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Rake
A motorcycle rake (frame neck angle) is the fork angle measured
from an imaginary 90 degree line.
The rake of a bike has a direct influence on the trail.
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Raked
Trees
I get lots of requests to put rake in the trees. Some people
want to use them to extend their stock bikes.
The simple answer is if you want that extended look . . .
consider, instead, raking your chassis by cutting your neck
and positioning it for longer tubes, chopper style.
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Offset
Both fork and, in the case of a springer front end, rocker
offset also have a direct influence on the trail.
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Trail
Trail is the distance between where the projected steering axis
hits the ground and where a vertical line down from the center
of the front axle hits the ground. |
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| Rake |
Rake
has a big influence on how the bike handles at different speeds
and under different riding conditions.
Increasing rake will improve stability when riding in a straight
line but an excessive rake can make bad handling in turns especially
at low speed. |
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| Trail |
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little or too much trail create handling problems. |
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diagram shows how both the fork offset and the rocker offset
on my springer push the wheel forward thereby reducing the trail. |
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Too
litte trail:
With negative or too little trail the bike will handle well
at low speeds but will easily develop a dangerous wobble at
high speed. |
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Normal
Trail:
The trail should be between 4 and 6.5 inches so that the bike
handles easily at both high and low speeds. |
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Too
much Trail:
You will have trouble balancing the bike at low speeds and it
will handle sluggishly at high speeds. |
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| Raked
Trees |
Using
"raked" trees will increase the angle of the forks
by 3 (or whatever) degrees.
This is NOT the same as adding rake because the steering axis
doesn't change. The result is that trail is DECREASED as the
contact patch of the tire moves closer to the steering axis.
This is OK if you have too much trail and want to decrease it.
BUT raked trees can result in negative trail.
Raked triple trees are really for use where the bike has a regular
glide font end and a neck rake angle of 40 degrees or more.
In these cases raked trees can reduce the trail to a shorter,
more manageable, distance. However too much rake in the trees
will result in too little trail. |
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