessor
driven switches allow us to effectively double battery run times.
Technically we can go much further than doubling run times but there
are trade offs in light output/performance. Once we break through the
50% duty cycle window the light becomes so yellow in color that
it is no longer an effective tool.
Lamps running at reduced duty cycles are not burning as hot as
those running at 100% duty cycles. So their light output is not
as good. For example: a 20W lamp running at a 10w or a 50% duty
cycle is not anywhere near as bright as a 12w lamp running at 100% duty cycle.
Basically you should view smart switching as a tool to increase your
battery pack’s run time by 20% - 30%. A good way to figure
out how smart switching will help you is to consider how much climbing
you have in your rides. While climbing you can run the lamp at a
50% duty cycle. This means for every minute you go up hill you will
only be using 30 seconds of battery time. So if you have 1 hour
of climbing in your ride you can add 1/2 an hour of run time to your
battery pack's maximum full power run time.
Battery Useful Life
A batteries life cycle is governed by 3 conditions. Time, use,
and overcharging, or any combination of these events. Generally
a battery is good for 400 charge and discharge cycles or 3 –
5 years. Which ever occurs first. Typically commuters wear out a
battery before the time has a chance to damage it. Casual users
typically are affected by time. Since all of JET Lite’s batteries
are shipped with a smart charger over charging is not a condition
that will damage our batteries.
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