Speedline Parts & Supercross BMX vs Tangent & Box One. Every number. No marketing spin.
| Fork | Class | Steerer | Offset | Weight (20") | Dropouts | Sizes | Price |
|---|---|---|---|---|---|---|---|
| Speedline Elite Carbon Junior / Expert |
Mini–Expert | 1" Full Carbon | — | 300g | 3/8" | 20", 24" Cruiser | $349.95 |
| Speedline Elite Carbon Pro — 3/8" Dropouts |
Pro | 1 1/8" Full Carbon | — | 409g | 3/8" | 20", 24" Cruiser | $349.95 |
| Speedline Elite Carbon Pro — 20mm Dropouts |
Pro | 1 1/8" Full Carbon | — | 409g | 20mm | 20", 24" Cruiser | $349.95 |
| Speedline Tapered Carbon Pro — Nanocarbon |
Pro | Tapered 1 1/8"–1.5" Full Carbon | 28mm | 453g | 20mm | 20", 24", 26" | $399.95 |
| Supercross BLK Carbon Fork Pro — T700S |
Pro | Tapered 1 1/8"–1.5" Full Carbon | 28mm | 445g | 20mm + 3/8" adapters included |
20", 24", 26" | $349.95–$399.95 |
| Competition | |||||||
| Tangent Faction Carbon Mini / Expert |
Mini–Expert | 1" Carbon | 26mm | 445g | 10mm | 20" only | $399.95 |
| Box One X2 Carbon Pro 20" / 24" |
Pro | 1 1/8" Chromoly Steel | 32mm | 610g | 20mm | 20", 24" | $297.49 |
Tangent's carbon fork only comes in one size: Mini/Expert. Box One's only comes in Pro. Speedline makes a full carbon fork for every class on the gate — Mini, Junior, Expert, and Pro — plus 24" and 26" Cruiser sizes. One brand, one store, every setup covered.
The Speedline Elite Carbon Junior/Expert fork transitions with the rider as they move from Junior to Expert class. Same fork, zero replacement cost. That's real-world thinking — not just a spec sheet.
The fork is the heaviest steerer-connected component on the front end. Every gram matters in a gate drop sport measured in hundredths of a second.
The 201g difference between the Speedline fork and the Box One is adding a quarter pound to your front end. And while people think a cro-mo steertube is stiffer, the bond joint of a carbon-to-cro-mo steerer is actually weaker and heavier — you have to make the carbon thicker just to hold the steertube in place, and the glue bond can come undone and allow the steertube to slip. That's exactly why we moved away from bonded steertubes almost a decade ago — to make sure you have the absolute best in BMX performance.
Every Speedline and Supercross carbon fork is built as a single monocoque carbon unit. There is no glue line between the steer tube and the legs. There's no bonded junction. There's no weak point. The steer tube will never slip, twist, or pull out — because it's not attached to anything. It is the fork.
This is the same construction method used in aerospace-grade carbon components. It takes more tooling, more precision, and more time — but the result is a fork that's measurably stronger, lighter, and more reliable than bonded alternatives.
The Box One X2 is marketed as a carbon fork — and it does use carbon fiber legs. But the steer tube is chromoly steel. Not carbon. You're buying a hybrid fork with a steel steerer at the top and carbon below it, bonded together at the crown.
That's a big part of why the Box One X2 weighs 610 grams while the Speedline Elite Pro weighs 409 grams. Steel is heavy. And a bonded steel-to-carbon joint is a potential failure point that a full monocoque fork simply doesn't have.
Speedline and Supercross BLK: full carbon steer tube. Every fork, every class. No steel. No bonding. One piece.
The Speedline Tapered Carbon Pro Fork and the Supercross BLK Fork are produced from Torray High Modulus Nanocarbon Composite — the same material used in the Supercross ENVY BLK carbon race frame. Torray is a Japanese industrial carbon manufacturer that supplies aerospace-grade material.
The nanocarbon compound is 27% stronger than standard carbon fiber and offers higher fatigue resistance and impact tolerance. Through a high-impact compaction process, Speedline produces denser, more consistent parts with fewer void areas — which means no hidden weak spots inside the laminate.
The Speedline Tapered and Supercross BLK forks run a 28mm offset. The Box One X2 runs 32mm. Lower offset means tighter, more responsive steering — exactly what BMX racers need in technical sections and out of the gate.
The Box One's 32mm offset was originally designed around its Oversized Technology geometry, which adds visual mass but also adds weight and alters steering feel. For pure racing, 28mm is the dialed-in choice.
Speedline and Supercross forks ship from the same warehouse at supercrossbmx.com. One cart, one checkout, one tracking number. No brand-hopping, no trust issues, no mystery shipping windows.
Looking for carbon bars to go with your build? See our carbon bars comparison — and the carbon stems comparison coming soon.