Reviews You Can Rely On

Bontrager Flatline - Women's Review

These kicks are a great option for someone who knows they like to have lots of freedom to adjust their feet on the pedals
Bontrager Flatline - Women's
Credit: Bontrager
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Price:  $130 List
Pros:  Lightweight, comfortable, varied tread for different conditions
Cons:  Lacking in breathability and protection
Manufacturer:   Trek
By Bo Outland ⋅ Review Editor  ⋅  Oct 3, 2019
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  • Grip - 30% 5.0
  • Comfort and Protection - 25% 4.0
  • Rigidity and Power Transfer - 20% 5.0
  • Breathability - 10% 9.0
  • Durability - 10% 6.0
  • Weight - 5% 10.0

Our Verdict

Bontrager's Flatline features Vibram rubber, which gave us a lot of wiggle room on the pedal if we placed our foot incorrectly. We think that something with more grip is better for overall safety, but if you know you like to have that freedom to move your foot, you may like the Flatline. These shoes are the lightest of all the models we tested, making them super comfortable. We especially like the anatomical tongue with tons of cushion for the top of our feet. There was not much protection in this shoe, so it may not be the best choice if you are a high-risk rider. They do run a bit big, so make sure you order a half size down if you decide on these shoes.

Our Analysis and Test Results

Bontrager recently released an updated version of the Flatline shoe. The new model has enhanced toe protection along with more ventilation and a new inForm fit. This version may still be available, but we have also tested the new version. -May 2022

Bontrager is a branch off of Trek, named after Keith Bontrager, who was integral in the development of how we know mountain biking today. The Flatline is lightweight and flexible, giving you a lot of control and feel of the pedals. We think this makes up for the lack of grip, especially in comparison to other shoes we tested and makes it worth considering for someone who likes to have more freedom to move their foot without disturbing the flow.

Performance Comparison

Bontrager Flatline - Women's mountain bike flat shoes - lots of movement on the pedal with vibram rubber.
Lots of movement on the pedal with Vibram rubber.


The Flatline has a similar grip to the other shoes we tested with Vibram rubber. We found the grip to be sticky, but still noticed these shoes slipping during technical climbing and when things got bumpy moving downhill. We think the shape of the lugs and the increased surface area with more texture on the Vibram rubber is what makes these shoes an edge. The toe and the heel feature a zig-zag pattern, we feel the variation in pattern helps when you have to take a short hike with your bike. However, when wet, the Flatlines feel slippery on the pedals.

Bontrager Flatline - Women's mountain bike flat shoes - vibram rubber on the flatline and the riddsance, as you can see the...
Vibram rubber on the Flatline and the Riddsance, as you can see the lugs are much larger on the flatline with more textured surface area. This is why we think there is slightly more grip with Bontrager Flatlines.

We recognize that there are lots of different types of riders out there, so this might be a great shoe for someone who likes to take their feet off the pedals or adjust their feet a lot — in that case, this might be a great shoe for you. If you need a shoe that is more grippy with a similar price point, we suggest looking at some of the other models we tested.

Comfort and Protection

For what the Flatlines lack in grip, they make up for in comfort. Our feet loved the feel of these shoes primarily because they are so light. The tongue of the shoe is very padded and does not put any pressure on the top of your foot. During long bike rides, our toes didn't go numb, and we've concluded there is not any part of the shoe that decreases circulation.

Bontrager Flatline - Women's mountain bike flat shoes - even though the toe is reinforced plastic we could still easily...
Even though the toe is reinforced plastic we could still easily press our finger into the toe.

These shoes could have more protection. There is reinforced material on the toe, and we could easily press our thumb into the material to make it flex. However, shoes with a specific anti-abrasion material perform much better.

We did find these shoes fit a little big, so if you are ordering, try to order a half size down from what you traditionally buy. The width is pretty average compared to the other shoes we tried.

Rigidity and Power Transfer

This shoe is on the more rigid side, but in comparison to other shoes tested it fell in the middle for rigidity. This shoe is also one of the lightest ones we tried, a fact that truly allowed us to be able to feel the pedal underfoot, especially when we wanted to make micro-adjustments. However, we had a hard time trusting this shoe after having our feet slip off and getting shinned by the pedal when riding powerfully.

Bontrager Flatline - Women's mountain bike flat shoes - lots of flex in the shoe allowed us to be able to feel the pedal...
Lots of flex in the shoe allowed us to be able to feel the pedal underfoot which made up for the insignificant grip.


The upper is made out of synthetic material and only has a few holes for breathability, so sometimes our feet got too toasty. But, not as hot as the other models we tested because there is less material, but still found them to be uncomfortable on hot, high-output days.


Our biggest complaint about these shoes is the size of the shoelaces. Bontrager did provide an elastic strap, but they made it much lower on the tongue to accommodate the size of the laces. We think the shoe would be better if the elastic strap was higher and the laces were shorter. We also found that the laces stuck out quite a bit even when they were tucked underneath the elastic strap, leaving the potential to get caught in our chainring.

Bontrager Flatline - Women's mountain bike flat shoes - extra-long laces on the bontrager flatlines.
Extra-long laces on the Bontrager Flatlines.

The upper material is fully synthetic. Despite the beating we gave them, these shoes barely showed any wear.


These were the lightest of the shoes we tested, making them an excellent option for someone who notices the weight on their feet. While they feel like feathers on your feet, they may not protect you when you hit a rock with your toe.


These are durable shoes, and because of that, your ability as a rider may outgrow them.


We think these are the perfect pair of shoes for someone newer to riding who may need more freedom to move their foot around on the pedal easily. They are very lightweight, making it easy to feel the pedal underfoot to help with bike management. And, they are very durable and will last you a long time.

Bontrager Flatline - Women's mountain bike flat shoes - that look after a really frustrating messy ride with bontrager...
That look after a really frustrating messy ride with Bontrager Flatlines.

Bo Outland
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