max load questions

[born rider]

A while ago an aluminum case designed for hanging. behind the spyder
when I look at the original trailer hitch instruction is spoken of max 40lbs tongue weight / nose weight for a trailer
ok .... I keep the max load, but I feel that one can carry more cargo
I saw on the forum that there are several drivers that are a platform on the trailer hitch had placed a bag.
.
I've been trying the case with 66lbs loading .. including box / mounting bracket etc.
and so I have several 100-mile ride with passenger duo ..
and the driving behavior is quite normal, I even think that it is better if the petrol tank is full and anterior trunk is also loaded
I wonder what the practical experiences .....?
What is the max load experience of spyder rider who have made ​​....? something similar
please info / experience ..... the people who carried away a luggage bag?

 

[Bob Denman]

BRP is showing a maximum tongue weight for trailering of 40 pounds.
I would think, that your setup is most similar to that... and I'd probably want to stay close to that limit... :shocked:

 

[born rider]

if you think about it for a moment ....
tongue weight for trailering or 40 pounds and a maximum weight of the trailer is 400 pounds ....
the pressure on the tow ball in snapshot ..... fast braking / cornering speed etc.
Is not the pressure on the ball variable?
Now I think the box preparing me so fierce on these variables.
the box is still a dead weight without additional forces or lateral loads that may occur when towing a trailer.

 

[cuznjohn]

40 pounds that is my lunch

 

[Frank G]

Center of Gravity

Loading a vehicle is like loading an airplane... you need to keep the center of gravity within the design specifications to preform satisfactorily. In the case of the airplane the results are not normally good!:yikes:

To help you out, the box on the back is acting as a cantilever, taking weight off the front wheels. The heaver the load the lighter the front gets. An empty fuel tank and Frunk combined with a 95 lb. rider may result in a unacceptable light front end.:dontknow: The BRP engineers has to publish specifications that cover all riders and conditions, so if you decide to venture outside there recommendations, do it wisely. Remember the loading for an RT is about 460 lbs and the maximum trailer weight is about 400 lbs. so this tells me that the RT has enough pulling and stopping capacity to handle an additional 860 lbs., but not all loaded on the RT.

Hope this helps you out, use prudent judgement if loading beyond the BRP recommendations.

 

[Bob Denman]

if you think about it for a moment ....
tongue weight for trailering or 40 pounds and a maximum weight of the trailer is 400 pounds ....
the pressure on the tow ball in snapshot ..... fast braking / cornering speed etc.

The weight hanging off the back of your bike; be it tongue weight, or your box...will always react in a similar manner.
Weight; is weight.

Frank's right; BRP came out with that 40 lb limit for areason; we don't know how, but we should trust their judgement in these things...
(They built the bike!)
That's my penny's worth! it ain't worth two-cents!

 

[NancysToy]

if you think about it for a moment ....
tongue weight for trailering or 40 pounds and a maximum weight of the trailer is 400 pounds ....
the pressure on the tow ball in snapshot ..... fast braking / cornering speed etc.
Is not the pressure on the ball variable?
Now I think the box preparing me so fierce on these variables.
the box is still a dead weight without additional forces or lateral loads that may occur when towing a trailer.

The trailer weight is borne by the trailer suspension and wheels. It is separate. The tongue weight is morn by the hitch and swigarm, as well as the rear tire. BRP had a reason for limiting it.

The weight hanging off the back of your bike; be it tongue weight, or your box...will always react in a similar manner.
Weight; is weight.

Frank's right; BRP came out with that 40 lb limit for areason; we don't know how, but we should trust their judgement in these things...
(They built the bike!)
That's my penny's worth! it ain't worth two-cents!

I don't know the reason either. It could be the hitch's structural capacity, the added load on the rear tire, the swingarm capacity, the swingarm bushing capacity/design...or a combination. I would not exceed 40# at the ball. Remember that if the rack hangs out twice as far as the ball is from the fulcrum formed by the Spyder's rear axle, the force at the ball will be twice what the rack and cargo actually weigh. As a result that leveraged weight must be reduced even further to stay within the 40 pound limit at the ball.

 

[spacetiger]

Yes, 40 lbs is the spec tongue weight.

But, I suspect like all spec weights, there is a built in safety margin. That means you don't fall off a cliff if you exceed that number. After all, there are several riders out there that exceed the allowable limits for the their bike.

The bike has a front end weight bias and you are not likely to add enough weight to the back to change that bias. That said, you need to be careful when you exceed a specified limit.

Jerry

 

[Dan_Ashley]

Yes, 40 lbs is the spec tongue weight.

But, I suspect like all spec weights, there is a built in safety margin. That means you don't fall off a cliff if you exceed that number. After all, there are several riders out there that exceed the allowable limits for the their bike.

The bike has a front end weight bias and you are not likely to add enough weight to the back to change that bias. That said, you need to be careful when you exceed a specified limit.

Jerry

If you bet your life on the belief that there is an adequate safety margin without solid knowledge, your bet could cost you dearly. There are a few things in this world that are just asking for trouble with no payoff in the long run: 1) Stuffing an oversized cartridge into your firearm, even if you can get it to fit. 2) Mixing ammonia and bleach, 3) Performing surgery on yourself. 3) overloading a vehicle.

Don't do it. You endanger yourself, your passenger and those who share the road with you, AND you will wear out your vehicle prematurely. All truck drivers know that the fines for being overloaded are extreme. They are this way for a reason: overloads are dangerous. It doesn't matter if you are driving a car, a truck, an eighteen wheeler, an airplane, or a motorcycle. Don't do it.

"Pulling power" mentioned above is just part of the issue, as is handling, and vehicle wear. (Remember handling in emergency situations which require quick thinking and action on the driver's part is what is important...not cornering in the twisties, or smoothness of acceleration, or having power to pass a slower vehicle on the super slab.)

Don't overload expecting that some unknown-to-you design safety margin is going to save your life. Your proposal to overload the hitch by 55% is a very bad idea.

 

[spacetiger]

Where did you get the 55% value? I didn't propose to overload the hitch to any value. The original poster indicated he has run total weights up to 66lbs but that included the weight of the hitch, case, and contents. When the factory specified the tongue load to be 40 lbs it did not include the weight of the hitch, so I suspect the 66 lbs the original poster was carrying minus the hitch would be closer to ~50-55 lbs. But I digress.

I stand by my original post that there are margins in all calculations. You cite a figure of 55%; I think the safety margin is way past that percentage amount. Structural design safety margins are just not that low. Two examples:
- The max payload amount for the RT-S is 525 lbs. I know there are riders that exceed that amount
- The max payload for the 20012 GL1800 is 418 lbs... almost NOONE stays under this amount when riding 2 up
If structural margins were [that] low, we would have numerous examples of spectacular failures.

I would be more worried about the fabricated hitch (it doesn't look like a factory offering) that is being used than the affect of the weight will have on the bike. The weight is slightly above the rear axle and looks to be less than half the distance from rear axle as the distance from the rear axle to to pivot point for the swing arm. What this means is that a 66 lb load at the end of the hitch would impart about half that amount (an extra 33 lb) upward force through the swing arm piviot point. That isn't enough to cause fatigue failure in the bike's mechanical structure. If anything, the extra weight in the rear will help balance out the polar moment of inertia so the bike will feel more neutral. As to the hitch fabrication, it has to be stout enough to carry the weight that looks to have about a 12" leverage arm. This hitch is mounted to the unsprung portion of the rear of the bike (swing arm/wheel), so there is no suspension help to ease all of the jolts coming from the rear wheel as it goes over the road. The smoother the road the easier it will be on the hitch. That said, the original poster has already indicated he has carried a total of 66 lbs with no noted ill effects so it is possible his hitch is stout enough. I noted he is a European rider so I have to believe their roads over there are not as smooth as our, so if his hitch isn't showing signs of fatigue I would be willing he is safe enough.

If it wasn't safe, John wouldn't be offering similar concept through his company.

Jerry

 

[Dan_Ashley]

(66 minus 40) divided by 40 = 55%

correction. My arithmetic was wrong. It is 65% overloaded AT THE HITCH. AT THE HITCH is what matters. Not at the hitch minus something.

 

[spacetiger]

Dan,

I see you are concerned about the loading so I will not try to dissuade you of that concern. I will only clarify my weight point I was trying to make.

The factory set up is the hitch weight + ball coupling weight + 40 lbs tongue weight. The original poster indicated the entire weight used in his setup was 66 lbs; that included everything, "including box / mounting bracket etc.".

So, I don't think it is right to use the 66 lbs subtracting 40 lbs and saying it is 26/40 or 65% overloaded. You have to add the weight of the factory hitch and ball coupler to the 40 lbs to get an apples to apples comparison. So, if the factory hitch, mud flap and ball coupler weighted 10 + 0.5 +1 or 11.5 lbs, then the factory set up adds 40 + 11.5 = 51.5 pounds to the swing arm. Then, by the point you are making the original poster would be 14.5 lbs (66-51.5) over a base of 51.5 lbs or 28.2% over the factory setup. If the weight of the factory hitch is 12 (not 10) lbs, the math works out to be 23.4% (12.5/51.5) and so forth.

If someone would post the weight of the factory hitch and ball coupler we could nail down the percent over factory spec with greater accuracy, but I would think 25% is a reasonable ballpark figure to cite. I understand that might not be within the comfort zone for some riders so if they go this route or buy a similar set up that John is offering from Seal Boards, they can weigh everything to make sure they do not exceed the factory specs even if it is probably only in the neighborhood of about 15 lbs.

Jerry

 

[Dan_Ashley]

Dan,

I see you are concerned about the loading so I will not try to dissuade you of that concern. I will only clarify my weight point I was trying to make.

The factory set up is the hitch weight + ball coupling weight + 40 lbs tongue weight. The original poster indicated the entire weight used in his setup was 66 lbs; that included everything, "including box / mounting bracket etc.".

So, I don't think it is right to use the 66 lbs subtracting 40 lbs and saying it is 26/40 or 65% overloaded. You have to add the weight of the factory hitch and ball coupler to the 40 lbs to get an apples to apples comparison. So, if the factory hitch, mud flap and ball coupler weighted 10 + 0.5 +1 or 11.5 lbs, then the factory set up adds 40 + 11.5 = 51.5 pounds to the swing arm. Then, by the point you are making the original poster would be 14.5 lbs (66-51.5) over a base of 51.5 lbs or 28.2% over the factory setup. If the weight of the factory hitch is 12 (not 10) lbs, the math works out to be 23.4% (12.5/51.5) and so forth.

If someone would post the weight of the factory hitch and ball coupler we could nail down the percent over factory spec with greater accuracy, but I would think 25% is a reasonable ballpark figure to cite. I understand that might not be within the comfort zone for some riders so if they go this route or buy a similar set up that John is offering from Seal Boards, they can weigh everything to make sure they do not exceed the factory specs even if it is probably only in the neighborhood of about 15 lbs.

Jerry

BRP specifies that the weight on the hitch should not exceed 40 pounds.

 

[Oldmanzues]

I do not claim to be a expert of any sort in this, but.
It seems to me that if the Spyder hits a pothole (lots of them around) with a trailer attached, some of the impacted will transfer to the trail suspension.
anything hard attached to the hitch will impact the hitch mounting with that impact. 60 lbs load will impact the mounting with a 60 lb impact.

Safety margins are meant to allow for a inperfections in manufacturing process and occasional over loads. Constant over load will weaken the material.
Safety margin in general: there was a airplane driver that decided a safety margin of 10% fuel supply was more then enough. After action reported headwinds of 18% more then planned for. Crew made it out alive.
Just my rambling on the subject
Old,manzues

 

[spacetiger]

IK geef.

Het is mijn hoop dat dit niet doodt creativiteit voor uitbreiding van de mogelijkheden van de Spyder ...

 

[Dan_Ashley]

Het is mijn hoop dat dit niet doodt creativiteit voor uitbreiding van de mogelijkheden van de Spyder ...

Could you translate into English? There are too many words I do not know....

 

[spacetiger]

Dan,

It is nothing evil or bad.

Maar je laatste post was zo op de mark

Jerry

 

[Dan_Ashley]

Dan,

It is nothing evil or bad.

Maar je laatste post was zo op de mark

Jerry

I could use Google translate if I knew what the language is. Otherwise, I must ask what is meant, or I must assume that the message is purposefully concealed.