What is the weakest link in my motorcycle "hitch motocarrier system" with extension?

[rc51kid]

What is the weakest link in my "hitch motocarrier system" with extension? I have a 4x4labs rear, 12" extension rated at 500lbs, Motocarrier rated at 400lbs and a 280lbs bike. When i carry it short distances or on rough roads i mount the spare tire inside the truck and it mounts very tight to the truck. I strap it also to the labs bumper and have NO movement or bouncing. But i need to carry it 2000 miles of highway and need the spare on the carrier. So i got this extension. This picture is just a mockup so it is not strapped well and does not have proper pins in place. But it will for the trip. I have a solid 3.5" of extra room. I was thinking of moving it 2" closer.

Simplest way is to move the tray 2" closer on the motocarrier. Other way is i could have a shop drill a new hole in the extension 2 or 2.5" forward and shorten the extension. I figure if i shorten the extension then it becomes better supported. Plus i could cut it to the perfect lenght to get it to extend as much as possible into the Labs bumper. What way would you go with it?

 

[bhsdriller]

idk but no way I would trust that going any kind of distance

The torque applied is the force*distance....further away you get from the mount the more torque applied.

 

[GreatWhtCrewmax]

he weakest link is that extension with all that leverage on it. I would add a strap from as far back on the extension through the spare tire to prevent it from bouncing and fatiguing the extension. Also I would cut it down to be as short as possible.

 

[mjosoba]

Is it possible to put the tire on the roof rack? (Looks like I can see some feet in the pic?) Or could you cantilever a couple square tubes out the back (if there is a roof rack) and have them take some of the weight off?

 

[rc51kid]

Having a machine shop knock 3" off it right now. I will take a look at it and see how sketchy it looks. I usually run a ratchet strap from the carrier up on to the spare and the ladder. I figure even if each one only takes 50 pounds that leaves only 175 pounds weight on the hitch.

 

[rc51kid]

Is it possible to put the tire on the roof rack? (Looks like I can see some feet in the pic?) Or could you cantilever a couple square tubes out the back (if there is a roof rack) and have them take some of the weight off?

Cant. I will have a kayak on the roof. But if i have to i can put it inside. But does really kill cargo space.

 

[eastoak]

I had a setup like that, put a receiver on one end of the bumper with an extension to the motorcycle carrier to bear some of the weight and keep it from rocking.

 

[projectcruiser]

That is sketch-city. Rent a trailer.

 

[leonard_nemoy]

Run a strap to each corner of the rack to the bumper, and if it rocks back and forth from play in-between the extension and the receiver tube use one of these. Amazon product

I drove from Utah to Georgia and back and used a rack like yours to carry my xr650l (350#'s) on my 98 Tacoma with a regular trailer hitch and it worked great. You have to realize when the manufacturers are putting weight limits on items they probably leave themselves 10% margin of error for liability.

 

[BILT4ME]

I would recommend you slide it forward, but I would redo it by drilling additional holes so it telescopes into the hitch or itself.

As you slide it forward, it MAY be harder to load, as the handlebars may be interfering with the spare tire.

The other thing I would do is like what we have on the wheelchair lift.

Instead of using a standard pin to slide into the hitch to hold it in, use a grade 8, zn plated 1/2"-13 x 5" bolt. Install a bushing 5/8" OD x 1/2" ID x 1/2" long on the bolt first. On the opposite end you will have a 1/2" flat washer and a Nylock nut.
You will drill the hitch receiver on ONE SIDE ONLY to a 5/8" ID. This will be the side that the bushing slides into.

Do NOT drill the insertable section. The purpose of this is that it tightens the inner square tube to the one side of the receiver and it stabilizes the side to side rocking a HUGE amount. Our wheelchair is 400 LB, hanging on a 125 LB lift, in the standard hitch. It all hangs out far enough that I can open the tailgate flat with the lift on the truck and the wheelchair is beyond that.

If you don't already have a set of airbags in the springs, I recommend the set from Airlift (Summit Racing) for about $90. Easy to install and it stabilizes and boosts the rear of the truck to help reduce the "hopping' you will feel from the truck wheelbase crossing over the seams in the road. If you are running a lift, contact Airlift direct and they can tell you what bag to use that is the same diameter, but longer in order to compensate for the lift.

If you want some pics or anything that we have on the WC lift, let me know.

 

[chap79]

I would replace the whole extension and the stock 2" receiver piece on the carrier with a longer thicker square tube and drill the holes where needed.

 

[leonard_nemoy]

Instead of using a standard pin to slide into the hitch to hold it in, use a grade 8, zn plated 1/2"-13 x 5" bolt. Install a bushing 5/8" OD x 1/2" ID x 1/2" long on the bolt first. On the opposite end you will have a 1/2" flat washer and a Nylock nut.
You will drill the hitch receiver on ONE SIDE ONLY to a 5/8" ID. This will be the side that the bushing slides into.

Or he could use one of these.

Amazon product

 

[Rivman1243]

I would have a custom built extension that actually slipped into the hitch and attached to another crossmember or to some braces. Think of it like a kids teeter toter, where your bumper is now the pivot point, so the further forward you can go with the extension the less leverage your motorcycle will have.

 

[BILT4ME]

Or he could use one of these.

Amazon product

True. $18 vs $3.

Remove two bolts and a pin to get it off or one bolt only.

Have a pair of bolts pointing down to drag on more crap on the trail or have nothing lowering his contact point.

You're right. He COULD use that. I don't, but that's because the WC lift uses this design for something that's a bit more expensive than any of those motorcycles you can squeeze on there.

 

[BILT4ME]

Cant. I will have a kayak on the roof. But if i have to i can put it inside. But does really kill cargo space.

Since you're loading so much weight way to the rear, make sure you push some of your heavier items to the front of the vehicle (inside or outside) if you can to place more weight on the front axle. It will help reduce the bounce and watching the tops of the trees with the headlights. I know you have a kayak on top, but it doesn't weigh much, but push it as much forward as reasonable as well. Just suggestions from traveling rear-heavy by requirement rather than choice. Being heavy and way out back, it can start to wag the dog, creating a sway situation.

 

[Somebodyelse5]

I wouldn't run that.

that 400lb rating for the 12" extension comes out to 4800 in*lbs at the receiver.

A conservative guess is that your mototote is another 12" extension to the 280lb moto (it may be more than 12" idk, I'm guessing based on photo).

So, the total moment at the receiver will be (12in+12in)*280lb = 6720 in*lbs

6720 in*lbs >> 4800 in*lbs

And that's just a conservative guess at static loading.... no dynamic effects from bouncing down the road....

 

[rc51kid]

Much better. I had the hold redrilled 3.5" forward decreasing the extension from 12 to 8.5". Then when i cut it i old trimmed off the min amount allowing it 2" more insertion into the Labs bumper. I will test fit it again and see. Thanks for all the advice. I did not really like to original setup. Sketchy.

 

[rc51kid]

I would recommend you slide it forward, but I would redo it by drilling additional holes so it telescopes into the hitch or itself.

As you slide it forward, it MAY be harder to load, as the handlebars may be interfering with the spare tire.

The other thing I would do is like what we have on the wheelchair lift.

Instead of using a standard pin to slide into the hitch to hold it in, use a grade 8, zn plated 1/2"-13 x 5" bolt. Install a bushing 5/8" OD x 1/2" ID x 1/2" long on the bolt first. On the opposite end you will have a 1/2" flat washer and a Nylock nut.
You will drill the hitch receiver on ONE SIDE ONLY to a 5/8" ID. This will be the side that the bushing slides into.

Do NOT drill the insertable section. The purpose of this is that it tightens the inner square tube to the one side of the receiver and it stabilizes the side to side rocking a HUGE amount. Our wheelchair is 400 LB, hanging on a 125 LB lift, in the standard hitch. It all hangs out far enough that I can open the tailgate flat with the lift on the truck and the wheelchair is beyond that.

If you don't already have a set of airbags in the springs, I recommend the set from Airlift (Summit Racing) for about $90. Easy to install and it stabilizes and boosts the rear of the truck to help reduce the "hopping' you will feel from the truck wheelbase crossing over the seams in the road. If you are running a lift, contact Airlift direct and they can tell you what bag to use that is the same diameter, but longer in order to compensate for the lift.

If you want some pics or anything that we have on the WC lift, let me know.

good info. I use a bolt setup like you describe when using just the carried. I also strap it to the bumper and ladder in several points. Zero wobble at all. Also have airbags installed. Contrary to the original picture i have put a lot of thought into this.

 

[1911garand]

Trailer!

 

[ZackR]

Normally I'd recommend avoiding a spare tire on a roof rack but this might be a situation where its better off so you can move the bike up close.