Range Loss Bike Rack Trailer Hitch? Model X

[RedXowner]

@ohmman, Got it. So it's all about hitting bumps that apply additional pressure to the hitch receiver. I was only thinking about the stationary (car not moving) case. If you hit a pothole with a trailer (moving), I do get that the weight pressing down on the ball would not substantially change. But the weight pressing down on the hitch receiver when hitting a pothole with a bike rack attached would be greater than just the weight of the bike rack because of the location of the center of gravity of the bike rack being behind the hitch. OK, makes sense now. It's not about the stationary weight. It's about the max downward pressure applied when hitting potholes.

For your after-market hitch, it must stay mounted all the time, right? So I'm assuming it protrudes beyond the plastic cover that fits over the factory hitch when the receiver is not installed, which means you would have the constant air drag when driving. Is that correct? If so, then the trade as I see it is the ability to eliminate the trailer hitch drag when not towing a trailer vs the tongue weight of a non-trailer attachment. That sound right?

 

[ohmman]

@ohmman, Got it. So it's all about hitting bumps that apply additional pressure to the hitch receiver. I was only thinking about the stationary (car not moving) case. If you hit a pothole with a trailer (moving), I do get that the weight pressing down on the ball would not substantially change. But the weight pressing down on the hitch receiver when hitting a pothole with a bike rack attached would be greater than just the weight of the bike rack because of the location of the center of gravity of the bike rack being behind the hitch. OK, makes sense now. It's not about the stationary weight. It's about the max downward pressure applied when hitting potholes.

For your after-market hitch, it must stay mounted all the time, right? So I'm assuming it protrudes beyond the plastic cover that fits over the factory hitch when the receiver is not installed, which means you would have the constant air drag when driving. Is that correct? If so, then the trade as I see it is the ability to eliminate the trailer hitch drag when not towing a trailer vs the tongue weight of a non-trailer attachment. That sound right?

You've mostly got it right. It's less about downward pressure than it is twisting (moment) forces. Like using a long handled wrench to break a nut free.

The Draw-Tite hitch, installed, doesn't protrude much. Here is a photo of it once I installed it and cut the panel to fit. I see very little downside. It fits flush with the bumper instead of protruding like the factory supplied Bosal does. You get around the stringent offset requirements of the Bosal hitch, and you get safety chain loops that are easily accessible. I've got another brand new Draw-Tite hitch in my garage right now awaiting my next X, which I plan to purchase very soon.

Remember that with the removable hitch, you're supposed to always remove it and replace the door to the hatch when it's not in use. This is because detritus collects in the underbody panel. If you're sticking with it, I definitely suggest doing so, because during my Draw-Tite installation, I probably emptied 3 gallons of gravel out of my panel!

 

[RedXowner]

Wow!! Amazing. I agree, and I do it religiously. Didn't know about the gravel issue. I was doing it (and still do it) for the aerodynamics.

 

[Yinn]

One more thing to note since there are folks who have said - I've done X and had no issues. We're talking about the rated capacities here. This doesn't mean that if you go 1lb over, it'll definitely fail. SAE has a safety margin factor because they anticipate us being idiots and ignoring the manufacturer recommendation. But even that has both a % of overcapacity as well as a probability of failure at that capacity rate measurement.

Some say the numbers are 20% conservative. Others say it's 40%. I personally have no idea. It's best to follow the manufacturer rating, but if you don't; just know that they thought of you specifically when they built in that margin.

 

[MTB_Han]

Also need to be very careful with Bike Racks on the back in Supercharger stalls, I have a 2 bike Kuat and it can be challenging to get close enough for the short Supercharger cables.

I can attest to this. I've gotten VERY close to hitting signs with the bike rack because the supercharger cables at some locations just barely make it to the stall with the 2 bike rack on. I'll try to get pics if I can remember.

 

[gangzoom]

Just done x2 160 miles trips with a road bike on a carrier. Have to say the range impact was pretty much zero.

Outbound leg saw us beat the TripAdvisor prediction by a massive margin due to a 10mph tail wind.

Return leg was wet all the way with one a 15 mile section of torrential rain, still beat TripAdvisor by about 10%.

.

This was however travelling at UK speeds - 70mph, and my bike rack is quite compact so hold the bike very close to the hatch.

 

[Dave EV]

The difference is the moment arm. The trailer tongue weight of up to 500 lbs has wheel support under the trailer, behind the hitch. That tongue weight pushes down more or less straight on the end of the hitch receiver because of how trailers are axled and because it's connected to a ball. The ball allows the connection to pivot without transferring torsion forces to the hitch receiver. Meanwhile, a cargo tray or hitch mounted bike carrier will have its center of weight well behind the hitch connection point. It doesn't connect with a ball. So every bounce and jiggle transfers a lot of torque into the hitch receiver.

Yep, because of this, load heavier bikes first, then lighter bikes to reduce stress on both the rack, hitch and car.

 

[EV-lutioin]

The difference is the moment arm. The trailer tongue weight of up to 500 lbs has wheel support under the trailer, behind the hitch. That tongue weight pushes down more or less straight on the end of the hitch receiver because of how trailers are axled and because it's connected to a ball. The ball allows the connection to pivot without transferring torsion forces to the hitch receiver. Meanwhile, a cargo tray or hitch mounted bike carrier will have its center of weight well behind the hitch connection point. It doesn't connect with a ball. So every bounce and jiggle transfers a lot of torque into the hitch receiver.

If you install an aftermarket hitch, such as the Draw-Tite hitch that I installed, you'll have a higher tolerance for those forces because it doesn't have the removable receiver so it's more similar to the Y hitch.

That looks like a much better option, I'm not sure why Tesla went with the quick release hitch.

 

[RedXowner]

So the driver can remove the hitch, replace the plastic cover, and have the aerodynamics of a Tesla. Tesla is first and foremost an EV with range for traveling. The exposed hitch reduces the Tesla's range due to aerodynamic drag. Additionally, debris can quickly build up in the plastic undercarriage of the car if the cover isn't replaced. 80+% of owners don't use the trailer hitch very much anyway, so Tesla built the car for the 80+%, not us 20%'ers.

 

[ohmman]

I think the thru-bumper solution on the Y is a better design because it's less prone to failure and remains hidden. But I also think the Bosal serves the purpose for which it was intended, which was to satisfy some ability for towing with the X.

 

[OILMAN]

I have recently completed the over 1000 km trip from Victoria, BC to Calgary, Alberta from sea level through the Rockies, twice, once with 2 bikes on the hitch rack and once without. Range impact of the bikes with rack was negligible.