Friday, January 20, 2012

Tall bike assembly

Back to the super secret off-site shop for a project that I have been dying to see completed -- a tall bike!  I honestly felt like a kid helping his buddy with his first bike.  The anticipation and excitement were overwhelming.  But let me calm down and recount the events.

Dave has been talking about doing a tall bike for a long time.  There of course is not really a bluprint for a tall bike.  There are many example out there.  That's kinda the beauty, people get to design and express there creativity.  Dave had a unique idea for the steering...we'll get to that in a bit.  A welder and experienced metal worker was needed to bring the vision to life, enter Tom.

After much discussion and planning, Tom went to work welding the 2 frames together.  In less than 2 weeks, frames were joined, a custom swooping seat stay was added, a fork was cut and bent and chainrings were welded on for steering.

After machining, Dave sanded and painted.  With the tall bike ready for parts, he asked me if I wanna come over and help with assembly...HELL YA!  Obviously Dave was excited too, as there were already some parts on the bike when I arrived.
cranks were on when I arrived

Tom added a custom step for mounting this beast

note the addition of a long seat stay
My initial thought was wow this is cool...and blue.  Much like a smurf.  The first order of business was to get the steering going.  The bottom bike's fork came on the bike from Tom.  With the chainring welded on top of the steerer, it is kinda permanent now.  We installed the headset and fork on the top bike.  After a little alignment, the chain was installed and steering was active.  Why the offset forks you ask?

Many tall bikes just weld the 2 fork up and have 1 continuous fork running through the 2 frames.  Much simpler design.  But, in doing so the bike's center is set back further than normal.  The rider is situated more over the real wheel causing the bike to be somewhat rear weighted.

Dave's design called for a 4" offset.  After assembly, the handlebars ended in almost the same relationship to the wheel and fork as it was when it was only 1 bike.  This should create a more stable and predictable ride.
Shadow was not sure what to think of this contraption
 Added stem,  handlebars, grips (blue of course) and the front wheel to finish off the front
 of the bike.

With the front end done, it was time to assemble the rear of the bike.  Dave built in a drum brake for the rear wheel.  Routing the chain was easy, but the chainline looks crazy!

Here are a couple final pics.  We ran out of steam and Sierra Nevada so the brake lines will have to be added later.  Obviously, there were many more small details that went into this project, I've merely bored you with the bigger ones.

long and burly kickstand to keep her steady
The call to be ridden was tremendous.  Unfortunately, there was snow and ice outside and it's a long ways to the ground.  Test rides will have to wait a few more months.  In the mean time, thoughts of a second design are swirling...

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