Not on the Cobra trailer, which has "proportional" brakes - the harder
you brake, the more the force is applied to the trailer tongue, which
applies more force to the brake shoes, which adds more retarding force
to the trailer. It is definitely not an ON/OFF system.

OK, so they're proportional. But besides jamming your brakes at all
kinds of speeds, how can you test them for function through the entire
range, or do you just have to assume they will work throughout their
entire range based on their lower level performances (lower level
being easily verified without risking damage to trailer's contents by
simply braking)


Why would I want to adjust the brakes? Why aren't they set correctly
from the start? I've never felt the need to adjust the brakes on my Cobra.

Because much like the air, conditions can change very rapidly on the
road. When I have the road to myself, and it is relatively flat I set
the auto engaging mechanism rather low. I prefer the lowest setting I
feel good about at any given time, as I like to drive efficiently, and
do not normally want the trailer's brakes 'leading' the car, thus
keeping the feel of the combo very natural. But when the road gets a
little more crowded, or I see people are starting to drive more
chaotically, I prefer to increase my stopping capacity, sometimes
significantly, to the point where the trailer is most certainly
pulling on the hitch (but it does not jerk it since the ramp up is
electronically regulated), and I can stop the combo in a shorter
distance than I can the van alone when set aggressively. Of course
they have a progression too (gyroscopically augmented pendulum
regulated), and the elec brake's adjustment range is actually just
setting the initial engaging voltage, thus flattening or steepening
the progression to the full 12v. I also like the brakes to be much
more reactive when driving mountainous/curvy areas. No matter what
setting the automatic engaging mechanism is set to, I of course still
have the manual override and again the whole jobbie has a digital
voltage readout that makes for a very user friendly interface, but can
be set and ignored too if you want.

I fail to see how a
thermal will affect me while driving,

A strong thermal can be very upsetting, because the winds are going in a
small circle that don't affect the tow vehicle and the trailer in the
same direction at the same time. Strong thermals can make my 11,000
pound motorhome towing my 2400 pound trailer deviate as much as a 20+
knot cross wind when coming out from behind a "cut" in a hill, and they
aren't as predictable. I don't drive over 60 mph except for passing, and
I can assure you the combination is dead stable at 90 mph, so it's not
like I'm close to the safe limit.

The real question is, how did you resist pulling over, assembling and
launching?

About driving 60: Although it may leave you with less energy in the
equation to manage, I feel like driving much below the speed limit
(like doing 60 in an 80 for instance) is far more dangerous to
yourself and the other drivers on the road, since you then make
yourself an obstacle that needs deviated around. With every car that
passes you, your odds of being hit by one of them increases. By
driving the same speed as the cars around you, you are much less
likely to be hit by one of them. Sometimes I slow down a bit too, but
usually only to get a different set of drivers around me because I've
had it with the knuckelheads around me. I am not worried about ME
crashing, I am indeed worried about one of 'them' hitting me though.
Most folks do not put much thought into driving, and it is usually
demonstrated for me every time I drive.

Perhaps the effect is very vehicle dependent.

Aerodynamics are indeed fickle.

Why do you think engine braking is hard on the engine and transmission?

Because you are putting load on it, load that is frankly quite
avoidable. Load = wear, period.

Well, yes, but it's a pretty light load, I think. It's just the pistons
sucking against a closed throttle during the intake stroke, and only the
tiniest power pulse (if any) on the power stroke, so the load is far,
far less than when the rig went up the hill with a lot of throttle, just
minutes before. If you want to reduce wear, slowing down slightly on the
upside is going to make a much bigger difference than using engine
braking on the down side.

Wear is wear, and it is cumulative. If even light wear (which I don't
believe this actually is) can be avoided, it should be avoided, but I
buy your wear theory about slowing for hills though. I used to use
cruise control (constant speed), but I have dramatically increased
fuel economy (which indicates less wear of course) by manually driving
constant RPM (which made me slow for climbs, but speed up for
descents) instead. I wish my vehicle had an option to use either
method.

I choose to put the load/wear my
brakes as opposed to major drive train components. The loading of most
braking is WELL within the safe tolerances of these systems.

I don't think it's a bad plan, and if your brakes can handle it, it's a
reasonable choice. What can happen is the brakes overheat before the
driver has enough warning to do something about it. I prefer to risk the
extra net wear on the vehicle than to experiment with the limits of
the braking system.


I've already experimented with several brake systems, and can't afford
new cars. I have experienced brake fade while driving a large buses
that had an automatic with no engine brake. It is not a sudden
situation with little warning, you can feel effectiveness diminishing
slowly and can take steps (assuming you haven't run yourself out of
options). It really made me appreciate hydraulic brake systems since
the stopping capacity is several magnitudes higher as a percentage
ratio. I have faith in my cars/van's brakes. Of course I don't ride
the brakes either, and if shaving the speed off in smooth but
strategic bites is becoming ineffective, I do indeed use the lower
gear. It's just that I have driven with lots of goofy drivers (some of
them pilots even) and have seen a lot of bad habits people use that
most of the time do not increase safety but usually greatly increase
wear. I even try to park vehicles so that I will not need to use
reverse to get out (towing or not), as the car will simply only go
into reverse x amount of times, so I try not to waste them. I do not
go very far out of my way to do this, but this mentality when added up
does extend the life of vehicles etc.


Naturally the car manufacture is NOT going to caution you against ruining expensive parts they are more
than happy to sell you.

Except for that pesky warranty... Basically, I agree with you: short
hills, brakes are fine; long hills, down shift and use the brakes
sparingly. Don't "ride" the brakes, is what I was taught, and I think
it's still good advice.

Warranties don't last forever, and quite often vehicles suffer
catastrophic failures of major components shortly after coming out of
warranty. I have seen very little from car manufacturers do dispel my
belief in the science of planned obsolescence.
http://en.wikipedia.org/wiki/Planned_obsolescence . I choose to use
the brakes generously and use the engine/transmission sparingly, and
again of course don't 'ride my brakes'.


No, I do not mean while backing down a hill. I mean when your trailer
is trying to overrun the tow vehicle while you are driving down a
steep enough hill and you had no idea your brakes were engaged for an
entire down grade-until you got to the bottom and smelled it-or a
wheel fell off etc. It was this very phenomenon that initiated my
original post on the subject some time back.

I've never noticed that. It might be because the Cobra trailer has a
pressurized shock absorber in the surge mechanism that prevents the
brake from applying unless there is significant force on the tongue.
This means it takes more than a gentle stop to overcome the pressure in
the shock absorber before the brakes will apply, and likely prevents the
brakes from applying when going downhill, unless it's quite steep.

You mean you've never noticed it with YOUR Cobra. Others have already
posted about this problem here, as well as a host of other surge/
tongue related issues that you would NEVER have with electrics. I have
never heard of anyone with electric brakes on their trailer having the
wheels fall off due to a brake related mishap either for that matter.

Tell me again why it's an advantage to keep a battery and charger in the
trailer, instead of none at all, like my surge brake system.

Because then you have a battery/charger in your vehicle. It is nice to
have emergency 12v power when and if it were needed. A lot of things
could be powered off that battery in a pinch.

How big is this battery? Can't the tow vehicles battery be used to power
stuff in a pinch?

I think 7ah, but I'm not sure. Sure you can use the tow vehicles
battery, assuming it is not dead or that the tow vehicle is even
anywhere nearby. How about for running lights in/on your trailer for
another example of the usefulness of a battery/charger in the trailer,
regardless of what brakes you have!

Best of all, you can
splice into the charging circuit and use it to keep your plane's
batteries topped off if you hook solar panels up to it.

You don't need a battery in the trailer to do that - just hook up a
solar panel and regulator that connects to the glider battery. To
reliably charge the glider in time for the next day will take a much
larger panel than one suitable for keeping a breakaway battery charged
up, so I don't see a savings there.

I don't propose this as a substitute for a real charger, so I don't
see how it would save money either (except indirectly perhaps if you
did happen to switch to electric brakes rather than fixing expensive
surges). If I fitted a panel to the trailer for it's brakes though, of
course it would be hearty enough to handle the glider's battery as
well.

Hmmm, now that
I think back, weren't YOU looking for a solution to keep your solar
panels from frying batteries a little while back?

Yes, and the problem I had (improper regulator) would have fried the
battery the trailer depends on for it's breakaway duties.

OK

that does not circumvent the fact that electric
brakes can outperform surges-as far as the action of braking is
concerned- in both stopping power and most certainly in finesse. There
is a reason electrics are the most common type of brakes in horse
trailers; they can be used smoothly but firmly if needed, but with an
amazing degree of control and usable adjustment range.

Is the reason the electric brakes need all this adjustment (in horse
trailers, for example) is to compensate for the large differences in
braking action required between a loaded and unloaded trailer? A surge
brake system automatically compensates for load variations, an ideal
situation in a trailer that might be 1700 pounds loaded and 1000 pounds
when the glider is out of it.

Electric brakes don't "need all this adjustment" as you put it (of
course they need the occasional pad adjustment, like any drum brake),
it is just that you have the OPTION to do so should you choose, and I
am a big fan of choices. The calibration range is simply a matter of
built in flexibility, to make the trailer adjustable to your taste
(which of course can continually change and still be accommodated for)
rather than the other way around. Electric brakes would be on lots
more vehicles were it not for the fact the boat industry adopted them
before there were good solutions for making the crucial electrical
components resilient to water, and boat brakes get dunked. This caused
a premature public opinion to form, which the surge brake moguls have
been more than happy to exploit. Another black eye for electrics has
been a lack of good controllers, none of which are a problem anymore.
These things are excellent, and I recommend putting some miles on a
good setup with them before you make your final judgement on them. For
me it is difficult to find the redeeming qualities of surges (and I am
trying), while the benefits of electrics are quite abundant.

Is there even one thing that surges can do that electrics can't do
better? (besides putting your wallet on a diet)

Sir Paul of Oakland,
Defender of Electric Brakes,
Flyer of Sailplanes,
Eater of Tacos