Ural (Урал) - Dnepr (Днепр)

Russian MotorcyclePart XIV: Plunger, Swing-Arm

and Torsion Bar Evolution(

Ernie Frankeeafranke@tampabay.rr.com

09 / 2017

Swing-Arms and Torsion Bars for Heavy Russian Motorcycles with Sidecars

•Heavy Russian Motorcycle Rear-Wheel Swing-Arm Suspension–Historical Evolution of Rear-Wheel Suspension–Rear-Wheel Plunger Suspension–Rear-Wheel Swing-Arm Suspension

• One-Wheel Drive (1WD)– Rear-Drive Swing-Arm

• Two-Wheel Drive (2WD)– Rear-Drive Swing-Arm

–Not Covered: Front-Wheel Suspension Torsion Bar•Sidecar Frames and Suspension Systems–Historical Evolution of Sidecar Suspension–Sidecar Rubber Bumper and Leaf-Spring Suspension –Sidecar Torsion Bar Suspension–Sidecar Swing-Arm Suspension

•Recent Advances in Ural Suspension Systems–2006: Nylock Nuts Used to Secure Final Drive to Swing-Arm –2007: Bottom-Out Travel Limiter on Sidecar Swing-Arm–2008: Ball Bearings Replace Silent-Block Bushings in Both Front and Rear Swing-Arms

Heavy Russian motorcycle suspension started with the plunger (coiled spring) rear-wheel suspension on the M-72. This was replaced with the

swing-arm (pendulum) and dual hydraulic shock absorbers on the K-750. Similarly the sidecar suspension was upgraded from the spring-leaf

to rubber isolators and a swing-arm approach in the M-72M.

Trans-Literated Terms• Cornet: Splined Hub• Journal: Shaft• Stroller, Pram: Sidecar• Rocker Arm: Between Sidecar Wheel Axle and Torsion Bar• Swing-Arm• Torsion Bar (Rod)• Sway Bar: Mounting Rod• Suspension Lever: Swing-Arm• Swing Fork: Swing-Arm

2

Not Covered: Front-Wheel Torsion Bar

3

History of Rear-Wheel and Sidecar Wheel Suspension•Rear-Wheel Suspension–Original M-72 Suspension•Plunger (Coiled-Spring) Rear-Wheel Suspension•Ural’s M-61 and M-62 Also Used Plunger Suspension System

–Upgrades to Rear-Wheel Suspension• In 1958/9 Dnepr (KMZ) Introduced K-750, New Frame with Pendulum (Swing-Arm) Rear-Wheel Suspension and Coil-Spring Shock Absorbers • In 1965 Ural (IMZ) Introduced M-63 (Ural-2), M-66, M-67 and 8-103.10 which Transitioned from So-Called Candle-Frame of M-72/M-61/M-62 to New Bike Frame with Swing-Arm, Pendulum Rear-Wheel Suspension and Hydraulic Shock Absorbers

•Sidecar-Wheel Suspension–Original M-72 Sidecar Suspension•Steel Leaf Springs

•Until 1947, IMZ Did Not Let Sidecar Design Out of Gorky Plant•Later Ural and Dnepr Used Swing-Arm Suspension and Rubber Blocks, Replacing Leaf-Springs

–In 1955 Ural (IMZ) Introduced M-72M with Sidecar-Wheel Torsion Bar Suspension•Retained Steel Leaf-Springs•Torsion Bar Mounted in Rear Cross-Member of Sidecar Frame

•M-72M, M-61, M-62 Had Torsion Bar on Sidecar•Chinese-Built CJ750 (copy of M-72M) Has Torsion Bar Suspension–Has Both Leaf-Springs and Torsion Bar

–In 1968/70 Ural (IMZ) Introduced M-63 (Ural-2), which Transitioned from Steel Leaf-Springs of M-72/M-61/M-62 to New Sidecar Frame with Swing-Arm, Pendulum Sidecar-Wheel Suspension and Hydraulic Shock Absorbers

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Time-Line of Plungers, Swing-Arms and Torsion Bars

Heavy Russian motorcycle production began with the plunger rear-wheel and spring-leaf sidecar suspension. Demands for operation on

rough roads gave rise to swing-arms on both the rear-wheel and sidecar-wheel.

1940 19701950 196019551945 1965 1975

Sahara

1975 20051985 199519901980 2000 2010

Ural “Sportsman”

Taiga

Dnepr MB-750

Wjuga

Pustinja

Raven

Basic

DneprMT-12

DneprMT-11, MT-16

Mother of All Russian Sidecars: M-72 Production

M-72 Minor Redesigned and Issued as M-72M,

Torsion Bar Added to Sidecar

Dnepr Introduced Swing-Arm Rear-Wheel with K-750

Ural “Patrol”(non-Diff 2WD)

Ural “Gear-Up”(non-Diff 2WD)

Ural “Patrol-T”(non-Diff 2WD)

Dnepr MB-650

DneprMB-650M

Ural Introduced Swing-Arm Rear-Wheel with M-63

Ural M-61, M-62 ProductionPlunger Rear-Wheel,

Torsion Bar on Sidecar

Ural M-63, M-66, M-67 Production,

Swing-Arm Rear-Wheel and Hydraulic Shocks

DneprMB-750M

DneprMB-650

DneprMB-750M

Ural M-63, M-66, M-67 Production,

Swing-Arm Rear-Wheel and Hydraulic Shocks

Ural 650cc Production,Swing-Arm Rear-Wheel and

Hydraulic Shocks

5

Ural (Урал) / Dnepr (Днепр) Sidecar Drive Train and Rear SuspensionUral (Урал) Model Production Drive Train Rear-Wheel

SuspensionRear-WheelSwing-Arm

SidecarTorsion Bar

Sidecar Swing-Arm

M-72 1941-1950 Straight Final Drive (1WD) Plunger None (Plunger) None None

M-72K 1952-1958 Straight Final Drive (1WD) Plunger None (Plunger) None None

M-72M 1956-1960 Straight Final Drive (1WD) Plunger None (Plunger) 7220227 None

M-61 1958-1961 Straight Final Drive (1WD) Plunger None (Plunger) 7220227 None

M-62 (Ural-1) 1961-1965 Straight Final Drive (1WD) Plunger None (Plunger) 7220227 None

M-63 (Ural-2) 1965-1971 Straight Final Drive (1WD) Swing-Arm 6309080-Б 7220227(None Later)

None(6320020 Later)

M-66 (Ural-3) 1971-1973 Straight Final Drive (1WD) Swing-Arm 6309080-Б None 6320020

M-67 (IMZ-8.101) 1974-1976 Straight Final Drive (1WD) Swing-Arm 6309080-Б None 6320020

M-67.36 1976-1983 Straight Final Drive (1WD) Swing-Arm 6309080-Б None 6320020

Sportsman IMZ 8.107 1995-1998 2WD with non-Locking Differential Swing-Arm IMZ-8.107-09081 None IMZ-8.103-20019-20

8.103 Series “650” 1WD 1984-2002 Straight Final Drive (1WD) Swing-Arm IMZ-8.103-09081 None IMZ-8.103-20019-20

8.103 Series “650” 2WD 1999-2002 1WD with Engagable 2WD (No Diff) Swing-Arm IMZ-8.107-09081 None IMZ-8.107-20019-6Б

“750”Series 1WD 2003-Present Straight Final Drive (1WD) Swing-Arm IMZ-8.103-09081 None IMZ-8.1037-20019-01

“750”Series 2WD 2003-Present 1WD with Engagable 2WD (No Diff) Swing-Arm IMZ-8.107-09081 None IMZ-8.107-20019-01

Dnepr (Днепр) Model Production Drive Chain Rear Suspension

Rear Swing-Arm

SidecarTorsion Bar

Sidecar Swing-Arm

M-72 1951-1956 Straight Final Drive (1WD) Plunger None (Plunger) None None

M-72N (H) 1956-1960 Straight Final Drive (1WD) Plunger None (Plunger) None None

K-750 1959-1963 Straight Final Drive (1WD) Swing-Arm 5309200 7220227 650202-Б

K-750M 1963-1977 Straight Final Drive (1WD) Swing-Arm 5309200 7220227 650202-Б

MT-12 (Dnepr-12) 1974-1982 2WD with Non-Locking Differential Swing-Arm ВП09800 None ВП50510

MB-750 1964-1973 2WD with Locking (Engagable) Diff Swing-Arm ВП09800 None ВП50510

MB-750M 1973-1977 2WD with Locking (Engagable) Diff Swing-Arm ВП09800 None ВП50510

K-650/MT-8 1967-1971 Straight Final Drive (1WD) Swing-Arm 65009200 None 650202-8Б

K-650/MT-9 1971-1976 Straight Final Drive (1WD) Swing-Arm 65009200 None 650202-8Б

MB-650 1968-1984 2WD with Locking Differential Swing-Arm ВП09800 None ВП50510

MB-650M 1985-1991 2WD with Non-Locking Differential Swing-Arm ВП09800 None ВП50510

MT-10 1973-1976 Straight Final Drive (1WD) Swing-Arm 65009200 None 650202-8Б

MT-10.36 1976-1984 Straight Final Drive (1WD) Swing-Arm 65009200 None 650202-8Б

MT-11 (Dnepr-11) 1985-1995 Straight Final Drive (1WD) Swing-Arm 65009200 None КМЗ-8.15720200

MT-16 (Dnepr-16) 1986-1995 2WD with Non-Locking Differential Swing-Arm ВП09800 None ВП50510

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Motorcycle (Factory) Suspension Type Production

M-72 (IMZ, KMZ) Plunger 1941-1956

M-72K (IMZ) Plunger 1954-1960

M-72M (IMZ) Plunger 1956-1960

M-72N (KMZ) Plunger 1956-1959

K-750 (KMZ) Swing-Arm 1959-1963

K-750M (KMZ) Swing-Arm 1963-1977

Ural M-61 (IMZ) Plunger 1958-1961

Ural M-62 (IMZ) Plunger 1961-1965

Ural M-63 (IMZ) Swing-Arm 1965-1971

M-72 pioneered the plunger (coiled-spring) suspension, which was replaced in the K-750. Ural’s M-61 and M-62 also used the plunger suspension system.

M-72 Rear Suspension

Early Rear-Wheel Swing-Arm Suspension•Every Ural and Dnepr Has Swing-Arm Suspension with Spring-Hydraulic Shock Absorbers

–Except for M-72, M-61 and M-62, with Rear-Wheel Plunger (Coil-Spring) Suspension–In 1959 the Dnepr K-750 Appeared, Losing the Old Plunger Frame Design in Favor of a Swing-Arm Design, Giving More Suspension Travel and a Better Ride Over Rough Terrain

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1. Rear Fork Base Cap2. Spring3. Spring Housing4. Right Suspension Support5. Guide Sleeve6. Bar7. Buffer8. Lock Screw9. Absorber10.Stuffing Box

1954 M-72 Rear-Wheel Suspension

1. End Caps of Rear Fork2. Spring3. Spring Housing4. Right Suspension Support5. Guide Sleeve6. Bar7. Buffer

The M-72 had a plunger (coiled-spring) rear-wheel suspension.

Coiled-Spring Isolation between Motorcycle Frame and Rear-Drive

Rear-Drive

Motorcycle Frame

Motorcycle Frame

Rear-Drive

Motorcycle Frame

Motorcycle Frame

8

Evolution from Plunger (M-72) to Swing-Arm (K-750) Rear-Wheel Suspension

M-72

K-750

Swing-Arm Suspension with Spring/Hydraulic Shocks

Plunger (Coiled-Spring) Suspension

9

M-72 Sidecar

Nearly all sidecars from the war vintage M-72 production have a rigid wheel suspension for the sidecar, as seen by a frame loop going over the

top of the sidecar fender. This was also used on Chang Jiangs to about 1970, when they added a torsion bar suspension.

The M-72 “Tub” Is Suspended on Leaf-Springs

Frame Loop over Fender

10

Torsion Bar Suspension•Torsion Bar Suspension, a.k.a. Torsion Spring Suspension, Uses a Torsion Baras Its Main Weight-Bearing Spring•Torsion Bar, the Elastic Absorber, Is a Metal Rod with Circular Splined Ends–One End Is Firmly Attached to the Sidecar Chassis–Opposite End Terminates in a Lever, Mounted Perpendicular to the TorsionBar, that Is Attached to a Suspension Arm, Spindle or Axle (Rocker Arm)

•Vertical Motion of Sidecar Wheel Causes the Torsion Bar to Twist around Its Axisand Is Resisted by the Bar's Torsion Resistance, thus Achieving Elastic Couplingbetween the Sidecar Wheel and the Sidecar Body•Torsion Feature Is that Rotation in Only One Direction - Towards Twisting•Effective Spring Rate of the Torsion Bar Determined by Its Length, Shape,Material, Cross-Section and Manufacturing Process•Another Feature: Torsion Bar Can Be Used to Adjust the Height of the Sidecar

Torsion Bar with No Load Applied

(Static)

Torsion Bar with Wheel-Axle Load Applied

Sidecar Wheel’s

Rocker Arm

Sidecar Wheel’s

Rocker Arm

Sidecar Frame Sidecar Frame

Sidecar Wheel AxleSidecar Wheel Axle

11

Sidecar Frames, Leaf-Springs and Torsion Bars•Sidecar Frame Has Rigid, Reinforced, Double-Frame, Welded Tubular Construction•Rectangular Frame Connected to Ball Clamps (3,23) and Two Adjustable Tie-Rods (9, 37)•Brackets Welded at Rear of Sidecar Frame for Quarter-Elliptic Steel Leaf-Springs•Sideacar Frame (11) Connected to Torsion Bar Suspension

1. Motorcycle Frame3. Front Collet Chuck4. Bolt Collet Fitting 9. Rear Tie-Rod Mounting Bar11. Sidecar Frame12. Spring13. Spring Ladder14. Lever Axle15. Sidecar Wheel Axle16. Wheel Protective Cap22. Shoe Springs23. Rear Collet Chuck24. Idler Arm Rear Suspension36. Adjusting Fork Rod37. Front Tie-Rod Mounting Bar

Sidecar Wheel Axle

Ural M-63

Torsion Bar Suspensionof Sidecar-Wheel

12

M-72M Torsion Bar Suspension on Sidecar-Wheel

M-72 Sidecar Torsion Bar and Cornets

M-72 Sidecar Torsion Bar Cornet

Sidecar Torsion Bar Cornet Part #: 7220209

Ural (IMZ) introduced the torsion bar on the sidecar with the M-72M. It continued with the torsion bar from 1955 to 1965 with the M-61 and M-62,

abandoning it with the M-63 with swing-arm sidecar suspension.

Splined Collet Firmly Anchored in Sidecar

Frame Cross-Member

Other End of Torsion Bar Anchored in Splined Collet of Sidecar-Wheel Rocker-Arm

M-72 Sidecar-Wheel Rocker-Arm

Sidecar-Wheel Axle

13

K-750, M-61 and М-62 Sidecar-Wheel Torsion Bar(figure on next slide)

•Torsion Bar Suspension Consists of Torsion Shaft (Bar, Rod) Made of Special Spring Steel and Mounted Across the Sidecar Frame•Torsion Wheel Suspension Mounted in Rear Cross Tube (4) of Sidecar Frame•One End of Torsion Bar (5) Rigidly Fixed to Sidecar Frame•Other End of Torsion Bar Fastened to Axis of Sidecar-Wheel Arm (Rocker-Arm)•Torsion Bar (5) Is Splined on Each End for Insertion into Collet (Inner Sleeve) (15)• Inner Sleeve (Collet) Is Splined and Firmly Attached to Sidecar Frame Tubing•Axle of Rocker-Arm (3) Is Hollow with Internal Splines to Accept Torsion Bar•Sidecar Wheel Moves Up-and-Down Relative to the Frame, Twisting Torsion Bar•Vibrations Are Absorbed by Elasticity of Torsion Bar•Movement of Lever Is Limited in the Vertical Plane by Bracket (9) Welded to the Right Longitudinal Tube of the Sidecar Frame•Maximum Upward Blows on the Lever Arm Are Absorbed by Rubber Buffer (10), Attached to Limiter-Stop Bracket (9)

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K-750, M-61 and М-62 Sidecar-Wheel Torsion Bar (cont.)

1. Torsion Cap2. Seal Clip3. Axle of Lever Hub4. Rear Tubing of Sidecar Frame5. Torsion Bar (Rod)6. Locking Screws7. Claw-Clamp to Motorcyce Frame8. Left Tube of Sidecar Frame9. Travel Stop Arm10. Rubber Buffer11. Sidecar Wheel Axle12. Axle Lever (Rocker-Arm)13. Seal14. Ring Seal15. Collet (Splined Inner Sleeve)

9. Limiter Stop

Sidecar-Wheel Rocker-Arm

Sidecar-Wheel Rocker-Arm

Sidecar Torsion Bar and Cornets

Limiter Range

15

The rear-wheel is suspended on a trailing swing-arm, pivoting on rubber (silent-block) bushings located by removable pins in the frame and supported by dual hydraulic shocks/springs. The final drive attaches to the right-hand side of the swing-arm.

The sidecar-wheel is carried on a forked, trailing-link swing-arm, supported by a single hydraulic/shock/spring, pivoting in silent block bushings around long bolts (“lever pins”).

Rear and Sidecar Wheel Suspension (2000 650cc Shop Manual)

1. Motorcycle Frame 2, 7. Adjusting Rods (front and rear) 3, 6. Collet Lower Frame Sidecar Mounting Points4. Sidecar Frame5. crank

1. Rear Suspension Swing-Arm 10. Collet Clamp 20. Sidecar Wheel Lever2. Rear Mud Flap 11. Collet Clamp Screw 21. Brake Tie Rod3. Rear Grab Bar 12. Motorcycle Stand 22. Brake Drum cover4. Spring-Loaded Hydraulic Shock Absorber 13. Brake Pedal 23. Sidecar Wheel Axle5. Seat (Saddle or Tractor) 14. Sidecar Wheel Brake Lever 24. Protective Hood6. Strap 15. Sidecar Frame Legs 25. Tie Rod Nut7. Motorcycle Frame 16. Sidecar Wheel Brake Rod 26. Sidecar Fender8. Sidecar Adjusting Strut 17. Rear Collet Clamp Bracket 27. Rubber Body Suspension9. Sidecar Frame Legs 18. Rear Bracket Fastening Bolt 28. Parking Brake

19. Lever Pins (Long Bolts)

16

M-61 / K-750 Sidecar Frame (bike78.narod.ru)(figure on next slide)

•Sidecar Frame (Chassis) –Welded Tubular Frame

•M-61 / K-750 Sidecar Frame Fastened to Motorcycle Frame at Four Points–Two Ball Chucks (collets) at Bottom (to motorcycle frame)–Two Bolted Connections at Top (front under tank and rear behind the saddle)–Ball Joints on Motorcycle and Collets on Arms of Sidecar Frame–Petal-Shaped Bowl Draws Ball into Socket Using Bolt–Tie-Rods Adjustable in Length, Allow Alignment Relative to Motorcycle

•Sidecar Wheel Axle Resiliently Isolated from Frame by Torsion Bar / Rocker-Arm–Swing-Arm Lever Pivots on Sleeve Bearing with Rubber-Metal Bushings (Silent-Blocks)–Torsion Bar, Spring Shock Absorbers (like shock absorbers installed in rear-wheel suspension), and Rubber Mounts Used for Isolation–Torsion Bar Implementation•Sidecar Wheel Axle (1) Mounted on Rocker-Arm (2)•Torsion Bar (3) Twists as Rocker-Arm Moves Up-and-Down

•Ural M-61 Sidecar Dual Leaf-Springs•Dnepr’s K-750 Sidecar Has Rubber Isolators Instead of Leaf-Springs

Sidecar Attachment Clamp Joint1. Clamp (Collet or Claw)2. Nut3. Bolt

Sidecar Mounting Bar (Tie-Rod)17

1. Sidecar Wheel Axle2. Lever Axle (Rocker-Arm)3. Torsion Bar (Rod)4. Locking Screws to Adjust Wheel Axle5. Splined Hub (Cornet)

M-61 Sidecar Frame1. Connection Ball (Clam-Shell)2. Connecting Rods3. Sidecar Frame4. Sidecar Fender5. Sidecar Wheel Axle

K-750 / M-61 Sidecar Torsion Bar Suspension and Frame (cont.)

The rocker arm for the sidecar axle was isolated using a torsion bar mounted in the rear cross-member of the sidecar tubular frame.

Ural’s M-61 sidecar still retained the dual leaf-springs for suspension,whereas Dnepr’s K-750 used rubber bumpers plus the torsion bar.

7-Leaf Spring

18

Ural М-63 Frame and Sidecar (Рама и коляска)•Frame Is Main Weight-Bearing Element

–All Components and Assemblies Are Attached

–Double, Tubular, Welded, Closed Type of Frame1 - motorcycle frame

2 - front motor pin

3 - front collet chuck

4 - bolt collet

5 - motorcycle stand

6 - foot brake pedal

7 - step right driver

8 - supports clipboard

9 – sidecar rod mounting

frame

10 - passenger footrest

11 - sidecar frame

12 - spring

13 - spring clamp

14 - wheel axle lever

15 - sidecar wheel axle

16 - protective cap kit

17 - protective disc brake

drum

18 – buffer

19 – sidecar fender

20 - turn lamp

21 - carrier body

attachment

22 - shoe springs

23 - back collet chuck

24 - idler arm rear

suspension

25 - shock absorber

26 - license plate bracket

27 - yoke back plate

28 - passenger seat

29 - passenger handle

30 - back plate

31 - driver's seat

32 - gas tank bracket

33 - left footrest Driver

34 - bracket motor

35 - rear motor hairpin

36 - adjusting fork rod

37 - sidecar rod mounting

frame

.Sidecar frame is connected to the motorcycle frame thru collets 3 and 23 and two rods (9 and 37). At the rear of the frame are welded brackets for

the quarter-elliptic leaf springs. The sidecar wheel frame (11) is connected to the torsion bar suspension. To protect against contamination of

brake drums, the inner cavity is closed (17).

Torsion Baron Sidecar Suspension

19

Ural М-63 Sidecar (коляска) Torsion Bar

1 - plug torsion

2 - gland (seal)

3 - hub axis of the lever

4 - rear frame tube

5 - torsion bar

6 - tightening bolts

7 - rear bracket collet connection

8 - left tube stroller frame

9 - stroke limiter control arm

10 - rubber buffer

11 - wheel axle

12 - lever of the wheel axle

13 - seal

14 – gland (seal) ring

15 - lever pivot pin

The torsion arm is mounted in the rear transverse frame tube (4). The torsion bar (5) has ends of small triangular splines for connecting

the inner tube and the axis of the coupling arm (15). The inner sleeve has a slot-pipe hole and is welded to the frame tube. The axis arm (3) is hollow with

internal splines. Outer surfaces polished lever pivot pin mounted in the hub axis (3). At the outer end of the shaft lever attached a woodruff key and

bolted wheel axle lever (12). The hub axis of the arm is inserted into the back of the frame cross (transverse) tube and the flange is attached to the frame of the sidecar. Moving the lever wheel axis in the vertical plane is limited by the

bracket (9) welded to the right of the longitudinal frame tube. Sharp fluctuations are absorbed by the rubber buffer (10) attached to the bracket.

20

MB-750

MT-16, MB-650M and MB-650M1

MT-12 and K-650

Sidecar Attachment Clamp Joint1. Clamp (Collet or Claw)2. Nut3. Bolt

Sidecar Attachment to Motorcycle1. Front Tie Rod2. Middle Tie Rod3. Rear Clamp4. Front Clamp

Mounting Rods or Sway Bars and Claw Fittings

Sidecar Claw Coupling

Collet or “Clamshell”

Sidecar Mounting Bar 21

With the tub removed, the sidecar drive shaft and gear reducer is clearly seen.

Dnepr 2WD Sidecar Transverse Drive Shaft

Sidecar Gear Reducer

Transverse Propshaft

Transverse Propshaft

22

Ural M-63, M-66, M-67 Swing-Arm Frame

1.Silent Block Pendulum Fork2.Spacer3.Plug4.Bolt lower tip5.Swingarm Rear Suspension Fork6, 7. Threaded Bushing Assembly8. Pendulum Fork Bolt9. Washer10, 11, 12, 13. Reinforcing Plate14. Rubber Bushing15. Frame16. Spring Shock Absorber

4 Holes for Mounting Swing-Arm Directly to

1WD Rear Drive Casing

Because Ural’s M-63 / M-66 / M-67 do not offer 2WD, the swing-arm is not C-shaped on the open end.

23

Ural M-63 (Ural-2) with Rear-Wheel, Swing-Arm Suspension

The M-63 was the first Ural to use a rear-wheel, swing-arm suspension. Unlike Dnepr (KMZ) bikes, the swing-arm is on the outside of the frame.

24

M-63 Suspension: Plunger, Torsion Bar or Swing-Arm?

1963 (Start of M-63 Production Line)

1972 (End of M-63 Production Line)

Torsion Bar (No Swing-Arm)

Swing-Arm (No Torsion Bar )

As strange as it may seem, Ural changed motorcycle and sidecar suspension in mid-stream. I’m sure that never happened before!

Plunger (from M-62 Parts)

Swing-Arm (from M-63 Parts)

25

Pining Down the Year of Change

1968 M-63

1970 M-63

It appears that by 1968/70, Ural had instituted changing replacing the plunger with the swing-arm on the motorcycle and

replacing the torsion bar with a swing-arm on the sidecar.

Swing-Arm (No Torsion Bar )

Swing-Arm (No Torsion Bar )

Swing-Arm

Swing-Arm

26

1WD versus 2WD Suspension of Rear Drive

Gearboxes are also distinguished by the appearance and method of fastening to an arm rear suspension.

2WD: C-Shaped Fork of Rear Drive Swing-Arm

•Swing-Arms Differ on the Drive Side–1WD Swing-Arm Has a Simple Plate Which Bolts to Four Studs around the Axle Hole of the Rear Drive Casing–2WD Swing-Arm Has a C-Shaped Fork Which Attaches to the Circumference Bolts on the Rear Drive Casing

27

MT-16 Rear Drive and Sidecar Wheel Gear Reducer

Swing-Arm Suspension

Differential rear Drive,Transverse Axle and Sidecar Gear Reducer

2WD Swing-Arm Suspension

Sidecar Pendulum Gear Reducer

Sidecar Pendulum Gear Reducerand Sidecar Wheel Brake

(Ken Ulrich U-2 Cycles)

28

IMZ-8.108-40 Tourist and IMZ-8.107 Sportsman

1. Rear Suspension Swing-Arm2. Rear Mud Guard3. Rear Grab Bar4. Spring-Loaded Hydraulic Shock Absorber5. Seat (Tractor or Saddle)6. Strap7. Motorcycle Frame8. Sidecar Adjusting Strut9. Sidecar Frame Leg10. Collet Clamp11. Collet Clamp Screw12. Motorcycle Stand13. Brake Pedal14. Sidecar Wheel Brake15. Sidecar Frame Leg16. Sidecar Wheel Brake Rod17. Rear Collet Clamp Bracket18. Rear Bracket Fastening Bolt19. Lever Pins20. Sidecar Wheel Lever21. Brake Tie Rod22. Brake Drum Cover23. Sidecar Wheel Axle24. Protective Hood25. Tie Rod Nut26. Sidecar Fender27. Rubber Member of Body Suspension28. Parking Brake

The sidecar frame is coupled to the motorcycle frame through collet clamps (10), rear collet clamp brackets (17) and two frame legs (9, 13).

29

Examining the Chang Jiang (CJ750) Motorcycle•Chang Jiang (CJ750) Is Daughter of M-72–CJ750 Motorcycle and Sidecar Based on the 1956 Soviet IMZ (Irbitski Mototsikletniy Zavod) M-72, Which Was Derived from the 1938 German R71–In the USSR, Now That the Side-Valve (SV) Model Had Become Obsolete, Manufacture of the Old M72 Offered It to Their Chinese Neighbors–In 1957, the M-72 IMZ Production Line Transferred to People’s Republic of China (PRC) State-Owned, Gan Jiang Machinery Factory, and Renamed the Chang Jiang 750–Early Motorcycles Built Using Various Imported Russian Parts, and Even Some Complete Russian-Made M-72s Relabeled as CJ750–Side-Valve CJ750 Still In Production with Few Changes from Original Design

•Examining the Chang Jiang (CJ750) Helps to Understand the Modern M-72–Often the CJ750Drawings Are Copies of 1955 M-72 Drawings

•Chang Jiang 750 M1, CJ750 M1S (Super) and CJ750 M1M All Have Torsion Bar Suspension, Rocker Arm for the Sidecar Suspension and Plunger Rear Wheel Suspension

CJ750 Sidecar Torsion Rod

CJ750 Sidecar-Wheel Shaft Rocker ArmCJ750 Sidecar Springs

30

Chang Jiang (CJ750) Side-Wheel Axle Assembly (Sidecar-Wheel Shaft Rocker Arm)

1. Split Pin (Cotter Pin) 2. Castle Nut 3. Washer 4. Drum Cap 5. Rocker Arm6. Torsion Rod 7. Side-Wheel Shaft 8. Screw9. Washer 10. Rubber Buffer11. Bolt 12. Plug 13. Locking Spring Ring 14. Nut 15. Tab Washer16. Lip 17. Sealing Gasket 18. Felt Ring 19. Sealing Washer 20. Bushing21. Fly Sleeve 22. Fly23. Key 24. Bolt25. Washer 26. Washer 27. Split Pin (Cotter Pin)

The CJ750 diagram clearly shows the torsion bar in the 1951 version of the Russian M-72.

Sealing Washer

Packing

Felt Ring

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CJ750 Sidecar Frame Assembly1. Sidecar Frame 2. Side-Wheel Mudguard 3. Mudguard Middle Support 4. Nut 5. Spring Washer 6. Bolt 7. Anti-Shock Screw Shaft 8. Washer 9. Support 10. Fillet 11. Bush 12. Leaf Spring U-Bolts13. Spacer14. Spring Steel Plate 15. Anti-shock Shaft Bracket 16. Spacer 17. Rivet 18. Spring Washer 19. Nut20. Bolt 21. Jaw Pipe Joint 22. Protective Plate 23. Nut 24. Spring Washer 25. Nut26. Adjusting Screw 27. Split Pin 28. Bolt 29. Nut30. Spring Washer 31. Rear Mounting Rod 32. Nut 33. Rear Mounting Screw34. Lug 35. Spring Washer 36. Nut 37. Nut38. Spring Washer 39. Joint for Mounting Rod40. Front Mounting Rod 41. Anti-Shock Rubber 42. Front Mounting Screw 43. Bolt 44. Washer 45. Screw 46. Spring washer 47. Washer 48. Nut

The CJ750 sidecar frame assembly mimics the 1951 version of the Russian M-72.32

CJ750

Because it was a Chinese, we can see some of the old features of the M-72, including the sidecar.

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CJ750 Frame Assembly1. Steering Bearing 2. Motorcycle Frame 3. Nut 4. Washer5. Bolt6. Fixing Bolt 7. Brake Rubber 8. Kick-Stand9. Cotter Pin 10. Kick-Stand Support Shaft 11. Kick-Stand Washer 12. Kick-Stand Spring 13. Foot Pedal Rod 14. Foot Pedal Rod 15. Foot Pedal Rubber Sleeve 16. Battery Short Strap 17. Battery Long Strap 18. Battery Tightening Nut 19. Engine Body Link Support 20. Angle Iron 21. Clip 22. Rubber Spacer 23. Spacer24. Nut 25. Screw 26. Spacer 27. Bolt28. Washer29. Nut 30. Nut 31. Washer32. Bolt

16-18 Battery Holder8-12 Kick-Stand

13-15 Foot Pedal

The CJ750 sidecar frame assembly clearly shows the attachment points for the plunger suspension system.

Attachment Points for Plungers

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M-72 Modeling (www.smcars.net)

Modeling of the old M-72 sidecar clearly shows the rigid frame over the fender.

7-Leaf Spring

Bracket for Sidecar Tub

Dual Spring-Leaf Suspension of the Tub

Plunger (Coil-Spring) Rear-Wheel Suspension

Original M-72 with Bar over Sidecar-Wheel Fender

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