TandemHearts

A few years ago, we decided that our Santana tandem wasn’t really working for us.  The biggest issue was the space for Veronica, in the stoker’s position.  On most tandems this space is significantly shorter than the comparable space on a regular road bike.  The handlebar position for the stoker also has very limited adjustability.  This leads to the stoker being folder over like a pretzel.  OK, maybe it isn’t that bad, and the  Santana is no worse than most tandems, but after riding her Rivendell Veronica found the tandem uncomfortable.  Secondary problems were the difficulty of packing 700c (road bike) sized tires in airline luggage, lack of disc brakes and the generic nature of it.  We wanted something with a little more character.

After looking around on the Internet, we picked Dave Bohm, Bohemian Bicycles, to build the bike.  Dave was originally trained as a jeweler and has made a variety of beautiful, unusual custom bikes.  He was not currently building any tandems, so it took some cajoling to convince him.  He decided that he would re-think every aspect of tandem design to try to improve it.  The result is amazing, quirky and sometimes odd.

The first thing to note about this bike is that it is long.  The wheel base is 4.5 inches longer than our other tandem.  That doesn’t sound like much, but it translates into more room for the stoker.  Bike tubes are not usually made this long, and won’t handle the stress of the spans required between captain and stoker.  Dave solved this problem by using massively over sized tubes and S&S couplers.  Single bikes use about 1 1/8″ diameter tube; the Santana has 1 1/4″ tubes; this tandem has 2″ tubes.   S&S couplers allow the bike to be made of shorter lengths of tube and also allow the bike to be broken down for transit.  Fully assembled, this bike is nearly 100″ long.

Because tandems have a fixed chain between the two riders, there needs to be a way to adjust the tension on this chain and to loosen it enough to be able to remove it.  This usually means moving the forward bottom bracket fore and aft as needed.  There are a couple of typical solutions to this.  This bike uses none of them.  Dave build a jewel of a bottom bracket, that looks like a piece of fine Victorian craftsmanship. Of course the Victorians didn’t have lasers to cut the parts.

With all that extra space in the stoker compartment, Dave built the world’s most adjustable stoker stem.  Veronica should have no trouble finding a comfortable position.

Rather than use the traditional derailleur system to change gears, this bike uses a Rohloff hub.  The Rohloff is a 14 speed internally geared hub.  This gives us a range of gears similar to bikes with a triple front chain ring, but removes all issues of adjustment or risk of damage in transit.  The hub also lets us use main stream cranks and chain ring setups, rather than tandem specific ones. The down side is that the hub is a little heavier than traditional shifting mechanisms.  The penalty isn’t significant considering the total weight of the bike, about 49 pounds ready to ride.

Since the bike is custom, we hand picked most of the components.  Carbon fiber brake levers are nice because they don’t get hot or cold.  The front brake rotor is a bit of whimsy from Dirty Dog.  The cranks are shapely works from Middleburn.

Dave added a number of finishing touches that really distinguish this bike from mass produced ones. The S&S couplers and seat post  binders are hand polished.  The drop outs have a level of decoration that only a custom builder would do.  There are a few heart designs on some smaller parts; mostly hidden from view.  The caps on the boom tube are wood; not for any reason other than it seemed like a good idea.

Over all, the bike is a work of art. It is truly one of a kind and we look forward to decades of riding.