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Team R.E.M.M Life:Waterproof Bike Seat Project Report

Michael Araya, Ravina Jain, Michael Tucker, and Elizabeth Overton

The Art and Science of Engineering Design: EE15N

Professor Goldsmith and Professor Le

Table of ContentsI. Abstract (Elizabeth Overton) ……………………………………………….….. 3

II. Executive Summary (Elizabeth Overton) ……………………………….…….3

III. Introduction and Overview

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A. Why do we need dry bike seats? (Michael Araya)……………….…..4

B. Problem Statement (Elizabeth Overton)……………………………....5

IV. Analysis of the Problem A. Current Solutions (Michael Araya) ……………………………….…....6

B. Design Constraints (Michael Tucker)…………………………….…….7

V. Design Alternatives Considered (Elizabeth Overton) …………………..….8

VI. Basis for Design Selection (Ravina Jain)……………………………………10

VII. Results of Alternative Analysis (Ravina Jain)……………………….………

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VIII. Design Selection, Features, and Cost Analysis (Ravina Jain)………......12

IX. Final Design Selection (Michael Tucker) ……………………………….……

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X. Future Implementation and Conclusion (Elizabeth Overton and Ravina Jain)…………………………………………………….……………………..……19

XI. Works Cited…………………………………………………….……………….…21

Report Editor (Elizabeth Overton)Head Engineer (Michael Tucker)PowerPoint Creator (Ravina Jain)SketchUp/Logo (Artist) Creator (Michael Araya)

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I. Abstract:In Palo Alto, the location of Stanford University, the annual precipitation is

16.18 inches1. In a campus that is larger than 8,000 acres, bikes are more or less

required for transportation and the weather results in frequent dew and rain covered

bike seats. Current solutions include plastic bags and paper towels, however, these

ideas require students to remember to bring a cover and are a large hassle. Our

solution to the problem is a retractable seat cover connected under the seat. This

resolution is efficient and intuitive.

II. Executive Summary: The problem Team R.E.M.M. Life set out to solve is wet bike seats at

Stanford University. Due to the spread-out layout of the approximately 8,000 acre

campus, nearly every student owns a bike, and many professors do as well.

Because of the moist Northern California weather, students often wake up to a wet

bike seat which continually makes them late to class and other activities. The current

solutions of plastic bags and paper towels present a huge hassle to bikers. The

plastic bags are easy to forget and do not have an adequate location to be stored

because students and professors cannot store them in their bags without getting

their materials wet. Additionally, if bikers use paper towels, they have to find a trash

can for them and that is an inconvenience and not environmentally friendly. Team

R.E.M.M. Life’s solution is a retractable bike seat cover, similar to the mechanism

involved in a projector screen. The bike seat is stored in a cylindrical holder that

connects to the post below the seat. When the rider is not on the bike, they pull the

cover out and connect it over the front of the seat to protect it from inclement

weather. When they want to get back on their bike, they unlatch the cover from the

front of the bike and it retracts into its holder, leaving a dry seat that is ready for use.

Our product is adaptable to any bike, making it even more convenient. Although we

identified the problem at Stanford, it is certainly not limited to the school and we plan

to expand the market first to the bay area and then beyond.

1 “Climate Palo Alto – California” U.S. Climate Data (2015)

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III. IntroductionA. Why do we need dry bike seats? Stanford University in Stanford, California is considered one of the most

prestigious institutions in America; according to the 2014 Princeton Review “College

Hopes and Worries”, Stanford University was named the number one dream school

by both parents and students2. Not surprisingly, the temperate weather and beautiful

palm trees play a huge role in persuading students to matriculate to Stanford over

the eight Ivy leagues in the cold east coast. During arduous dead and finals weeks,

the cold, snowy weather can be detrimental to the students’ mental health. While

students may be struggling during these times at Stanford, the warm weather and

amazing palm trees help slightly pacify their stress level.

With approximately 8,180 acres of land, Stanford University is the largest

campus in the USA and the second largest in the world3. Travelling to class does

indeed become exasperating. To counter that obstacle, students use various modes

of transportation, but primarily bicycles. At Stanford, there are over 18,000 bikes

racks to accommodate for the innumerable bicycles. The bike culture at Stanford is

not only for fun, but also essential to students’ daily commute to classes and off-

campus adventure.4. Bikes are ubiquitous on campus - even professors utilize them.

Contrary to other campuses, it is almost absurd if you do not have a bike or any

means of transportation on campus.

Although Stanford is regarded as the athletically and academically

impressive college with stunning, warm weather, the university still faces one

problem: the rainy monsoons in the winters. According to the U.S. Climate Data, an

average of about 16.18 inches of rain annually precipitates5. While this may seem

like a meager number compared to the rest of the USA, much of the rain is highly

concentrated into just a few months in the year. A majority of the rain occurs from

the months of November to March. This can become a problem for Stanford

2 ”College Hopes and Worries Results” Princeton Review (2014)3 “The Stanford Lands: The Campus Plan” Stanford University (2015)4 “Bicycling at Stanford” Stanford Parking & Transportation Services (2011)5 “Climate Palo Alto – California” U.S. Climate Data (2015)

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students and people who ride bikes because their bike seats end up becoming

drenched in the rain. Students have to wake up from a long night of studying only to

be greeted by a wet bike seat and have to suffer from a wet butt. This is a problem

because a wet caboose can ruin a person’s mood! We have discovered a way to

keep butts dry. Although the problem may seem limited to only a certain group of

people (Stanford students), this trouble is actually prevalent throughout the world. In

China, a population of 1,342,700,000 people, more than 500 million people use

bikes6. Additionally, in Japan, the country with the second largest population of

bicycle users, about 72,540,000 people use bikes. This is out of a population of

127,370,000 people7. With a large annual rainfall in each country89, keeping bikes

dry is an ongoing issue for them, showing that the problem spreads beyond

Stanford. It is a widespread obstacle in even some of the most populated countries.

From these results, we can clearly see that a more adequate and sufficient way to

handle this problem is necessary.

B. Problem StatementAttending Stanford in northern California, having a wet bike seat is a recurring

problem. We hope to explore developing a solution, because we know that this is an

issue for people in many more places than just Stanford. Let’s say you are in a

hurry for a meeting or class and run out to your bike only to find a wet bike seat. If

you’re wearing a nice outfit you will have to run inside to get a towel, towel it off, and

bring the towel back inside, which could take up to 3 or 4 minutes. By that point, you

are late. Some students put plastic covers over their bike seats, and take it off before

they ride it. However, this is a hassle because they are usually dripping wet and the

students have to remember to put it on when they park it. The team R.E.M.M. Life

will investigate the issue to try to find a solution to ease students’ angst because no

6 “Top 10 Countries With Most Bicycles per Capita” Spokefly (2015).7 “Top 10 Countries With Most Bicycles per Capita” Spokefly (2015).8 “Precipitation Map of Japan” World Trade Press (2015).9 “Precipitation Map of China” World Trade Press (2015).

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one wants a wet butt in the morning. Our device will propose a convenient

alternative to appropriately drying off bike seats without tarnishing the bike’s current

mechanism, function, and comfort.

IV. Analysis of the Problem A. Current Solutions

As a way to currently alleviate the wet bike seat epidemic, students utilize

plastics bags to cover seats right before an expected rain shower, but there is still a

fault in this answer. Where does one place the drenched plastic bag after use? A

student cannot simply throw the bag in his or her backpack because then his or her

papers will become wet. This solution could ruin assignments, homework, and

projects and cost a student his or her grade and expensive laptop. Alternatively,

instead of keeping the bag, the student can throw away the plastic bag in a

trashcan, but this solution is very wasteful and can squander a student’s time just

trying to search for a near by trashcan. Another solution is to use paper towels to

manually dry the seat off. Although this method might sound effective, there are still

faults built into it. This process will increase the number of used paper towels and

play a negative role on the environment. Already in the US, “3 billion pounds of

paper towels are used each year. That’s over 45 pounds of paper towels per

person, per year”10 . Paper towels are already being wasted and continuing to wipe

bike seats off with them will only exacerbate the problem. With this method, we can

reduce the amount of paper towel consumption with an environmentally friendly

approach. Also, it is very easy to forget to bring power towels from the nearest

restroom and by the time one remembers to grab some, he or she will already be at

his or her bike. It will be a hassle to run back into his or her dorm. Consequentially,

this can cause the student to be late to class.

B. Design ConstraintsBefore coming up with the possible solutions for our problem, our team

considered the constraints that framed our problem. First we considered the fact that

our goal is not necessarily to keep the bike seat dry, but to keep the rider’s butt dry.

10 “Banish the Paper Towel” The Energy Co-op. (2015)

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So our first constraint is that our product needs to help reduce the amount of water

on a rider’s butt more effectively than current solutions.

Next, the team looked at the issue with current bike seat covers, namely how

to remove the device/solution when not needed so that it’s as convenient as

possible. This means designing a solution that doesn’t have many negative

externalities in terms of the solution’s non-use life. We want to avoid having to worry

about a wet plastic bag or bike seat cover, and create a solution that you can use

and then forget about when you don’t need it.

In addition, we wanted our solution to be able to be activated in under 20

seconds so that it doesn’t interfere in making people late to classes/meetings. This

also is beneficial as riders don’t want to spend too much time in the rain if they’re

caught on a rainy day.

We also wanted to consider the environment, as we realized some of the

current solutions (utilizing plastic bags and paper towels) were wasteful. Thus we

wanted a solution that would cause the least amount of waste as possible.

Lastly, we wanted to create a product that could be affordable to as many

people as possible. With this in mind, we wanted to try to create a solution that,

mass produced, could be affordable to college students, to commuters, and to

anyone with a bike. Thus our final goal is to make a product for under $10.

V. Design Alternatives Considered

Team R.E.M.M. Life considered four products besides the final design choice.

We decided initially that our aim was that the bike seat doesn’t get wet, or that if it

did get wet, it wouldn’t matter. The team also determined that the product was

required to have two attributes: reliability and durability.

The first idea involved using super-hydrophobic spray, which is a spray now

available on the market, that when put on a surface, completely repels water. This

seemed like a perfect solution and at first we didn’t understand why it wasn’t already

a product, however, we then found that the spray had a fault that disallows it from

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becoming very popular. The spray functions on a nano-technological scale that is

very delicate. It becomes inactive when it experiences substantial friction or

abrasion11. That simply wouldn’t work for a product with a one-time installation

because friction from bike riders was enough to disrupt the water-phobic properties

of the spray. We also considered a device that periodically sprayed on your bike

seat, however that would be extremely expensive and we figured that people

wouldn’t pay for that.

The second product that we considered was a removable bike seat that is

carried with the user and Velcro’s to their backpack. The bike seat would have to go

inside some sort of cover in case it was currently raining. Although this eliminates

the problem completely, it would cause a lot of hassle for the user. In our opinion,

the hassle of carrying the bike seat with you outweighed the advantages. We were

also unsure on how to adopt existing bike seats to disconnect easily and we would

have to create an entirely new bike seat, which would be expensive.

The third idea that we considered was a weather application that notifies the

user when they need to cover their bike seat. Our advisor Gary Banta explained that

dew on bike seats is related to the black body effect, which involves temperature

differences between the atmosphere and the bike seat, and that we would need to

take that into account as well. This broke the assumption that the solution had to be

a physical product, but the problem is that it wouldn’t solve the initial issues of

having to carry around a bike seat cover. The user would have to go to their bike

and cover the seat whenever they are notified and that would arguably be just as

big, or bigger of an inconvenience than covering their bike seat every time they are

not riding it. Additionally, as we all know, weather predictors are very commonly

incorrect so it would be impossible to completely fix the issue this way.

The final idea that R.E.M.M. life seriously considered and eliminated last was

the flip-over bike seat. This idea involved having a hinge that connected the seat

post and the bike seat and would flip open to the side with the press of a button. The

11 “Superhydrophobic Coatings” NEI Corporation.

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user would flip over their bike seat every time that they got off their bike. As shown in

the diagram below, the user would have to manually flip over the bike seat, with the

pencils representing the hinge that would rotate during the process. This is last idea

we eliminated and therefore did lots of further testing on it.

Figure I: Flip-over bike seat diagram

VI. Basis for Design Selection

While brainstorming various designs we believed simplicity, intuitiveness, and

cost were the most important objectives that our final design needed to fulfill. We

wanted our customers to be able to immediately comprehend how to use the

waterproof bike seat and not have a large part of the burden be on them. For

instance, one of our ideas -- having a removable bike seat -- was eliminated

because we felt that making the user carry the bike seat around would make the

bike seat be more prone to becoming lost. In addition, if the user lost the bike seat or

forgot to bring it while it is raining outside, that would create a bigger hassle than just

having a wet bike seat. The user would thus not be able to ride the bike and only

make the individual even more late to class. In addition having a bike seat that would

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flip over ultimately seemed on the more complicated side given the likelihood that

the bike seat could break due to a hinge breaking or screw coming out. In addition,

after creating a prototype of this version of the bike seat, we tested the seat by

pouring water down the bottom of the bike seat (when the seat was flipped over) and

noticed that water trickled down and ultimately made the whole bottom seat wet.

Thus, because functionality was prime, we neglected the flipped over bike seat idea.

Aside from functionality, simplicity and cost were primary objectives in

choosing a bike seat. Our goal is to create a bike seat that keeps the rider dry, yet

simultaneously is quick and easy to use, requiring as little time as possible to use

and figure out how to use. Figure 2: Objective Tree

Figure 3: Priority Checkmark Chart

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Figure 4: Best of Class Chart

VII. Results of Alternative

Analysis

During testing, we found that our idea of flipping the bike seat over would still

spray water onto the top of the seat during the flip. In addition, it would collect water

on the bottom, be very expensive, and would probably have to require buying an

entire bike seat. If we created a universal hinge that could be added to any bike

seat, it would require a complicated set-up. It would also require a lot of

maintenance because there are a lot of moving parts. We decided that although it is

an interesting and innovative idea, functionality is our most important credential and

it does not meet it adequately.

Figure 5: Flip-Over Bike Seat Testing Figure 6: Testing Continued

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VIII. Design Selection, Features, and Cost AnalysisOur waterproof bike seat is made of various simple parts that we collected

from the hardware store. We kept the idea of having a cover, however, improved it in

such a way that the bike rider would not have to remember bringing a cover each

time it was raining outside. Instead, the cover would already be under the bike seat,

rolled up inside a cylindrical cover, allowing the rider to pull the cover out or letting it

snap back in whenever the rider would be using or removing the cover.

Our waterproof bike seat cover is made up of these various materials: one

tarp, one PVC pipe, two tape-measurers, three metal dowels, one bike light

connector, and four nuts.

Features

(1) Tarp

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Tarpaulin, also known as tarp, is a strong, thick, waterproof material made of

polyethylene. The material is coated with Low Density Polyethylene12, which helps

make the material waterproof and water-resistant. Tarp is often used for extreme

outdoor use, is resistant to mildew and chemicals, and doesn’t cause any adverse

environmental effects13. We chose tarp because it is inexpensive, economical,

durable, flexible, and environmentally friendly. In addition, the tarp is thick enough to

withstand inclement weather and is sturdy enough to endure the tension that may

form as a result of the bike seat pulling on the tarp when it is pulled out.

(2) PVC Pipe

PVC pipe is a plastic cylinder-like pipework that is often used for containing

heating and cooling fluids, chemicals, waste-water, and drinking water. We used

PVC pipework because it is cheap, durable, and easy to work with14. The PVC acted

as a case for the tarp that was kept rolled around within the PVC pipe. The tarp

would then be pulled out of the pipe when needed to be used to wrap over the bike

seat.

(3) Tape Measures

We used two tape measures to encase the cylinder on each side. Tape

measures are durable, thick, cheap, and sturdy, thus the case was useful in

implementing nuts and bolts on each side to piece the bike cover mechanism

together in one piece.

Cost Analysis

Tape Measure: $4.49 x 2

Tarp: $5

Rods: $2

PVC Pipe: $3

---------------------------------------------

Total: $18.98

12 “What is a Tarp?” Tarp USA (2009).13 “What is a Tarp?” Tarp USA (2009).14 “Plastics Pipes, Fittings and Valves for the Transport of Fluids” ISO (1970).

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The total cost of our product is about $20. Although it isn’t that expensive, our goal

for the future is to try and decrease the total cost of the product.

VIII. Final Design Selection

The ultimate design our team decided on was a retractable seat cover. Our

aim was to create an apparatus which would attach to either the underside of the

seat or the post of the seat. From this, one can pull out a cover out and over the top

of the seat (where it would latch on) to keep the seat dry. When the cover is not

needed any longer, the cover will then be unlatched from the seat and retract back

into the apparatus which houses it.

Figure 7: Bike cover prototype ideaWith our goals in place we started

ideating possible ways to bring this design to

reality. We briefly talked over just having a

seat cover attached underneath that would just be

pulled out and stored manually, but then

realized that wouldn’t be much more effective

than a typical seat cover. So we decided to

look for other solutions. We then came up with

the idea of having the seat cover retract back

into a device much like a tape measure or

projection screen would. We all thought this

would be an appropriate plan and set about determining the mechanisms needed to

create such a device.

Talking with our mentor Gary Banta, we discussed the possibility of a custom

3-D printed device to house and retract the seat cover, however, due to time and

cost issues, this possibility was dropped. To then further spawn ideas, the team met

with a wide variety of random material (ranging from tape measures to pencils,

markers, a standard bike seat cover) to create ideas.

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With a tape measure as inspiration, we then turned to it as a source of device

ideas. By taking apart a tape measure, we found the internal coil spring which

retracts the tape measure after use. Expanding on this device, we reasoned that

having a coil spring at either end of our apparatus would allow for us to create a way

to automatically wrap up our cover after it is done being used.

We determined that connecting metal dowels between 2 tape measure spring

coils, we would successfully wrap the tarp up using the spring. We found through

testing that using three dowels spaced out around the springs would have the best

result. From here all that was needed was to find a housing for our apparatus.

During one of our meetings with mentor Gary Banta, he suggested that we looked

into PVC piping as a potential housing for our seat cover. As it is relatively cheap

and easy to build with, we agreed to go down that path.

So with this, we took a trip to a local hardware store and bought a small

length of PVC pipe and tarp that would make up our apparatus. For construction, we

began by cutting out a long length of tarp with the width just larger than a large bike

seat and long enough to cover the seat and attach to the seat post, we then sewed

the front of the cover back to create a pocket to cover the nose of the seat. We

attached the metal rods to the springs and sewed the cover to one of the rods. The

rolling mechanism was then slid into the PVC pipe enclosing, where a slit was cut

out to allow for access to the cover. With this, we attached a bike seat attachment so

that the apparatus can attach to the seatpost of a bike.

The apparatus fits under both normal and large bike seats and covers both

effectively. We have succeeded in creating a functional prototype, but of course

more work would be needed to make this device ready for the market.

Figure 8: Sketchup Model of Internal Spring Mechanism

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Figure 9: Spring Mechanism Testing

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Figure 10: Sketchup Model of Prototype

Lateral view: Anterior view:

Figure 11: Final Prototype

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Figure 12: Prototype Testing

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IX. Future implementation and ConclusionThe materials required for our prototype in total cost about $19 dollars buying

directly from the store, but we believe that it could be mass-manufactured easily and

that we could expect to put the product on the market for 10 dollars. Our target

demographic would expand much further than Stanford students, it would spread to

professors, commuters, and anyone who uses their bike for transportation around

the United States and eventually, beyond. We would begin by marketing in the bay

area, and then spread further than that later. One idea we had that would possibly

give the product more appeal is personalization. We realized that drawer-liners were

made of a very similar material to tarp, and that they are already available in many

different prints and colors (see picture below). This material may even be better than

tarp for rolling into the PVC Pipe contraption.

Figure 13: Personalized Bike Covers

Additionally, looking to future design

research and implementation, R.E.M.M.

life would look for a solution for wet bike

handles, and always continue to perfect

our solution to a wet bike seat. We would

also work to make the PVC pipe that holds

the cover much smaller.

Our bike seat currently occupies a

large amount of space underneath the bike

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seat, however, our priority was having the user maintain a dry butt while times of

inclement weather; size was not our priority. Thus, for our future models we plan to

reduce the size of our product, make it mechanically more equipped such that the

user simply has to press a button that would eject the bike cover out of its cover, and

lastly, have it be able to eject the cover if it detects rain is about to pour, preventing

the seat from being wet at all costs.

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<http://tarpusa.com/common-questions>.