Brakes loads

[Guest]

Hi Guys
I know, its me again. I was thinking about things in general inregards to
the brakes and weights in relation to the cruiser.
Correct me if im wrong or just insane but it has been said that you can pull
a 3 ton trailer with the cruiser, is that if the trailer has its own brakes
or will the cruisers surfice to stop the whole thing. If this is the case
why do we talk about stopping the cruiser with better braking power if it
can stop a trailer and itself. I read somewhere that the max load that can
be put on the roof is 200 kg after that you may be left holding the load on
your lap. If that is the case and you can load the boot with stuff, I dont
know what weight you can carry in the boot so if any one knows please tell
me, what is the max loading , boot/trailer/roof and people that the cruiser
can stop with using the standard brake system. I think if it can do all this
why o why upgrade the brakes at all.
If there is a weight limit for the boot is this because of the suspension
and nothing else or are there other thinks involved. Because if this is the
case then all one has to do is upgrade the suspension and viola you can
carry more, I have to be wrong dont I, come on tell me I have had my med so
ill be Ok. The point im trying to find out is if the weight in the boot
drags the back down and the brake adjuster on the rear axle adjusts to
compensate then if the suspension didn't allow the back to drag or drop
sorry guys, them this would be good YES.
Does the load on/in the cruiser have more of an effect on the brakes because
of the imbalance in the level of the cruiser or does it not make a
difference at all, maybe it all comes down to the weight and thats that.
Hope this makes sense its just me head is filling up again with questions,
makes a change fromit being up there dah.
John C
92HDJ 80 1HDT Ireland

 

[Guest]

John
| I know, its me again. I was thinking about things in general inregards to
| the brakes and weights in relation to the cruiser.
| Correct me if im wrong or just insane but it has been said that you can pull
| a 3 ton trailer with the cruiser, is that if the trailer has its own brakes
| or will the cruisers surfice to stop the whole thing. If this is the case
| why do we talk about stopping the cruiser with better braking power if it
| can stop a trailer and itself.
You are allowed roughly 0.75 tons payload in the vehicle itself, and to tow a braked trailer of up to 3.5 tons (or an unbraked one of up to 0.75 tons). So the maximum all-up weight you can have is 3 tons car (2.25 empty + 0.75 payload) + 3.5 tons trailed =3D 6.5 tons.
The vehicle brakes would bring an UNbraked 3 ton trailer to a halt ... eventually. But your stopping distance would be horrendous and the whole thing totally unsafe in anything other than a (long) straight line. The legal limit of 0.75 tons for an unbraked trailer is a very sensible one, and even that - see below - makes a noticeable difference to the handling.
Beefing up the suspension will improve the vehicle's ability to carry heavier loads safely, and make it more comfortable when laden, but it won't raise that legal limit which is set by the "type approval" testing.
| I read somewhere that the max load that can be put on the roof is 200 kg after
| that you may be left holding the load on your lap.
You are right that 200kg is the max (distributed) roof load. But from a thread discussing this a few months ago it became clear that using this sort of roof load in very bumpy African conditions will cause the "A" posts (front windscreen pillars) to fail due to fatigue. Bear in mind also that adding that sort of weight at roof level will make it a lot more wallowy and unstable when cornering.
| Does the load on/in the cruiser have more of an effect on the brakes because
| of the imbalance in the level of the cruiser or does it not make a
| difference at all, maybe it all comes down to the weight and thats that.
If your rear brake proportioning valve is working correctly then weighing down the back axle will cause the rear brakes to do more work. However this won't compensate fully for the extra weight: the more you are carrying the longer it will take you to stop.
In my experience of towing trailers with the overrun brakes we get here, so long as the trailer brakes are properly adjusted the extra load on the towing vehicle is not that great. In fact I'd say my unbraked baby trailer laden at 0.75 tons requires more brake pedal effort to stop than the 3 horse (braked) trailer at 2.5 tons.
I've regularly hauled the horses with a fair old load in the car, giving me between 5 and 5.5 tons combined weight. I have standard brakes and suspension and I have absolutely no trouble stopping it at all - in fact I am regularly astonished at how I can bring that much mass to a halt with so little effort. Yes, the stopping distance with a trailer is greater, perhaps 50% longer, but you just drive more slowly and carefully to compensate.
The one time you might get a bit of trouble with the brakes when towing is descending long, steep hills without using low gear. But if you use engine braking you should be fine.
So in my experience the standard brakes and discs (model year 1996) are fine for towing in normal on-road European driving conditions if you drive in a reasonably sane fashion.
Speed is just as important as mass when considering stopping: the energy to be dissipated (in heat) in the brakes is
0.5 x mass x speed squared.
So stopping 6.5 tons (the max allowed vehicle + trailer weight) from 60 mph (max allowed speed on motorway with a trailer) is actually about the same for the brakes as stopping 2.25 tons (empty vehicle weight) from 100 mph. But in the first case the heat will be dissipated from 8 wheels, not four, so in fact it is actually far easier on the car's brakes.
Personally I think the standard suspension is OK when empty, but a bit like my school reports ("barely adequate") when loaded up. If I have a full load of people I have to go really slowly on twisty roads if I am not to make them car-sick because it wallows so much. Those carrying permanent extra weight have tended to beef up their suspension - but note Julian's comments of earlier today about the unhappy combination of stiff suspension and pregnant wife!
It really depends upon what you want to do with the truck, how much weight you want to carry and whether you want to raise the ground clearance.
Sorry. I've been rambling on ... I'd better get back to doing some work!
Christopher Bell
Devon, UK
1996 1HD-FT

 

[Guest]

Hey Christopher
Thanks a million for all that and in plane english too. I must be having a
good day I seem to be understanding a hell of a lot which makes me wonder am
I ill or or or some thing worse, maybe the info about the cruisers is
sinking in, nah that cant happen could it really. No really thanks for the
time. I hope that every one else that does not know now knows after all it
cant just be me or can it, tune it soon to the next installment of John
ans his ----------- questions coming very very soon.
John C
92HDJ 80 1HDT Ireland
----- Original Message -----
From: "Christopher Bell" <[Email address removed]>
To: <[Email address removed]>
Sent: Wednesday, July 06, 2005 4:37 PM
Subject: RE: [ELCO] Brakes loads
John
| I know, its me again. I was thinking about things in general inregards to
| the brakes and weights in relation to the cruiser.
| Correct me if im wrong or just insane but it has been said that you can
pull
| a 3 ton trailer with the cruiser, is that if the trailer has its own
brakes
| or will the cruisers surfice to stop the whole thing. If this is the case
| why do we talk about stopping the cruiser with better braking power if it
| can stop a trailer and itself.
You are allowed roughly 0.75 tons payload in the vehicle itself, and to tow
a braked trailer of up to 3.5 tons (or an unbraked one of up to 0.75 tons).
So the maximum all-up weight you can have is 3 tons car (2.25 empty + 0.75
payload) + 3.5 tons trailed = 6.5 tons.
The vehicle brakes would bring an UNbraked 3 ton trailer to a halt ...
eventually. But your stopping distance would be horrendous and the whole
thing totally unsafe in anything other than a (long) straight line. The
legal limit of 0.75 tons for an unbraked trailer is a very sensible one, and
even that - see below - makes a noticeable difference to the handling.
Beefing up the suspension will improve the vehicle's ability to carry
heavier loads safely, and make it more comfortable when laden, but it won't
raise that legal limit which is set by the "type approval" testing.
| I read somewhere that the max load that can be put on the roof is 200 kg
after
| that you may be left holding the load on your lap.
You are right that 200kg is the max (distributed) roof load. But from a
thread discussing this a few months ago it became clear that using this sort
of roof load in very bumpy African conditions will cause the "A" posts
(front windscreen pillars) to fail due to fatigue. Bear in mind also that
adding that sort of weight at roof level will make it a lot more wallowy and
unstable when cornering.
| Does the load on/in the cruiser have more of an effect on the brakes
because
| of the imbalance in the level of the cruiser or does it not make a
| difference at all, maybe it all comes down to the weight and thats that.
If your rear brake proportioning valve is working correctly then weighing
down the back axle will cause the rear brakes to do more work. However this
won't compensate fully for the extra weight: the more you are carrying the
longer it will take you to stop.
In my experience of towing trailers with the overrun brakes we get here, so
long as the trailer brakes are properly adjusted the extra load on the
towing vehicle is not that great. In fact I'd say my unbraked baby trailer
laden at 0.75 tons requires more brake pedal effort to stop than the 3 horse
(braked) trailer at 2.5 tons.
I've regularly hauled the horses with a fair old load in the car, giving me
between 5 and 5.5 tons combined weight. I have standard brakes and
suspension and I have absolutely no trouble stopping it at all - in fact I
am regularly astonished at how I can bring that much mass to a halt with so
little effort. Yes, the stopping distance with a trailer is greater,
perhaps 50% longer, but you just drive more slowly and carefully to
compensate.
The one time you might get a bit of trouble with the brakes when towing is
descending long, steep hills without using low gear. But if you use engine
braking you should be fine.
So in my experience the standard brakes and discs (model year 1996) are fine
for towing in normal on-road European driving conditions if you drive in a
reasonably sane fashion.
Speed is just as important as mass when considering stopping: the energy to
be dissipated (in heat) in the brakes is
0.5 x mass x speed squared.
So stopping 6.5 tons (the max allowed vehicle + trailer weight) from 60 mph
(max allowed speed on motorway with a trailer) is actually about the same
for the brakes as stopping 2.25 tons (empty vehicle weight) from 100 mph.
But in the first case the heat will be dissipated from 8 wheels, not four,
so in fact it is actually far easier on the car's brakes.
Personally I think the standard suspension is OK when empty, but a bit like
my school reports ("barely adequate") when loaded up. If I have a full load
of people I have to go really slowly on twisty roads if I am not to make
them car-sick because it wallows so much. Those carrying permanent extra
weight have tended to beef up their suspension - but note Julian's comments
of earlier today about the unhappy combination of stiff suspension and
pregnant wife!
It really depends upon what you want to do with the truck, how much weight
you want to carry and whether you want to raise the ground clearance.
Sorry. I've been rambling on ... I'd better get back to doing some work!
Christopher Bell
Devon, UK
1996 1HD-FT