Introduction: Homemade Sport Utility Bike (SUB)

About: Engineer making renewable energy products for African entrepreneurs.
I was faced with two options for my bike cargo needs - build and hitch a trailer or find another less cumbersome solution. Enter the Xtracycle.

From the Xtracycle website:
With a bike trailer, you'll leave it at home because you prefer the way your bike rides without it, then later wish you had brought it along.

Great, I'm sold! Except... College... Money.... Oh yeah, lackofcash-itus :( Here's my $10 solution for a great idea!

Sorry Xtracycle guys - At the moment, I just can't afford to pay for the engineering :(

Step 1: Materials

Donor Bike with rear suspension (note the type of swing arm used)
Conversion Bike
Steel Tube
Grade 8 Bolt

Step 2: Disassemble and Test Fit

First, make sure your current rear wheel will fit in the dropouts on the donor bike's swing arm. If it fits, disassemble the donor bike's swing arm assembly leaving the axle bearing intact.

Step 3: Attach Swing Arm to Bike Frame

Using the threaded rod coming out of the swing arm bearing, attach the swing arm on the drop outs of your conversion bike.

To align the swing arm, attach the wheel and fold over as shown - the wheel should be in line with the seat tube. Once aligned, tighten the swing arm.

Step 4: Frame Support

We need to prevent the swing arm from flopping over and make the bike ridable. I bought a 3 foot section of steel tubing and made a support bar that links between the swing arm (where the spring/damper normally would connect) and the kick stand mount.

I drilled the holes.... With a Dremel. Even that angled hole. Terrible, I know, but I made due with what I had.

This support bar is held at the kickstand mount with a half inch grade 8 smooth shank bolt. I had a grade 5 full threaded bolt at one time - it failed (bent). It was my fault, I didn't take the time to do the engineering (which I was capable of) and I would have easily seen that it was not sufficient.

Step 5: Brakes, Chain and Derailleur

You'll need long cables for your rear brakes and rear derailleur. If the cables you're finding just aren't long enough - ask for tandem bike cables ;)

For my chain, I combined my donor's chain and my conversion bike's chain to make a suitable length. This is quite easy with a chain tool which you can buy for a few dollars at any bike shop. I keep the chain tool in my tool pouch in case I need to convert back while on the road.

You may be wondering - why didn't I attach the support tube at the top of the seat tube? My goal was to make this 100% removable and not require any welding. The sacrifice is higher stress loads through my support tube which has not been a problem after over five hundred miles of use ;)

Now you've got plenty of room to mount an extra big rack to carry all your groceries, large items or even a passenger!