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Original Year
1991
# of pieces
243
Categories
Other: Motorcycles
Dimensions
31(L)x11(W)x21(H)
Features
Steering, kickstand, V-2 engine
front and rear suspension
Other Views

8838 Shock Cycle

iso revolve
Click the image to download the LDraw file of this model.
Model by Koyan


Set 8838, released in 1991, was the first motorcycle to have both front and rear suspension.  It is a realistic looking off road motorcycle with a number of aesthetic features including a radiator and a rear fender.  It features a steerable fork, a retractable kickstand, a chain driven V-2 engine, and full suspension with a trailing arm in the rear and downtubes in the front.  Construction uses very few standard studs and is an early example of pinned construction with very few square angles.

There were quite a number of firsts with this motorcycle.  It utilizes the new head tube to support the fork and four of the new longer shock absorbers.  The rear wheel is chain driven by the V-2 engine.  The new wheels and tires first appeared on this model.  It is also the first motorcycle to include an engine using the round pistons.

This is one of my favorite Technic motorcycles.  It looks great and functions very realistically.  It's hard not to make a motorcycle sound when pushing this thing around.

Features

Steering
The front fork can be steered using the handle bars which are constructed of toothed connectors and axles.  The fork pivots around an axle which passes through the new head tube part.  A pair of triangle parts are used as triple trees.  The handlebar angle is fixed using toothed connectors.  The fork rake angle is set by the head tube.  The telescopic fork tubes are made from the new shock absorber elements.




steering     steering
Click for an animation of the steering in motion.
Engine
The V-2 engine is located in the frame under the fuel tank.  It is coupled to the rear sprocket via a chain.

The engine is made from cylindrical engine elements and is driven by the rear wheel.  The 24 tooth sprocket on the wheel is connected to a 16 tooth gear on the transmission.  A pair of 24 and 8 tooth spur gears further change the ratio.  Finally, a pair of 14 tooth bevel gears turn the torque at a right angle and into the crankshaft.   The crankshaft is offset 1/2 stud from center, giving the pistons a stroke of 1 stud.

The final gear ratio is (24:16) * (24:8) = 4.5:1.
engine     engine
Click for an animation of the engine in motion.
Kickstand
The split center stand is preloaded with a rubber band.  This serves to both hold it up and hold it down since the axle the band attaches to travels over center.
kickstand
Suspension
This model has both front and rear suspension with long travel using the new shock absorbers.  The layout is very standard for this type of motorcycle.

The rear suspension uses two shocks running from the seat down to a point just above the rear wheel axle.  The trailing arm pivots on the rear transmission axle, which also rotates with wheel motion.  The shocks bottom out before the tire hits the bottom of the seat.

The front suspension is a conventional telescopic fork type.  Compressing the front shocks by putting weight on the seat puts a lot of stress on the head tube part due to the rake angle.
suspension    suspension
Click for an animation of the front suspension in motion.
Click for an animation of the rear suspension in motion.
Wheels and Tires
This set uses two new 6 spoked white motorcycle wheels and tires.
Wheels
 

Other Views

Side View
side view
Top View
top view
Front View
front view
Back View
back view
Computer Render
Render

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