Dec 07

Detailed Body Measurements

By Graham Uncategorized Comments Off
As per Jay’s email. Your measurements are. As we discussed these are to the center of the knee, center of the hip and to the bottom of the foot.
Caroline- Upper Leg- 20 inches, Lower Leg (with shoes)- 22.5 inches, feet (with shoes)- 13 by 4 and 7/8
Reid- Upper Leg- 20.25 inches, Lower Leg (no shoes)- 20.75 inches, feet (no shoes)- 11 by 4
Jay- Upper Leg- 22 and 1/8 inches, Lower Leg (no shoes)- 22.5 inches, feet (no shoes)- 11.75 by 4.5
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Dec 07

First Round Geometry Study

By Graham Uncategorized Comments Off

I am homing in on the geometry. Basically what I did, was take 62cm road bike geometry, and then add in the known dimensions for the rear section. Where where the dimensions were undefined I created them. Next I will go through your body measurements and I will refine the bottom bracket location, and seat location.

After we have firmed up the seat/bottom bracket position, I will need to go through and create a clearance path for Reid’s and Caroline’s feet. This is to be sure that there is enough clearance for the whole foot throughout the pedal cycle.

More to follow

.geometry_rev1

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Dec 03

Couplers?

By Graham Uncategorized Comments Off

In our last conversation we discussed the possibility of using couplers in the frame to combine the frame of the TriBike and running cart. I have been thinking more about this and I think that it is a great idea! Check out these sketches:

Tribike using couplers in Cycle Mode

Tribike using couplers in Cycle Mode

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This design would require the use of 7 couplers. In this configuration the conversion could be made from the Cycle mode to the running mode by breaking 2 couplers, and by joining 3 couplers. Here are a couple of side views:

3web4web

I really like the modularity of this system. I think that it allows a tremendous amount of flexibility of use, as well as the ability to take it entirely apart for transport. I also think that the articulated coupling between the lead bike and the trailing bike, is a great way to maintain maneuverability while spreading the load between 2 shorter spans (giving less frame flex than a single span).

Lets talk in a few hours, in the mean time I am working on some basic CAD models and am putting your measurements to start nailing down geometry. Assuming that you like this configuration I think that we are ready to start putting things into computer space and actually start getting quantitative about the design and geometry.

Nov 16

Hi guys. After a bit of a hiatus I am back. We moved our shop to a new location which was a LOT more work than I anticipated. The move is now over with and I can hopefully dedicate more time to the TriBike.

I have done some exploratory sketches focusing on the TriBike. I figured that this part of the project is much more involved than the running cart, and so I am planning to focus on it for this round of concepts.

There goes:

I started off by exploring possible structures that would be stiff enough to support the load with a single span frame. This first sketch shows the preferred layout that we discussed in our last conversation. Because of the large span and high loads that the bike will be required to withstand the frame must have some triangulation to avoid too much frame flex.

tribike4sm

This is basically a variation of the theme. In this case there would be a space frame that would form the chassis of the bike, and then the seating and drive trains would be mounted to the chassis.

tribike5sm

This frame is a wishbone frame where the load of the front rider gets split between the 2 rear members. The recumbent bike behind are each mounted on an arm of the wishbone. This has the potential to be more rigid than the previous concepts.

tribike6sm

One big concern that I have with all of these concepts is the overall length that the bike will be and the fact that we will have to support a load over the entire length span of the bike. While it is definitely possible to build a bike that will work well, I worry about maneuverability, and ease of transport of such a long bike. This lead me to rethink the configuration to come up with ways to shorten or articulate the frame.

One way of doing this is actually to place the rear bike behind the 2 recumbents. This eliminates the length of the rear triangle and the need for clearance for the legs of the rider diamond frame bike.

With this in mind I started sketching:

tribike2sm

While this configuration would definitely reduce the length of the frame I felt that the bike could be further simplified by employing a standard diamond frame bicycle in the TriBike. This would bolt onto the back of a side by side recumbent at the front fork, eliminating the need for a customized diamond frame, and creating an articulated bike. This would greatly increase the maneuverability of the bike, and it would also reduce the cost of building it.

tribike3sm

realizing the benefits of an articulated frame for maneuverability and transport, I thought that this could be equally well accomplished, in the desired 1 fore 2 aft configuration. So my final sketch is of this concept. While this bike will be very long, since it articulates at the joint between the diamond frame and the recumbent tag along, it would be relatively maneuverable compared to a fixed frame. These separate frames could then be split apart for ease of transport. Furthermore the load span has been considerably reduced which means that frame flex will be less of a problem.

tribike7smLet’s plan to talk tomorrow to see what you guys think about this as a direction for the bike.

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Oct 22

It was good to talk to you guys this afternoon! Here is a summary of my notes from our conversation.

Preference was for concept 1: 1 fore 2 aft geometry (the first set of sketches).

Jay and Reid are athletically different. So this means that they should have separate drive trains, so that they can ride at different a cadence to one another.

Width of the bike should not exceed 5’6″ if at all possible.

Jay rides a 62cm frame and Reid rides a 58cm frame. A frame of 60cm would be ideal.

Seating for Caroline needs to be fairly upright in the 75-90 degree range with some adjustability. Her seat will need some restraints including a chest strap. Caroline can operate one rapid fire shifter (it was agreed that Reid could operate the other shifter for her).

We talked about who would sit where, and it seems best to have Jay on the lead cycle as the strongest member of the team, and Reid next to Caroline on the recumbent portion of the trike.

We agreed that Caroline’s feet could be attached to the pedals of her bike with cycling toe clips. We also discussed the need for there to be an additional restraint system to catch her feet should they come out of the pedal clips.

We talked about possible drive train scenarios. It was agreed that the cycle should have 3 rear wheels, each driven independently by the three members of the team. This is for several reasons:

  • To allow for Jay and Reid to be able to crank at different cadences.
  • To avoid the need for too many non-standard bicycle parts involved with combining the power generated by both Jay and Reid through a shaft system.
  • This would provide an additional wheel which would lend strength to the bike.
  • This will allow for standard single bicycle chain lines.

In this project we will try to keep to bicycle standards including 700c road wheel sizes. This is important for after sale repairs and replacement parts.

As for the Running Cart we talked about the different configurations presented. We agreed that the best option would be front wheel drive with rear wheel casters.

We also agreed that toe clips would work for Caroline’s feet including a footrest under the pedal system that would catch her feet in the event that they came out of the toe clips.

The final item of the call was the Triathlon of May 9th, and how this is a hard deadline which cannot slip.

Given our circumstances, I gave my assurances that we would do everything in our power to have the both the TriBike and the Running Cart finished and in the possession of the Owen’s siblings before that date. In the event of unforeseen fabrication delays which are beyond our control, I will develop an alternative backup plan to get the bike fabricated and shipped to them in time for their event on May 9th 2010.

I have worked closely in the past with good reliable fabricator in Albuquerque, NM. I will contact him to determine the logistical and economic consequence of this worst case scenario of having the frame fabricated in Albuquerque for rush delivery. I will do this as a top priority so that I can offer an absolute assurance of delivery by May 9 2010 with a worst case cost estimate.

Oct 22

First round concepts – ‘blue sky’

The TriBike

These are basic and quick sketches to convey the idea of a concept. In reality the wheels will actually be round!

First round sketches 013

One fore 2 aft 3 person bike

One fore 2 aft 3 person bike

This is a one in front 2 behind configuration with the front rider being in a conventional bicycle riding position with the 2 rear riders being in a recumbent riding position side by side. This would have 3 wheels, and a load bearing beam frame between front and rear contact patches.

Long frame side by side

Long frame side by side

Based around a tandem concept, this would include a long tandem style frame for the primary bike with a pair of single wheeled longseat recumbent style bikes on either side of the primary. This could either be three or four wheeled (three wheels in the rear axle line)

The side car concept

The side car concept

This concept is a shorter wheelbase than the last one. This would have a pair of side cars with a single wheel that is not driven. The power from the rider of the side car would be transmitted to the primary bike drive train. This bike would have a single driven wheel at the back of the primary bike. The primary would have an extended frame to increase the wheelbase to accommodate the length of the side cars.

The articulated 1 fore 2 aft trike.

The articulated 1 fore 2 aft trike.

This is a side by side recumbent style bike hitched to the back of a road bike modified to have a structural hitch on the back. This configuration would be extremely long but would have the advantage of being narrower than the previous concepts. This design would also have the advantage the the lead bike could be ridden independently when not hitched to the recumbent rear.

3 person side by side recumbent style bike

3 person side by side recumbent style bike

3 person side by side delta style recumbent trike. In this configuration all three people are sat side are in a recumbent position. This trike would have the advantage of a relatively short wheel base and high maneuverability but would also be very wide.

One aft 2 fore 3 person bike concept

One aft 2 fore 3 person bike concept

1 rear driven wheel and 2 front steering wheels with one person on a conventional style bicycle on the rear with 2 people on recumbent style bicycles on the front.

Front wheel drive rear wheel steering configuration

Front wheel drive rear wheel steering configuration

This has a front rider with conventional bike geometry, but with a front driven wheel. The two people on the rear of the bike are side by side and they also drive the front wheel. The rear wheel is the steering wheel. The advantage of this system is a very simple and light weight drive train. The disadvantage comes with the challenge of rear wheel steering geometry.

The Running Cart

All of the concepts for the running cart are single speed with a target bike gear ratio of 9 minutes per mile.

The running cart

The running cart

This configuration has a single driven front wheel and a pair of large pneumatic casters at the rear. The handlebars are attached at the rear.

This configuration could equally well have a single caster in the rear and a pair of non steering front wheels that are driven.

Rear wheel drive running cart

Rear wheel drive running cart

In this configuration the running cart is rear wheel drive. There are 2 front caster wheels. This clearly will have a lot of chain getting from the cranks to the rear wheel.

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Oct 21

The TriBike Project!

By Graham Uncategorized Comments Off

The Tribike project is a design project to create 2 trikes for Jay Reid and Caroline to be able to compete in a triathlon this upcoming spring.

The trikes:

The Three Person Trike (TriBike)

For the cycle portion of the race a three person recumbent tricycle to power all three members of the team at road bike speeds. Two of the three riding positions are required to be in a side by side format so that both riders can be in visual contact so that they can communicate by signing to one another.

The Running Cart

This is a pedal operated single speed bike with a target maximum speed of the 9 minute mile. This vehicle has handlebars attached to the back so that 2 people in the team Run along to compete the running portion of the race.

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Oct 21

Reid:
Height: 6’2″
Weight: 190lbs

Jay:
Height: 6’4″
Weight 220lbs

Caroline
Height: 5’10″
Weight: 150lbs

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