What this headset is
A fully integrated (IS) headset designed for older Scott MTB frames like:
- Scott Scale 2017
- Scott Spark 2017
Brand: Syncros
Key Standards (Compatibility)
-
Top: IS42/28.6
-
Bottom: IS52/40
Meaning:
- Head tube:
- Top inner diameter: 42 mm
- Bottom inner diameter: 52 mm
- Fork:
- Tapered 1 1/8" → 1.5"
- Crown race: 40 mm
Features
- Sealed stainless steel cartridge bearings
- 45° / 45° contact angles
- Fully integrated design (IS)
- Built for MTB use (more sealing, slightly heavier than road equivalents)
Weight
- Measured: 71 g
(slightly heavier than your Foil headset at 58 g — normal for MTB durability)
What’s included
- 2 × bearings (top + bottom)
- 1 × top cover
???? IMPORTANT: Comparison with your previous headset
| Feature |
Foil 2023 Headset |
Scale/Spark 2017 Headset |
| Top standard |
IS44/35 |
IS42/28.6 |
| Bottom standard |
IS52/40 |
IS52/40 |
| Bike type |
Road (aero) |
MTB |
| Compatibility |
❌ Not interchangeable |
❌ Not interchangeable |
The bottom is the same, but the top is different.
Key takeaway
These two headsets are NOT compatible with each other because:
- Your Foil uses a larger upper bearing (IS44)
- This one uses a smaller upper bearing (IS42)
Even though both are “integrated,” 2 mm difference = won’t fit at all.
When to use this one
This headset is correct if:
- You have a Scott Scale or Spark around 2017
- Your frame specifically requires:
- IS42/28.6 (top)
- IS52/40 (bottom)
Quick rule to remember
- IS42 top → usually MTB / older designs
- IS44 top → newer road / aero bikes
