The 3-Sum


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The 3-Sum™ is the sum of the three event triathlon experience. Lightweight, fast, and lightly cushioned, the 3-Sum™ is built for triathletes who demand the ultimate in performance. With a seamless upper, easy-on transition pull-tabs, quick-draw lacing system and heel/forefoot drain holes, the 3-Sum™ minimizes transition time and maximizes performance. The Zero Drop™ design allows for natural loading of the calf and Achilles, while optimizing the landing angle to ensure powerful speed with minimal impact. The Altra 3-Sum™ – get off the bike and run like there is no tomorrow!

Technical Stuff

  • Ideal Uses: Triathlons, Running, Road Racing, Speed Work
  • Designed to Reduce: Your PR, Shin Splints, Knee Pain, Forefoot Pain, Bunions
  • Platform: Zero Drop™ Platform, Foot-Shaped Toe Box, Natural Ride System
  • Weight: 6.7 oz
  • Stack Height: 18 mm
  • Midsole: Blended EVA/AltraBound™
  • Outsole: Blown Rubber SpeedPod
  • Insole: 5mm Contour
  • Upper: Minimal Liner / Sock-free Liner, Treated for Anti-odor / Anti-bacterial
  • Lacing Structure: Custom Yankz Quickdraw Laces for customized fit and faster transition
  • Other Features: Seamless Upper, Easy-on Transition Pull Tabs, Quickdraw Laces, Heel and Forefoot Drain Holes, Vegan Friendly, Natural Ride System

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Customer Reviews for the The 3-Sum

Cross-training Wonder
By RunAnnaBelle on Mar 18, 2014
Average Rating: 5.0 / 5.0
I am a cross-fitter/distance runner, and was looking for a shoe with zero drop. The 3-Sum has been amazing! I wear it to lift with correct posture,jump ropes and boxes, and then run three miles. I love that when I'm not cross-training, I can use them for nice long Saturday runs. My knee pain that wo... (Read more)
Amazing Shoe!! Nailed it!
By BridgetRuns on May 23, 2013
Average Rating: 5.0 / 5.0
I have to admit I was skeptical when I first saw this design, but after testing them out I am blown away. I thought I'd only want to wear them on short runs, but I want to wear them all the time. They are comfortable and light, but strong. And I love that you can wear them without socks! I really do... (Read more)
Exceeded All Expectations
By runritarun on Jun 28, 2013
Average Rating: 5.0 / 5.0
Bought these from Boston Marathon Expo. Took about two weeks (120klm) to get used to these shoes. Now doing 30klm runs in these shoes (long runs with sox, shorter speedwork without sox) and planning to wear in my next marathon in 4 weeks time. Prior to these shoes I had been wearing minimalist (zero... (Read more)
By Helenstu on Jul 17, 2013
Average Rating: 5.0 / 5.0
Love this shoe. I was hopeful that this shoe was going to work but not optimistic. I am EXTREMELY picky about shoe fit. I had never found a shoe I could wear without socks but my socks and laces were costing me time in transition. These shoes are fabulous. The fit is perfect. Not to wide, not ... (Read more)
Perfect shoe
By Fancyface on Jul 30, 2013
Average Rating: 5.0 / 5.0
I'm currently training for my first marathon and i am happy i went with this shoe after a lengthy research period. I have no reason to try anything else, i have no complaints about this shoe and i will never use another shoe for running. This is it. Would love to see more colors though.
Favorite Shoe
By kelliannebrown on Mar 2, 2014
Average Rating: 5.0 / 5.0
This is my favorite shoe! I am not a triathlete, but decided to run with it anyway. I love it! Hands down the best shoe I've ever ran with.
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