Hitch extension

[marlinsfan]

I have searched for this and found nothing.

I have a Thule bike rack (which I also use as a ski rack with the ski rack adaptor). The problem I have is that the tailgate is so long, I can't open it when the rack is on.

Bike rack is something like this one:
https://www.amazon.com/Thule-956-Pa...sr=1-3&keywords=thule+4+bike+rack+hitch+mount

Ski rack adaptor is this one:
https://www.amazon.com/Thule-987XT-...r=8-20&keywords=thule+4+bike+rack+hitch+mount

I need about a 2 foot extension to the hitch to be able to open the tailgate with the rack attached.

Reese makes this 12 inch adaptor
https://www.reesehitches.com/products/Receiver_Hitch_Extension,1804005

And in the description it states that it reduces the tongue weight capacity by 1/3. I called them with 2 questions, and they couldn't answer:

1) if our 5th Gen tongue weight is 550 lbs, does this mean that with this adaptor, it is now 368.5 lbs?
2) if that's the case, and I add 2 adaptors to give me the 2 foot clearance, would the tongue weight now be 247 lbs?
3) the rack with the 4 bikes weigh less than 250 lbs. Is this a bad idea??

Thanks.

 

[Jetboy]

First - It's a bad idea generally, but if you keep it light enough it might work. The tongue weight is a combination of factors including the weight the rear suspension can handle, not just the twisting force on the rear cross member that the receiver is mounted to.

The calculation of reduced hitch capacity on the extender is totally wrong. Both mathematically and theoretically. Theoretically it's wrong because it assumes the only failure being considered is the torque force on the cross member. Trailer towing characteristics are going to be effected in many other ways. It's a horrible way to tow a trailer.

That said - even if you only consider the bending moment (torque) on the cross member, by moving the point load of a hitch ball from 8 inches to 20 inches away from the center of the cross member, you've reduced your load capacity from 500 to 200lbs. If you add 2 of them, you will reduce the load capacity in this respect to 125lbs. With a bike rack you're already starting with your load cantilevered out quite a bit. Lets assume you start at 24" away with 2 bicycle. Each weighs 30lbs plus 40lbs of rack. So it's 100lbs total. You're already at 60% of the hitch's capacity. By going to 36" away with your load you're at 90% of the hitch capacity and adding 2 of these to get you 48" away will exceed the rated 500lb capacity by 20% (assuming torsion is the failure mode).

Do I think you'll actually bend the hitch? Probably not. But you might. If you hit a bump hard for example the force would be quite high. Additionally the thing is going to bounce like crazy because it's not dampened and all the loose fittings will cause a lot of play.

So basically - don't do it. Buy a proper swing away bicycle rack if you want to open the hatch. Or use the window.

 

[marlinsfan]

First - It's a bad idea generally, but if you keep it light enough it might work. The tongue weight is a combination of factors including the weight the rear suspension can handle, not just the twisting force on the rear cross member that the receiver is mounted to.

The calculation of reduced hitch capacity on the extender is totally wrong. Both mathematically and theoretically. Theoretically it's wrong because it assumes the only failure being considered is the torque force on the cross member. Trailer towing characteristics are going to be effected in many other ways. It's a horrible way to tow a trailer.

That said - even if you only consider the bending moment (torque) on the cross member, by moving the point load of a hitch ball from 8 inches to 20 inches away from the center of the cross member, you've reduced your load capacity from 500 to 200lbs. If you add 2 of them, you will reduce the load capacity in this respect to 125lbs. With a bike rack you're already starting with your load cantilevered out quite a bit. Lets assume you start at 24" away with 2 bicycle. Each weighs 30lbs plus 40lbs of rack. So it's 100lbs total. You're already at 60% of the hitch's capacity. By going to 36" away with your load you're at 90% of the hitch capacity and adding 2 of these to get you 48" away will exceed the rated 500lb capacity by 20% (assuming torsion is the failure mode).

Do I think you'll actually bend the hitch? Probably not. But you might. If you hit a bump hard for example the force would be quite high. Additionally the thing is going to bounce like crazy because it's not dampened and all the loose fittings will cause a lot of play.

So basically - don't do it. Buy a proper swing away bicycle rack if you want to open the hatch. Or use the window.

Thanks, [MENTION=118321]Jetboy[/MENTION]. I appreciate the time to write all that up. Very clear, and clearly not a good idea. We take the bikes (and the skis) from NJ to VT often, and given what you wrote, I will probably do damage.

I have been using the window, which is fine. It sucked last weekend, though, trying to get a big suitcase thru the window. I ended up folding the hitch so the bikes hit the asfalt, then had to push it all up. Had to do a front squat / power clean to get the hitch back up!

 

[Jetboy]

While we're on the subject, don't do this either. It's asking for trouble.

 

[Jetboy]

Thanks, [MENTION=118321]Jetboy[/MENTION]. I appreciate the time to write all that up. Very clear, and clearly not a good idea. We take the bikes (and the skis) from NJ to VT often, and given what you wrote, I will probably do damage.

I have been using the window, which is fine. It sucked last weekend, though, trying to get a big suitcase thru the window. I ended up folding the hitch so the bikes hit the asfalt, then had to push it all up. Had to do a front squat / power clean to get the hitch back up!

No problem. Just trying to keep you safe. The reality is that there's probably at least a 3x safety factor - so you'd probably not actually break it. But I'm sure that it would bounce like crazy. And bikes are expensive. Even if you just damaged your bike it would be a bummer. I actually do have a 36" hitch extender just like that one - but I only use it for launching my sailboat. So when I get to the ramp I unhitch and install it. My sailboat only weighs 700lbs so there's maybe 100lbs of tongue weight and it flexes quite a bit when it's out that far, which is about where you'd be at.

I have to use it because of the trailer situation means my boat has to go so far into the water on some ramps I'd be over the rear bumper of the 4runner before I could launch the boat. That's just the nature of sailboats. They have to sit high on the trailer.

 

[gundrted+t4r]

Yes there is a reduction is capacity when you add an extension or any time you move the load backward. You are basically creating a lever and it all comes down to physics.

I run a 36in extension on my F250 to clear the bumper of my truck camper. It even has basket welded to the top of it. I've used that for towing lots of stuff. Its all about using the correct tool for the job.

Skis and bikes don't weight anything when you are talking about a Class3 2in receiver hitch. If you were putting a 400lbs motorbike back there, then I may start to worry.

I ran an 18in extension for years on my Wrangler. It also dropped the rack down as well. I needed it to clear the swing gate of the Wrangler. Without it you couldn't open the gate or glass. I used a Saris rack that carried 4 bikes. I never had any issues with load. The biggest issue I had was rack movement. My Saris has a built in tensioner, but the extension didn't. That equaled a lot of movement when driving down the road.

Remember that some people get stuck on the numbers and lost in theory. The reality is a 12-14in extension on your bike/ski rack will make zero real world difference.

Will an extension make our 4Runner unsafe ... NO. Will it reduce the load rating .. YES. Will it matter carrying bikes and skis .... NO. Will it add lots of sway .... Maybe.

I would say this ... DO NOT mount extensions to extension. Get the correct size for what you need.

I my 2cents is get the extension and try it. Its a LOT cheaper then buying all new racks.

Here is similar question I found on eTrailer.com.

https://www.etrailer.com/question-15985.html

 

[philsey]

[MENTION=118321]Jetboy[/MENTION] = the new [MENTION=66316]1engineer[/MENTION] (rip)

 

[Soneill]

While we're on the subject, don't do this either. It's asking for trouble.

Please enlighten us. I've heard 50/50 on this subject.

 

[marlinsfan]

I would say this ... DO NOT mount extensions to extension. Get the correct size for what you need.
https://www.etrailer.com/question-15985.html

Thanks for you insights on this subject. I appreciate it. I'm only thinking of combining 2 extensions because I can't find a 24 inch extension. Biggest I have found is 18 inches, which won't give me the clearance to open the tail gate with the bike rack mounted.

 

[marlinsfan]

[MENTION=118321]Jetboy[/MENTION] = the new [MENTION=66316]1engineer[/MENTION] (rip)

did [MENTION=66316]1engineer[/MENTION] pass? Chit. I had not heard.

 

[philsey]

did [MENTION=66316]1engineer[/MENTION] pass? Chit. I had not heard.

Nah. He dumped us for a different ride.

http://www.toyota-4runner.org/5th-gen-t4rs/238538-extended-permanent-vacation.html

 

[Jetboy]

Please enlighten us. I've heard 50/50 on this subject.

Hitches aren't designed to carry weight like that. They'll work- temporarily. But if you ever watch one flex - it's just a matter of time before metal fatigue catches up with you. How many miles it takes depends on the load and the vehicle. The more you load it up - the shorter the lifespan. And it causes poor vehicle dynamics. Wight cantilevered out over the ends is the worst possible spot for it for vehicle handling. 4runners are already relatively short wheelbase suvs. Hanging 500lbs a few feet off the end of the frame on a 2" square tube far exceeding the design capacity of the rear cross member is a recipe for disaster.

Also - you should drive one and try to make a slalom maneuver once. No thanks. If you need a trailer for all your shit - buy or rent a trailer. Or consider a larger vehicle.

 

[Jetboy]

[MENTION=118321]Jetboy[/MENTION] = the new [MENTION=66316]1engineer[/MENTION] (rip)

I think he actually knew what he was talking about. I just make shit up.

 

[Salvo Jimmy]

Hitches aren't designed to carry weight like that. They'll work- temporarily. But if you ever watch one flex - it's just a matter of time before metal fatigue catches up with you. How many miles it takes depends on the load and the vehicle. The more you load it up - the shorter the lifespan. And it causes poor vehicle dynamics. Wight cantilevered out over the ends is the worst possible spot for it for vehicle handling. 4runners are already relatively short wheelbase suvs. Hanging 500lbs a few feet off the end of the frame on a 2" square tube far exceeding the design capacity of the rear cross member is a recipe for disaster.

Also - you should drive one and try to make a slalom maneuver once. No thanks. If you need a trailer for all your shit - buy or rent a trailer. Or consider a larger vehicle.

You can help the side to side / up down flex that can cause metal fatigue with turn buckles / chain to hitch safety chain eyes / front tie downs eyes. Pics on page 3 of this thread shows what I did front/ rear.


http://www.toyota-4runner.org/5th-gen-t4rs/213975-front-hitch-receiver-3.html

No that said, I don't put much load on my racks with just ice / beer / bait, but then there is that occasional 60 # fish. LOL

 

[1engineer]

I think he actually knew what he was talking about. I just make shit up.

No you don't. You know your stuff. I'm only posting to prove I'm not dead. See ya.

 

[Brandon_Reed]

Rakattach, solid equipment.

Sent from my SM-G930V using Tapatalk

 

[philsey]

No you don't. You know your stuff. I'm only posting to prove I'm not dead. See ya.

Boom! Phil pulls out the stalker. He loves us.