Just added the tow receiver

[bwilson4web]

Hi,

Installed on Monday:

Sad to say it does not include the trailer electronics and the vendor does not have a kit. I'll have to rig this up later.

I went with the more common 2" receiver.

I started assembling the wheel chair carrier. I'll need a 2" hitch to complete installation. It is too early to report any handling or MPG effects. I'll want to do those tests with the wheelchair.

Bob Wilson

 

[johnnylingo]

Original BMW or aftermarket?

Can't imagine it's designed for towing anything over 500 lbs. Would be great for a bike rack though.

 

[jadnashuanh]

It's aftermarket...BMW, as far as I've seen, does not promote or suggest the use of a trailer hitch on the i3.

 

[bwilson4web]

First test drive:

The side view shows the low clearance with the receiver. There are inches to spare opening the hatch so I don't have to pull the quick-release pin to access the rear. I may experiment with some sort of strap to help raise the assembly as it appears to droop.

The back-up sensors complain but you can see around the chair. Raised a few inches, I still expect the warnings but better view under the rack. Once you go over 6-8 mph, the alarms turn off.

The rear view mirror view is not obstructed but will have to check again after getting a taller receiver.

The blue knob on the top adjusts an arm that holds the chair firmly in the rack. The small blue knob on the lower right is the quick release that tilts the rack so the big wheels touch the ground. Very easy to load or unload.

This is what it looks like walking up to the car.

I don't like this receiver (sold separately) because the chair rack is too low. When pulling out of the driveway, there is a gutter between the curb and driveway and it started to scrape. Driving at an angle worked but only because I knew it was there. In an unloaded car, it cleared the 'speed bumps' (i.e., sleeping policeman?) A few extra inches should do it.

I also bought a 5/8" x 2 1/2" bolt and locking nut as the original was too long to fully seat. I also don't care for lock-washers over a locking nut with plastic insert. A general hardware bolt, I may look for a higher quality bolt and locking nut.

I was not trying to do handling or drag tests until I get the ground clearance right. When I took it off, keeping the receiver (the part that inserts) is the easiest way ... take wheel chair off first. <grins>

Bob Wilson

 

[I33t]

Looks way too far out and as you say, too low.

Looks like it needs a tilt mechanism to bring the top of the chair towards the car so that you have better ground clearance and less leverage on the tow hitch. Usually, you can get different height tow hitches to connect to the towbar, you might be able to mod the carrier to lift it up but you still have to be able to remove the chair.

 

[alohart]

Might law enforcement complain that your rear license plate is obscured?

We almost always drive with our rear seats folded down because we rarely have rear seat passengers. This makes it easy to carry larger cargo. If you don't frequently have rear seat passengers and have space for the folded wheelchair, it would seem much easier to just lay the folded wheelchair in the cargo area with the rear seats folded down. The wheel chair would remain much cleaner and dryer when carried inside as well.

 

[jadnashuanh]

IN many countries outside of the US, when carrying something like that that obscures the license plate, another plate attached where visible and maybe a light panel is required. On my other car, while I don't move the plate, I do plug in a light panel (bought it in England for cheap), and with the thing plugged into the car's electronics, it shuts off the rear sensors and changes the stability logic. It also changes the camera view in case you were trying to align with a real trailer. I seriously doubt the i3's internal logic has that provision since it is not offered from the factory with an optional tow bar.

I carry my recumbent trike in the back of my i3, rather than behind it like on my other car, mostly because I didn't want to deal with the alarm, and I like the security of having the thing inside, verses out, even if it might be locked to the carrier. When that was first introduced, they offered me one for free to test and post my results, but given those two issues, I passed.

FWIW, I've not been hassled while I've been carrying my trike, which pretty much obscures the plate in the rear. Doesn't mean it can't happen, just hasn't happened yet over the last 4+ years.

 

[bwilson4web]

Hi,

I had this problem of an 8 degree droop:

Leaving the driveway, the gutter led the carrier to dragging on the hump.

I bought an 8 degree, wedge shim used by off-roaders who lift their suspension. A wedge shim handles
the new body-to-spring-to-axle angle. After re-drilling the mount hole to 5/8", here it is installed:

Notice the platform is now parallel within a degree or so of a line drawn axle-to-axle of the wheels.

Here is the wedge shim in the assembly:

The tow ball mount droops a little then you can see the small end of the steel wedge. On top of
the wedge is an alignment part that comes with wheel chair carrier to keep it from rotating around
the bolt and shifting to the rear. The wedge actually over-corrects a little but the 'slop in the system'
lets the carrier droop to level.

Now one potential problem is the bolt holding everything together has to deal with an 8 degree
angle. Cocked at an angle, one side of the bolt-head would be over stressed and the other side,
unloaded. Over time, road vibration would lead to a crack and the head separating ... not good.
I used a 9 degree, wedge washer:

Annealed, the washer conforms so the bolt-head is evenly loaded. It also means stress will in
effect keep the bolt-head from any rotation.

Now the only metric for fuel consumption has been 40 MPG @65 mph between Knoxville TN
and Cleveland TN on my first drive home. But I've added a receiver hitch and now the
wheelchair carrier and wheelchair with a rain cover. So I replicated the benchmark @65 mph:

So loaded, it is running 73 miles / 2 gallons ~= 36 MPG. This is the mileage I need for trip
planning. Here is the electrical version (after coming to a stop) of the 65 mph benchmark:

The temperature was +90F, comfort mode, and AC set to 74F. These were taken at the Shell
station right off of the Interstate. And then the flap for the gas tank would not open and
I was completely out of gas.

So I drove over to the BMW dealer and they showed me the manual over-ride. They also
showed it is not a one-time use and then go to dealer. For now, they asked that I do
a power-on, RESET of the software which is in progress. I'll back out the 'code' and
if it doesn't work, I'll schedule an appointment. The major technical issues have been
addressed.

Minor issues:

• Safety chain ... bolt failure would be bad ... dragging on road, less bad.
• Fitting 1 gallon spare can in front trunk (frunk).
• License plate replica behind chair carrier with light.
• Left-turn light is blocked but that may not be a problem.
• Rust protection (?) and double-nut the bolt.

Suggestion? Thoughts?

Bob Wilson

 

[I33t]

Re Double Nut: Make the second nut a nyloc nut.

Looks sorted, Bob!

 

[alohart]

Fitting 1 gallon spare can in front trunk (frunk).

Doesn't seem smart to carry flammable gasoline in the front crumple zone. This could turn a survivable accident into a fiery death. Would there be a way to carry a gas can on the wheelchair carrier?

 

[bwilson4web]

Fitting 1 gallon spare can in front trunk (frunk).

Doesn't seem smart to carry flammable gasoline in the front crumple zone. This could turn a survivable accident into a fiery death. Would there be a way to carry a gas can on the wheelchair carrier?

Hummmm, placed so it is visible to following traffic on top of two empty boxes:

Maybe that will get the tailgaters to follow at a safer distance,

Bob Wilson