Introduction: Steel and Wood Bicycle Cargo Rack

     I've recently started riding my bike more often. Driving to campus is becoming impractical, and finding parking is increasingly frustrating since the school decided to build new facilities over some of the parking lots. Riding a bike certainly has its advantages, but bikes don't normally have a place to carry your things. Handlebar baskets are too girly for me(I'm a guy), and in my opinion look funny on a mountain bike. I decided building my own would be cheaper and more fun than buying a rack at the local bike shop.

I intend to paint my bike and the rack at some point, however I wold like to leave the wood it's natural color. I'm looking for paint ideas that would go well with the natural cedar look. Give me some tips in the comments if you have any.

Pro Tip: Listen to jazz while you work!

Step 1: Design Goals, Materials, and Tools


Design Goals:
     -build it myself
     -save money
     -good lookin'
     -very sturdy
     -no welding
     -square bucket pannier compatible


Materials:
     -flat bar(many sizes will work)
     -1"x2" wood of your choice(I used cedar)
     -all thread or round bar around 1/4"
     -4 or 6 nuts and bolts to mount the rack
     -2 or four nuts and bolts to attach the supports and rack together
     -6 nuts to mount the wood planks
     -nuts, washers, or spacers to separate the wood planks and align them on the all
      thread or rod(there are 12 spots that need something)

I've omitted some amounts here as they will change depending on your bike and personal design.


Tools:
     -vice
     -large hammer
     -angle grinder or file
     -drill or drill press
     -hack saw
     -wood saw
     -wrenches
     -sandpaper
     -a die(to thread the round bar if you choose it over all thread)
     -marker
     -ruler


Step 2: Design

After looking at racks I decided that I should stick to the traditional design. The rack should have a flat platform the sits above the rear tire parallel to the road. There will be attachment points both below the seat and near the rear axle. The pictures show the measurements I decided on, though you should probably grab ruler and hold it up to your bike and decide for yourself what you want. The rack actually ended up about seven inches wide. I'm not sure how that happened. I do know that when I was bending it was coming out different than measured because of the bend itself taking up some material.

Top View:

This is basically just the outline of the rack's platform. You can see the two tabs on one end where it will mount to the bike.

Side View:

This view shows the supports that will hold the platform over the tire and where these supports mount. near the bottom of the photo you can see two dots. These dots represent mounting holes that are intended for a disc brake caliper. I skipped the longer support when I found that the rack was really strong with just the vertical support.

Step 3: Bending the Platform Frame

Once you've decided for sure on the size of your rack's platform you are ready to get your material and start bending. Make sure you have a piece of flat bar that is more than long enough to make the entire platform frame out of. Head over to your vice and grab your hammer. You'll want to start on one end of your material and make bends toward the other end.

1. Measure and mark where the first bend should be.
2. Clamp the material in the vise so that the longer portion of the material sticks straight up in the air.
3. Square the material to the vice so that it is perpendicular to the top of the jaws of the vice for a straight bend. This is important!
4. Bend!
5. Repeat for the other bends.

How to bend.
1. Place your hand on the material about 10 inches above the vice. You did leave the long end on top right?
2. Push the material with your hand to the point that the steel feels like it is about to bend(don't actually bend it yet!)
3. Grab the hammer in your other hand and strike the steel where it goes into the vice.

Your bar should bend sharply when you've got it right. Simply pushing the steel over with your hands will yield a bend with a large radius. Simply hitting it with a hammer will probably take a long time. Using both works well because your hand will be putting most of the necessary bending force on the material and the hammer will put the additional necessary force right where you want the bend.
If you bend something too far(more than 90 degrees) simply leave it in the vice and gently pull the material back with your hands. It should bend back easily. The steel will "want" to bend back towards its original shape for a while.

You can see the rack ended up wider than planned. This happened because the jaws of the vice were taller than 1-3/8" so those bends ended up longer than planned. I simply made them as short as possible and adjusted on the other end to match.

Step 4: Mount the Rack Platform and Cut Supports

To figure out the exact length of the supports You'll probably just want to mount the rack where it goes and take a measurement. You can see my bike had very convenient brackets for mounting. I took advantage of this and hope you can as well. If your bike is lacking these brackets you'll have to find a workaround. Put the rack on the bike with some bolts and tighten them up enough that the rack will stay up where it goes or prop it up. Be sure to level it how you want it then measure the length of the supports. If you measure from the rack to the mounting hole be sure to add a little to make room for holes on both ends of the support. Cut the supports to length and drill holes in the ends.

Step 5: Mount Supports and Attach Them to the Platform

      Now that you have supports you can go ahead and mount them to the bike. You can stand them up straight to mark the holes on the rack platform. Once you've done this remove the platform and drill those holes. Put the platform back on and attach the supports. If it looks good you may want to take everything apart and round off any sharp edges and corners with an angle grinder.


      By now you can definitely see what your rack is going to look like. It's a good time to make sure you're happy with all the work you've done so far as you're mostly done with the load bearing portion of the rack.

      If everything is bolted on tight you can put some weight on the rack and see how it reacts. I was able to put enough weight on the very back that front end of the bike came off the ground. It took a lot of weight for this, and the rack felt sturdy under the weight. I would be comfortable with a person riding on this rack so long as they're not too big.

      I should mention that my bike did not have gears when I mounted the supports. After I got the gears back on the mounting bolt interfered with gear changes. I now have to get bolts that will fit the thread in the holes. This so far has been a pain though I haven't made it to the bike shop yet. Please comment if you know what size bolt I need. I've found some that are the right size, but the thread seems wrong.

Step 6: Adding the Wooden Platform

If you're happy with what you've done so far it is time to get to work on building a platform so your stuff has a place to sit. I decided wood would be a nice touch to the look of the rack. My dad builds fences for a living and had some 1"x2" cedar scrap laying around from a fancy wood fence he built.

Three boards are what fit best for me. You may have to trim yours down to get three in. Cut them to length(about 15" for me)

My idea here is simply to get three boards and drill three holes in each so a piece of all thread or rod can slide through to support them.

You can see how there will be a gap between the wood and frame. This will allow for pannier hooks later.


1.Cut the boards

2.Sand them smooth and round off the edges and corners

3.Line the boards up and mark them to be drilled

4.Drill the holes in the boards. Be sure to

4.Cut three pieces of all thread the width of the platform frame(I left mine a little long for now)
   -Leave a nut on both sides of the cut. you can use them to fix the threads that will get messed up when you cut the all thread.

5.Slide the boards and spacers onto the all thread how ever you want them
   -This is when spacers or washers are better than just nuts. It takes forever to thread the nuts all the way down.

6.If you've used nuts as spacers adjust them so that everything is straight and doesn't move

7.Set the platform on the platform frame and mark where holes should be drilled

8.Punch and drill the marked holes in the platform frame

9.Install the platform into the frame and secure it with lock nuts

10.Trim any excess all thread off so it looks nice and is no longer a hazard

Step 7: Finish It Up!

Put everything back together and you should be done now! Hope you like it. I haven't mentioned paint or finishing the wood because I'm gonna let you figure that out. There are plenty of excellent instructables on both of those topics. I plan to oil the wood and paint the metal parts of the rack whenever I get around to painting the whole bike. Bare metal will do for now.

I think I've pretty much met all of the design goals. I'm pretty happy with everything except my mom promptly called it cute when she saw it :-/

I plan to add a milk crate and a small tool box soon. I'll post some pics when I get around to it.

Comments

author
weldyrack (author)2015-02-13

Teak oil works well on the wood. Seals it, and brings the grain out. I have just joined this site, as I intend to build a cargo bike, and your type of rack was something I toyed with. Lighter than metal and looks good. Well done!

author
pyrogreasemonkey (author)2012-04-21

hey dude just go to any hardware store and they can help you. its probably a 5 or 6 mm x 1 thread per mm

author
escher7 (author)2011-10-23

Also - there should be some way to attach bungee cords. I use a rear rack all the time and you need to fasten things down for obvious reasons

author
jrh065 (author)escher72012-01-09

Well it seems the notifications system missed your comments or something. Oh well, I'm here now.

You can attach bungee cords to any point on the frame, so there are plenty of possibilities for that.

I did trim the bolts and replaced the nuts with acorn nuts, so they're actually smooth now.

author
escher7 (author)2011-10-23

2 minor criticisms. The projecting bolts are a disaster waiting to happen - ripped clothing etc. And the wood could be varithaned to bring out the grain and protect it from weather.

author
stormy0314 (author)2011-07-15

You asked for info on bolts. The threads are one of several standard sizes, from very fine to very course. Most people that work with hardware on a regular basis can just look at it and tell you the size. Just stop in a local mechanics shop aand they can tell you the size of the thread by sight. Now your next 'ible can be a front mounted bracket to balance your load.

author
jkm (author)2011-07-13

great job.
suggestion: there's hardly a perpendicular part on a bike, I don't think it would compromise strength if you aligned the supports at an angle similar to the seat post, or another part of the frame. (for looks & symmetry)
Also, consider cap nuts (if that's what they're called in the US), to protect the delicate skin of any passengers from chafing ;-)

author
scraptopower (author)2011-07-12

Sweet, this looks nice.

author
jrossetti (author)2011-07-10

Instead of trimming the ends of the cross-bolts, you could also just dip them in plastidip and use them for bungie strap points.

author
jrh065 (author)jrossetti2011-07-10

You have no idea how bummed I am. That's a really good idea, but I just trimmed those off about an hour ago. I'm sticking your idea in the 'ible at some point if you don't mind.

author
jrossetti (author)jrh0652011-07-11

It all balances out. :) I just bought a new rear rack a couple days ago, but I like your idea a lot more than the one I bought.

author
davis65536 (author)2011-07-11

Good work. The mounting points you're screwing the upper part of the rack to are indeed rack mounting points. They're sometimes called "braze-ons" (because they were always brazed on), and, if a bike doesn't have them, one can usually use "P Clips" to create mounting points.

I think you'll also find that the holes at the very top of the rear wheel dropouts are for mounting a rack and are M4 or maybe M5 thread. Does your bike have bottle cage bolts you can try for size?

Nice work though; wood's pretty classy.

author
ChrysN (author)2011-07-10

Nice!

author
redplanetcorridor (author)2011-07-10

Looks great!

Two points of feedback, which you asked for :)

- Use the little yellow window image tagging deal to tell us more about what's going on in the photos

- You don't have to tell us it's incomplete. It's like a cook apologizing for the meal before we've tried it. If you never said it wasn't done, I'll bet not many would have noticed. It's built, installed, and doing it's job already - It's just waiting on some paint. No biggie...

4 Stars!

author
jrh065 (author)redplanetcorridor2011-07-10

Thanks man!

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Bio: I'm a CS major at Louisiana Tech university. I make stuff when I get stressed out.
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