Closing the Loop

After spending a month and a half, hundreds of man-hours, and a heaping mound of wood, we've finally completed the track of Cyclodrome. In a last blitz day of track-building, we put together the last quadrant and screwed the last piece into place.

The last piece was a smooth fit.

While the most intense building is finished and it's possible to ride the track in its present state, our work is still ongoing. Some of the final safety measures are still under construction and we must still sand and paint the track for a smoother, long-lasting ride. All that aside, after so much time spent planning, building and visualizing, it's satisfying to step back and admire a fully-constructed track. It looks smaller and steeper in real life than it did on paper or in renders, but that only adds to the appeal of riding it.

Watch this space for video of Cyclodrome in action - and for bulletins on when and where you can ride it too.

Bikes are optional.

Forged in Fiberboard

Above: Cyclodrome two days before this post.

As the team has worked up to our full pace of production, that pace has proven to be more than we could have imagined at the start of our work. It took weeks to fine-tune and build the first quadrant of track, but with the lessons learned from those weeks, the second and third quadrants have been built in only the last two days. The team has circulated from role to role enough that each of us has come to understand how to identify and overcome the challenges of building each type of component.

We tested several backing materials.

One of those component types that has occupied our attention in the past few weeks is the thin (1/8 inch) Masonite backing that encircles the entire Cyclodrome. In a structure made of sturdier lumber and thick plywood, this may seem out of place - one does not need to be an experience builder to suspect that a thin sheet of Masonite does little to improve the strength of the structure. And indeed, the backing does little to support loads and thus improve strength - but does a great deal to prevent movement and thus improve stability, particularly in higher sections that are prone to greater movement.

Track braces provide additional stability.

This is an important concept in structural design, and one that will be with us for the rest of our careers. To be stable, a structure must resist movement in every direction; even small movements that are encouraged by relatively small forces can be devastating to a structure if not resisted. For instance, in steel construction it is common to see massive I-beams braced by comparatively tiny reinforcing members, placed to thwart small but critical twisting forces.

As the track comes together, it's more and more evident what kind of forces it will have to take. A cyclist going at even twenty miles per hour can exert great force in many directions on a track - to say nothing of more than one cyclist, at what may be far greater speeds. Under such conditions, every source of stability counts, and all act together to keep our track safe and sturdy.

Above: Cyclodrome one day before this post.

Every Which Way

With the first quadrant of Cyclodrome done, our next task has been to set up a process of construction that builds upon the existing work while keeping everyone busy. Setting up any one frame element or piece of track involves only a fraction of the working hands that we have available, so we have begun construction in both directions. To keep both groups from competing for a single wood shop, we've also set up multiple sawing stations right outside of the King Pavilion, which give us the added benefit of making the innumerable trips between the velodrome and the shop faster.

While most of the group has formed into teams cutting frame or track, some of us have set to work dealing with some of the many small technical problems that have been discovered in the process of building the first quadrant. Edge misalignment between the large bottom pieces and small top pieces of track has been corrected by fixing both to extra backing. Some have been working on the more serious problem of reinforcing the longest and steepest sections of frame. Under extreme pressure these frame elements are prone to noticeable bowing, so we've devised braces to stabilize the frame at the center of the track, giving it strength where it is weakest.

Even with some of us working on smaller issues, going both ways has allowed us to accomplish a lot in little time. The development of the first quadrant has taught us much about the issues that we face in a project like this, and allowed us to build that much faster. We've done a lot of productive work in a little time, and are ready to do a lot more.

Above: Cyclodrome one day after the top picture was taken.

June 9th time-lapse

June 8 time-lapse

June 8

June 6th work

May 27th

May 26

progress time-lapse, May 25

In the News

The word about the Cyclodrome is hot and spreading around Ames and Des Moines. A recent article in the Iowa State News has helped spread the excitement. Check it out here.

Now, I know what you are thinking - "I want to ride it." Well, that opportunity is quickly approaching. Keep checking back to find out when and where.

Safety First

As we begin laying track on the first quadrant of Cyclodrome, some discussion of what we're doing to make that track safe to ride is in order. As would be expected when designing a bike track, the first question we asked was "How do we prevent crashes?" Most of our design of the triangular supports was based on answering this question and ensuring a smoothly curved ride on a track wide and stable enough to accommodate riders of all skill levels. We believe that through calculation and trials we have come up with a basic shape of the track that will minimize crashes.

Still, the Cyclodrome will be a very steep, sharply-curved track - a new and faster experience even to cyclists that have experienced larger velodromes. Our study of velodrome cycling has shown us time and again that even the best professional riders on far larger and shallower tracks still crash often. Acknowledging this reality led us to ask our second design question: "There will be crashes. How do we prevent injuries?" Answering this question is just as important as answering the first question - we have a commitment to public safety as architects, the safety of the track reflects on both us and the Bike Collective, and the first people to crash while riding Cyclodrome will probably be us. Thinking about injury prevention has required us to exercise some imagination and picture just where and how quickly a crashing rider would go. Many things can go wrong, but they mostly boil down to two basic scenarios: One in which a rider crashes onto the track, and another in which a rider crashes over the side.

To prepare for the possibility of riders crashing onto the track, we've worked to ensure smooth motion along the track. Even the smallest piece of wood sticking out of the track could become a large and dangerous splinter if hit at small velocity. Likewise, with wear and tear even a track with perfectly smooth transitions could come loose. To ensure a continuously smooth ride, our elements are arranged such that all seam faces point in one direction - forming a single correct direction in which to ride. We're also pre-drilling holes for every screw connecting the track to the frame to ensure that screws dig in properly without pushing out fragments of track.

The possibility of riders crashing over the side of the track is part of the reason why our turns are so high and steep. If riders fall, it's far better for them to fall two feet from low, straight track than from a far higher section of curved track - so we've built our curved track high enough and steep enough to make biking off of it extremely difficult. Likewise, in the event of a fall it is better for bikers to land on the floor and distribute the impact rather than hit a triangular support, so we've extended each piece of track to completely cover the supports, even if that meant adding extra pieces of track as shown to the right. We opted not to fence the track for similar reasons.

As Cyclodrome comes together, it's sometimes scary to imagine riding on such an extreme track - but we're doing everything we can to make sure that the thrills we build remain safe.

Real Smooth

In architecture, the solution to a problem is often found not in discussion or on paper but by building something tangible to test our ideas. The same is true for finding problems in need of a solution. While we've calculated, drawn and modeled the Cyclodrome, many facts about its operation have only made sense once it was built.

To ride on the Cyclodrome (or any velodrome) a rider must maintain friction with the track to counter the downward pull of gravity. To maintain friction, the track must constantly curve toward the rider, or at least remain flat. At no point should it slope down, for even the slightest bump or jump will remove the upward resistance of friction, leaving the rider nowhere to go but down. When finishing the frame of the first quadrant, we found that the transition between straight track and curved track was a little too sharp - risking just such a bump.

Above: A support returns from the shop.

The problem lay with our design of supports. We had two systems for measuring the change in support heights down the track - one for curved track, in which angles rose gradually to our maximum angle, and one for straight track, in which angles lowered sharply. When straight track rose to meet curved track, it did so too sharply, producing a bump. After some discussion, we found a solution - raising the lower straight-track supports to produce a higher track with one consistent system of curvature. With some testing, we found new heights for the lowest supports that fit with the rest of the Cyclodrome for a smooth ride once more. With our construction methods, supports were adjusted quickly and easily. Along with these modifications, we also spent the day beginning work on the next quadrants' supports, to ensure a smooth transition along the whole track.

Above: A smooth ride is cause for celebration.

Starting the Assembly Line

One of the greatest advantages that our team has in the final construction of Cyclodrome is an abundance of labor. We have a very large team (15 people) compared to the scope of our project, and so can keep a very large amount of work going at once. This makes working to our maximum potential a continuous challenge - in the hectic atmosphere of a busy shop in which materials are constantly in motion, it's difficult to keep 15 pairs of hands productive at once. To help solve this problem, we've formed groups to keep clear which students are doing which tasks. Groups regularly change depending on whether the day's work is triangular supports or track, and we aim to have each student do every job at least once.

In today's construction of triangular supports, the first group measured and cut the horizontal and upright members of each element.

The second group linked together the horizontal and vertical members with corner base plates.

After measuring the resulting angle, the third group measured and cut the angled members of each triangle to fit snugly into the complete element.

A fourth group cut and placed plates to hold the complete triangle in place. These edge plates are made of larger pieces of wood to provide greater strength at points of extreme stress.

Finally, all completed frame pieces were fitted into their places in the King Pavilion. With our organized process, we were able to build enough frame for one quadrant of the Cyclodrome in only three hours! With progress like this, we look forward to completing the rest in the coming weeks.

Staying on Track

With the frame of our prototype in place, we've spent the last few workdays tackling a much tougher challenge: fitting the track onto our frame. Turning square pieces of flat plywood into curved, angled pieces of track is no easy matter due to the complexity of the shape required. Each piece must be individually measured and cut to interlock with each of the other pieces and the frame, without any cracks or unevenness that could endanger riders. This process has its tradeoffs - the maximum width of the track exceeds the maximum width (eight feet) of standard plywood, usually at the sharpest point of the track's curve. To once again focus on safety, we opted to add extra plywood sheets only at the furthest reaches of the curve, where riders are less likely to encounter a joint between two sheets.

The curved nature of our track presents an additional challenge, since flat plywood tries hard to stay flat. Screwing pieces of track to the frame will hold a curve, but the track must be thin enough to be bent into shape, while at the same time remaining thick enough to remain stable under the forces that the finished track must carry. Since our initial testing found half-inch plywood to be too unstable, we tested our prototype with 3/4-inch plywood.

When that turned out to be too difficult to bend, we adjusted by cutting a series of grooves into the back of our sheets to approximate a more pliable 5/8-inch depth. For the sake of efficiency and price, this means that our final construction will be done with 5/8-inch plywood, as cutting grooves is extremely time-consuming and the structural benefit of the extra material is negligible. Finding the right depth of track has been been one of many lessons learned through the challenges of prototyping, but we're confident that the final Cyclodrome will be that much better for our experience.

With the power of imagination, it's more than just a prototype.