Dual Motor R1T on a steep slippery boat ramp?

[mpfurnari]

I'm presently driving a 4wd Frontier and pulling a Malibu 21' boat. Loaded, the boat + trailer is at the limit for the truck - around 6500 lbs. When pulling the boat out of a steep slippery boat ramp, I have to use 4WD. This truck doesn't have locking differentials. My question is: Will a dual motor R1T work as well coming up the ramp, or do I have to go quad? (I know the quad will work because I've seen them used successfully with the same boat. For reference, the ramp I'm referring to is Barton's Creek on Falls Lake in NC... on a busy weekend.) Feedback from dual-motor owners would be most appreciated!

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[Cycliste]

@R.I.P. ?
I am looking forward to learning from this thread.
Your 4WD Frontier has open differentials, correct?

 

[R1Tom]

I think RIP will say DM will be vastly superior....QM might fishtail into vehicles on adjoining ramps....

Haha!

 

[Cycliste]

If the Frontier can pull the boat up the ramp with an open diff, would not the Rivian with a dual motor and open diffs be able to pull the boat up? Do tires make much of a difference with boat ramps having those grooves? If tides allow for moss to grow on the ramp, how does that influence tire selection? Do fresh water lakes get a lot of slippery moss growing on boat ramps?

 

[jjswan33]

I am pretty sure if a QM loses all traction on one side it will spontaneously flip over on that side.

 

[mpfurnari]

@R.I.P. ?
I am looking forward to learning from this thread.
Your 4WD Frontier has open differentials, correct?

Correct, They don't lock.

 

[mpfurnari]

If the Frontier can pull the boat up the ramp with an open diff, would not the Rivian with a dual motor and open diffs be able to pull the boat up? Do tires make much of a difference with boat ramps having those grooves? If tides allow for moss to grow on the ramp, how does that influence tire selection?

Good questions. I'm hoping to hear from someone who has tried it. I've asked all the Rivian folks who have contacted me to complete my sale, and none can answer it, so I want to hear from someone with experience. Good question on tires; My truck has Michelin LTX M/S. I wonder how the stock 21" road tires would do in comparison. I'd hate to have to shorten range with a more aggressive tire.

 

[kylealden]

DM shouldn't be meaningfully disadvantaged. QM has more raw horsepower but DM can use brake vectoring to send all the power to one side, so it may actually have more power per wheel. The real-time anti slip characteristics should be comparable if not favoring the open diff.

 

[R.I.P.]

Lool

@R.I.P. ?
I am looking forward to learning from this thread.
Your 4WD Frontier has open differentials, correct?

Lol.

Oh boy, here we go again.

I do not have direct experience with your specific application; what I assume is boat ramp with no side camber.

I do have 50+ years of muddy/slippery hill climbs, however, so here's what you can expect from the three drivetrain types:

Locked Diff's:
least likely to slip it all, as all four wheels are turning at exactly the same speed. If there is any slipage, all four wheels will slip, but on a uphill with no side grade, give it some gas and it will scramble up with maximum traction.

Quad R1 (or Hummer/ CT Tri):
All four wheels can slip independently (rears on the tri's), so if you start to lose traction, you will see oscillation from side to side front and rear as all four try to find the maximum power that can be put to the ground. As long as there is no side camber, this should perform great for you.

R1 Enduro:
If traction is lost, you will see greater single wheel spin from one front and one rear wheel, but leave traction control at 100% and it will quickly transfer the appropriate torque to the other side. This vehicle should come up the ramp as easily as the locked diff and quad machines, but may have a little bit more wheel spin drama.

Notes to consider:
Often, the extra wheel slip experienced with the unlocked differential can actually help you. It can help dig through the slime, mud or snow and find better traction below quicker than if all the wheels are slipping at once (like the locked rig).

As has been noted so many times, if there happens to be a camber on the boat ramp, both the locked rig and the quad will immediately start moving toward the downhill side when the slipping starts.

I did the Buckhorn run yesterday with the R1. This is not a run you normally take your nicer truck on (scratches), but I am really growing to enjoy the quiet wheeling the R1 lets me do. The melting Snow over the red clay always results in about the slipperiest conditions you will ever find this time of year. I continue to be extremely impressed with the Enduro drive train, and the traction control Rivian has built into it. The new slightly wider wheels seem to be making just enough difference, keeping the body of the vehicle off the rocks and the banks, I think that is a sweet spot for wheeling as well.

This truck is quickly becoming my go-to for all but the most challenging trails.

 

[Cycliste]

Thanks!

And camber = scary. I know winter backpacking with a pulk/sled on a trail with camber, or side hilling is not fun and scary-ish

 

[moosehead]

You are well inside R1T’s tow abilities and capacity with that load. Either DM or quad. This rig is a seriously capable tow machine well beyond the Frontier. No offense.

Regardless, snot slick ramps are no joke so I always carry sand for launches and retrievals and tend to scout unknown ramps on foot first.. No one wants to be a boat ramp blooper.

 

[Dark-Fx]

Measure out where the ramp is 42" deep and make sure you stay in front of that spot when you dunk the truck.

 

[COdogman]

I am pretty sure if a QM loses all traction on one side it will spontaneously flip over on it's side.

Within spec

 

[mpfurnari]

Lool

Lol.

Oh boy, here we go again.

I do not have direct experience with your specific application; what I assume is boat ramp with no side camber.

I do have 50+ years of muddy/slippery hill climbs, however, so here's what you can expect from the three drivetrain types:

Locked Diff's:
least likely to slip it all, as all four wheels are turning at exactly the same speed. If there is any slipage, all four wheels will slip, but on a uphill with no side grade, give it some gas and it will scramble up with maximum traction.

Quad R1 (or Hummer/ CT Tri):
All four wheels can slip independently (rears on the tri's), so if you start to lose traction, you will see oscillation from side to side front and rear as all four try to find the maximum power that can be put to the ground. As long as there is no side camber, this should perform great for you.

R1 Enduro:
If traction is lost, you will see greater single wheel spin from one front and one rear wheel, but leave traction control at 100% and it will quickly transfer the appropriate torque to the other side. This vehicle should come up the ramp as easily as the locked diff and quad machines, but may have a little bit more wheel spin drama.

Notes to consider:
Often, the extra wheel slip experienced with the unlocked differential can actually help you. It can help dig through the slime, mud or snow and find better traction below quicker than if all the wheels are slipping at once (like the locked rig).

As has been noted so many times, if there happens to be a camber on the boat ramp, both the locked rig and the quad will immediately start moving toward the downhill side when the slipping starts.

I did the Buckhorn run yesterday with the R1. This is not a run you normally take your nicer truck on (scratches), but I am really growing to enjoy the quiet wheeling the R1 lets me do. The melting Snow over the red clay always results in about the slipperiest conditions you will ever find this time of year. I continue to be extremely impressed with the Enduro drive train, and the traction control Rivian has built into it. The new slightly wider wheels seem to be making just enough difference, keeping the body of the vehicle off the rocks and the banks, I think that is a sweet spot for wheeling as well.

This truck is quickly becoming my go-to for all but the most challenging trails.

Thanks for the explanation @R.I.P. !!

A few follow ups clarifications, please... I'm not a 4WD expert. My use case is mostly getting in and out of the boat ramps without damage to my truck, my boat, other boats, and the ramps LOL . By side-camber, you mean is the ramp tilted left or right in addition to straight back? I've not studied that, but I think it is mostly level right/left.

If I read correctly, you are saying that the dual-motor Enduro should be at least as good as the 4wd on my Frontier (which does not have locking differentials.)? I'm not looking for a guarantee, just an experienced opinion.

You drive the dual motor? For my scenario, would you recommend the dual motor over the quad? Again, just looking for your experienced opinion.

Also, recommendations on tires? I'd like to keep the street tires with the longest range, but not at the expense of damaging stuff .

 

[mpfurnari]

Measure out where the ramp is 42" deep and make sure you stay in front of that spot when you dunk the truck.

This ramp is fairly steep... Barely get the tires wet before the boat floats. By stay in front: Do you mean the rear end of the truck?

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