Mini Chopper Plans

Designed By Solution Design (Design Images not to be used without written permission) P.O Box 10, Cottam On, N0R 1B0 (Not To Be Resold Or Circulated) More info at www.minichopperplans.com

COPYWRIGHT 2002, SOLUTION DESIGN NOT TO BE RESOLD OR CIRCULATED

1

MINI CHOPPER PLANS BY SOLUTION DESIGN (Revision2A Nov6, 05)

CLICK HERE TO REGISTER & UPDATE

Frame#1 The Little Stretch (Page 6)

Frame#2 The Little Tyke (Page 27)

Frame#4 The Easy Brute (Page 62)

Frame#3 The Rat Fink (Page 41)

Frame#6 The Hulk (Page 90)

Frame#8 The High Boy (Page 116)

Frame#7 The Low Boy (Page 104)

Frame#5 The Black Widow (Page 74)

Most Popular



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Need To Know How? Need To Know NOW?

Then check out the worlds largest mini chopper resource on the web!

HardCoreMiniChoppers.com Heres a small sample of the topics you can learn from and

participate in:

Frame Building Engines Clutches/Torque Converters Bodywork / Paint Front ends Electrical Bar Stool Racers & Other Custom Rides

Some of the most knowledgeable builders in the industry call the Hardcore Mini Chopper Forum home.shouldnt you?

Welcome to Hardcore Mini Choppers



3

INTRODUCTION

Research the necessary cost & tools required to start this project. It would be a disappointment to start but never finish. Keep in mind that you could rent or have the more complex work done for you if you do not have the experience or the tools. Get written quotes for material and labor. This will help protect you from being overcharged.

Tools Required Tube bender Welder, (I use a small Lincoln 135t portable welder) Drill Wrenches, sockets, grinder, screwdrivers, hole saw, etc.

Where to Begin I started by building the frame, bending the necessary tubes to create the main

frame and the handlebars. I used the details I have provided to make these parts. I tack-welded the frame only until I had the complete mini bike built. I wanted to be sure the position of the handlebars; foot pegs and seat fit my nephew.

Make sure the engine and clutch are aligned straight with the rear sprocket. This is critical to smooth operation.

Make sure the rear tire is also aligned straight. I used a make-shift wooden jig to hold the frame while I measured to ensure the axel bolt was in the right position. I drilled the holes first, then using clamps, positioned them in the right position before tack welding.

Do not allow any pre-test runs before the brakes have been added. I have seen a few minor spills that could have been much worse because the bike was ridden without brakes.

Have all worked checked by a professional. Good welds are vital to safety! Measure twice - cut once. Be safe!!!!! I miscalculated a few times and had to go

back for more tube. I found out that it is a heck of a lot more expensive when you only buy in small quantities. Quite often the cut charge is more than the piece you may have needed.

Use only D.O.M tube. All water pipe, conduit, fencing, etc., have different properties. They

also are not a true and perfect diameter. When you bend these using a precision bender, the bends are weak because they do not fit the dies

correctly.



4

Disclaimer and Limitation of Liability

THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF MATERIALS, INFORMATION,

ACCURACY, ADEQUACY, COMPLETENESS, CURRENTNESS, VALIDITY AND QUALITY OF

INFORMATION IS WITH THE USER. IN NO EVENT WILL SOLUTION DESIGN BE LIABLE TO ANY

PARTY FOR ANY DIRECT, INDIRECT, SPECIAL, PUNITIVE OR CONSEQUENTIAL DAMAGES OR ANY CLAIM ATTRIBUTABLE TO ACCIDENTS, MISHAPS, FIRES, ROLLOVERS, EXPLOSIONS, FAILURES, ERRORS, OMISSIONS, OR OTHER

INACCURACIES IN, OR DESTRUCTIVE PROPERTIES OF ANY MATERIALS, MANUALS, INFORMATION

ECT

READ THE FOLLOWING ENGINES, AND THE EQUIPTMENT THEY DRIVE

ARE AND CAN BE VERY DANGEROUS TO OPERATE. THEY ARE ALSO DANGEROUS TO

WORK ON. IT IS ASSUMED THAT ALL PERSONS WORKING ON OR WITH THE MATERIALS IN

QUESTION ARE CERTIFIED AND QUALIFIED TO WORK ON OR WITH THE REQUIRED TOOLS.



5

Helpful Hints

Plan, Plan, Plan - Building on the fly is fun but can be costly! Take the time to understand the project, the materials and the total cost.

Measure twice - cut once!!!!!!!!!!!!!!! This is the golden rule!!!!!!!!

Good professional welds are important!! Do not compromise

safety!!!!! When welding the frame, tack it first!!!! You may want to change

the frame to fit your needs and a tack can be easily removed!

Build the jig; it is well worth the extra time. It will ensure the frame is straight and accurate

Ebay has some great deals!!!!!!!!!!!! Shop around for the best

prices!

Be sure you have brakes! Resist the temptation of that first ride unless the bike is complete.

Take your time!! Do not cut corners!! You will end up with a

much better final project

Be sure you know how to operate the required tools. If you dont, seek the assistance of somebody who does. This project can be a great learning tool.

Wear all necessary protective clothing when working with

grinders, welders, and other power tools.

Always wear safety glasses when working with ANY tools.



6

Frame Bill Of Material

Item Name Description Purchased Fabrication

Reqd Quantity

1. Frame D.O.M See frame B.O.M Yes Online links 2. Steering Neck D.O.M See frame B.O.M Could be either Online links 3. Engine mount plate See detail Could be either Online links 4. Axel hangers See detail Could be either Online links 5. Front gusset See detail Yes Online links 6. Jack shaft hangers See page Yes Online links 7. Fender supports See page Yes Online links 8. Fender mount brackets See page Yes Online links

Front End Bill Of Material 9. Front tire mount brackets See detail Could be either Online links 10. Front fork tubes See front end B.O.M Yes Online links 11. Triple Trees See detail Could be either Online links 12. Steering Bolt 3\4- 10nc x 6 long Yes Online links 13. Handle bar risers See detail Could be either Online links 14. Handle bars See detail Could be either Online links 15. Front tire assembly 16" or 20" See page Yes Online links 16. 17.

Engine Drive Train Bill of Material 18. 3.5hp - 6h.p side shaft engine I used a 5hp Tecumseh Yes Online links 19. Option #1 standard clutch & jack

shaft set-up See page Yes Online links

20. Option #2 belt driven torque-converter set-up

See page Yes Online links

21. Chain length to suit option 1 or 2 See page Yes Online links Online links

Rear Wheel Bill Of Material 22. Axel hangers See page Yes Online links 23. Bearing cages See page Yes Online links 24. 1" Diameter bearings See page Yes Online links 25. 1" Diameter live axel with retainers See page Yes Online links 26. Rear tire size 18.8-8.5-8 for wide tire

frame Or

15-6.00-6.00 for medium tire frame

See page

Yes

27. Rear Rim 4 bolt See page Yes Online links 28. Rear disc See page Yes Online links 29. Rear disc hub See page Yes Online links 30. Rim Hub See page Yes Online links 31. Rear sprocket See page Yes Online links 32. Rear sprocket hub See page Yes Online links 33. Throttle assembly See page Yes Online links 34. Front brake lever and cable See page Yes Online links

Custom Parts to Suit Your Taste 35. Gas tank See page Yes Online links 36. Seat See page Could be either Online links 37. Rear fender See page Yes Online links 38. Kick stand See page Yes Online links



7

Mini Chopper #1 The Little Stretch MEDIUM TIRE FRAME SERIES

REAR TIRE SIZE 15 X 6.00 6 FRONT TIRE 16 BICYCLE

ENGINE SIZE 2-6.5 HP

Suitable for riders who may want to convert their conventional mini bike into a mini bike chopper .If you have never rode a stretched-out mini bike, you might be better off

moving on to the next frame - The Little Tyke

NOT SUITABLE FOR BEGINNERS

Riding mini bikes with stretched-out forks requires skill and balance. Learn the basics on a conventional mini bike before graduating to a chopper



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Medium Tire Frame Bill Of Material

FRAME B.O.M

Detail # Material Wall Thickness Length Required 1 1.0Dia D.O.M .083 34.0 2 1.0Dia D.O.M .083 26 3/4 3 1.0Dia D.O.M .083 38.5 4 1.0Dia D.O.M .083 38.5 5 1.0Dia D.O.M .083 12 21/32 5a 1.0Dia D.O.M .083 12 21/32 6 1.0Dia D.O.M .083 20 7/16 7 1.0Dia D.O.M 083 18.5

8 (3 Required) 1.0Dia D.O.M .083 9.0 9 1.0Dia D.O.M .083 10 3/32 10 1.0Dia D.O.M Note***.120 6 1/4



9

FRAME DETAIL #1

Tube length 34.0, Diameter 1.0, Wall thickness .083 Two notches required



10

FRAME DETAIL #2

Tube length 26 3/4, Diameter 1.0, Wall thickness .083 Two 90 degree bends required I like to add a few extra inches to the ends and trim them to length when I tack weld the frame



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FRAME DETAIL #3

Tube length 38.5, Diameter 1.0, Wall thickness .083 One 75 degree bend with a 15 degree tube notch Bend radii is 3.5



12

FRAME DETAIL #4

Tube length 38.5, Diameter 1.0, Wall thickness .083 One 75 degree bend with a 15 degree tube notch This notch is opposite to that of detail #3 (See 3D view for more info) Bend radii is 3.5



13

FRAME DETAIL #5

Tube length 12 21/32, Diameter 1.0, Wall thickness .083 One notch and minor grinding to match to center frame tube (See 3D View for more info)



14

FRAME DETAIL #5a

Tube length 12 21/32, Diameter 1.0, Wall thickness .083 One notch and minor grinding to match to center frame tube

(See 3D View for more info)



15

FRAME DETAIL #6

Tube length 20 7/16, Diameter 1.0, Wall thickness .083 Two notches required



16

FRAME DETAIL #7

Tube length 18.5, Diameter 1.0, Wall thickness .083



17

FRAME DETAIL #8

Tube length 9.0, Diameter 1.0, Wall thickness .083 Two notches required 3 of these required for seat & jack shaft mounting



18

FRAME DETAIL #9

Tube length 10 3\32, Diameter 1.0, Wall thickness .083 Two notches required



19

FRAME DETAIL #10

Tube length 6 1/4, Diameter 1.0, Wall thickness .120

ENGINE MOUNT PLATE

Use plate steel 3\16 thick Center your engine and then transfer holes



20

AXEL & FRAME MOUNT PLATE

Use 1\4 thick plate steel if making these from scratch The hanger below is a modified hanger that you can buy cheap, just weld a

triangle shape extension to the top of the hanger to match the frame angle See the assembly views in the rear for axel and bearing mount info Transfer bearing mount holes to ensure proper pattern These can also be purchased on my website minichopperplans.com



21

FRAME GUSSET

Use 3\16 thick plate steel

When your frame is complete and you are happy with the angles and the position of the forks, be sure to add frame gussets. You can use a cardboard template and make a mock gusset and then trace it onto your plate steel.



22

MEDIUM TIRE FRAME JIG

This is the most important step in building your frame, this jig will ensure the frame is

assembled straight and accurate



23

Medium Tire Frame Jig Bill Of Material



24

Frame Assembly Information

Clamp or screw axel hangers in position, then tack weld

Weld detail 1, 2 & 10 together to make a sub-assembly

Finish the frame by measuring to be sure the frame details are in

their proper position



25

Main Starting Point for The Frame 1. Begin by tack welding the lower frame rails, foot rest and rear support. The

position of the rear support is dependant on the size of your rear tire. I also use it to hold the rear fender. Only tack weld these pieces !!!!!!!!!!!!!!!!!!!!!!!!!!! You may run into problems and find you would like to move some of the frame parts !!!!!!!!!

This set up will be the most important!



26

Medium Tire Frame Side Profile



27



28

Mini Chopper #2 The Little Tyke

REAR TIRE SIZE 15 X 6.00 6 FRONT TIRE 16 BICYCLE

ENGINE 2-6.5HP

Suitable for young riders and smaller engine sizes (2hp to 6.5hp). One of the benefits of a frame this size is the availability of parts. Most of these parts can be purchased from a go-kart or mini-bike parts supplier. This is a great frame for younger

riders because the forks are not as stretched-out as other models.

A GREAT BEGINNER

BIKE



29



30

FRAME DETAIL #1

Tube length 34 1\4, Diameter 1.0, Wall thickness .083 One notch required



31

FRAME DETAIL #2A & 2B

Tube length 14 3\4, Diameter 1.0, Wall thickness .083 One notch required per detail



32

FRAME DETAIL #3 & 4

Tube length 53 1\4, Diameter 1.0, Wall thickness .083 One notch required per detail

FRAME DETAIL #5

Tube length 9.0, Diameter 1.0, Wall thickness .083 Two notches per detail



33

FRAME DETAIL #6

Tube length 9 5\8, Diameter 1.0, Wall thickness .083 Notch 2 Places

FRAME DETAIL #7

Tube length 9 5\8, Diameter 1.0, Wall thickness .083



34

ENGINE MOUNT PLATE DETAIL

Use 1\8 mild steel plate

FORK DETAILS

Use 1 1\2 .085 wall tube



35

Little Tyke Rear Profile



36

Little Tyke Frame Dimensions



37

The Little Tyke Jig Bill Of Material



38



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40



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Fasten details 3 & 4 into the wooden jig Screw or clamp the axel hangers into position Weld the steering neck, detail #1, detail #2A, detail #2B and detail #7, together

then place into the jig Check to make sure all components are straight then tack weld Once complete, remove the frame, weld completely, and then move onto the drive

train



42

Mini Chopper #3 The Rat Fink WIDE TIRE FRAME SERIES

REAR TIRE SIZE 18.5 X 8.5 8 OR 205-50-10 FRONT TIRE 20 BICYCLE

ENGINE SIZE 2-9HP

NOT SUITABLE FOR BEGINNERS

Riding mini bikes with stretched-out forks requires skill and balance. Learn the basics on a conventional mini bike before graduating to a chopper



43

Wide Tire Tube Frame Bill Of Material

FRAME B.O.M

Detail # Material Wall Thickness Length Required 1W 1.0Dia D.O.M .083 38 11/32 2W 1.0Dia D.O.M .083 30 11/16 3W 1.0Dia D.O.M .083 43.5 4W 1.0Dia D.O.M .083 43.5 5W 1.0Dia D.O.M .083 17 5/32 5aW 1.0Dia D.O.M .083 17 5/32 6W 1.0Dia D.O.M .083 20 7/16 7W 1.0Dia D.O.M Note*** .120 23.0

8W (3 Required) 1.0Dia D.O.M .083 12.5 9W 1.0Dia D.O.M .083 11 1/8 10W 1.0Dia D.O.M Note***.120 6 1/4



44

FRAME DETAIL #1




45

FRAME DETAIL #2

Tube length 30 11/16 , Diameter 1.0, Wall thickness .083 Two 90 Degree bends required. I like to add a few extra inches to the ends and trim them to length when I tack weld the frame



46

FRAME DETAIL #3

Tube length 43.5, Diameter 1.0, Wall thickness .083 One 75 Degree bend with a 15 degree tube notch, Bend radii is 3.5



47

FRAME DETAIL #4

Tube length 43.5, Diameter 1.0, Wall thickness .083 One 75 Degree bend with a 15 degree tube notch, Bend radii is 3.5 Be sure to notch the tube opposite of detail #3



48

FRAME DETAIL #5





49

FRAME DETAIL #5a





50

FRAME DETAIL #6




51

FRAME DETAIL #7

Tube length 23.0, Diameter 1.0, Wall thickness .083



52

FRAME DETAIL #8

Tube length 12.5, Diameter 1.0, Wall thickness .083 Two notches required



53

FRAME DETAIL #9




54

FRAME DETAIL #10

Tube length 6 1/4, Diameter 1, Wall thickness .120

ENGINE MOUNT PLATE

Use 3\16 thick plate steel Center your engine and then transfer holes



55

AXEL & FRAME MOUNT PLATE

Use 1\4 thick plate steel if making these from scratch The hanger below is a modified hanger that you can buy cheap. Just weld a

triangle shape extension to the top of the hanger to match the frame angle See the assembly views in the rear for axel and bearing mount info Transfer bearing mount holes to ensure proper pattern These can also be purchased on my website minichopperplans.com



56

FRAME GUSSET

Use plate steel 3\16 thick When your frame is complete and you are happy with the angles and the position of the forks, be sure to add frame gussets. You can use a cardboard template and make a mock

gusset and then trace it onto your plate steel.



57

JIG WIDE TIRE FRAME

This is the most important step in building your frame; this jig will ensure the frame is assembled

straight and accurate



58

Wide Tire Frame Jig Bill Of Material



59



60



Weld detail 1, 2 & 10 together to make a sub-assembly

Finish the frame by measuring to be sure the frame details are in their

proper position



61

Main Starting Point for The Frame

Begin by tack welding the lower frame rails, foot rest and rear support. The position of the rear support is dependant on the size of your rear tire. I also use it to hold the rear fender. Only tack weld these pieces !!!!!!!!!!!!!!!!!!!!!!!!!!! You may run into problems and find you would like to move some of the frame parts !!!!!!!!!

This set up will be the most important!



62

WIDE TIRE FRAME DIMENSIONS



63

Mini Chopper #4 The Easy Brute

WIDE TIRE FRAME SERIES

REAR TIRE SIZE 18 X 8.5 8 OR 205-50-10 FRONT TIRE 20 BICYCLE

ENGINE SIZE 2-9 HP NOT SUITABLE FOR BEGINNERS

Riding mini bikes with stretched out forks requires skill and balance. Learn the basics

on a conventional mini bike before graduating to a chopper



64



65

FRAME DETAIL #1




66

FRAME DETAIL #2


FRAME DETAIL #3

Tube length 12 1\2, Diameter 1.0 Wall thickness .083



67

FRAME DETAIL #4 Tube length 53 1\4, Diameter 1.0, Wall thickness .083 One notch required

FRAME DETAIL #5

Tube length 53 1\4, Diameter 1.0, Wall thickness .083 One notch required



68

FRAME DETAIL #6


Engine Plate Detail

Use 3\16 thick mild steel plate



69

Frame Profile



70

The Brute Jig



71

Screw together - Do not nail



72



73



74

Load details 3, 4, & 5 into the jig Weld detail #1 to the steering neck outside of the jig Screw or clamp the axel hangers into position Tack weld detail #2 to the axel hangers Tack weld in detail #1 with the steering neck Check to make sure all components are straight, then tack weld Once complete, remove the frame, weld completely and then move onto the drive

train



75

Mini Chopper #5

The Black Widow



ENGINE SIZE 2-9 HP



76



77

Detail #1 For this detail use a 1 Diameter, .083 Wall, D.O.M Tube 37 11/16 long Make two notches as shown below



78

Detail #2 For this detail use a 1 Diameter, .083 Wall D.O.M Tube, 34 1/8 long Make (2) 90 degree bends and (2) 50 degree bends as shown below



79

Detail #3

For this detail use a 1 Diameter, .083 Wall D.O.M Tube 36 1\8 long Make (2) 90 degree bends and (2) 17 degree bends as shown below



80

Detail #4 & #6

For this detail use a 1 Diameter .083 Wall D.O.M Tube, 10 3/8 long Make one bend & two notches This detail does not have to be exact. It will hold the jack shaft mounting tabs



81

Detail #5 For this detail use a 1 Diameter .083 Wall D.O.M Tube, 12 1\2 long Make two notches

Engine Mount Plate Detail

For the engine mount plate, use a 12 X 7 3\4 plate, 3\16 thick Transfer the holes from the engine to mount in the proper location



82

Detail #7 & Detail #8

For this detail use a 1 Diameter .083 Wall D.O.M Tube, 50 1\8 long Make one bend and add two notches to complete A compound notch will be required to fit this tube to the neck Make sure the notch at the steering neck matches the neck tube diameter



83

BLACK WIDOW JIG





84

Black Widow Jig Bill Of Material



85



86



87



Weld detail 1 & 9 together but measure to make sure it is centered

Use clamps to align the frame and make sure all the frame pieces are square Only tack weld the frame first! You may want to make a change later Measure and Measure! Make sure the frame pieces are in the proper location! Detail #4 & #6 will mount as shown, these will hold the jack shaft



88

Black Widow Frame Side Profile



89

Black Widow Rear Profile



90



91

Mini Chopper #6 The Hulk



ENGINE SIZE 2-9 HP



92



93

Detail #1 For this detail use a 1 Diameter .083 Wall piece of D.O.M tube, 36 1\8 long Notch both ends as shown The 25 degree notch must match the steering neck tube diameter



94

Detail #2 & #3

For this detail use a 1 Diameter .083 Wall D.O.M Tube 36 1\8 long Detail #2 and #3 are the same



95

Detail #4 & #5 For this detail use a 1 Diameter, .083 Wall D.O.M Tube 49 1\8 long Make one bend and add two notches to complete A compound notch will be required to fit this tube to the neck

Make sure the notch at the steering neck matches the neck tube diameter



96

Detail #6 & #7

For this detail use a 1 Diameter, .083 Wall D.O.M Tube 10 3/8 long Make one bend & two notches This detail does not have to be exact. It will hold the jack shaft mounting tabs



97

Detail #8 For this detail use a 1 Diameter, .083 Wall D.O.M Tube 11 1/16 long Make two notches to match frame


For the engine mount plate use a 12 X 7 3\4 plate 3\16 thick Transfer the holes from the engine to mount in the proper location



98

The HULK JIG





99

The Hulk Bill of Material



100



101



102


Clamp or screw axel hangers in position, then tack weld Weld detail 1 & 9 together but measure to make sure it is centered

Use clamps to align the frame and make sure all the frame pieces are square Only tack weld the frame first! You may want to make small changes later Measure carefully! Make sure the frame pieces are in the proper location!

Detail #6 & #7 will mount as shown; these will hold the jack shaft



103

The Hulk Frame Side Profile



104

The Hulk Rear Profile



105

Mini Chopper #7 The Low Boy WIDE TIRE FRAME SERIES

REAR TIRE SIZE 18.5 X 8.5 8 OR 205-50-10

FRONT TIRE 20 BICYCLE ENGINE SIZE 2-9 HP



106



107

FRAME DETAIL #1




108

The Low Boy Side Profile



109

The Low Boy Jig



110

BE SURE TO SCREW THE JIG TOGETHER DO NOT NAIL

PRE DRILL THE SCREW HOLES SO THAT YOU DO NOT CRACK THE WOOD



111

FRAME DETAIL #2 & #3

Tube length 36.0, Diameter 1.0, Wall thickness .083 Two bends required



112

Detail #4 For this detail use a 1 Diameter, .083 Wall D.O.M Tube, 11 1/16 long Make two notches to match frame

Detail #5 & #6

For this detail use a 1 Diameter, .083 Wall D.O.M Tube, 10 3/8 long Make one bend & two notches This detail does not have to be exact. It will hold the jack shaft mounting tabs



113

Detail #7 & Detail #8 For this detail use a 1 Diameter, .083 Wall D.O.M Tube, 44 1\8 long Make one bend and add two notches to complete A compound notch will be required to fit this tube to the neck Make sure the notch at the steering neck matches the neck tube diameter


For the engine mount plate use a 12 X 7 3\4 plate, 3\16 thick Transfer the holes from the engine to mount in the proper location



114



115



116

The Low Boy Side Profile

Load details 7, 8, & 3 into the jig Weld detail #1 to the steering neck outside of the jig Screw or clamp the axel hangers into position Tack weld detail #2 to the axel hangers Tack weld in detail #1 with the steering neck Check to make sure all components are straight, then tack weld Once complete remove the frame, weld completely, and then move onto the drive

train



117

Mini Chopper #8 The High Boy WIDE TIRE FRAME SERIES

REAR TIRE SIZE 18.5 X 8.5 8 OR 205-50-10

FRONT TIRE 20 BICYCLE ENGINE SIZE 2-9HP



118



119

FRAME DETAIL #1




120

FRAME DETAIL #2 & #3 Tube length 36.0, Diameter 1.0, Wall thickness .083 Two bends required


Tube length 31 7/8, Diameter 1.0, Wall thickness .083 One bend & two notches required



121

FRAME DETAIL #6 Tube length 21 3/8, Diameter 1.0, Wall thickness .083 One notch required


For the engine mount plate use a 12 X 7 3\4 plate 3\16 thick Transfer the holes from the engine to mount in the proper location



122

FRAME DETAIL #7




123

Detail #8 & #9

For this detail use a 1 Diameter, .083 Wall D.O.M Tube, 10 3/8 long Make one bend & two notches This detail does not have to be exact. It will hold the jack shaft mounting tabs



124

The High Boy Side Profile



125

The High Boy Jig Plans



126

BE SURE TO SCREW THE JIG TOGETHER

DO NOT NAIL PRE DRILL THE SCREW HOLES SO THAT YOU DO NOT

CRACK THE WOOD



127



128

Load details 3, 4, & 5 into the jig Weld detail #1 to the steering neck outside of the jig Screw or clamp the axel hangers into position Tack weld detail #2 to the axel hangers Tack weld in detail #1 with the steering neck Check to make sure all components are straight, then tack weld Once complete, remove the frame, weld completely, and then move onto the drive

train



129

MINI CHOPPER FRONT END PLANS FOR BOTH MEDIUM AND WIDE TIRE

FRAMES

Detail # Material Wall Thickness Length Required 1 D.O.M .083 20.0 2 D.O.M Note*** .120 7.0

3A D.O.M Note*** .120 6.25 3B D.O.M Note*** .120 6.25 4 PLATE STEEL SEE DETAIL N\A 5 D.O.M Note*** .120 40.0 6 BAR STOCK SEE DETAIL AS REQD 7 PLATE STEEL SEE DETAIL SEE DETAIL



130

DETAIL #1

Tube length 20 , Diameter 7/8, Wall thickness .083 Two bends required, bend radii is 3.5

BE SURE TO USE 7\8 DIAMETER TUBE FOR YOUR HANDLE BARS, THIS IS THE INDUSTRY STANDARD. MOST HAND LEVERS AND CONTROLS ARE DESIGNED TO FIT 7\8 HANDLE BARS. IF YOU USE 1 YOU WILL HAVE A

TOUGHER TIME FINDING LEVERS



131

Detail#2 Tube length approximately 8.0 , Diameter 1.0, Wall thickness .120 Notch for 7\8 handle bars

Make the riser to suit your body position. You may also wish to buy a bolt-on type riser. I formed mine by cutting the arc on a 2x6. I heated the tube and bent it to the desired arc. I

then welded it to the triple trees.

FRAME DETAIL #3A & 3B STEERING NECKS

The most common steering neck is a 1 5\8, .120wall piece of D.O.M tube (this will require two bearings to be pressed-in). This is the best way to go!

Some older frames use a 1, .120 wall tube. This requires no bearings.



132

FRAME DETAIL #4 ** Scale this on a photocopier to use as a tracing template, use the dimensions to check scale accuracy.



133


Tube length 40, Diameter 1.0, Wall thickness .120



134

FRAME DETAIL #6

1\4 PLATE 1.5 X 3.75 Weld this detail to the forks, it can be welded on center or to the inside as shown

below



135

Mounting the Forks to the Frame! Option #1

Mount the forks to the frame using a 3\4-10nc x 8 or 1\2-16nc x 8 bolt Option #2

You may also choose to replace detail 3 with a 1 5\8, .120 wall D.O.M tube; this will allow you to use bearings in the neck. You will have to adjust the tube notches on the other frame components.

Option #1

Option #2



136

Jack Shaft Drive

1 Clutch More Info 2 Locking collar More Info 3 Bearing More Info 4 Jack shaft More Info 5 Sprocket More Info 6 Locking collar, bearing, Flangettes More Info 7 1 Diameter axel shaft & locking key More Info 8 Wheel hub More Info 9 Sprocket hub More Info 10 Rear sprocket More Info 11 Chain to match your sprockets More Info

The above picture shows a jack shaft set-up, which has been used to redirect power to the opposite side of the bike. To mount a jackshaft

you must weld two jackshaft mounting tabs to the frame. See the following page.

6

7 8 9

10

4 1

2

3

5 11



137

Jack Shaft Mounting Info

Medium Tire Frame

Wide Tire Frame

For the chain to clear the frame you will need to mount the jackshaft mount tabs above the base of the frame



138

Torque Converter Drive A torque converter set up is not as complicated as it may sound. When

you buy the unit it comes complete with everything you will need to mount it and use it. In most cases you can install one of these units in about 15 minutes. The unit will bolt to your engine using 4 bolts. The primary drive pulley will mount to your engines shaft.

T



139

If you choose to use a torque converter set-up you will need to add a

roller. I used a roller from a two-stroke dirt bike and mounted a small bracket to the frame. This will act as a support and guide to the chain

and keep it from rubbing on the frame.

Comet Torq-A-Verter TAV2-30



140

Live Axels Continued

Above you have a complete live axel set up



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Rear Brakes

Below I show a mechanical type brake caliper. This unit will need to be mounted to the frame. There are other options such as hydraulic disc brake set-ups and friction bands. If you are planning to use a mechanical brake system, I suggest the rotary brand mechanical disc brake part# 04-9306.

The rotary brand mechanical brake as shown above is one of the best

mechanical brakes available.



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Hydraulic Disc Brakes

You can dress up your chopper with a tricked-out hydraulic brake system. The rear disc brake can be easily mounted using two bolts as shown below. The pedal assembly will mount the same way.



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Other Rear Brake Options

Clutch Band Clutch Band: This style of brake is common on mini bikes. Using an angle iron bracket, it rides on the clutch. As the brake is activated, the band tightens around the clutch, stopping the bike.

Rear Drum Brake

Rear Drum: There is also a drum style brake available. I have never used one, but they do look slick.

Caliper Type Disc Brake The caliper brake system shown below rides on the rear drive sprocket. This unit can be mounted by making a custom bracket.

Chain Guard

Dont forget safety! Be sure to protect your little riders by adding a chain guard. This unit is available at mfgsupply.com



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Custom Front Pegs

Here are a few screen shots of my tricked-out foot pegs. I wanted a look that was a little different and was quite pleased with the results.



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You can even make the seat

Make a seat frame with 2 pieces of plywood cut to fit your frame. Glue high density foam to the plywood Then cover with leather, vinyl or any material you choose Staple the covering to the wood Hot-glue a piece of felt to hide the wood and staples

Choose your look!!!!

If old school is the look you are after, try adding a solo seat and a set of ape hanger handlebars



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Helpful Info

If your seat rides on the fender. Be sure to add supports!!!!!!!!!!!!!!!!!!!!!!!!!!!!

This is when you will want to be sure your engine fits correctly. Also be sure your rear tire has enough clearance. If you are using a rear disc brake, be sure the width of the frame is adequate. Also check for proper alignment from the rear sprocket to the front drive sprocket. I use a long straight edge to be sure they are straight.

This is a good time to position the engine mount plate and holes.



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Tube Notch Templates Cut the following templates and tape or scribe the profile onto your tube.

You can then grind the contour for an accurate tube notch

SOME PRINTERS MAY DISTORT THE SCALE OF THESE TEMPLATES. IF YOU MEASURE THE DIMENSIONS AND

FIND THEY ARE NOT TO SCALE, USE A PHOTOCOPIER TO RETURN THEM TO THE PROPER SIZE. THIS CAN BE EASILY DONE BY EXPANDING OR SHRINKING THE DRAWING USING THE PHOTOCOPIER CONTROLS.



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High Quality Parts

TRIPLE TREES

AXEL HANGERS &

FRONT TIRE MOUNT BRACKETS

AVAILABLE AT

https://www.minichopperplans.com/



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Online Part Suppliers

U.S Parts Suppliers

www.bmikarts.com www.mfgsupply.com

www.tricountysupply.com www.gokartsupply.com

www.cvmkarts.com http://www.georgessales.com/

www.johnsgokarts.com www.jsesc.com

www.crosstec.com www.minibikekits.com

Canadian Parts Suppliers

www.gokartexpress.com

www.idealkarts.com

Thanks & Good Luck!



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Other Projects Available From Solution Design

1.5 Diameter tube bender plans

1.0 Diameter tube bender plans

6 X 10 Utility trailer plans

2 Seat Dune Buggy Plans

4 Seat Dune Buggy Plans

Mini Bike Plans



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Be Sure To Sign Up At HardCoreMiniChoppers.com

Check out the worlds largest mini chopper resource on the web!

HardCoreMiniChoppers.com Heres a small sample of the topics you can learn from and

participate in:

Frame Building Engines Clutches/Torque Converters Bodywork / Paint Front ends Electrical Bar Stool Racers & Other Custom Rides

Some of the most knowledgeable builders in the industry call the Hardcore Mini Chopper Forum home.shouldnt you?

Welcome to Hardcore Mini Choppers



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MINI CHOPPER PLANS BYSOLUTION DESIGN (Revision2A Nov6, 05)INTRODUCTIONTools RequiredWhere to BeginREAD THE FOLLOWINGHelpful Hints

Fabrication Reqd

Engine Drive Train Bill of Material

Custom Parts to Suit Your TasteFRAME DETAIL #1FRAME DETAIL #2FRAME DETAIL #3FRAME DETAIL #4FRAME DETAIL #5FRAME DETAIL #5aFRAME DETAIL #6FRAME DETAIL #7FRAME DETAIL #8FRAME DETAIL #9FRAME DETAIL #10ENGINE MOUNT PLATEAXEL & FRAME MOUNT PLATEFRAME GUSSETFrame Assembly Information

FRAME DETAIL #1FRAME DETAIL #2A & 2BFRAME DETAIL #3 & 4FRAME DETAIL #5FRAME DETAIL #6FRAME DETAIL #7ENGINE MOUNT PLATE DETAILFORK DETAILSThe Little Tyke Jig Bill Of MaterialFrame Assembly Information

FRAME DETAIL #1FRAME DETAIL #2FRAME DETAIL #3FRAME DETAIL #4FRAME DETAIL #5FRAME DETAIL #5a(See 3D View for more info)FRAME DETAIL #6FRAME DETAIL #7FRAME DETAIL #8FRAME DETAIL #9FRAME DETAIL #10ENGINE MOUNT PLATEAXEL & FRAME MOUNT PLATEFRAME GUSSETWide Tire Frame Jig Bill Of MaterialFrame Assembly Information

FRAME DETAIL #1FRAME DETAIL #2FRAME DETAIL #3FRAME DETAIL #4FRAME DETAIL #5FRAME DETAIL #6Black Widow Frame Side ProfileBlack Widow Rear ProfileThe Hulk Frame Side ProfileThe Hulk Rear Profile

FRAME DETAIL #1FRAME DETAIL #2 & #3FRAME DETAIL #1FRAME DETAIL #2 & #3FRAME DETAIL #4 & #5FRAME DETAIL #6FRAME DETAIL #7DETAIL #1Detail#2

FRAME DETAIL #3A & 3B STEERING NECKSFRAME DETAIL #4FRAME DETAIL #5 & #6FRAME DETAIL #6

Mounting the Forks to the Frame!

Documents

Mini Chopper Plans