I hate walking as a mode of transportation.  It is just a slow, inefficient way to get from one place to another.  So this summer I decided it would be fun to have a tandem bike for Emily & I to get back and forth from the apartment to the Claremont Village. To my dismay the cheapest tandem I could find was on walmart.com and costs over $300.  Not much as far as bikes go, but I wanted to be thrifty and go used & cheap, if possible.  Then I found a custom tandem beach cruiser frame made from two bikes welded together for $30. Except for it lacking all the other parts that make up a bicycle, it was perfect.  I figured if I shoped online & salvaged from old bikes, i could build the thing for about $100.  So the build began.

Next up was buying a cheap old beach cruiser to strip of parts. Then came forks, bearings, cranks, chain rings, chain, chain tensioner, handlebars, stems, seats, seat posts and the pain of putting it all together. Nothing on this went together smoothly.

1st up was the front fork. I found a low rider springer fork, however the steering tube on the frame is too long for it, which makes it difficult to put on, plus the weight of the steel frame plus two riders seems too much weight for the spring. I still like the look and plan (soon) to brace the spring with metal pipe. It will eliminate any shock absorption, but at least it'll feel sturdier. Also, the low rider forks, although do look cool, ride horribly. Having the front wheel so far forward throws off the traditional physics of riding a bike.  Its a bit tricky to even ride it by yourself and requires a little extra practice with 2 people.

Second was the seat posts. the amount of rust inside the tubes made it impossible to slide the seat posts. So I bought a small honing tool and then used a sanding flap wheel. It got the rust but the seat posts were still way to tight. I even took it to the bike shop to verify I had the correct size seat posts - which I did.  Frustrated at the amount of wasted time I spent, I started hammering the seat posts into the frame.  Then my hammer's handle split in two.  After a hammer replacement,  I went to install a seats.  All the hammering mushroomed the tops of the seat posts and they needed to me cut off.  Plus the front seat post only goes in about 4 inches where it is caught from going further by some welding slag.  No problem, just more of the seat post to cut off. 

Third was the chain. It takes 3 regular bike chains to make the 2 chains of a tandem. No problem I thought, as a kid I took chains apart with a nail & vise grips.  Apparently things have changed in the bike chain world and a special tool is now absolutely required to add or remove links.  Thank goodness for friends with bike tools!  Tandems I learned must have 2 of the same size chain rings in order to keep the pedals in sync. Makes logical sense once you think about it, but having never dealt with tandems, why would I think it matters if both people pedal in sync? Well, apparently feet can hit, the frame has equal stress and it helps with balancing if both people are in sync.  So one of the only new parts on this bike is the front chainring. I bought it a a bike shop and paid about 4x more than I could have if I bought it online, but at that point I just wanted to finish and if the bike shop guy said its what I needed, then damit I was willing to pay anything. I regret this now because he sold me a solid black BMX chainring, however a traditional schwinn 'circles' style ring would have matched the look i was going for. But it works, its installed and it'll probably stay that way.

Then came the issue of chain tension.  The one and only thing the frame came with was a small gear to be used as a chain tensioner.  My chioce of chainrings (44T) on this particular frame happened to create an inconveniently goofy distance that made the chain very sloppy but removing one more link would have made the chain too short to connect at all.  The chain tensioner that came with it was too small to do anything useful, so I had a larger gear welded to a hub to use as a tensioner, unfortunately this didnt provide enough tension either.  So I drilled another hold in the mount and went back to the smaller tensioner gear. This works reasonably well, however if peddling fast, the chain will still come off, eventually I'll either add a second tensioner gear or opt for a spring loaded tensioner.

So I get the thing together and we try to go for a ride.  Turns out Emily's knees hit the rear handlebars.  Since I hammered in the seat posts, replacing it with a kicked back post was not an option.  So my options were limited to changing the seat or the handle bars.  Turns out I need to do both.  The seat I replaced with a "like new" banana seat from craigslist, and the handle bars are 7/8" however the rear handle bar stem is for 1"+ handlebar.  Ive cranked it down as far as it will go and the bars still rotate easially.  I have it shimmed temporarially, but I really need to change the bars (or the stem). Im thinking of changing both sets of bars to big ape hangers. One day soon it'll happen.

Once I thought I was finished, I realized the head set I was using was lacking a lock nut - apparently this is important to prevent the entire front end from unscrewing itself after repeatedly turning left and right.  So I bought a new one.  If anyone has installed a springer fork knows, to change the head set I needed to dismantle the spring assembly.  In doing so I broke the bolt off in the ring that connects to the steer tube.  (During the previous assembly, I cross threaded the bolt and tightened it down by force.  In taking it off, it just snapped.)  So after having the broken threads removed, I replaced the bolt with one that is 1/2" longer & automotive grade steel.  The extra length made it much easier to reassemble, plus I used a second nut to secure it, as I am now dubious of the locking abilities of the re-threaded ring.  

Then there was the handle bars. Since everything is parted from random bikes, the handle bars I had needed shims because they were just a little too small and riding a bike with loose handle bars is a little scary.  Plus, while riding it I had to hunch over to grab the bars. So in lieu of the shims I ended up at the Pomona indoor swapmeet for new 22" ape hangers and a stem.

Overall I am fairly happy with it.  How many low riding tandem cruisers do you really see around? However bike parts, even used, add up quick and I blew past my $100 budget.


Tandem Frame              $30
Old Beach Cruiser          $40  - for wheels, front crank arms, pedals
Front Fork                     $15
Rear handle bar stem     FREE
BMX junker                   FREE  - welded its rear wheel hub to a gear for a tensioner
Old Mountain Bike          $5      - for Handle bar stem, rear cranks, pedals,
Chains from Walmart     $18
Seat Post                      $9
New 44T chain wheel     $28  - could have been under $10 on ebay but I was over it.
Two New Seats              $30

Banana Seat                  $5

sissy bar                       $10  

Handle Bars                   $5
New Headset                  $8
Misc Nuts & Bolts            $1.25

Ape Hangers                  $25

new stem                       $8 
-------------------------------------------
Subtotal                       $237.25


Tools
Replace Broken Hammer     $10
Automotive Honing Tool       $10
Metal Cutting Wheel             $9
-------------------------------------------
Subtotal                              $29


I sold the extra bikes once I was done with them
Beach Cruiser Frame           ($10)
BMX Frame                         ($5)
Mountain Bike Frame           ($10)   
-------------------------------------------
Subtotal                              ($25)

TOTAL COST                        $241.25 + blood, sweat & labor

  
Part Duex

So just as Im almost done & eagerly waiting for the seats to arrive from amazon.com a coworker comes up to me and says "I hear you are building a tandem, you want mine for $100?" I go check it out and appreciate the fact that his is rideable, so I bought it.   Now I have 2 tandems.  Just the thing someone living in a 650 sqft condo with a 1 car garage needs.  But its all good, I foresee friends coming over and having bikes enough to transport everyone to the bars will be a good thing.  Plus if I cost average the bikes, in effect I paid under $175 per bike.

The fact that the chain rings are different size bothers me (note how the pedals aren't in sync), plus both bikes need hand grips.  Other than that this second bike rides good enough.  Just a few more things to do & Ill be done...hopefully....

Low rider update 2/14/09  - SOLD for $200 - I really only lost about $12 plus my time on this thing (I still have the tools). Im happy just owning the one.