Designed to go high and fast in the skatepark. The 2021 Fly Sion was designed by some crazy park riders. The Sion features 2 pegs and hub guards, along with full chromoly parts. This bike weighs 24.9 lbs and is built to hold up to the best riding.
- ✅ – Full Chromoly
- ⛔️ – Under $500
- ✅ – Double Wall Rims
- ✅ – Pegs
- ✅ – Fully Sealed Bearings
- ✅ – 3 pc. Cranks
- ⛔️ – Freecoaster – What is a freecoaster?
- ✅ – Brakes
- ✅ – Gyro tabs
- ⛔️ – 4 pc bars
Other Fly Bikes
|Bike Model||Bike Price||Bike Quality|
|2021 Fly Neo||$450||Kids Bike|
|2021 Fly Nova||$450||Kids Bike|
|2021 Fly Supernova||$540||Mid/high level kids|
|2021 Fly Electron||$450||Beginner|
|2021 Fly Neutron||$540||Beginner|
|2021 Fly Proton||$650||Mid-level|
|2021 Fly Proton FC||$650||Mid-level|
|2021 Fly Sion||$720||High-level|
|2021 Fly Orion||$690||High-level|
|2021 Fly Omega||$820||High-level|
|2021 Fly Omega FC||$820||High-level|
|– 75º degree head tube angle / 30mm fork offset / 13.2” rear end – Fuego tires|
|– Sierra seat|
|– Volcano Front load stem|
|– Tractor 28 tooth sprocket – 2 nylon pegs & hub guards|
The Sion is designed for park riding with the input from Larry Edgar and Sem Kok to make it just right for blasting ramps with speed and style.
The 2021 Sion comes in a Flat Metallic Red colorway with all black parts and a full Flat Black colorway that should do the trick!
Available in RHD or LHD. Specify your preference on “comments” when you place your order.
Bike will be shipped as shown on the photo otherwise.
RHD: Right Drive Side (Sprocket on the right side)
LHD: Left Drive Side (Sprocket on the left side)
|FRAME: FULL 4130 CRMO / 21″ / REMOVABLE BRAKE MOUNTS / CHAIN TENSIONERS|
|FORK: INTEGRATED CONE SHAPE DESIGN / FULL 4130 CRMO / 1 PIECE STEER TUBE / 27MM OFFSET|
|BARS: FULL 4130 CRMO / 9.25″|
|GRIPS: FLY DEVON / 160 MM LONG|
|STEM:FLY VOLCANO FL 2 / 6061-T6 ALUMINUM CNC MACHINED / 50MM|
|HEADSET:TREBOL / SEALED BEARING / CNC MACHINED / 6061-T6 ALUMINUM|
|LEVER: TREBOL/ FORGED /6061 T-6 ALUMINUM|
|BRAKE: TREBOL SPRINGHANGER / FORGED / 6061 T-6 ALUMINUM|
|CRANKS: TREBOL 3PC / 4130 CRMO / 175 MM ARM LENGTH|
|BOTTOM BRACKET: MID / SEALED BEARING|
|SPROCKET: FLY TRACTOR / CNC MACHINED / 7075 ALUMINUM / 28T|
|PEDALS: FLY RUBEN GRAPHITE / NYLON – FIBERGLASS COMPOUND|
|CHAIN: 512 TYPE / 70 LINKS|
|RIMS: FLY PIRAMIDE / DOUBLE WALL / 6061-T6 ALUMINUM|
|FRONT HUB: TREBOL BUENO / SEALED BEARING / 3/8” FEMALE AXLE / 36H|
|REAR HUB: TREBOL / SEALED BEARING / 14MM MALE AXLE / 36H / 9T|
|TIRES: FLY FUEGO 2.30 FRONT & REAR / 60 TPI / 120 PSI|
|SEAT: FLY SIERRA TRIPOD / 100% SYNTHETIC LEATHER / 7 MM THICKNESS|
|POST: FLY TRIPOD / CNC MACHINED / 6061-T6 ALUMINUM / 135 MM LONG|
|PEGS: TREBOL BUENO / NYLON SLEEVE / 1 PAIR|
|HUBGUARDS: TREBOL BUENO / NYLON / 1 FRONT & 1 REAR|
|WEIGHT: 11.3 KG. / 24.9 LB.|
A: Top Tube Length: 21″ – Learn what size is right for you here.
This is a tall toptube.
Perfect for riders that are between 5’7″ to 6’4″
Getting a top tube that is taller than suggested will make the bike feel more controlled and less responsive
Getting a top tube size that is smaller than normal will make the bike feel a lot more snappy and responsive.
B: Chain Stay Length: 13.4″ – Learn About Chain Stays Here
This is a long chainstay.
A long chain stay will make the bike feel more stable and controlled.
A short chain stay makes the bike feel twitchy. Spins will be easy, but airing and jumping might feel hard to control.
A long chain stay will make the bike feel really controlled. Spins will feel sluggish, but manuals and air tricks will feel nice because it will be more stable and controlled.
C: Head Tube Angle: 75.5° – Learn About Head Tube Angles Here
Steep head tube angles make the bike “snappy” meaning more responsive to fast turns.
A less steep head tube gives you more control.
D: Seat Tube Angle: 71°
E: Bottom Bracket Height: 11.75″
F: Stand over height: 9.25″
This is a tall standover.
A tall standover gives the bike a responsive and snappy feeling. Good for barspins and controlled riding.
Bar Geometry – Learn more here
G: Rise: 9.5″
Riding a tall rise, will give you more leverage on the bike. Making it easier to pull back and lift the front wheel up.
H: Width: 29″
This is a medium width.
Narrow bars make barspins easier.
Wide bars give you more control and stability when steering.
I: Backsweep: 10º
What does backsweep do?
As far as I know, there is a sweet spot for backsweep. Too much will make the bike feel weird, and too little will make the bike unstable. It seems like the sweet spot is around 11º to 12º. If you need something a little more aggressive and straight feeling, go for 10º, but only do this if 11º is uncomfortable.
J: Upsweep: 2º
This is a normal upsweep!
What does upsweep do?
There is a lot of discussion about 1º upsweep vs. 4º upsweep. Some people are running experiments and testing if the greater upsweep will make drops feel better. It seems like a lot of street riders run 4º to 5º upsweep. This helps for wrist pain and lessens the impact of big drops.
I get it, $720 is a lot of money for a complete bike. Personally, when I was starting out, I never would have had enough money for something like this. However, for someone who wants a really good bike to LAST. This is a good choice
The Sion is a high-level borderline pro-level bike. With everything needed, like full chromoly, double-wall rims and unique aftermarket parts. This bike really stands out against other “park” bikes.
Buy if you are learning:
- High airs
- Almost any trick
Don’t buy if you are learning:
- Good for all riding but best for street!
Since I started reviewing the Fly bikes last year, I became obsessed. I love the colors and I love the quality. The only thing i’d change is the price. They are such high quality that it makes them a little expensive.
The 2021 Sion is perfect for a rider who wants to progress in bmx and keep riding for a long time. I always say this because I’d hate for someone to get into bmx with the sion for a few months and then give up on riding. That would be a huge waste of money. Only get this bike if you are serious about bmx.
- Where can I buy this bike? As an affiliate for sourcebmx.com, I always recommend them. They have a warehouse in the USA so shipping is pretty fast and they do so much to support bmx. Buy it here
- Is this bike for park, dirt, or street? It is designed for park riding. P
- How much does it weigh? 24.9 lbs