Mounting Spare on Back of T@B

AnOldUR

The Boondock Yakima rack for the back of a T@B is pricey and overkill for mounting the spare tire. I'd like to get it off of its current ground level location. Has anyone come up with an alternative, either DIY or purchased? My thought was to attach two bars in line with two of the horizontal frame cross members and attach a plate between the two to mount the tire to.

Dalehelman

Those cross members are not very substantial. Your idea has come up before. I don’t remember seeing a good solution. You may be the one. Good luck

MuttonChops

@AnOldUR ;
Lots of folks have moved the spare to a tongue mounting location.
Most common is to mount on backside of Jack Post.  Search the forum . . . there are several threads on the topic.

My solution:

AnOldUR

@Dalehelman ... The cross members not being substantial enough is my concern. The reason I considered it is because the Yakima rack that nuCamp installs attaches to them. The difference is that they are secured to 10 of the cross members, but they are flexible rails that don't distribute the weight. Each of the two horizontal bars that the cargo basket attaches to only apply force to a single location on the rail. It appears to me that what I proposed would be equal to what the nuCamp installation accomplishes. More important, I would only be attaching the spare tire compared to the load capacity of a cargo basket.

@MuttonChops ... I am specifically looking for a rear mount solution. My TV has a low tongue weight capacity and I already have a second box mounted up front. The spare there would throw me over the limit.

Dalehelman

@AnOldUR.  I believe the Yakima racks are attached to the side wall rails which are more substantial than the horizontal rails. Certainly the joint at that intersection would be much stronger. At the very least mounting a spare in the middle would require a backup plate on inside probably a minimum 1 foot square 1/4” aluminum to save weight. The curved designed could require the plate to be bent to match the interior contour.

AnOldUR

@Dalehelman ... A couple of pictures attached that show the T@B frame and Yakima rail installation. The Yakima spacing matches the T@B. I do agree that mounting closer to the side wall would make a big difference. My plan was to add two bars to the outside that parallel the trailers horizontal bars. Then, as you suggested, attach a backup plate to them.

Dalehelman

@AnOldUR. 

I know that aluminum cross beams on the top of the roof will not support very much weight. Someone tried mounting an RV air conditioner which caused the roof to bow. As you move down the roof it becomes more vertical there for stronger I suppose. Time would tell if it is strong enough to support the weight as it bounces down the road. If you are successful others will likely follow. Good luck and please keep us informed.

AnOldUR

@Dalehelman ... I'd be using the last two or the 2nd and 3rd bar, so hopefully take advantage of that addition support. By going lower, the inside cabinet should offer additional support. Now all I need is work up the courage to try.

Google searching, I think I found a thread on the roof mounted air conditioner sagging on another forum. Interesting, informative read. Definitely worth consideration.

Homebodyatheart

Not my rig, but now you can see where the aluminum framing is. 

Tampakayaker

Homebodyatheart said:

Not my rig, but now you can see where the aluminum framing is. 

That's one way of finding the beams are!

dragonsdofly

@Tampakayaker, welcome to the frosty north. Care to join us? Having survived being stranded in November, 2018, prox 7,000 ft altitude in Evanston, Wyoming, we survived several days in the -10° F range in our t@b. We saw the pictured phenomenon up close and personal virtually every morning of our 16 day stay. It's a special thing reserved for us in the frigid north, like walking (and driving) on water. Something you won't experience unless you visit between October and April or May. My best wishes are that you never experience this or any other cold temperature related t@b phenomena unless it is the vacation you are seeking!

Tampakayaker

dragonsdofly said:

@Tampakayaker, welcome to the frosty north. Care to join us? Having survived being stranded in November, prox 7,000 ft altitude in Evanston, Wyoming, we survived several days in the -10° F range in our t@b. We saw the pictured phenomenon up close and personal virtually every morning of our 16 day stay. It's a special thing reserved for us in the frigid north, like walking (and driving) on water. Something you won't experience unless you visit between October and April or May. My best wishes are that you never experience this or any other cold temperature related t@b phenomena unless it is the vacation you are seeking!

Nopity nope!  I was an upstate (Hudson Valley) NYer until 1978.

Decided that moving to FL was the way to go when I was freezing solid (with ice in my beard) while on a telephone pole repairing cable TV the winter of 77.

Nice to visit, wouldn't want to live there.  We  visited my daughter when she lived in Omaha during 1 winter.  That was enough winter/snow for us.

My wife has been freezing the last couple of days with temps in the 60s and grey overcast skies.

AnOldUR

Well, not that I though it was an original idea, but looks like someone beat me to it. My wife found this picture on a Facebook T@B user group. The topic of the post was not related to tire mounting, so I'll contact the member for more details. This give me the confidence to go ahead with the project.

edit to add:
Heard back for Facebook member.
"You can buy it in Germany with this feature."

ScottG

That's a European T@B. Different company entirely. I've no idea if they are structurally built the same way as nuCamp T@Bs.

Dalehelman

ScottG said:

That's a European T@B. Different company entirely. I've no idea if they are structurally built the same way as nuCamp T@Bs.

I new there was a something different. I just thought it was a newer model. I didn’t catch the euro license plate. I think it is a much older model. I don’t think they have made them in Europe for years.

ScottG

They are still listed as a product of Knauss-Tabbert in Germany! 

4ncar

For the record...the Yakima Rack is through bolted to the vertical frame in at least 2 locations.  You can see them if you take the speakers out(as I recall).  Not sure if they have been through bolted further up as well.

AnOldUR

@4ncar ... Every installation I’ve seen looks like it is only attached to the horizontal cross members. Can you show where and how it connects to the vertical frame? It sounds like it would be a much sturdier method.

Sharon_is_SAM

I have to agree with @AnOldUR.  Here is a picture of the rear framing.  The vertical metal wall framing is covered by the final plastic trim.  The vertical sides of the rack are at least 6-8 inches in from the sides of the trim.

AnOldUR

@Sharon_is_SAM ... Thanks for the pictures. They make understanding how the T@B is framed much easier.

Made more progress on the tire mount today until I ran out of daylight. The two black bars run parallel to second and third horizontal struts seen on the right T@B in your first picture. I drilled all the way through them and fastened to the inside wall in the rear cabinet. Still need to make a plate to mount the spare to. The two longer screws extending into the center storage bin will be short like the others once the plate is in place. Hope to finish up tomorrow.

Sharon_is_SAM

The European TaB example looks like the horizontal bars are mounted farther apart - maybe straddling a middle bar.  Do you think backing the through bolts with some thin plywood would offer any support?

Dalehelman

@AnOldUR
No turning back now. Only time will tell. IMHO I think it will work. Besides additional support could be added if necessary. Good luck.

AnOldUR

Dalehelman said:

@AnOldUR
No turning back now .... Good luck.

Thanks! I have to admit that my heart was racing and I had nervous sweats while drilling the first holes. It was a relief seeing that I hit the struts and the hole came out where I had planned.

@Sharon_is_SAM ... I though about skipping a rung like the European T@B, but liked the idea of the bolts all being in the cabinent. The way my steel bars and the T@B aluminum bars are sandwiched together, I don't think any additional support will be necessary. The rear cabinet and its dividing partitions should be effective at preventing any bowing and provide extra support. 

4ncar

In seeing the very detailed pictures of the unskinned tab, it couldn’t be the verticales. But through bolted non the less.  

AnOldUR

@4ncar ... Your comment on fastening all the way through is what motivated me to do the same with my installation. I used ten 2-1/2” long 3/8-16 bolts.

I was under the impression that the Yakima rails only used sheet metal screws that went through one wall of the T@B’s rectangular tubing. I am curious what diameter and length screws they use. Anyone know?

ScottG

@AnOldUR, did you drill the holes purely based on external measurements, or did you also confirm the location of the frame by some other means.

I can see why you were sweating those first couple holes--nice job!

AnOldUR

@ScottG ... A little of each. The confusing part is that there are multiple sources with different dimensions for locating the cross members. What helps is that the outer shell is flexible and by pressing down on it you can feel where there is support underneath. Not exact, but enough to confirm the location. 10" up and then 8" between centers seemed to match my 2020 T@B 320S. The 1-1/2" width of tubing is a pretty big target.

Tampakayaker

AnOldUR said:

@ScottG ... A little of each. The confusing part is that there are multiple sources with different dimensions for locating the cross members. What helps is that the outer shell is flexible and by pressing down on it you can feel where there is support underneath. Not exact, but enough to confirm the location. 10" up and then 8" between centers seemed to match my 2020 T@B 320S. The 1-1/2" width of tubing is a pretty big target.

Did you use any type of sealant around the bolts?

AnOldUR

@Tampakayaker ... I ran weather stripping the length of the exterior mounted bars and it compressed when tightening the bolts to form a seal between the bars and shell.

4ncar

@AnOldUR: To measure the bolt diameter, I need ti remove the speaker.  I am in the midst of getting ready to go FT(packing house, etc).  As soon as I get out to the trailer to prep it for the Life Change, I'll pop the speaker.

AnOldUR

Ready to hit the road with spare relocated. My only real regret is that I used the old mount from under the trailer and it uses two of the five bolt pattern. The result is that the tire is offset to one side. If not pointed out, I doubt if anyone would notice, but my OCD is working overtime. On the positive side, I hung all my body weight on the mounting bracket with my wife inside to see if there was any flexing or other indication that there was a problem. Nothing budged a bit. Very solid.