Extended A-frame to reduce tongue weight

m_lewis · November 2020

I am contemplating extending the a-frame of our T@B-400 BDL forward 12-18 inches to reduce tongue weight. Serious surgery, I know. But I feel the 550 pounds is just a bit too much for my TV, especially if we load up the rear cargo area for a long trip. I would like to get it in the 375-400 pound range.
Interested in any comments (that do not include getting a new TV), opinions, or experiences.

DougH · November 2020

@m_lewis Is there a place in the back of the camper to put a few AGMs? It would similarly cut into your spare GAWR budget, but would have the benefit of more battery capacity. 125Ah Group 31 batteries are 70lbs apiece.

rfuss928 · November 2020

IMO Make shift measures to compensate for marginal TV capacity are ill advised.

Verna · November 2020

I have to agree with @rfuss928.

NüCamp and the trailer manufacturer have spent countless hours fine tuning the designs of both the camper and trailer to be the best match for each other.

Any modification of your frame will void the warranty.

m_lewis · November 2020

@rfuss928, with my vehicle and hitch combination, using the lower of the two specs, I have 700lbs tongue weight capacity and 4400 lbs towing capacity, plenty of horsepower and torque. I don’t feel I’m approaching capacity limits nor is the tow vehicle marginal for the task.

I’m interested in a better total trailer to tongue weight ratio, 11.5-12.5% vs the current 15.5%. To compensate for the loss of stability from the lower tongue fraction of total weight and to effect. that lower tongue weight, I am considering the extended tongue.

m_lewis · November 2020

@Verna, our dealer made it clear to us that there is absolutely no warranty, as we bought it used and the warranties only apply to the original purchaser.

The camper showed virtually no wear and we inspected everything except the wheel bearings, deciding the price we negotiated was worth the risk.

I agree that the camper might be well designed to match the undercarriage for an average of TVs, but I am somewhat of a perfectionist, always looking to make good things better.

m_lewis · November 2020

@DougH, that was a consideration. We have found that the factory solar option and the mod I put into charge the batteries at >30 amps from the TV’s alternator are more than sufficient for the conditions we camp in.

When towing, we load as many of the heavier items as far to the rear as possible and of course empty the grey and black tanks.

Other than putting some lead in the extreme rear of the under bed storage or maybe building a rack on the back for the spare tire, I can’t think of anything else to do without changing the axle/tongue geometry. Moving the axle forward is just not an option.

Dalehelman · November 2020

IMHO Simply a bad idea. Unless you or someone has the proper engineering skills to design the modifications, and a fabricator to do the reconstruction. Good luck.

VictoriaP · November 2020

m_lewis said:

@rfuss928, with my vehicle and hitch combination, using the lower of the two specs, I have 700lbs tongue weight capacity and 4400 lbs towing capacity, plenty of horsepower and torque. I don’t feel I’m approaching capacity limits nor is the tow vehicle marginal for the task.
I’m interested in a better total trailer to tongue weight ratio, 11.5-12.5% vs the current 15.5%. To compensate for the loss of stability from the lower tongue fraction of total weight and to effect. that lower tongue weight, I am considering the extended tongue.

I cannot find any model year of the BMW x3 that is in your signature with a 700 lb tongue weight limit. They appear to range from 350 to 440 depending on how old. Having a hitch capable of a greater tongue weight doesn’t make the vehicle capable of a greater amount. Even a weight distributing hitch cannot do that.

So I have to assume you are dangerously over limit at 550 pounds, and towing that weight risks damaging this particular car, in addition to the liability issues that come from being over any weight limit provided by the manufacturer. Modifying the trailer frame is well above my pay grade, so the only thing I’ll note there is that any time you make major modifications to an RV, you risk devaluing it significantly on resale. And structural mods are something that will cause many folks to walk away without buying.

Realistically, your choices are to get a more capable vehicle, which you have said is not an option, or get a trailer that is correctly sized for the X3. Some model years of the Tab 400 are lighter in front though with only 440 lbs to work with, I wouldn’t recommend it; the 2019 you bought is actually the heaviest of them all. The good news is that with the RV market in overdrive, you should be able to sell the trailer without taking a significant loss.

Good luck with your decision!

Denny16 · November 2020

Aging to the tongue length will move the trailer axle back, and change the towing dynamics. You should do some research on thus first. If you do this, you will need to reduce your towing speed to 55mph max, to prevent inducing traiker sway.

This is how Europe deals will RVs, the EU TaB has a longer tongue, reducing its weight, but also reduces their max towing speeds.
c

m_lewis · November 2020

@VictoriaP, I appreciate your arguments. Those tongue weight specs are similar to what the manufacturer lists with their hideaway hitch option (350/3500). I found its construction to be a bit on the wimpy side, so I instead went with a much stronger receiver. It is rated at 750/7000 lbs. I can't recall nor immediately find where I got the 700 lb maximum number for the vehicle.

Nonetheless, a new vehicle may be the only reasonable option at this point. While it is a fine car, we don't love it quite as much as we do the T@B.

It looks like I would need to extend the tongue much more than I anticipated to drop the weight 150 lbs, something that would be quite obvious and not to my liking.

m_lewis · November 2020

@Denny16, I am aware of the poorer aerodynamics from separating the trailer from the TV, and a resulting decrease in gas mileage. However, all my research says that a longer coupler-to-axle trailer is LESS likely to sway, all else being equal.
Do you know how much longer the Euro T@Bs are?

VictoriaP · November 2020

m_lewis said:

@VictoriaP, I appreciate your arguments. Those tongue weight specs are similar to what the manufacturer lists with their hideaway hitch option (350/3500). I found its construction to be a bit on the wimpy side, so I instead went with a much stronger receiver. It is rated at 750/7000 lbs. I can't recall nor immediately find where I got the 700 lb maximum number for the vehicle.

Yeah, unfortunately, a better hitch still only raises the limit to whatever the limit of the car is, so unless the owner’s manual lists a higher weight for a specific hitch, you’re still stuck with the vehicle maximum. Also note that some aftermarket hitches can compromise the structural strength of the vehicle itself, especially any vehicle with unibody construction, as they are usually anchored at different points than the hitch provided by car manufacturer. I only learned that in that couple of months myself. 😕

If I were shopping for a vehicle for your particular 400 model year, I’d be looking for a minimum 6000 lb towing limit rather than the 5000 lb we normally use around here as a minimum guideline for the 400. That model’s tongue weight is just WAY heavy, and you’ll want to upsize to accommodate that.

Alternatively: trucks like the F150 actually have two weight ratings, and are the exception to the hitch doesn’t increase tongue weight rule because they are actually designed to haul greater weights when using a weight distribution hitch. If you check the owners manual for any vehicle, it will detail whether or not a WDH will change the towing limits, or whether one can even be used with your new vehicle. Note that only certain kinds of WDH will work with the C channel frame of a Tab 400, so definitely search this forum before buying one.

falcon1970 · November 2020

extending the tongue would seriously affect the towing characteristics of the trailer. And you may only discover how it is affected as you are going down the road some day.

JCALD · November 2020

Have you actually weighed the tongue at the ball. I never weighed our 400 but purchased a scale for the Avia. With 40 gals of fresh water it comes in at 680, but with an empty fresh water tank it is 550. It tows better with a full tank.

m_lewis · November 2020

@JCALD, yes I have a scale. 558 lbs with our normal load, black and grey empty, fresh 1/2-2/3 full.

Denny16 · November 2020

Adding a weight distribution hitch on a large TV like a F150 is a bad idea, as you could overload the TaB trailer axle Weight limits. A WDH distributes thr weight across the three axles, so you are going to add weight from thr truck to the trailer.

Lewis, sorry, do not have the actual tongue length, and you are correct extending the rear axle distance can create a more stable tow, if the TV also has a long wheelbase. Boat trailers are a good example of long axle to hitch distance, with the axle behind center line by a larger margin, than RV trailers.
A boat’s weight tends to be more at the rear (outboard engines or inboard engines are aft, so more of the boat is shifted forward of the axle to increase tongue weight, by adding more boat forward.

You need to be careful not to get too little of a tongue weight, which in USA tend to be a minimum of 10% of gross weight, with 15% being more average, thismis because of our (North American) faster towing speeds.

Cheers

VictoriaP · November 2020

Denny16 said:

Adding a weight distribution hitch on a large TV like a F150 is a bad idea, as you could overload the TaB trailer axle Weight limits. A WDH distributes thr weight across the three axles, so you are going to add weight from thr truck to the trailer.

@Denny16 If this is the case, we have a number of owners that I’ve seen here and on FB that may be in trouble. The F150 without a WDH maxes out at 500 lbs tongue weight, and plenty of 400s (not just the 2019, though they’re the heaviest) that have been weighed at over 500 once loaded, so people are using the WDH to fix that issue. Hmmm.

Denny16 · November 2020

Yes, I saw a video a guy did showing how a light axle like the TaB 400 @3500 lbs, get some of the TV weight shifted to the trailer axle when using a WDH. His take was this was causing more issues than it solved. If you think about it, a WDH takes the total weight of the aTaB and trailer, and then distributed this total weight across all three axles. A full size 1/2 ton truck,is going to have more weight than a TaB, so the GaB gains weight from the truck. This is a bad idea in my book.

Another way to reduce your tongue weight is to shift more weight behind the axle. This is what nüCamp did, on the 2020 model, and some late 2019 TaB400s they moved the battery all,the way back under the middle of the rear bunk, shifting some 200 lbs all the way aft. The weight is centered over the floor frame supports, and the battery is sitting directly on the Azdel floor panel, as shown here:

As yiu cam see the sub/false floor is gone, and Lino on top the Azdel panel is the floor,on the storage area, and battery area. Plumbing is concealed in area at bottom of photo, which is frint area of under bunk storage area.

On the 2021 model, in addition to the battery shift, they moved the axle forward to shift more of the trailer weight aft.

On th2 2018 and early 2019 models, the batrery was on the pax side, forward part of the bunk. This sat on a plywood sub floor, sitting 1.5-inches above the Azdel floor, and all the plumbing and wire runs were under this false floor. The battery area had additional 1.5-inch blocking under the plywood, to transfer the battery weight to the frame, as shown here:

Wood blocking between wire and water piles in upper right corner supports the battery located above this area:

Azdel floor o this area.

I wanted to mod our TaB 400, to move the battery aft per the first example shown above on the 2021 model, but this would require removing the sub floor and adding support blocks, so I I left the battery in its original location shown above,
cheers

ckjs · November 2020

m_lewis said:

...
It looks like I would need to extend the tongue much more than I anticipated to drop the weight 150 lbs,

Have you considered replacing the batteries with Lithium ones? I did this to reduce my 320-CSS tongue weight. A 100AH LiFePO4 is under 30 pounds, and you can discharge them substantially below 50% without damage.

Denny16 · November 2020

Charles, Lewis, the OP has a 2019 TaB400, and the battery is located inside the trailer behind the axle, so adding a lighter battery would result in more tongue weight, as you woukd be reducing weight behind the axle, and reducing the counter weight, which reduces tongue weight. A trailer is like a boat, the location of the weight is just as important as the amount of weight.
cheers

m_lewis · November 2020

@Denny16, I too have thought of moving the two batteries all the way back, as it would help take 40-50 lbs off the tongue. Although it’s a lot of work, it would be easier than extending the tongue!

ckjs · November 2020

@Denny16: Whoops, I forgot about the battery location on a 400. Thanks

Marceline · November 2020

VictoriaP said:
Also note that some aftermarket hitches can compromise the structural strength of the vehicle itself, especially any vehicle with unibody construction, as they are usually anchored at different points than the hitch provided by car manufacturer. I only learned that in that couple of months myself. 😕

<rant>I'm sorry to disagree but I this is misleading. The problems that I've heard of with people installing aftermarket hitches on unibody vehicle are almost invariably due to some shady shop trying to install the wrong hitch bar for that vehicle. Unibody vehicles rated for towing have reinforced locations on the body specifically designed for attaching the hitch - whether a factory or dealer installed hitch or a DIY aftermarket hitch. And you can absolutely buy an aftermarket hitch that matches those attachment point patterns. The problem arises when some yayhoo tries to install the wrong hitch and just drills holes willy nilly through the body. If you ask for a hitch to be installed on a unibody vehicle and someone starts drilling holes in the body of your vehicle you need to run for the hills.

I installed an aftermarket hitch myself on my vehicle 16 years ago and I have have towed thousands and thousands of miles with it. There is no problem with installing an aftermarket hitch as long as you buy the right part and use the right tools. </rant>

4ncar · November 2020

@Marceline: I would agree with you in that with unibody construction, there are very specific attachment points that have been strengthened my the manufacturer of the vehicle in question. Deviating from these attachment points could prove disastrous. However, my takeaway from what @VictoriaP was saying, and I agree with also and the point has been well taken is, that just because an aftermarket hitch assembly is rated for x# of lbs, doesn’t increase the TV’s ability to safely tow more(increased value of said hitch assembly).

GatorEgg · November 2020

Just get the right tow vehicle so a not to become a YouTube “trailer fail” video.

Marceline · November 2020

4ncar said:

@Marceline: I would agree with you in that with unibody construction, there are very specific attachment points that have been strengthened my the manufacturer of the vehicle in question. Deviating from these attachment points could prove disastrous. However, my takeaway from what @VictoriaP was saying, and I agree with also and the point has been well taken is, that just because an aftermarket hitch assembly is rated for x# of lbs, doesn’t increase the TV’s ability to safely tow more(increased value of said high assembly).

I was disagreeing with the specific point that I quoted. It’s misinformation that I’ve seen very often (more on the FB groups than here). Aftermarket hitches aren’t “usually anchored at different points than the hitch provided by car manufacturer.”

But I do agree with her point that a beefier hitch doesn’t increase a vehicle’s towing capacity.

rfuss928 · November 2020

m_lewis
Time to start looking at X5s ?? There is nothing better than a comfortable, confidently capable TV to make the travel part of traveling much more enjoyable. The constant attention required when running at or near full TV capacity is fatiguing and stressful.
Good luck finding your solution. Have fun

m_lewis · November 2020

I just checked the max tongue weight of Ford F-150 trucks: 500 pounds on the Class IV hitch! That's for the factory towing package, not a bumper mounted ball.

What tow vehicle are you folks finding that is spec’d for 550 or more?

What TV will tow a T@B400 safely within the manufacturer’s specified limits?

m_lewis · November 2020

@rfuss928, yes, the X5 has a 600 lb tongue limit and at least 6200 lb total trailer weight, so the 400 would be within spec. Funny that the very popular F150 only has a 500 lb limit.

I am just a little shy of the $60k + needed to acquire an X5.

Denny16 · November 2020

I use a Jeep Gladiator truck, 6500/600 tow rating. Also a Ram 1500 will tow a TaB400, as will a Chevy Colorado with OEM tow package. You need a OEM tow package on the TV, either truck or large SUV, not a pumper hitch found on many stock PU trucks. Check the TV towing specs with OEM specific tow package.

The biggest issue with TaB 400 is its tongue weight, figure it at around 450-500 lbs depending on how the trailer is loaded. Ours is at 400 lbs dry, no LP in tank, no water in Gray or Black tanks (well 1-gal,in black tank) and only 1/2 water tank. I have not weight the tongue loaded, but calculated it is around 450-475 lbs.
cheers

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