Bike Rack, for Grizzly Peak Century
The Grizzly Peak Century can use a lot of bike racks, and each one we add potentially
improves the experience of our riders. We have successfully borrowed bike racks in the past,
but this has been less than optimal, and some of our better sources just don't exist anymore.
So I built the prototype shown below. Learning as we did from the borrowed bike racks, I wanted to
make one that was very strong (to support a lot of bikes, and to survive at least some abuse), would be
easy to move around, intuitive to assemble and disassemble, and be easy to store. Many of the otherwise
excellent bike racks we borrowed had intricately welded structures that were anything but stackable.
The racks were completed February 29, thanks to Jim Rosenau, Chris Witt and Micky Bloom of
Grizzly Heavy Industries. Click here
to see how they did it.
(Click on any picture to get a humongous version of it.)
The rack is a simple "saw horse" style frame, 10 feet long. The legs are 35° apart. Some have opined that we
might still need to connect the bottoms of the legs (with a wire?) to prevent them from spreading (which would bend
the legs). I "chinned" myself on this prototype in the middle, and on my smooth concrete driveway the legs didn't move at all.
Since I weigh as much as 10 carbon fiber zoot-bikes, I think we should be okay without extra bracing.
This prototype is obviously too high at 52". While the bicycle shown here is small (43cm), I'm guessing the correct
height is right around 45". This is an easy modification (I have lots of tools for making things shorter, not so
many for making them longer). Once we determine the optimal height we can go from there.
The legs are "splayed" 10° from vertical, which should substantially reduce racking (side to side) stress. This makes
the bike rack a little harder to fabricate (I am not just drilling a hole straight through the cross-beam), but I've figured
out a way to do it. The legs fit into the cross-beams fairly well, but if you lift the cross-beam and shake it,
there is a chance the legs will fall out. If this is a problem for assembly, a rubber band around the protruding ends (on top)
should help them stay put.
The black tube projecting from the end is a) a friction fit cap that holds the legs inside the tube for storage (see below), and b)
an interlink to connect racks together. While ground uneveness may prevent doing this in a lot of cases, if you have a string of
three bike racks you can hook them all together by inserting the "interlink" into the end of each bike rack. While I wasn't able to
specifically test this (I only made one prototype), the legs are designed so that they should be able to inter-leave with the
adjacent bike rack without bending the leg.
So far this is just a really good bike rack. But where it really shines is putting it away. The four legs all fit inside the cross-beam,
and the black tubes friction-fit into the ends as caps to keep the legs from falling out. Once packed, the bike rack is just a 2"x10' cylinder,
with nothing sticking out of the sides.
Since the packed racks are so compact, 14 could easily be stored in an ordinary joist space. (Don't go nuts; the racks weigh about 2.2 lbs per
lineal foot, so 14 racks are adding about 30lbs/sqft of live load.) You would need a joist space that is continuous (no blocking) for 10'.
But since any garage has lots of joist spaces, even if you could only store 5 or 6 around the x-blocking, it would be easy to store
a lot in very little space.
The collapsed racks weigh about 10 kilograms (22lbs) each. The parts to construct one (not counting the one custom made tool)
cost about $25 each.
For more information, contact Jeff Kurtock.