2 hrs + 4130 Tubing = New Rear Rack

By the time you read this, I should be up in the Northwoods at our Peeksville deer camp. I typically use a backpack and sling my rifle over my shoulder when I ride my blaze orange Schlick Northpaw out to my stand. Because this year I am moving to a stand deeper in the woods, a couple of miles further down the fire lane and I plan to bring some camera gear, I decided to build a rear rack for my fatbike to help haul gear.

A decent bender, some 4130 Chromoly steel tubing and a round file are really all you need to make a rack.

Although I don’t have much time to build any more, I still have everything I need in my basement shop to put together a bicycle or a rack. This rack had to be pretty basic in order to get it done in the little spare time I had before I headed up north. That meant no drawings, no bracing and no extra braze-ons.

Grabbing a length of 3/8 inch Chromoly tubing, a ruler, sharpie and a bender, I went to work. I started with the top, and bending the struts so to keep it as close to the tire as I could and still leave enough clearance for a fender (if I ever get one). My technique for attaching the rack to the rack bosses is simple: flatten the ends of the tubes, drill a hole and round the corners with a 10″ bastard cut fine. Nothing fancy but it works.

Well, you also need a welder or a torch set, some flux and bronze brazing rod. Silver brazed joints are not considered to be strong enough for a rack.

To miter a tube to the proper length and angle, you mark it, file and put the tube back in place to check the fit. Too long or wrong angle? Back in the vice, file a tad bit more, and check the fit again. Repeat as necessary until you get a nice tight joint.

Next I bolted that finished piece into place on the frame with the rear wheel removed. Then I eyeballed the two struts, rough cut the tubing with a hack saw and flattened the ends so I could mount them to the lower rack bosses. Because my bike has an offset frame, one strut was longer than the other. Once mounted, I could position them to they matched and mark the joint and miter angle with a sharpie. Into the vice they go and I cut the miters with a 10″ bastard cut round file.

Then I put them back on the bike, fluxed up the joint, grabbed a stick of brazing rod and fired up the Oxy-acetylene torch.  My eyes are about 15 years older than they were when I worked at Waterford. If I was going to build professionally again, I would have to invest in some glasses that fit under my brazing goggles. Never mind that though, since this was a rush job and I was the only quality control inspector, I brazed on!

A finished miter, sometimes called a “fish mouth” for obvious reasons.

With the struts in place I cut three sections of tubing to brace the top of the rack, mitered them with the round file, drilled vent holes and brazed them in place. Without vent holes in the tubes the hot expanding gases in trapped in the tube would blow the through when you brazed up the last end joint.

Then I put the tire back in place to check the alignment. The rack passed QC, so I pulled it off and soaked it for half an hour in some hot soapy water to remove the remaining flux. After I pulled it out of the water and let it drain, I heated the rack back up with the torch to vent out any remaining water that might have been trapped inside the tubing. Let the rack cool a few minutes, do some very minor clean up around the joints with emery cloth backed up by a 10″ half round file and I was done.

One of the unfinished (meaning not filed or sanded) fillet brazed joints on my rack. I could use a bit more practice to get back in the flow, but it is not embarrassing and will be a strong joint.

Phase one done! I still plan to add some cross bracing when I have some time after I get back from hunting so I left it bare metal.

Total time invested was just over two hours. The rack fits well and will allow me haul my extra gear out to my stand. I left the rack unpainted because I plan to add some cross bracing to keep the rack from twisting under side loads.

I will keep you all in the loop about how the rack performs and if I get a deer after Thanksgiving when I get back. Until then, happy turkey day everyone!

 

About Dave Schlabowske, Deputy Director

Dave was the first full-time staff member hired to open the Bike Fed's Milwaukee office 15 years ago. A former professional photographer and life-long Milwaukee resident, Dave likes wool, long rides, sour beer, and a good polar vortex once in a while.

6 thoughts on “2 hrs + 4130 Tubing = New Rear Rack

  1. Looks good Dave! It was darn cold and windy up in Price Co. suspect the same by you. Saw plenty of fresh tracks and cam pictures, but no movement in daylight.

    • Yep, it was 8 below zero when I rolled out to my stand one morning. I saw deer every day, but none were shooters. The same was true for the rest of the guys in my group of 10 hunters in Unit 28A in Ashland County. We all had cameras on our stands over about 260 acres and a five pointer was the biggest buck caught on camera and seen during the day. We did one small drive that didn’t shake up a shooter either. We follow an eight points or better rule to shoot. This was the first year nobody got a deer. We attribute it to a long winter kill given their was a foot of snow still on the ground in May.

    • Unfortunately I have not had to figure that one out since I started riding the bike to hunt last year :( I’ll let you know what I do next season when my luck turns!

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