Group 22 - Beginner Cruiser Motorcycle

PRODUCT SUMMARY

Beginner Cruiser Motorcycle

Group 22 and Group 21 are going to disassemble a beginner Cruiser Motorcycle. Our group (Group 22) will disassemble the back half of the motorcycle while Group 21 will disassemble the front half of the motorcycle. Both groups will work simultaneously on the engine ensuring that it is done carefully and that it only needs to be reassembled once.

GROUP INFORMATION

Steven Leslie: Group Leader and Communications Manager:

• Main contact and coordinator for the group. Responsibilities include notifying all team members of meeting time, places, and goals.
  

Tom Nowak: Dissection and Photo Documentation Expert:

• Responsibilities include documenting the dissection of the product with photos, and aiding in the overall dissection of the product.
  

Ted Pitera: Dissection Manager and Solid Modeling Leader:

• Responsibilities include creating the solid model used in final documentation of the product, as well as overseeing the dissection process by all other members of the group.
  

Malcolm Adams: Chief Wiki and Dissection Expert:

• Responsibilities include chief editor of the wiki page, as well as overall editing of the project. Also aids in the overall dissection of the product.
  

Matt Handley: Dissection Expert and Product Documentation:

• Responsibilities include written documentation of the entire product dissection process and aiding in the overall dissection of the product.

REQUEST FOR PROPOSAL

Work Proposal

Work Proposal:

Group 22 and 21 are working on the mini road bike. Group 21 is reverse engineering the front half of the bike while our group, 22, is taking apart the back end of the bike. For front half of bike disassembly see Group 21. Although both groups are working independently, both groups will be meeting the third week in order to take apart the engine together. This will ensure neither group is short handed time for dissection.

Materials:

For our group to reverse engineer our product, we need to have the right tools. A few of the tools that will be needed are a ratchet and socket set, an Allen wrench set, needle nose and Flathead pliers. The Allen wrenches as well as the ratchet and socket set will be used for the majority of the disassembly. The Philips and Flathead screwdrivers will be used for smaller components such as the light. The Flathead will be specifically used for the valves on the carburetor. A crescent wrench will be used for removing the front fork from the frame of the bike. A gear puller and channel locks are also good tools to have for the project.

Time:

1. We will take a week to take apart the brakes, gears, and rear wheel assembly. Our plan is to take everything behind the engine while group twenty-one takes everything in front of the engine.
2. The front fork, headlight and handle bar assembly will be taken apart by Group 21. This will eliminate the need for both groups to perform the assembly and disassembly of the bike twice. For front half of bike disassembly see Group 21.
3. Finally the engine and clutch will take the remaining two weeks to take apart and analyze.

For a more detailed view of Group 22's proposed time line see the Gantt chart under the Management Proposal section.

Challenges:

Some challenges we are expecting to encounter include taking apart the clutch, reassembling the engine, reassembling the pull start, taking the gears off, and putting the brakes back into working order. The clutch works on centrifugal force using springs to engage and disengage the power to the rear wheel, group members who have worked with clutches before explained how difficult they can be to work with. The reassembly of the engine needs to done in such a way that all of the peaces must go in and be tightened to a manufacturer specific tolerance. As for the gears some of them look to be held on by only a bolt while others look like they were pressed onto a spine and if that’s the case a gear puller may or may not work. The reassembly of the brake is the last part that we foresee having a problem with, not that we think it is overly difficult but experience says that it may take a few tries to get them to an acceptable state.

Capabilities:

Members of group have owned a motorbike prior to project and are familiar with the parts and components of the project bike. One member has experience with computers well enough to work on the Wikipedia web site. One member has experience completely taking apart an engine. The back end of the bike has the brake components, and multiple members are familiar with taking off and reapplying brakes on vehicles.

Shortcomings:

Most members don’t have much solid modeling skills or web site building skills. Time constraints on the due dates will be challenging since all members are full time students. Most of the group members have not taken apart an engine, and the engine is agreeable to be the most testing part on the project.

Management Proposal

The following Gantt chart outlines our plan from start to finish including reassembly and delivery of the project. The chart starts from October 20th 2009 and is separated into 10 day increments until the final due date of December 11th 2009. The opening steps of the project are located at the bottom of the chart and the final portion of the product is located at the top of the chart.

Table 3.1: Gantt Chart

Initial Product Assessment

What is the intended use of your product?

Our product is meant to be used as a recreational vehicle for off road riding, as well for regular day-to-day transportation. The product is more aimed at home use rather than professional use. The bike has off road and racing capabilities. The two functions that can be used for this product are transportation and even the possibility of hauling small loads. Also, and possibly the most fun, would be the function of racing the motorbike.

How do you think the product works?

A 196cc gasoline engine drives our product. The gasoline is used in a combustion process that powers a shaft that will turn a chain attached to the rear wheel. The front of the bike has a freely rotating wheel that enables the bike to turn, as well as an automatic headlamp for safety. During the combustion process, chemical energy is used to produce mechanical energy. There is also electrical energy, radiation energy, and internal energy used in our system. The chemical energy is transformed into mechanical energy to move the bike, and into electrical energy to power the headlamp. The light in the headlamp is emitted radiation energy, and there is internal energy stored in the original gasoline used to start the system.

How complex is the product?

The most complex part of our mini road bike is its engine. However looking more closely, each individual component becomes less and less complex as your break it down. The mini bike is less complex then a regular motorcycle, or even a car, but much more complicated than a human powered bike. We estimated that there were around 50 or so components used. This number includes the brakes, frame, tires, light, engine, capacitor, chain, shaft, and many other components that go into making the bike functionable.

What materials are used?

The product is comprised of many different materials both seen on the surface of the bike and in the engine. Some of the materials that are not clearly visible are different metals, rubber, plastics, copper wires, and padding for the seating. More materials that are visible include glass, metal, plastics, and leather/fabric for the seat.

If you had to use this product, would you be happy with it?

Our group decided that yes, we would all be happy with using this product, especially after testing out the product on 10/7. The seat on the bike is very comfortable with ample cushioning for a comfortable ride. The bike is also extremely easy to use. There are no gears to worry about, as well as no worry of accidentally switching into neutral. Yes, the product does require some regular maintenance. The servicing can include maintenance on the engine, oil, fuses, tire pressure, and replacing a light bulb. The service on the bike does range from easy maintenance to difficult/time consuming maintenance.

What other alternatives to this product are there?

Being as there so many different bikes available, there are always alternatives to our mini motorcycle. You can always use alternative transportation such as a car, a train, or a bus. A few alternatives to our mini bike include a Baja Heat mini bike, costing about $720, a Harley Davidson motorcycle costing around $16,500, and a 200cc dirt bike costing about $800. Some advantages for the Harley are the performance and the name. The dirt bike is able to go faster than our mini bike, and is quite more agile. The Baja Heat mini bike is a comparable item to our in cost and performance. The disadvantages include the cost of a Harley motorcycle. In addition, a dirt bike can be very dangerous, and you have to buy extra gear for all of the bikes. Also bad weather will inhibit a motorcycle rider for riding, and accidents are often more deadly and dangerous on a motorcycle than in any other vehicle.

PRELIMINARY PRODUCT REVIEW

Causes For Corrective Action

There was no real cause for any corrective action during the disassembly of the product. Our management plans worked fairly well due to the fact that all group members have similar schedules and were able to attend meetings regularly. Our group met twice a week every time the dissection lab has been open. By designating the front half of the bike to Group 22, we were able to remain on schedule easily. Each member handled their responsibilities with precision. By each member being present and on task we were able to complete each step in a timely fashion. Our group did not stray from the time line established on the Gantt chart. One challenge we approached was being unsure where to place our disassembled portions of the bike. Due to the congestion of the dissection lab space was severely limited. However, that was resolved by making use of space under a counter in a corner of the dissection lab. With this space we were able to stack all of our remaining materials in an “out of the way” location in an attempt to prevent any potential accidental tampering with the product.

Product Dissection Plan

Day 1:The Rear End of the Bike

Step 1:

Seat Attached to frame

Seat Removed from frame

Begin by removing the seat from the frame. There are 3 bolts attached to the seat that come down through a bracket and the frame and is fastened by 3 separate nuts. The middle nut is unscrewed using a ¾ inch wrench while the remaining 2 nuts are unscrewed using ¼ inch wrench. After the nuts are removed the seat can be lifted off the frame and the bracket removed.

Part List:

• Seat
• Bracket
  • 2, ¼ inch nuts
  • ¾ inch nut
    

Difficulty: 1

Step 2:

Back fender attached to frame

Inside of the Back fender

Back fender attached to frame

The fender is to be taken off next. To accomplish this there are 4 9mm nuts and bolts holding the fender onto the frame, 2 bolts on each side. Both sets of bolts have a metal bracket that sits between the fender and the nuts. The nuts are removed by using a 9mm socket wrench. When the nuts are removed the brackets slide off, the bolts are removed, and the fender can be lifted off the frame.

Part List:

• Fender
• 2 Brackets
  • 4, 9mm bolt
  • 4, 9mm nuts

Difficulty: 1

Step 3:

Axel

The wheel is removed next. Remove the chain from the drive gear located on the tire. The chain won’t be removed from the assembly since it is still attached to the engine. Loosen the nut on the end of the axle by using a 12mm socket wrench on one end while using a 12mm wrench on the other to hold it in place. There are two washers attached to the axle that have a bolt attached to it perpendicular to the axle. They are located on either side of the tire and each is attached to the frame by 9mm nuts. Remove these nuts by using a 9mm socket wrench. The axle can now slide out of the tire. The axle has two cylinder spacers that will come off with the axle.

Part List

• Axel
  • Nut
    • 2 thick cylinder washers
    • 2 bolt-washers
    • 2 washer
    • 2 nuts

Difficulty: 4

Step 4:

The rear wheel removed from the bike

With the axle out, the wheel is still attached to the frame due to a bracket that is attached to the drum brake and frame. Remove the nut and bolt holding the bracket to the frame by using a 10mm socket wrench. The brake line runs from the drum brake to the handle. Remove the handle from the bike by loosening the bolts that hold together the top and bottom bracket (See step 10). Zip-ties also hold the brake line to the frame in 3 locations. Cut the zip ties with clippers. The wheel and brake system can now be taken off the frame.

Difficulty: 2

Step 5:

wheel and drive gear

The drum brake can slide out of the wheel. On the other side of the wheel there is the drive gear. This is held onto the wheel by 4 bolts and nuts. To remove these, use a 9mm wrench.

Part List

• Tire
  • Wheel barrings
  • Valve cap
• Drive Gear
  • 4 9mm bolts
  • 4 washers
  • 4 nuts

Difficulty: 1

Day 2: Brake System

Step 7:

Remove nut on brake line to free the drum brake from the handle and break line.

Difficulty: 1

Step 6:

Bracket attached to drum brake

Bracket removed

Remove bracket from the drum brake by using a 10mm socket wrench on the bolt fastening it. There is a pin that has to be pulled out from the bolt before it can be unfastened.

Part List:

• Bracket
  • 10 mm bolt
    • Pin
    • 3 washers

Difficulty: 1

Step 8:

Brake line removed

Drum Brake with coiled spring

Drum Brake

On the top side of the drum brake there is a bolt that holds together a bracket which covers a coiled spring. The bolt is removed by using a 10mm wrench. By twisting the bracket clockwise the spring unclamps from the bracket freeing it from the drum brake. There is a tabbed circle that can now be taken off along with the coiled spring.

Part List:

• Bracket
• Tabbed circle
• Coiled Spring
• 10mm bolt
  • 3 washers
  • Nut

Difficulty: 2

Step 9:

Inside Drum Brake

On the bottom side of drum brake, the shoes are held together by 2 springs. Needle nose pliers are used to loosen the springs from the system. With the springs are off the brake shoes can now be taken off along with the metal cylinder pin that separates the shoes and hold it to the drum brake.

Part List:

• 2 Springs
• 2 brake shoes
• Metal cylinder pin

Difficulty: 3

Step 10:

Hand Brake and Brake line

Now that the drum brake has been completely dissected. We moved on to the hand brake and brake line. The hand brake consisted of 3 parts; the top bracket, bottom bracket and the handle. The top and bottom bracket can be separated by removing the 2 bolts with a 9mm wrench. The handle and the top bracket can be separated by using a Phillips head screw driver and remove the single screw. After they are apart the brake line is no longer pinched to the system and can be removed.

Part List:

• Top bracket
• Bottom bracket
• Handle
• 2 9mm bolts
• Screw
  • Nut
  • 2 washers

Difficulty: 3

Step 11:

Kick Stand

Kick Stand

Remove and dissect the kick stand. Use needle nose pliers to assist in taking of the spring that connects the stand to the frame. After the spring is removed use 10mm socket wrench to unfasten the bolt that attaches the stand to the frame. Remove the stand from the frame.

Part List:

• Stand
• Spring
• 10mm bolt
  • Nut

Difficulty: 3

Day Three: Dissection of the Engine

Step 1:

Frame

Engine Removal: We removed the entire engine off of the bike frame using a 12mm socket wrench and regular 12mm wrench. The engine was connected only using 4 screws and bolts.

Part list

• Engine
  • 4 – 12mm screws
  • 4 – 12mm bolts

Difficulty 3

Step 2:

Chain and Pull-Start

Large and Small Chain removal: After removing the engine from the frame, our group needed to remove the chains to continue with disassembly. We used a pair of needle nosed pliers and a flat head screw driver to remove the master link from the chain to remove both small and large chains.

Part list

• Small and Large Chain

Difficulty 3

Step 3:

Disassemble Pull Start

Removal of the Pull Start Assembly: After the chains were removed, our group removed the pull start assembly located on the right side of the motorcycle using an 8mm wrench.

Part list

• Pull start assembly
  • 3 – 8mm screws
  • 3 washers
  • Large Spring
  • 2 Small Springs

Difficulty 4

Step 4:

Clutch

Removing the Clutch from the Engine: To remove the clutch we had to use a ¾ inch socket on the fly wheel side of the motorcycle, and use a 12mm socket on the chain side of the motorcycle. During this step we could not find a socket wrench for the ¾ inch socket, and used a pair of vice grips to hold the bolt in place while we unscrewed the bolt using the 12mm socket wrench.

Part list

• Clutch
  • 1 – ¾ inch bolt
  • 1 – 12mm long screw
  • 4 – 12mm screws
  • 4 – 12mm nuts

Difficulty 4

Step 5:

Fuel Tank

Removing the Fuel Tank: The fuel tank was removed from the top of the engine using a 10mm socket wrench. Two of the nuts were located towards the back of the fuel tank, while one was located near the front.

Part list

• 3 – 10mm nuts

Difficulty 1

Step 6:

Flywheel cover

Remove the Fly Wheel Cover: Removed the fly wheel cover from the rest of the engine using a 10mm socket wrench. This part was hard to get off because of high tension on the bolts.

Part list

• 4 – 10mm bolts

Difficulty 4

Step 7:

Heatshield

Remove the Heat Shield: Using a 10mm wrench, we removed the heat shield.

Part list

• 3 – 10mm bolts

Difficulty 2

Step 8:

Remove the Fuel and vapor line: Removed the fuel and vapor line to provide easier access to the engine. We removed these parts by hand.

Part list

• Fuel Line
• Vapor Line

Difficulty 1

Step 9:

Air Filter Cover

Air Filter

Remove Air Filter Cover: By hand our group removed the plastic air filter cover by unscrewing a wing nut on the top of the cover, and two other wing nuts on the underside of the cover.

Part list

• 3 Wing nuts
• Plastic Air Filter Cover

Difficulty 1

Step 10:

Air Intake

Remove the Air Intake: Using a 12mm wrench, we removed the air intake from the carburetor located on the engine block.

Part list

• 2 – 12mm nuts

Difficulty 2

Step 11:

Removal of Gasket 1: After removing the air intake we removed the gasket that sat between the intake and the carburetor.

Part list

• Gasket #1

Difficulty 1

Step 12:

Throttle

Removing the Throttle: Using needle nose pliers, we remove 2 springs that connected the throttle to the connecting rod as well as a screw that controlled the amount of gasoline to flow into the engine.

Part list

• 2 springs
• Connecting rod
• Phillips head screw

Difficulty 3

Step 13:

Removing the Carburetor and Gasket 2: Next, the group removed the carburetor from the engine block and then removed the gasket separating them by hand.

Difficulty 4

Step 14:

Removing springs from the Governor Assembly: Using needle nose pliers we removed springs 10mm from the Governor Assembly

Part list

• Spring
• 10mm

Difficulty 3

Step 15:

Magneto

Removal of the Magneto and grounding wire: Using a 12mm wrench, we removed the magneto from the fly wheel, and then removed the grounding wire by hand.

Part list

• 2 – 12mm bolts
• Grounding wire

Difficulty 2

Step 16:

exhaust

Removing the Exhaust: Next, we removed the exhaust from the engine using a 12mm socket wrench.

Part list

• 2 – 12mm bolts

Difficulty 2

Step 17:

Removal of the spark plug: After disconnecting the magneto and the grounding wire, we removed the spark plug from the engine by hand.

Part list

• Spark Plug

Difficulty 1

Step 18:

Removal of the Valve Train Cover: Next, our group took off the valve train cover using an 8mm socket wrench.

Part list

• 4 – 8mm bolts

Difficulty 5

Day 4: Dissection of the Engine

Step 19:

Inner workings of the engine

Removing the Train Cover: We removed the train cover using a 10mm socket wrench. We had to use a lot of force because this part of the engine is not intentionally supposed to come apart unless there is maintenance that needs to be done to it. We had to use 2 flat head screw drivers to increase our leverage on the cover to remove it from the engine.

Part list

• 6 – 10mm screws

Difficulty 5

Step 20:

Flywheel

Removal of the Fly Wheel: We tried to remove the fly wheel with a 19mm socket wrench, succeeded in removing the nut, but could not remove the rest of the fly wheel because of stripped Phillips head screws. We were able to take off the plastic and metal caps on the end of the fly wheel using a flat head screw driver and our hands.

Part list

• 19mm nut
• Plastic cover
• Metal cover

Difficulty 5

Step 21:

Springs and rods

Removal of the Motor Head: We used a 10mm socket wrench to remove the head of the motor. In doing so we revealed the springs and rods that the piston pushed when combustion occurs in the engine.

Part list

• 4 – 10mm screws

Difficulty 4

Step 22:

Piston

Removal of the Piston Cover: After the motor head was gone, the group removed the piston cover using a 12mm socket wrench. This released the push rods from the springs and revealed the piston used in our 169cc engine.

Part list

• 4 – 12mm screws
• 2 push rods

Difficulty 4

COORDINATION REVIEW

Component Summary

Component Name	Sub Part Name	Number Of Parts	Materials	Manufacturing Process
	10mm bolts	4	Steel	Die Casting
Fuel Line		1	Plastic	Injection Molding
Vapor Line		1	Plastic	Injection Molding
Wing Nut		3	Steel	Die Casting
Plastic Air Filter	Cover	1	Plastic	Injection Modeling
	12mm Nuts	1	Plastic	Die Casting
Gasket		2	Plastic	Injection Molding
Springs		2	Stainless Steel	Hot Rolled Forming
Connecting Rod		1	Aluminum	Drilling, Die Casting
Phillips Head Screw		1	Steel	Die Casting
Carburetor		1	Zinc	Die Casting, Taping
Heat Shield		1	Aluminum	Die Casting
Hand Brake Assembly	Hand Brake	3	Aluminum	Die Casting
	9mm Screws	2	Steel	Die Casting
	9mm Nut	1	Steel	Die Casting
	9mm Washer	2	Steel	Die Casting
Kickstand Assembly	Kickstand	1	Steel	Injection Modeling
	10 mm Bolt	5	Steel	Die Casting
	10 mm Nut	1	Steel	Die Casting
Engine to Frame Assembly	12 mm Screw	8	Steel	Die Casting
	12 mm Bolt	4	Steel	Die Casting
	12 mm Nut	4	Steel	Die Casting
Chain		2	Carbon Steel	Die Casting
Pull Start Assembly	8 mm Screw	3	Steel	Die Casting
	8 mm Washer	3	Steel	Die Casting
	Large Coil Spring	1	Stainless Steel	Hot Rolled Forming
	Small Spring	2	Stainless Steel	Hot Rolled Forming
Clutch		1	Steel	Die Casting
Fuel Tank		1	Aluminum	Injection Molding
Magneto Assembly	12 mm bolts	2	Steel	Die Casting
	Grounding Wire	1	Copper
Exhaust	12 mm bolts	2	Steel	Die Casting
Spark Plug	Metal Casing	1	Nickel	Die Casting, Cold Forming

Design Revision

• One design revision would be to change the position of the exhaust. Currently, the exhaust it is positioned to blow hot air on to the seat. If you were to ride the bike for a long time the seat would get very hot and you could potentially burn yourself on the seat and the metal surrounding the seat. We would move the exhaust by placing the exhaust exit near the back of the bike close to the wheels, such as in a Harley Davidson bike. If we were to fix it on the current bike we would put a funnel where the exhaust exits and run the funnel to the back of the bike by the wheel. By changing the exhaust you make it more comfortable and safer to ride for a long period of time. Making these changes would not increase the price very much. The material added to the bike would not add to the weight enough to affect the speed or gas mileage of the bike. We are surprised that they still have the exhaust blowing on the seat as it is very uncomfortable.

• A second design revision we would consider for the road bike would be the steering ability of the Baja Mini Bike. During our initial testing of the bike, we found that the turning capabilities of the bike were nothing to be desired. There is a bar on the front wheel which inhibits the bike from turning sharply. Because of the bikes inability to turn effectively, a rider could potentially crash when trying to maneuver the bike in tight spaces. The only way we can fix this problem is if we were to remove the turning stopper already in place on the road bike. Another fix for this problem would be decreasing the size of the bar, giving the bike better turning abilities rather than giving the bike full rotation. In doing so, this would increase the functionality of the bike, as well as making a safer ride for the owner. This design change would cost the company very little or money at all, and wouldn’t be hard to complete. It would be a very easy change for the company to make in their design, and would yield more satisfied customers.

Solid Model Assembly

Engineering Analysis

Problem Statement:

Using Engineering analysis identified in class:

The brake cable has snapped. How much force was needed to snap the brake cable?

Diagram:

Simplified version of the brake handle:

Assumptions

• The cable is a static problem.
• The cable is made of steel (most brake cables are made from steel).
• The tensile strength of the steel assuming it is type: AISI 1060 0.6% carbon is 2200X106 N/m2 (http://en.wikipedia.org/wiki/Tensile_strength).
• The radius of the wire is .25 cm.
• No friction on cable.
• No outside forces acting on the cable.
• No gravitational force on the cable.
• No fatigue on the cable.
• The force from hand acts at a single point in only the Y direction.
• The brake cable doesn’t slip when the brake is applied.

Governing Equations

Static Problem: Moment (at pin) = 0 = Force*distance Tension (needed to snap wire) = Tensile strength * area

Calculations

0=-F(.13) +.05(T)
TS= 2200000000 N/m2
T= TS *A
A= .0025 m2*π
A=.000019635 m2
T= 2200000000 N/m2*.000019635m2
T= 43197 N
F= .05T/.13
F= (.05*43197)/.13
F= 16614 N

Solution Check

The units check out for force, and the answer seems reasonable for the strength of steel and the way the handle is oriented. The moments were correctly configured and the math checks out. The force to break the cable is more than a human can apply so it shouldn’t break from forces of the rider.

Interpretation and Discussion:

The answer will vary depending upon how much fatigue the wire has experienced. As the cable experiences more fatigue, the smaller the force it would take to break the cable. Friction would also cause fatigue on the wire. On the real mini bike the steel may be different than the one I assumed, and therefore would have a different strength. There is no way to find out as it is not listed on any web sites and I don’t know how to tell different types of steel apart from sight. If the radius of the cable was changed, this would change the outcome. The greater the radius, the more force you would need to snap the cable. The cable is not a static problem in real life so the outcome would be different. The gravitational and other outside forces would have an effect on the fatigue and the force on the cable. The force on the brake in real life wouldn’t act as a single force but would be spread out all over the brake. If the tensile strength were stronger you would need a greater force to snap the cable. The force required is very high, too high for the rider to snap it. I expected that because steel is very strong and a human cannot break it by themselves. The only way the cable could snap from the riders force would be if it wore down from friction or fatigue. Also, when the break is pulled, there is some give on the cable from the hand brake, which would change the force to snap to cable. The distance from the pin would also change the answer. The farther away the force is applied the greater tension is applied. The force also would be spread out over the brake not as I assumed. This would change the force applied to the brake and where it acts. It would act as a function over the hand brake not as a single force. This would change the force applied and the force applied to the cable. Also, the hand brake on the bike would most likely deform or break if that much pressure was applied. The pin connecting the cable to the hand brake would also break before the cable was to fail if this much pressure was applied.