BMW K bikes (Bricks)


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Ed


Life time member
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as this is more relevant to the technical side of things , thought I would add it here , for easier reference.
Hope Damien has progressed further with his weight balancing.

found this recently, 
if anyone else may be contemplating adding a trailer to their K.


Trailer balancing..  Can i move the weight further to the rear? - Page 2 Pic_0224

the following is worth a read as well, for first timers like myself.

Pulling a trailer with a motorcycle

by sam • July 19, 1993 • 5 Comments

Motorcycles by design are unable to carry copious amounts of luggage or cargo. Sidecars increase loading capacity and distribution of weight, but there is nothing better than a well manufactured trailer to alternatively load a motorcycle. The main problem with loading the back-seat of a motorcycle is improper weight distribution, wear and tear, and handling problems. With proper technique, design, and loading a trailer can be added to most motorcycles.

A quick perusal through most owners manuals will provide the famous words “Vehicle not manufactured for use with a sidecar or trailer” ” use of a sidecar/trailer can/will void warranty”. Obviously the addition of any accessory to a motorcycle must use caution, the manufacturers place these warning for reasons. The selection of a trailer would be an entire article by itself, what we will deal with here is the operation and techniques of trailering.


The hitch on the motorcycle should be sturdy (connected at least to four points on the bike). Hitches should not be connected to moving suspension components, swing-arms, shock-absorbers, or drive shafts for the obvious reasons. There should be no movement in the hitch. Hitch height should be at hub-level of the rear wheel. The distance between the rear wheel and the hitch should allow the rear wheel to move up and down unimpeded, but it should not be an excessive distance from the hub.


The best designs of trailers use the largest tire height possible and high speed bearings in the wheels. Beware the use of cheap lawn and garden tires on trailers. These types of tires are made soft and compliant so as not to damage lawns and are in no way recommended for highway use.


Trailers come in all shapes and sizes. A trailer should contain the following design features. A hitch assembly rated at a significant value higher than the gross vehicle weight of the trailer (total weight of the trailer). The trailer should have an axle width to tongue length of around 1 to 3 approximately. A significantly shorter trailer tongue will not track behind the motorcycle correctly, and a significantly longer trailer tongue will create cornering problems. There should be enough overhang to the rear of the trailer of the cargo area to allow proper loading. However, it should not be so great of overhang as to possibly drag the curb when leaving your favorite gas-stop.


A trailer is an alternative method of loading gear. A motorcycle has particular design characteristics that are being modified to allow the operator to carry more gear. As the operator you will have to decide how much is enough. A trailer is not a “blank check” to bring everything. Some simple rules for loading trailers is to take everything you would put on or in the bike and put it in the trailer instead. This is true alternative loading. Of course if you look down at the wide open maw of the emptiness of the trailer and start filling remember; the trailer total weight should be distributed over the axles so that the tongue weight is about 10 – 20 percent of the total weight of the trailer. Figure the total allowance of weight for the bike by looking in your owners manual. Add all the gear weight on the bike including passengers and riders. Don’t forget to add the tongue weight of the trailer. If you are in the positive and not overweight your doing good. If the amounts are over start shedding gear. Motorcycles are very finicky on how much weight they are moving.


Remember all of the weight (trailer, motorcycle, rider) is still going to be stopped by those same brakes, and accelerated by the same drive train. Depending on the weight of the trailer you choose to tow, all of the components on the motorcycle are going to wear a lot faster. Brakes and tires may be the most effected component on the motorcycle. Proper loading is going be the most important part of trailering because its going to effect every other part of the handling of the motorcycle.


When starting out and stopping a trailer you want to be as straight as possible. The degree of difference at the hitch between the trailer and motorcycle is going to create side forces on the motorcycle as it begins to move. The resistance to moving of the trailer will pull the bike over in the direction the trailer is. For an example if the motorcyclist stops with the trailer “kicked out” to the right the motorcycle will be pulled to the right as it begins to move forward. With the motorcycle and trailer in line the resistance will not effect balance. If the hitch is to high, and is mounted significantly over the level of the hub a lever of force will be created when starting out lightening the front wheel of the motorcycle. The resistance of the trailer creates this effect and steering wobble is usually the result. The effect of the trailer on the bike can be very slight or so severe a hazardous riding condition will result. No matter how well the trailer or bike is setup and designed the trailer will have some of these effects.


When stopping a motorcycle trailer combination allow increased room to stop. Only experience will show how much, but the increased weight being stopped of the bike and trailer will require more brake effort over longer distances. When stopping the bike should be kept as upright and straight as possible. The surge of the trailer forward as the bike stops should be directed as straight as possible through the bike. If the bike is leaned over and turning during braking the surge will have a tendency to push the bike over in the opposite direction, or push the rear wheel to the side. This effect can be minimal or severe depending on the amount of braking and the weight of the trailer.


If the hitch is set up wrong another problem can occur. On hitches that are above the rear hub of the motorcycle when braking the weight shift normal to stopping lightens the rear wheel. This effect will be exaggerated even more by a high hitch. Some trailer manufacturers attempt to engineer methods that lessen or do away with this effect by the way their trailers are made.
Another frightening effect can be the front wheel lightening on braking. Excessively heavy trailers on low slung hitches can lighten the front wheel and create a wobble when slowing. A simplification of the problem would be a five hundred pound trailer with fifty to sixty pounds of tongue weight. Most of the weight of the trailer during braking is being transmitted to the hitch. Depending on the degree of difference between the hitch and hub that weight can transmitted in a downward direction on the hitch increasing tongue weight significantly. The effect would be similar to a five hundred pound giant standing on your hitch while you try to balance and stop.


Depending on the weight and design of a trailer in slow speed turns it will tend to pull the bike aside in the direction of the turn. This effect will be dependent on the weight of the trailer and the resistance to rolling. In high-speed (highway turns) the trailer can track on the outside of the turn pulling the bike up-right. This effect is usually minimal but can drastically effect the operation of the motorcycle if the trailer is overloaded.


Obviously the motorcycle trailer combination is going to operate easier if it is properly maintained. Most trailer manufacturers have excellent suggestions on tire inflation, bearing care, and care of hitches. The problem usually lays in the operator not doing the recommended service. Tires fail and so do bearings. The operator is the final inspector for safety when a trailer goes out on the road. Most manufacturers recommend at least seasonal maintenance on bearings and side-wall pressure ratings of tires for fully loaded trailers. As part of your pre-ride inspection of your bike include the trailer and inspect every item just like you do on your bike. Include the hitch assembly depending on the type of hitch check for obvious problems and wear. On hitches try and insure proper lubrication and fit to the bike.


Safety chains should be included on all trailers. We all have heard the excuses for improper safety chains. Some riders state they would rather have the trailer “break away” in case of accident or massive failure. Some riders think that safety chains are not required on motorcycles. Most states require safety chains or cables. If the trailer “breaks away” where is it going to go and who is it going to hurt. Ultimately the rider is responsible for any damage his vehicle or trailer causes.
Safety chains should come in pairs and be attached to the frame of the trailer and motorcycle. Some states allow appropriate cables to substitute for chains, but check your local police for verification. Chains or cables should not drag the ground and should cradle the tongue if the hitch fails. Insure that the chains or cables are long enough to allow the bike to turn.


Trailers allow a motorcyclist to include the extra gear desired and not pile the bike high with everything. A trailer may be the way to entice the significant other to come along, lured by the charms of an opulent camp sight. The trailer allows a motorcyclist to bring “real” luggage when checking into a hotel. With proper technique and set up a trailer allows more flexibility for touring/grocery getting. The signs of shock from check out staff at the local grocer are excellent.



"Grover" (quote)
finally took the time to empty out the contents of my Kart today,after a trip up to the Karuah rally.
but before doing so , I thought I might grab some stats. So I did a "weigh in" on the tow ball hitch.

these are the results .

Ali lite trailer, with steel chassis, 10" inch high speed boat trailer wheels .
Specs :     Tare - unladen weight  =  55 kg
                GTM - Gross Trailer Mass  ( trailer + load)   =  Max - 200kg
                tyre pressure ( recommended ) = max 28 psi   , currently running on 20psi
               Towball hitch to axle = 1400mm ,  outside wheel width = 1100mm , total height = 750mm, total length = 1800mm


unladen weight ( once empty )   = 7.5kg ( 16lb ) at the ball. remember this is only a 55kg ( 121lb ) alloy trailer.

loaded weight ( moderate camping gear, no gas cylinders ) came in at  18kg ( 33lb) at the ball.


tried out some weights . using 5kg ( 11lb ) concrete pavers.

90KG load spread 2/3 to the rear over the axle. didn't change the ball weight much.    
 ball weight 18kg.
Trailer balancing..  Can i move the weight further to the rear? - Page 2 Kart_010Trailer balancing..  Can i move the weight further to the rear? - Page 2 Kart_011



60kg load ,   50/50  load spread  front and rear.
ball weight 20kg.
 note how much difference it makes removing weight from the trailers rear, without adding extra to the front
Trailer balancing..  Can i move the weight further to the rear? - Page 2 Kart_012Trailer balancing..  Can i move the weight further to the rear? - Page 2 Kart_013

I removed the final balance of weights from the rear , leaving only the 30kg on the front, (no pic ) scales tipped in at 22kg ( 48lb ) at the ball.

next job will be to check some gear and rough weights per item , just as Damo did with his fish scale. I can't imagine I'll come up with as much , but it'll be handy to know.

still need to lengthen the towbar upright stays by about 1.5 - 2 inches, to bring the hitch into a better horizontal plane. 
originally Damo had it mounted to the gearbox /frame bolt, it is currently down below the ABS.
Trailer balancing..  Can i move the weight further to the rear? - Page 2 Kart_015

Trailer balancing..  Can i move the weight further to the rear? - Page 2 Kart_014

At this stage , I would probably feel comfortable with a maximum load of 100kg , as this allows reasonable braking, and moderate speed during touring.


" Alby " (quote)
I will throw in my limited learnings here as well..  Grover has made it easily clear to see how the weight moved can change a lot of things.

The one thing Nicole and I found that made the best improvement to handleing was to have the line of push (as it were) from the tow hitch to tow bar on the same level as the centre of final drive/tow bar . This means when you use the engine or brakes to slow the force is pushing straight foward with the bike. not foward and up. Just as the extra 1.5 - 2 inches will do.

The small amount of height at the front of the trailer at rest is levelled out when the bike is loaded with our weight  (Goondiwindy on the way home after Narrrendarra/Dubbo)

Trailer balancing..  Can i move the weight further to the rear? - Page 2 Tow_li10

"Rick G" (quote)
Exactly right especially when braking so as not to lift weight from the rear wheel.

    

Johnser

Johnser
Silver member
Silver member
I am astounded at the amount of carrying capacity some of you guys require!! I have always felt pretty extravagant with the K's massive panniers and a sleeping bag strapped to the back.

Not supposed to be a dig, I'm genuinely impressed at the commitment to riding you must have. I'm afraid I'd have caved in and taken something with 4 wheels if I needed half of that list.

My only helpful comment might be to hunt out some outdoorsie shops and see what you can find that's lighter. Or maybe do some research on a hiking or bicycle touring forum, some of those guys get really intense about weight saving - I met one guy that weighed everything he carried and even cut the handle off his toothbrush to save a few grams. It all adds up.

Edit:
how about a super quiet generator? ~1kw for under 10kg
http://www.aussiegenpower.com.au/index.php?route=product/product&product_id=50

With something like that you could loose the lanterns for lighter and smaller electric lights as well

    

Rick G

Rick G
admin
admin
Can I use to run the 42" LCD tele and 2 kilo food processor.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

Albyalbatross1

Albyalbatross1
Life time member
Life time member
Johnser wrote:I am astounded at the amount of carrying capacity some of you guys require!! I have always felt pretty extravagant with the K's massive panniers and a sleeping bag strapped to the back.

Not supposed to be a dig, I'm genuinely impressed at the commitment to riding you must have. I'm afraid I'd have caved in and taken something with 4 wheels if I needed half of that list.

My only helpful comment might be to hunt out some outdoorsie shops and see what you can find that's lighter. Or maybe do some research on a hiking or bicycle touring forum, some of those guys get really intense about weight saving - I met one guy that weighed everything he carried and even cut the handle off his toothbrush to save a few grams. It all adds up.

Edit:
how about a super quiet generator? ~1kw for under 10kg
http://www.aussiegenpower.com.au/index.php?route=product/product&product_id=50

With something like that you could loose the lanterns for lighter and smaller electric lights as well
We carry everything we  need to be comfy for 5-10 days.  All of our gear is what we used for backpacking, climbing, caving ect in New Zealand and Auzzie. Its just not packed down to its optimum size. it would all fit into two backpacks.  Also some comforts ensure my partner continues to come along. i am happy with sleeping bag and fly sheet!!!

    

Ed

Ed
Life time member
Life time member
maybe get me a sandwich press for those lovely cheesy melts, sitting by the electric flame heater, sipping on a frothy latte  , on those cold freezing sleepouts.
then again maybe not. but I will try a few campouts with the Kart at least. be good to share the experience , if anything , to at least offer the services of baggage boy at the bottl"o for the Krew.



Last edited by groverK on Sun Apr 12, 2015 6:48 am; edited 1 time in total


__________________________________________________
1993 K1100RS  0194321         Colour #690 Silk Blue  aka " Smurfette"
2018 Kart upgrade.
Trailer balancing..  Can i move the weight further to the rear? - Page 2 10_x_110
    

Johnser

Johnser
Silver member
Silver member
You may take the piss, and a genny is not something I would consider, but it could potentially save 10 or more kilos if the OP swapped it for the mega battery. 10 kg is a LOT.

    

Ed

Ed
Life time member
Life time member
Johnser, your comments are well appreciated , it helps to listen to alternate views, if not for my benefit , but for others contemplating trailer use.

Our family camping trips consist of just the basic supplies , and the kids love it.
we always try and steer clear of those with gennies , even the quietest dB gens these days , you can hear them above the natural habitat.
with my wife and I getting to a stage of being able to occasionally disappear for a weekend sortie , the trailer will give us the opportunity to travel in comfort.
I can leave her to ride unobstructed on her boulie cruiser, and I can plow along on my K. 

we like the option of the following. this is the bulky stuff.
 elevated sleeping - either flip over tent top or folding double camp stretcher. 
until I find a suitable tent top, a seperate tent will suffice.
 taking a table and a couple of chairs  , tarp ( 3m x 4.5m) and tent
gas items including a  1.5 -3kg bottle with single burner attachment and lantern, 
 40L esky , with ice bricks , 5-10L drinking water, 
because we have the trailer , there is nothing like taking your favourite pillow.
I'll add some pics and load ratings later when loaded, just to compare. be good to see how we differ Damo.
Not sure what others carry on board?

I was reading elsewhere that here in Oz , vehicle speed limits apply also to M/cycles with trailers, can anyone concur this?



Last edited by groverK on Fri Mar 28, 2014 5:17 am; edited 1 time in total


__________________________________________________
1993 K1100RS  0194321         Colour #690 Silk Blue  aka " Smurfette"
2018 Kart upgrade.
Trailer balancing..  Can i move the weight further to the rear? - Page 2 10_x_110
    

Rick G

Rick G
admin
admin
Speed limits apply to trailers only in Western Australia and only in 110kph areas where they are restricted to 100kph.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

Ed

Ed
Life time member
Life time member
given the speeds suggested here , I didn't think it true. I knew you guys wouldn't lead anyone astray.


__________________________________________________
1993 K1100RS  0194321         Colour #690 Silk Blue  aka " Smurfette"
2018 Kart upgrade.
Trailer balancing..  Can i move the weight further to the rear? - Page 2 10_x_110
    

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