The FSA Flowtron Dropper Post

Ride Smarter, Descend Harder, and Finally Feel in Control — Without Paying $300 for a Dropper Post

Retail: $281 | Your Price: $99.97

Choose Your Size Below

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30.9mm x 150mm 30.9mm x 175mm 31.6mm x 125mm
31.6mm x 150mm 31.6mm x 175mm 27.2mm x 100mm
What size do I need?
×

Dropper Post Size Guide

Step 1: Seat Tube Diameter (mm)

This must match your bike’s seat tube exactly. Most common sizes are 27.2mm, 30.9mm, and 31.6mm. You can usually find this printed on your current seatpost near the bottom. If not, use a digital caliper or ruler to measure the inside diameter of your seat tube.

Step 2: Travel Length (dropper movement in mm)

This determines how far the seat can drop. General tips:

  • 💡 100mm: Ideal for gravel riders or smaller frames with limited insertion depth
  • 💡 125mm–150mm: Great all-rounder for trail and all-mountain riders
  • 💡 175mm: Best for aggressive riders, taller riders (5’10” and up), or those riding steep descents

Quick Rules of Thumb:

  • If you’re under 5'7": consider 100–125mm
  • Between 5'7" and 6'0": 125–150mm is safe
  • Over 6'0": 150–175mm if your frame allows

Still not sure? Click here to message us — we’ll help you choose the right size fast.

Not Sure It’ll Fit? Not a Problem.

- Full Compatibility Support Before & After You Order.

- 30-Day Returns.

- 100% Refund If It Doesn’t Work for You.

Choose Your Size Below

30.9mm x 150mm 30.9mm x 175mm 31.6mm x 125mm
31.6mm x 150mm 31.6mm x 175mm 27.2mm x 100mm
What size do I need?
×

Dropper Post Size Guide

Step 1: Seat Tube Diameter (mm)

This must match your bike’s seat tube exactly. Most common sizes are 27.2mm, 30.9mm, and 31.6mm. You can usually find this printed on your current seatpost near the bottom. If not, use a digital caliper or ruler to measure the inside diameter of your seat tube.

Step 2: Travel Length (dropper movement in mm)

This determines how far the seat can drop. General tips:

  • 💡 100mm: Ideal for gravel riders or smaller frames with limited insertion depth
  • 💡 125mm–150mm: Great all-rounder for trail and all-mountain riders
  • 💡 175mm: Best for aggressive riders, taller riders (5’10” and up), or those riding steep descents

Quick Rules of Thumb:

  • If you’re under 5'7": consider 100–125mm
  • Between 5'7" and 6'0": 125–150mm is safe
  • Over 6'0": 150–175mm if your frame allows

Still not sure? Click here to message us — we’ll help you choose the right size fast.

  • Become Unstoppable

    The Flowtron is for those ready to level up. Those who want to go from the one holding up the group to the one leading the charge. What once felt intimidating will now feel exhilarating.

  • Zero To Hero

    The Flowtron is a confidence game changer. Taking you from zero to hero with a feeling of mastery over your bike. Fear will be replaced with an addictive mix of confidence and control.

  • Easy To Install

    The Flowtron includes a full installation guide for an easy, at-home installation. With simple instructions, you'll be back on the trails in no time. To stay riding longer, check out these installation + maintenance guides below: flat bar, drop bar

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Ships in One Day From the U.S. 🇺🇸

- All Orders Shipped Within One Business Day From Crosslake Minnesota.

- Instant Tracking On Shipment

- Average Delivery: 2–4 Business Days

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