Tri-Maine Series - Training & Preparation

Bicycle Tires Are a Drag

Your bike tires may be costing you time, lots of time.

“Come on,” you say, “a bike tire is a bike tire, right?”

Or “I paid $50 per tire for my Continental Force and Force Attack tires. The bike shop said they were the fastest. They are fastest, right?”

Well, not according to Tri-Maine race leader, Kurt Perham, they are not. Perham is nearly obsessed with what he refers to as “free speed.” From fast transitions to perfecting bicycle aerodynamics, Kurt is always on the hunt for an edge. In a recent interview with OA, the race leader and multi-sport coach shared with us the fact that we could replace our Continentals with a set of Michelin Pro Race 2s and save ourselves both time and money. A set of Pro Races 2s can be purchased on line for $30 less than you can buy the Continentals, and they will save you as much as a two minutes over a 40K bike course like Urban Epic or Lobsterman.

How is this so? Kurt shared with OA a presentation he developed with his colleague, Rick Ashburn, on bicycle tire drag. The discussion is a little technical but well worth the read.

“A pneumatic (air-filled) tire has a flat spot where it touches the ground - the contact patch. About half of a rider’s weight is on each tire, making an oval flat spot a little less than one square inch in size. As the tire rolls forward, the leading edge of the contact patch moves around the tire. Some rubber from the tire that began its life round becomes bent and flattened. As that spot on the tire leaves the back end of the contact patch, it bends back into its favored round shape. That bending and un-bending action doesn't happen freely - it involves friction within the tire. That little bit of friction, happening constantly and rapidly, adds up and slows the bike down.

Now, before you go thinking that pumping the tire up really hard will reduce this drag, you need to consider bumps in the road. While it is true that high-pressure tires can minimize the bending and unbending friction, they do so at the cost of bouncing over tiny bumps in the road instead of "squishing" over them. Every bumpy bounce causes the bike to divert some of its kinetic energy into an up-and-down direction instead of forward, and that energy is effectively lost. So, a nicely rolling tire needs to strike a balance between being pumped up enough to minimize the contact patch drag, and not so much as to have it losing speed to the tiny constant bumps encountered on normal asphalt.

The answer to this little optimization problem is found by tire testing. Cutting to the chase, the answer is: For racing on normal public roads, you should pump your tires to between 100 and 120 pounds. Just because the tire might have "190psi" printed on the side of it doesn't mean you should do it! That is a maximum number printed for your protection, and would apply only if you were racing on a track.

There is an equation for calculating the drag that the tires impart to the bike. For our purposes, it is convenient to express that drag force in terms of watts:

Watts to overcome tire drag = Crr*M*g*V, where

Crr = Coefficient of Rolling Resistance (determined by testing the tire)
M = Mass of bike plus rider
g = The gravitational constant, 9.8m/s^2 (remember high school physics!)
V = The ground speed of the bike.

Since M is nearly fixed, and g is most certainly fixed, you can see that tire drag varies directly with Crr and with bike speed. If you go twice as fast, you use up twice as many watts overcoming tire drag. Since you want to go as fast as you can, the sole variable left under your control is the Crr of your tires.

The Crr of a name-brand racing tire will range from 0.004 to 0.007. At a glance, those numbers look like they are close together, and you can buy highly regarded and expensive tires at both ends of that spectrum. However, let's do a little math

Crr = 0.004 or 0.007
M = 66 kilograms
g = 9.8m/s^2
V = 8.94 m/s (20 mph)

Rolling along at IM bike pace, I am expending either 23.12 watts or 40.48 watts to overcome tire drag. Which would you prefer? This difference of 17.36 watts represents - are you sitting down - about 2.5 minutes in an 40K bike race!”

Check this link for a listing of Crr for brand names bicycle tires.

Urban Epic Triathlon Race Results

Tri-Maine race leader Kurt Perham crushed the field in the inaugural edition of the Zone Urban/Epic Triathlon with a winning time of 2:14:54, almost seven minutes ahead of second place finisher, Griffin Weiler at 2:21:23, and Sam Evans-Brown in third at 2:22:00. Perham was the only participant to complete the 40K bike course in less than 1 hour, and he had the fastest transition times of all the top participants.

Katie Payson lead the women's field with a time of 2:29:45, just ahead of the Tri-Maine women's race leader, Erin Brennan at 2:31:31 and Carrie McCusker at 2:33:54.

The Top 25 finishers of the Urban Epic are as follows:
1 73 KURT PERHAM BRUNSWICK ME 2:14:54
2 263 GRIFFIN WEILER BOALSBURG PA 2:21:23
3 109 SAM EVANS-BROWN PORTLAND ME 2:22:00
4 191 ROBERT MAHONEY MANCHESTER ME 2:22:10
5 197 OWEN MCGONAGLE BOSTON MA 2:22:51
6 327 MATT BOOBOR PLYMOUTH NH 2:23:50
7 147 JOHN FLANAGAN COHASSET MA 2:23:58
8 295 PETER WEILER BOALSBURG PA 2:25:37
9 85 RANDALL WOODS PORTLAND ME 2:25:43
10 28 JOSEPH CORCORAN CAMBRIDGE MA 2:26:39
11 280 JIMMY BUNNELL DUXBURY MA 2:27:02
12 260 ROB SMITH CUMBERLAND FORESID ME 2:27:21
13 230 CATHARINE PAYSON CAPE ELIZABETH ME 2:29:45
14 176 STUART OLSEN NEWBURYPORT ME 2:30:27
15 110 JON MCGONAGLE PORTLAND ME 2:30:29 2
16 82 IAN SIMON SOMERVILLE MA 2:30:50
17 229 ERIN BRENNAN PORTLAND ME 2:31:31
18 71 DAVID GAUTHIER STOUGHTON MA 2:31:46
19 37 THOMAS HEDSTROM CAMDEN ME 2:32:24
20 192 GREG GOODHUE SIDNEY ME 2:32:27
21 79 DOUGLAS DELAPP MYSTIC CT 2:32:33
22 103 GRADY JACKSON CAPE ELIZABETH ME 2:32:49
23 87 JEFFREY ARONIS WALTHAM MA 2:33:53
24 212 CARRIE MCCUSKER CAPE ELIZABETH ME 2:33:54
25 268 RICK DURGIN WESTBROOK ME 2:34:04

For the complete results and story visit MaineToday.com

Congrulations to all Urban Epic race participants.

Urban Epic Personal Safety Considerations

by Scott Marr, M.D.

The Urban Epic Triathlon presents triathletes with a number of special challenges.

First, the Urban Epic features an open water swim in Portland's Casco Bay. Current temperatures in Casco Bay are approximately 62 degrees Fahrenheit. Without a full body wet suit, even an active triathlete could expect to become hypothermic within 10 to 15 minutes. To avoid hypothermia, a full body wet suit is absolutely essential. Tri-Maine Productions will also be providing participants with race caps, which all participants are required to wear to keep the body warm.

Waves averaging 2-3 feet, crosscurrents and ocean "chop" can make the swim even more challenging. Keeping a straight line with a focused destination will minimize your time in the water and the chance of becoming hypothermic. The risk of taking in some unwanted seawater is also a risk. Triathletes exiting the water to the mini-transition area may want to have some drinking water available to rinse out the mouth and take on some fluid, as salt-water intake can hasten dehydration.

The Urban Epic is unique among triathlons in that it features a mini-transition area prior to T1. Triathletes will need to strip from their wet suits, put on a pair of running shoes and sprint 1/2 mile to T1. To avoid blood rushing to the head, triathletes are advised to sit down in the mini-transition area to put on their shoes, rather than bending over to tie up the laces. Athletes may lose a small amount of time, but this will minimize potential problems from fainting.

The early part of the bike course runs through a densely populated area of Portland. People and cars will be on the road, so triathletes will want to ride defensively during the early part of the course. The same is true for the latter part of the course as participants return to the city.

Since most triathletes will be out on the course beyond two hours, proper nutrition and hydration will also be critical to an injury-free race. Both the bike course and the run course offer little tree cover or shade. If it is a sunny, warm day, then dehydration is definitely a factor. Athletes should plan to hydrate well before the race begins, avoiding too much in the way of diuretics like coffee. Thereafter, athletes should plan to take in between 24 oz and 32 oz of fluid per hour of racing. So, an athlete expecting to complete the course in 2.5 hours, should plan to drink 60 to 80oz of fluid.

Likewise with nutrition - athletes should come to the Urban Epic well nourished with muscle glycogen stores full. Participants should then plan to consume between 250-300 calories per hour in the form of carbohydrate for the race to provide the body with adequate fuel to finish the race strong. Less than 250 calories per hour and the athlete risks bonking. More than 300 calories and the athlete risks gastrointestinal discomfort.

Being mindful of the challenges presented by the Urban Epic racecourse will enable participants to complete the course safely and quickly. In the event that you do experience problems, OA medical staff will be on site to assist triathletes. Look for OA medical staff at the transition area and along the course.

Be safe and have a great race!

Dr. Marr practices Sports Medicine at the OA Sports Medicine Center. He is a Fellow in the American College of Sports Medicine and currently serves as the Team Physician for the University of New England and Windham High School. Dr. Marr has a special interest in endurance athletics including performance physiology and injury prevention. He is the current Medical Director of the Tri-Maine triathlon race series.

Tri-Maine Series Race Standings

Prior to the inaugural edition of the Urban Epic Triathlon in Portland on August 18, Kurt Perham leads the both the men's competition and the overall competition, while Erin Brennan leads the women's competition.

Here's the top 10 triathletes in the Tri-Maine Series race standings:

1. Kurt Perham
2. Sean Teel
3. Charles Carter
4. Rob Smith
5. Matthew LeBrun
6. Greg Goodhue
7. Robert Turner
8. Shawn Berry
9. Marcus Deck
10. Erin Brennan

Kurt Perham, Rob Smith, Robert Turner, Greg Goodhue and Erin Brennan are all registered from the Urban Epic this weekend. Look for the leaderboard to change on Saturday!

Urban Epic: Course Assessment

OA spoke to Tri-Maine race series leader Kurt Perham about the unique challenges faced by triathletes in the first edition of the Zone Urban Epic Triathlon taking place this weekend in Portland.

Earlier this week, Kurt completed a practice run of the Urban Epic course, and he told OA that the swim course could be a little challenging. At 1.2+ miles, the open water swim in Casco Bay is longer than most Olympic Distance triathlons. And while the current created by the Presumpscott River at low tide will increase speeds towards the end, it will still swim longer than the typical .93 mile Olympic Distance course. Kurt estimates that a strong swimmer will finish in the Urban Epic swim in the 25-27 minute range, compared with 20-21 for a typical shorter course. The open water, the current and the ocean chop will also make the swim more challening, especially for those that do not have their open water skills refined. Swimming straight and drafting effectively will play important roles. And newbies will have to overcome the inherent fears of swimming in the ocean. A wet suite and a Tri-Maine series cap will be mandatory attire for the cold open water swim.

Largely, however, Kurt thinks that the Urban Epic will play out similar to other international distance races, except for the inclusion of the mini-transition area. Swimmers will exit the water into a mini-transition area where they will dump their wet suits and put on a pair of running shoes. They will run up hill about 1/2 mile before entering T1 for the transition to the bike. Kurt thinks that the mini-transition might actually help get blood into the legs so that triathletes can rider harder on the bike from the get-go.

Kurt says that the bike route is quite fast except for Walnut and Fox Streets on the way out and on the way back. Walnut Street, in particular, is very steep and runs through a residential area. The rest of the ride is very fast thereafter except for the return up Fox and Walnut Streets. "That will leave a little sting in the legs after 24 miles on the bike."

From T2 the 10K run course of Urban Epic heads straight back up the Fore Street Hill towards the Eastern Prom. So it starts out tough, but Kurt says its really "pretty easy" until the 4.5 to 5.0 mile mark where there is another big hill that race organizer Tri-Maine seems to have added just to make the course more challenging. Thereafter, the Urban Epic 10K race course runs through the Red Bull arch and drops back down to the bike path and the finish line.

What's it going to take to win the inaugural edition of the Zone Urban Epic Triathlon? Kurt says, "Go real fast." And fast, he does go. He completed the Shipbuilders Triathlon in late June in 2:05, but he says not to expect a PR given the swim and the hills. He says to look for a winning time in the neighborhood of 2:10.

We'll see on Saturday...

Urban/Epic Olympic Distance Triathlon

On Saturday, August 18, three hundred fifty (350) triathletes will be transported via ferry from Portland's East End to Macworth Island, and the premier edition of the Zone Urban/Epic Triathlon and Festival will be underway.

The Urban/Epic Triathlon is the fifth featured event in the Tri-Maine Series races, and according to race organizer Will Thomas of Tri-Maine Productions, the Urban/Epic has become all that more epic over the past several weeks.

The unexpected death of a 38-year old man during the swim leg of the inaugural edition of the Cohasset Triathlon at Sandy Beach on July 8 prompted the Coast Guard to revisit Tri-Maine's plan to have swimmer's jump from a barge located a mile off shore on Casco Bay. Early in the month of June, Tri-Maine's Thomas had visited the Escape from Alcatraz Triathlon in San Francisco Bay to observe logistics for the Urban Epic swim. With the unfortunate turn of events in Cohasset, Thomas had to adapt the race to satisfy the safety concerns of the Coast Guard.

According to Thomas, the revised swim from Macworth Island is spectucular. "Macworth is a desolate island that looks back directly at the Portland skyline. It's absolutely beautiful." Tri-Maine race participants will swim straight toward the B&M Baked Bean Factory and go through a gate marked with boueys. As triathletes near the shore, they will encounter the current generated by the Presumpscott River emptying at low tide. The tide will cause swimmers to sweep toward East End Beach. The total distance of the swim is slightly longer than planned at 1.2 to 1.3 miles, but according to Thomas, "It will swim like 1 mile because of the current that will move athletes swiftly towards the first transition area."

Only triathletes and Tri-Maine staff will be transported to Macworth for the mass start race. Fans, friends, family and media will be able to observe the swim from a Casco Bay Ferry anchored safely along the course. Tri-Maine Productions has charted the ferry, and interested spectators can go on the boat for free. The boat launches at 6:40am.

As swimmers meet the East End shoreline, they will enter a mini-transition area. Athletes will strip their wet suits and put on their shoes which Tri-Maine Productions will transport in a numbered gear bag designated for each race participant. Triathletes will then run approximately 1/2 mile along a path before entering T1 and heading out on a 40K (24.84 miles) bike ride throughout Greater Portland. Athletes are advised to pack a second set of shoes (not your race shoes) for the mini-transition run to T1, which is located within a boat-building warehouse.

Race participants will want to make sure to pace themselves as the bike race begins by climbing a steep hill on Fore Street. It will be quite easy to redline in the first mile of the race! "That would be a mistake," relates Thomas, "because athletes are going to need everything they have to complete the bike course which includes two steep climbs back up to the Peninsula, one on Fox Street and the other on Walnut Street."

Then, athletes can settle into a beautiful 10K (6.21 miles) race along the Eastern Prom and the Back Cove Path. This course is literally on the ocean from start to finish!

One thing is for sure, the premier edition of the Zone Urban/Epic will be just that - EPIC!