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2-SPEED TRANSMISSION
The NT1 is equipped with a 2-speed transmission, allowing for explosive acceleration and high top
speeds. The 2-speed is controlled by centrifugal force. The 1st gear drives the layshaft through the
1-way bearing and the layshaft drives the front and rear transmissions. At a certain RPM of the
layshaft, the 2-speed shoes overcome the spring load binding them and they move outward where
they contact and “grab” the 2nd speed drum, thereby engaging 2nd gear; the 1st gear freewheels
on its 1-way bearing. As speed decreases, the spring load at some point overcomes the centrifugal
force and returns the 2-speed shoes onto the layshaft, thereby re-engaging 1st gear.
The 2-speed transmission in the XRAY NT1 may be adjusted for shift point and shoe gap:
• Shift-point screws determine when the transmission shifts between 1st and 2nd gear
• Gap setting setscrews adjust the gap between the 2-speed shoes and the 2nd gear drum
SHIFT POINT
The 2-speed transmission has spring-loaded shift-point screws that allow you to fi ne-tune the point at which the transmission shifts between 1st
and 2nd gear.
Determining the best shift point is mostly done through observation of the car is you drive it. You should be able to hear a change in engine tone
as the transmission shifts from 1st to 2nd gear.
There are three considerations when setting the shift point:
•
When to shift:
Relates to power/torque of the engine. Try to set the shift point before the engine “winds out.”
•
Where to shift:
Relates to specifi c tracks. The transmission should not shift into 2nd gear right before diffi cult corners or sections — this will lead to
inconsistency and tendency to overshoot those corners or misdrive those sections. Adjust the shift point so the car is easy to drive on the
particular track.
•
Gear ratio:
Gear ratio will affect the shift point setting. Ideally, the engine should stay well within its maximum powerband when shifting from 1st to 2nd
gear. This is a matter of experimentation and experience.
Shift-point Screw
Gap-setting Setscrew
XCA CLUTCH
CLUTCH SHOES
XRAY offers different clutch shoes for XCA clutch to change the characteristics of the clutch
and also wear and durability.
EFFECTS OF DIFFERENT CLUTCH SHOES
#338574 Clutch Shoe - White
• softer material
• higher initial bite, but more slippage
• more wear
#338575 Clutch Shoe - Yellow
• harder material
• less clutch slippage
• less wear
ADJUSTING CLUTCHBELL ENDPLAY
Clutchbell Endplay – Default Setting:
minimal (0.05 ~ 0.15mm)
Adjust the clutchbell endplay to a minimal amount (0.05 ~ 0.15mm) so that
there is only a slight amount of movement detectable. The clutchbell should
rotate freely.
1. Set the clutch shoe clearance before adjusting clutchbell endplay.
2. Remove the thrustbearing and clutchbell assemblies (including all ball-
bearings).
3. Push/pull the clutchbell along the crankshaft to measure the axial endplay.
There should be minimal movement (0.05 ~ 0.15mm).
4. If there is excessive endplay, remove the thrustbearing and clutchbell
assemblies (including all ball-bearings) and place shims (small size) over
the end of the crankshaft, in front of the clutch nut as indicated.
5. Reassemble the clutch.
6. Repeat steps 3–5 until there is minimal endplay.
7. Spin the clutchbell. It should spin freely without binding or dragging.
Measure endplay with this bearing installed
Apply shims on crankshaft to set endplay
to 0.05
~
0.15mm
Summary of Contents for NT1
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