Project back ground
Since 1988
Building something that is truly your own is awesome. In the past I've
tried using different steering yokes and all kinds of things, but I never
really sat down and thought the modifications through. I just tried whatever
I thought might look good, and added stuff to increase performance. Because
I had no clear focus, it was difficult to adjust the settings on the bike
and there was always something else that needed work.
1989
Then
I got to work with a frame builder, Mr. Tabata, on a Kawasaki 1000cc works
racing bike project. I really got interested in the actual dimensions
of the bike and started to study it more. I began looking for ways to
have more fun riding my bike with its limitations rather than creating
something "totally new".
Another factor was the availability of parts. I moved from Japan to Hawaii about a year ago, but the availability of parts in Japan and the cost factor is quite different than that of the U.S. So the type of restrictions (financial ones were among the biggest) that I had, plus weather and actual riding conditions of the Japanese streets also helped shape the design of my bike.
Planning of frame components
1.
Caster Angle
Taking the limitations of the frame into consideration, I chose the largest
angle possible, 26 degrees. In actuality the angle on my bike is about
25.7 degrees.
2. Fork Offset
45mm is the amount of offset used in the 80's. The 80's was kind of the
bridge in designs between the old and the new. I bought a Z1000 S1 stem
set and based on that, I had a stem made for my H2.
3. Trail
The trail is designed at 105mm, but of course it is dependent upon the
type of tire, tire air pressure, and the fork settings.
4. Wheel base
I took the standard wheel base. The swing arm I had it made longer than
the standard so that I could adjust it anywhere between 1410 mm ±30mm.
5. Height
In order to increase the bank angle, I raised the height. I based the
setting on the Z1000R works machine. DimensionsI wanted my H2 to be more
of a sleek racing bike. In order to give it a slight under steer, I used
an 18" front wheel, decided on a 45mm fork offset, and so the trail
is 105mm and the wheel base is 1410mm. I based the design on the AMA Super
bike Kawasaki Z1000JR and KR1000F of the 80's. Decide on the "Character"
of the bike.
Deciding the Amount of Offset
A
change in the amount of offset affects the trail and the actual handling
of the bike. If you choose not to change the wheel size, but decrease
the amount of offset, it will increase the stability of the ride. If you
increase the offset, it will give you quicker handling. First decide on
the type of bike you want, after you choose the wheel size, you can decide
on the amount of offset.
Steering Yoke Plan1. Amount of Front Fork Offset
The amount of offset is determined by the type of wheel and the "character"
of the bike. I have found that the use of a smaller amount of offset (like
those for modern bikes especially sportsbikes) on a bike with a frame
like the H2 causes the handling to become clumsy and increases the unstableness
when hitting the corners. Of course this is also affected by the size
of the wheel and tire.
In order to give it a slight under steer, I used an 18" wheel and decreased the amount of the offset to 45mm, the same offset as the Kawasaki works machines of the 80's. Steering Yoke.
