DIY tunnel stiffener

[stomper]

I want to put a Canada sled parts tunnel rack on my BTX but have heard lots of horror stories of bent tunnels from carrying cargo. I can see why, they are paper thin. Im not a big fan of the ones that go on the outside of the tunnel so I designed my own out of 1/8” aluminum. It goes On the inside from in the front of the suspension mount right to the very back. I drilled out the existing aluminum rivets that hold the bumper on and replaced them with the stavex multi grip rivets I had left over from rebuilding the chassis on my wife’s apex. They will be much stronger. I have a few more rivets to install yet but I want to paint them to match the sticker on the outside of the tunnel. This should make things a lot stronger for cargo and pulling a small sleigh. I won’t be hauling much so this will be more than I need.

 

[stomper]

The bottom picture loaded sideways for some reason. Sorry

 

[blueironranger]

The top of the tunnel "dished" out from pounding down a rough trail all day with a large tunnel bag on it. I built an aluminum cross brace that goes across the top of the tunnel back near the tail light that ties the tunnel protectors to the outsides of the tunnel. I haven't had the tunnel dish out since. If you look at it the rears of the tunnel protectors are not supported very well. I really like your idea also, I have a big sheet of .090 sitting around that I could build supports with!

 

[stomper]

The dishing out of the tunnel is a concern of mine also. If you look and the second picture you can see where the stiffener starts at the outside edge of the tunnel protector and goes over to the edge and 90’s down. That upper flange is where my rack will get bolted to transferring the weight to the strong side panels. There should be very little weight on the top of the tunnel, A lot of the racks I have seen while searching don’t even have a “floor” with them. I couldn’t imagine just tossing cargo right on the tunnel. It is so flimsy and would bend and scratch so easily. My sled came with a small tunnel bag that clips behind the seat and probably the only reason the tunnel hasn’t dished out is because it is so small it can’t hold much stuff. The rack that I am getting has small rods that make up the bottom floor that I’m not to crazy about so I will most likely fabricate something better. I have an idea in mind but will know more when I get the rack.

 

[stomper]

One issue to be aware of is the transition where the tunnel goes from horizontal to vertical isn’t a true 90 degree, it’s closer to 85 ish degrees. Believe it or not both sides were different. I just used an adjustable T square to find the angle and adjusted the angle of the stiffener with a piece of 2x4 and a big dead bow hammer. It was much easier to open up the angle from 90 to 85 than it would have been to close the angle. To find where I had to drill the mounting holes in the stiffener to match up with the existing holes that holds the bumper on, I put the stiffener in place and tapped it with a hammer where the rivets are. This transferred a perfect circle of the existing rivet to the stiffener. I removed the stiffener, drilled out the holes, then drilled out the rivets in the tunnel and everything fit perfect.

 

[Mike P]

How much weight are you guys putting on your tunnels? I might be pushing my luck with mine. I was told that the RT-X does not seem to have a problem with the flimsy tunnel, any idea if this is correct?

 

[stomper]

I haven’t put any weight on mine yet but once I get things done it will only be a some ice fishing gear and possibly a small can of fuel. Anything heavy will be pulled in a sleigh. My BTX 153” has lots of real estate behind the seat and I can’t imagine what the MTX has. It also depends on the style of riding you do. I live in the north and most of my my riding is off trail exploring on lakes and bouncing down washboard trails to get to fishing holes. So that adds to the stress in the tunnel.

 

[nevikyami]

I want to put a Canada sled parts tunnel rack on my BTX but have heard lots of horror stories of bent tunnels from carrying cargo. I can see why, they are paper thin. Im not a big fan of the ones that go on the outside of the tunnel so I designed my own out of 1/8” aluminum. It goes On the inside from in the front of the suspension mount right to the very back. I drilled out the existing aluminum rivets that hold the bumper on and replaced them with the stavex multi grip rivets I had left over from rebuilding the chassis on my wife’s apex. They will be much stronger. I have a few more rivets to install yet but I want to paint them to match the sticker on the outside of the tunnel. This should make things a lot stronger for cargo and pulling a small sleigh. I won’t be hauling much so this will be more than I need. View attachment 151482View attachment 151483

 

[stomper]

Here’s the almost finished product. I still have to install the rack when it gets here. Once it’s bolted into place it will secure the top flange into place.

 

[stomper]

Finally got done the finishing touches done on the stiffeners and rack. The floor of the rack is 1/8” aluminum with spray box liner on it. The tunnel bag still fits with the front rod removed. I have 3 spare rods that can be installed anywhere in the holes in the sides of the rack.