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| Event | Distance | When | Entry fee | Cap |
|---|---|---|---|---|
| Olympic Aquabike | AquabikeBike 0.9 mi | Jul 10, 20277:30 AM | $144$154 after Dec 31, 2026 | – |
| Olympic Relay | Olympic TriathlonSwim 1,500 m · Bike 28 mi · Run 5.3 miRelay or teamOpen water swim | Jul 10, 20277:30 AM | $265$284 after Dec 31, 2026 | – |
| Olympic Triathlon | Olympic TriathlonSwim 1,500 m · Run 5.3 miOpen water swim | Jul 10, 20277:30 AM | $144$154 after Dec 31, 2026 | – |
| Sprint Duathlon | DuathlonRun 1.5 mi · Run 3.5 mi | Jul 10, 20277:30 AM | $123$131 after Dec 31, 2026 | – |
| Sprint Relay | Sprint TriathlonSwim 750 m · Bike 14 mi · Run 3.5 miRelay or teamOpen water swim | Jul 10, 20277:30 AM | $216$232 after Dec 31, 2026 | – |
| Sprint Triathlon | Sprint TriathlonSwim 750 m · Run 3.5 miOpen water swim | Jul 10, 20277:30 AM | $123$131 after Dec 31, 2026 | – |
| Open Water 1 Mile Swim | 1 Mile | Jul 10, 20278:30 AM | $55$59 after Dec 31, 2026 | – |
Entry fees exclude processing fees. Prices and dates come from the race's registration page and refresh nightly.
The Duathlon fee goes up to $131 on Dec 31, 2026.
This is an open water swim at Halfmoon Lake.
From the organizer's own race information. Venues and rules can change from year to year; the race's current athlete guide decides.
Around July 10, Halfmoon Lake typically runs about 81°F at the surface (77 to 85°F across 2011 to 2020). The water usually runs above 78°F at this date: wetsuits are allowed but make you ineligible for age-group awards.
A model estimate from the USGS lake temperature model (daily surface temperatures for US lakes), not a measurement. Wetsuit cutoffs are USA Triathlon age-group rules. The race's own water temperature reading on race morning decides.
Online registration closes Jul 10, 2027, unless the race fills first.
Sunrise on race morning is at about 6:07 AM, and the Olympic Aquabike starts at 7:30 AM. The start sits about 930 feet above sea level.
Fees exclude processing fees. Comparisons use current entry fees and published results from races nearby.
Halfmoon Lake Day Use Facility, Pinckney Recreation Area, Gregory, MI 48137
The pin marks the address the race lists, which is usually the start. Course maps are the organizers' own.
The 3.7-mile run course climbs 236 feet, about 64 feet a mile: hilly.
| Course | Distance | Climbing | Terrain |
|---|---|---|---|
| 3.7 mi Running Route in Pinckney, MichiganRun | 3.7 mi | 236 ft | hilly |
From the course maps the organizers publish on Ride with GPS and MapMyRun; climbing is the total gain the map reports. Courses can change between editions, so check the date on the map.
Aggregated from official results for Ann Arbor Tri, Du, & Aquabike. Individual finisher names are not stored here.
At the 2024 Sprint, the fastest tenth finished in 1:35:00 or better, the top quarter in 1:40:57, and half the field in 2:00:31; the last tenth came in after 2:34:34.
At the 2024 Olympic, the fastest tenth finished in 2:36:08 or better, the top quarter in 2:52:55, and half the field in 3:14:25; the last tenth came in after 3:52:41.
At the 2024 Sprint Duathlon, the fastest tenth finished in 1:34:31 or better, the top quarter in 1:40:58, and half the field in 1:48:37; the last tenth came in after 2:30:32.
| Age | Women | Men |
|---|---|---|
| 20-29 | 1:36:34 | 1:54:19 |
| 30-39 | 1:42:34 | 1:28:10 |
| 40-49 | 1:49:47 | 1:37:55 |
| 50-59 | 2:09:10 | 1:52:43 |
| 60-69 | n/a | 1:43:27 |
| 70+ | n/a | 2:06:30 |
Groups with fewer than five finishers are left out. Awards vary by race; check the race's rules.
Where a finish time would have placed in 2024.
At the 2024 Sprint, the run decided the most: the middle of the field lost about 10:39 to the top quarter there, 43% of the gap across the three legs.
Compared with a typical sprint triathlon in Michigan, the median swim here was 2:01 slower, the bike 9:03 slower and the run 10:14 slower (swim lengths differ from race to race).
| Leg | Top 10% | Top 25% | Median | Slowest 25% |
|---|---|---|---|---|
| Swim | 15:12 | 17:15 | 20:41 | 24:02+ |
| T1 | 1:36 | 2:05 | 2:51 | 3:54+ |
| Bike | 43:38 | 47:56 | 53:56 | 1:01:06+ |
| T2 | 0:56 | 1:06 | 1:38 | 2:13+ |
| Run | 29:01 | 32:31 | 39:51 | 47:24+ |
Each column ranks finishers on that leg alone, from the race's published results. T1 and T2 are transitions.
At the 2024 Olympic, the bike decided the most: the middle of the field lost about 15:47 to the top quarter there, 50% of the gap across the three legs.
Compared with a typical olympic triathlon in Michigan, the median swim here was 1:51 slower and the bike 11:49 slower (swim lengths differ from race to race).
| Leg | Top 10% | Top 25% | Median | Slowest 25% |
|---|---|---|---|---|
| Swim | 26:24 | 29:25 | 33:10 | 38:38+ |
| T1 | 1:21 | 2:00 | 2:40 | 3:40+ |
| Bike | 1:19:26 | 1:26:36 | 1:36:41 | 1:43:27+ |
| T2 | 1:06 | 1:32 | 2:08 | 2:48+ |
| Run | 44:34 | 48:23 | 56:08 | 1:07:59+ |
Each column ranks finishers on that leg alone, from the race's published results. T1 and T2 are transitions.
Up 10 percent since 2021.
All events combined, from official results.
From 2021 to 2024, the field went from 128 to 121 finishers, and the median time dropped from 2:07:58 to 2:00:31.
| Year | Finishers | Median | Fastest tenth | Winner |
|---|---|---|---|---|
| 2024 | 121 (+27%) | 2:00:31 | under 1:35:00 | 1:24:30 |
| 2023 | 95 (-1%) | 1:52:14 | under 1:32:57 | 1:21:36 |
| 2022 | 96 (-25%) | 2:19:03 | under 1:54:26 | 1:32:13 |
| 2021 | 128 | 2:07:58 | under 1:44:07 | 1:31:05 |
From each year's official results for the Sprint Triathlon; virtual options are left out.
Slower than most US sprint triathlons
The fastest quarter of the 2024 sprint triathlon field finished under 1:40:57, against 1:24:09 in a typical US sprint triathlon, so times here run 20 percent slower.
Compares the fastest quarter of each field, so walkers and first-timers do not skew it. It reflects the course and the field together: a flat course, cool weather, or a competitive crowd all make times faster.
Around July 10 the day usually runs from 64°F at dawn to 82°F in the afternoon, with measurable rain on about 39% of days. Cold snaps dip to 59°F and hot years reach 88°F.
Based on 75 days within a week of the date over the last 5 years, from historical weather for the start area. Not a forecast.
What the organizers of Ann Arbor Tri, Du, & Aquabike cover on their registration page, in brief.
Schedule and packet pickup
Aberdeen Bike will be on-site to help you with any last-minute bicycle needs before the start of the race! We also recommend visiting Aberdeen in Chelsea, MI before race day to make sure your bike is race-ready! Meet Kevin, owner of…
Schedule and packet pickup
Packet Pickup Information. Participants have three opportunities to pick up their race packets before the race. Your packet includes your bib number, bike stickers, swim cap, and T-shirt. Please bring a photo ID. You may pick up for…
Schedule and packet pickup
Please join us the Tuesday before race day at noon for our Pre-Race Athlete Briefing via Zoom. All you need to know for a successful race will be presented, followed by Q&A. We strongly suggest you attend. The Zoom link will be sent to all…
Schedule and packet pickup
Triathlon 101. Time: 5 p.m. (during packet pickup). Place: Transition Area at the race site. What: Meet the race director to learn what you need to have the best race ever! She will address course details, equipment, rules, and race hints…
Parking and travel
There is plenty of parking in the park. Follow Event Parking signs as you enter the park at 8725 Hankerd Rd, Gregory, MI. Please be sure you have a current Recreation Passport. Vehicles without Recreation Passports will be issued notices…
Rules and FAQ
Part 1: Registration. If you are a Team Captain: Click “Register”. Select “Relay”. Continue with Registration, including filling out the following questions:“CREATE TEAM”. Pay for the registration in full, your team members will pay you…
Organize this race? Add details or a correction
Since 1986, the iconic and classic Ann Arbor Tri has been held in the Pinckney Recreation Area at Halfmoon Lake, one of the largest state parks in all of Michigan. You’ll swim the open waters of Halfmoon, bike the rolling paved country roads of the surrounding rural area, and then run the Potowatomi Trail. It’s a classic course you’ll come back to again and again.
Choose Your Challenge!
Olympic Triathlon — 1500 meter swim (64 lengths in a standard metric pool), 28-mile paved road bike, 5.3-mile trail run (Yes, it's really an Olympic: (USAT Distances Defined)
Sprint Triathlon — 750-meter swim (32 lengths in a standard metric pool),14-mile paved road bike, 3.5 mile trail run