Neil Shirley, riding a Focus e-mountain bike, makes it look easy to navigate the deep sand of the eMTB race Friday at the Sea Otter Classic in the hills near Monterey, California.
Tyler Pattullo soars over the rock garden at the 2017 Sea Otter Classic eMTB race as spectators cheer him on. He finished the race in 44:29.
Monterey cyclist Chris Toplarski thought the Sea Otter Classic e-mountain bike race would be fun -- but then the competitive instincts kicked in.
German bike maker Haibike was one of the early entrants into the e-mountain bike market. This full-suspension Xduro AllMtn 8.0 costs $8,000 and has a 500Wh battery and 350W motor from Bosch.
E-mountain bikes make climbing much easier. Here, Cole Cherpak leads Neil Donoghue up a steep ascent. Even with the battery boost, strong lungs and legs were essential for winning the race.
The ultimate winner of the Sea Otter Classic eMTB race, Xavier Marovelli, bumps down the rock garden.
The Focus Jam2 e-mountain bike is a rarity sporting new battery and motor technology from cycling component giant Shimano.
The Focus Jam2 e-mountain bike has two batteries, one built into the down tube behind the front wheel and another that can be locked onto the outside of the down tube. If you're going on a shorter trip, you only need one. The internal one can be replaced by removing the motor -- a complicated operation most likely done by a shop.
Janel Holcomb rides across the highest-elevation point of the Sea Otter Classic's eMTB race. She finished the course in 50 minutes, 26 seconds.
An e-mountain bike racer gets a kick from his motor as he navigates the mushy sand at the Sea Otter Classic eMTB race.
The Sea Otter Classic e-mountain bike race made four 2.9-mile loops over the hills of the Mazda Raceway Laguna Seca near Monterey, California. Much of the course was the same as that ridden by pros on the cross-country race with conventional mountain bikes.
E-mountain bikes in races are limited to models that amplify your pedal stroke -- no throttles allowed -- and whose motors cut out once you're going faster than 20mph. This racer was disqualified because his bike had a more powerful motor.
Neil Donoghue, winner of the men's 30-39 category at the 2017 Sea Otter Classic eMTB race, lofts his Giant electric mountain bike over the rock garden.
Electric motors help riders run fatter tires that are heavy but perform better. This is Andrew Slater bumping over the Sea Otter Classic eMTB race's rock garden.
Alan Harris of Hayward, California, bought a used Santa Cruz bike and retrofitted it with a Kranked e-bike motor and battery.
E-mountain bike racers had to navigate this boulder-studded descent at the 2017 Sea Otter Classic eMTB race. Big tires and long-travel suspension helps.
A sand bog on the 2017 Sea Otter Classic was an opportunity for riders to benefit from an electric motor.
Not everyone took the 2017 Sea Otter Classic eMTB race super seriously. Along with this racer dressed as a butterfly was an Easter bunny and very sweaty yeti.
Pro bike racer Ben Goyette, a video game programmer by day, was at the Sea Otter Classic to race his conventional mountain bike. But he's fine with e-mountain bikes, and says riding them is like a really good day on a conventional bike.
Electric mountain bikes come in many forms. Most have full suspension, but wheel size is variable. This is a 29-inch model.
Racers at the 2017 Sea Otter Classic eMTB race had to ride up long switchbacks.
An e-mountain bike racer rides a level section above dozens of booths from bike and equipment makers at the 2017 Sea Otter Classic.
Trek, one of the biggest bike makers around, showed off this sleeker commuter bike at the Sea Otter Classic. Many e-mountain bikes have more ungainly battery mounts and motors.
This Trek commuter e-bike still has a removable battery. It's made by Bosch, the dominant supplier of e-bike battery-motor components.
Some e-mountain bikes are sleeker than others. This Specialized model has a battery built into the down tube behind the front wheel.
The sand bog claims two victims who couldn't ride through at the 2017 Sea Otter Classic eMTB race. These racers are Gil Norman, left, and John Miller.
Electric motors are helpful for cargo bikes, too.
Michael Pannone churns through the sand on a Haibike e-mountain bike. Haibike, a German bike maker early to the eMTB market, was a sponsor of the Sea Otter Classic's eMTB race.
Monterey cyclist Chris Toplarski finished second in the men's 50-59 category for the 2017 Sea Otter Classic eMTB race. It was the race's second year in existence.