Saw this Harley on the back of a 5er yesterday

[TurnThePage]

Does this belong to a member? Looks good. Looks HEAVY.

[Maverick50]

dapperdan wrote:
R12RTee,

I'm jealous, I'd love to have a lift like yours on our Suites but I can only imagine what kind of fabrication would need to take place to install something like that on our trailer! Looks really good. I'll bet you get a LOT of looks!

We have the stock frame offered by DRV, you knew going into your deal you were having the lift put on. Smart, very smart. :W

Thanks for sharing the info on your rig, I saw it once before on here and have always wondered about your setup.

Dan

You might want to look into Idaho Totes. idahotote.com

[valhalla360]

PUCampin wrote:
Just for the sake of discussion, what is being missed in the back and forth regarding reduction in pin weight is the fact that there are springs between the load and the ground. These springs have a "spring rate" in which they compress a distance per specified amount of load (leaf or torsion, the effect is the same). The spring rate is also usually variable, usually increasing as the spring is compressed (i.e. engaging more leafs).

Given the example where the pin is twice the distance to the lift, using statics shows the pin will decrease 1/2 the load on the lift. In addition, statics shows the load bearing on the fulcrum (axles) increases by the summation of the new load on the lift and the load removed from the pin. So for 600 lbs on the lift, the load on the fulcrum (axles) would increase by 900 lbs. However, all this is true ONLY if the fulcrum is fixed (i.e. supported by stands at the frame)

But of course, in fact, the axles are NOT fixed in relation to the load, and thus this is not a simple statics problem. When you place a bike on the lift, a good deal of that force goes into compressing the springs rather than lifting the pin. The instant you apply the load, the spring can't resist and begins to compress. As the springs begin responding to the new load, they begin increasing the resistive force and acting somewhat as a fulcrum and removing some pin weight, which then travels back and goes into compressing them further before they resist more. The overall effect is much of the weight on the lift will go into compressing the springs, and how much is removed from the pin due to the partial fulcrum effect is actually COMPLETELY DEPENDENT on the spring rate (which is usually itself variable). So it is entirely possible for fj12ryder to see only 40lbs removed from his pin and someone else to see more on a different trailer. To mathematically solve for the weight removed from the pin would either require the spring rate, or the distance the spring was compressed.

Unless the springs are compressing by several feet, the math still doesn't work out.

Assuming the trailer remains relatively level, the effect of spring rate is negligible. Draw a free body diagram with the springs compressed to their maximum and it will still be nowhere close to resulting in the 40lbs off the pin weight.

[valhalla360]

ZOSO wrote:


So, now because you can't grasp reality, you're calling fj12ryder a liar?!

I'll give this one more shot.

In actuality, variables in loading etc, etc. will change that 40 pound reduction like changing socks. On that particular day, that's what was indicated by the scales. Get yourself a stick. Put your finger one inch to the left of center. Push the high side of the stick till it goes down. Now move your finger three inches to the left of center. Push the high side till it goes down. See how you had to push harder the second time? See how weight loading and fulcrum shift can change things? Is the light bulb going on yet?? Are you still in the dark??

Quite honestly, I don't think you are going to be able to pick this up. fj12ryder is right.....Ugggghhhh academia!! Everything in "real life" is not black and white like the textbooks would have you believe. I can't discuss this anymore. I think I'm gonna go have a drink and join fj12ryder! I'm done!!! Over and out!!

Most likely he isn't a liar. More likely he made a math mistake.

The idea that he changed the loading was my first thought but he claimed nothing else was changed, so your loading theory doesn't work.

[Winged_One]

ZOSO wrote:


Very sweet setup!!!!

Thank you!

[PUCampin]

Just for the sake of discussion, what is being missed in the back and forth regarding reduction in pin weight is the fact that there are springs between the load and the ground. These springs have a "spring rate" in which they compress a distance per specified amount of load (leaf or torsion, the effect is the same). The spring rate is also usually variable, usually increasing as the spring is compressed (i.e. engaging more leafs).

Given the example where the pin is twice the distance to the lift, using statics shows the pin will decrease 1/2 the load on the lift. In addition, statics shows the load bearing on the fulcrum (axles) increases by the summation of the new load on the lift and the load removed from the pin. So for 600 lbs on the lift, the load on the fulcrum (axles) would increase by 900 lbs. However, all this is true ONLY if the fulcrum is fixed (i.e. supported by stands at the frame)

But of course, in fact, the axles are NOT fixed in relation to the load, and thus this is not a simple statics problem. When you place a bike on the lift, a good deal of that force goes into compressing the springs rather than lifting the pin. The instant you apply the load, the spring can't resist and begins to compress. As the springs begin responding to the new load, they begin increasing the resistive force and acting somewhat as a fulcrum and removing some pin weight, which then travels back and goes into compressing them further before they resist more. The overall effect is much of the weight on the lift will go into compressing the springs, and how much is removed from the pin due to the partial fulcrum effect is actually COMPLETELY DEPENDENT on the spring rate (which is usually itself variable). So it is entirely possible for fj12ryder to see only 40lbs removed from his pin and someone else to see more on a different trailer. To mathematically solve for the weight removed from the pin would either require the spring rate, or the distance the spring was compressed.

[tsenior]

Alpine 3900 RE suits my purpose. 1000lb capacity in the bonus room accommodates my Harley Streetglide. Although the clearance is very close. http://www.campingworld.com/rvsales/fifth-wheel-trailer/2015/keystone-alpine/431537/

[ZOSO]

valhalla360 wrote:

ZOSO wrote:

valhalla360 wrote:

fj12ryder wrote:
Gotta love academia. I'm done.

Please show us the math for how it could only be 40lbs. I would be happy to learn something new.

If the scales were correct, you should be able to show the math to support the measurements.

Listen, seeing as how Fj12ryder is done, I'll try to get it through your head. He's already told you...A TRI-AXEL IS NOT A PERFECT FULCRUM!!!!

Noodle on that for a while.

I'll give you the benefit of the doubt and assume the fulcrum is at the rear axle (the most favorable possible position to get a 40lb reduction in pin weight) and it still is going to be an order of magnitude higher when you run the numbers.

I understand it perfectly well. As stated previously, show us the math to support the 40 lbs off the pin when you hang 600lbs off the back.

Until then noodle-on but the 40 lb claim is patently false.

So, now because you can't grasp reality, you're calling fj12ryder a liar?!

I'll give this one more shot.

In actuality, variables in loading etc, etc. will change that 40 pound reduction like changing socks. On that particular day, that's what was indicated by the scales. Get yourself a stick. Put your finger one inch to the left of center. Push the high side of the stick till it goes down. Now move your finger three inches to the left of center. Push the high side till it goes down. See how you had to push harder the second time? See how weight loading and fulcrum shift can change things? Is the light bulb going on yet?? Are you still in the dark??

Quite honestly, I don't think you are going to be able to pick this up. fj12ryder is right.....Ugggghhhh academia!! Everything in "real life" is not black and white like the textbooks would have you believe. I can't discuss this anymore. I think I'm gonna go have a drink and join fj12ryder! I'm done!!! Over and out!!

[valhalla360]

ZOSO wrote:

valhalla360 wrote:

fj12ryder wrote:
Gotta love academia. I'm done.

Please show us the math for how it could only be 40lbs. I would be happy to learn something new.

If the scales were correct, you should be able to show the math to support the measurements.

Listen, seeing as how Fj12ryder is done, I'll try to get it through your head. He's already told you...A TRI-AXEL IS NOT A PERFECT FULCRUM!!!!

Noodle on that for a while.

I'll give you the benefit of the doubt and assume the fulcrum is at the rear axle (the most favorable possible position to get a 40lb reduction in pin weight) and it still is going to be an order of magnitude higher when you run the numbers.

I understand it perfectly well. As stated previously, show us the math to support the 40 lbs off the pin when you hang 600lbs off the back.

Until then noodle-on but the 40 lb claim is patently false.

[ZOSO]

Winged One wrote:

frizzen wrote:

So half of the weight of your swivel wheel trailer and payload was on the tongue? Doesn't seem likely. The only way for that to happen would be if the wheels were at the rear end of the trialer or have the cargo way forward.
Double axles aren't a perfect fulcrum but the effective fulcrum isn't going to be far from the common anchor point for the leaf springs between the axles.

Not getting into your guys argument, but, the swivel wheel does put about half the weight on the tongue. The wheels are at the very end of the trailer. In fact they stick out the back a bit. This pic of mine shows that.



Plus, the manufacturer states about a 46% tongue weight:

Tongue weights will vary with the deck load as well as where the load is situated within the deck perimeter. The below example is with a HD Fat Boy loaded in the center of the deck into a locking wheel chock.Weights with HD Fat Boy Motorcycle (Single Wheel) HD Fat Boy Motorcycle (Centered) = 690 Lbs
System Weight = 404 Lbs

Weight at the system tire = 574 Lbs

Tongue Weight = 501 Lbs


Their math is a bit fuzzy, 1094 lbs versus 1075 lbs, but you get the idea.

Very sweet setup!!!!

[ZOSO]

valhalla360 wrote:

fj12ryder wrote:
Gotta love academia. I'm done.

Please show us the math for how it could only be 40lbs. I would be happy to learn something new.

If the scales were correct, you should be able to show the math to support the measurements.

Listen, seeing as how Fj12ryder is done, I'll try to get it through your head. He's already told you...A TRI-AXEL IS NOT A PERFECT FULCRUM!!!!

Noodle on that for a while.

[ZOSO]

frizzen wrote:

fj12ryder wrote:

valhalla360 wrote:
A swivel wheel will be similar but you have to find the center of gravity of the swivel wheel trailer and run a similar calculation between the hitch pivot point and the swivel trailer wheels to find out how much is supported by the wheels vs the hitch.

Still no way to violate the laws of physics. 800lbs at 10' behind the axles and pin 20' in front of the axles (adjust as needed for your particular trailer) will result in approximately half the weight of the bike coming off the pin weight.

If the guy who is claiming it's only 40lbs really didn't change anything else, he needs to get his money back...but the scales are usually pretty accurate so I'm still betting he changed something and didn't realize it.

Geeze I don't believe you people. I have the scale tickets, and they work. The weight on the back was 600 lbs., not 800 lbs. and like Rhagflo says, the tandem axles are not a perfect fulcrum.

Looks like you need to get money back on your math classes.

So half of the weight of your swivel wheel trailer and payload was on the tongue? Doesn't seem likely. The only way for that to happen would be if the wheels were at the rear end of the trialer or have the cargo way forward.
Double axles aren't a perfect fulcrum but the effective fulcrum isn't going to be far from the common anchor point for the leaf springs between the axles.

Before you make any more cracks about refunds for math classes, you are welcome to sit in on my multivariate calculus class. Tuesday and Thursday at 7 pm

See, that's good news Fj12Ryder, the guy IS taking some math classes! He should take some shop classes as well. It's obvious he hasn't the faintest clue how a swivel wheel trailer works!!:B Nor does Valhalla. Maybe they could carpool to a good technical shop class together.

[valhalla360]

fj12ryder wrote:
Gotta love academia. I'm done.

Please show us the math for how it could only be 40lbs. I would be happy to learn something new.

If the scales were correct, you should be able to show the math to support the measurements.

[fj12ryder]

Gotta love academia. I'm done.

[Winged_One]

frizzen wrote:

So half of the weight of your swivel wheel trailer and payload was on the tongue? Doesn't seem likely. The only way for that to happen would be if the wheels were at the rear end of the trialer or have the cargo way forward.
Double axles aren't a perfect fulcrum but the effective fulcrum isn't going to be far from the common anchor point for the leaf springs between the axles.

Not getting into your guys argument, but, the swivel wheel does put about half the weight on the tongue. The wheels are at the very end of the trailer. In fact they stick out the back a bit. This pic of mine shows that.



Plus, the manufacturer states about a 46% tongue weight:

Tongue weights will vary with the deck load as well as where the load is situated within the deck perimeter. The below example is with a HD Fat Boy loaded in the center of the deck into a locking wheel chock.Weights with HD Fat Boy Motorcycle (Single Wheel) HD Fat Boy Motorcycle (Centered) = 690 Lbs
System Weight = 404 Lbs

Weight at the system tire = 574 Lbs

Tongue Weight = 501 Lbs


Their math is a bit fuzzy, 1094 lbs versus 1075 lbs, but you get the idea.