What this headset is
A fully integrated (IS) road headset designed for:
- Scott Addict
- Scott Solace
Brand: Syncros
Key Standards (this is the critical part)
-
Top: IS41/28.6
-
Bottom: IS46/34
-
Steerer: 1 1/8" → 1 1/4" tapered
Meaning:
- Head tube:
- Fork:
- Upper steerer: 28.6 mm (1 1/8")
- Lower steerer: 34 mm (1 1/4")
This is a lighter, road-specific taper (1 1/4" instead of 1 1/5 or 1.5")
Key features
- Sealed cartridge bearings
- Alloy construction
- 9 mm stack height
- Designed specifically for Scott’s mid-era road platforms
Important: How it compares to your other two
| Feature |
Addict/Solace |
Scale/Spark |
Foil 2023 |
| Top |
IS41/28.6 |
IS42/28.6 |
IS44/35 |
| Bottom |
IS46/34 |
IS52/40 |
IS52/40 |
| Fork taper |
1 1/8 → 1 1/4
|
1 1/8 → 1.5 |
1 → 1.5 |
| Bike type |
Road |
MTB |
Aero road |
| Compatible with others? |
❌ |
❌ |
❌ |
Key takeaway (this matters most)
This headset is completely unique among the three you posted:
- Smaller top (IS41) than both others
- Smaller bottom (IS46) than the MTB/Foil ones
- Uses a 1 1/4" lower steerer, which is uncommon today
???? So:
- ❌ Will NOT fit a Foil
- ❌ Will NOT fit a Scale/Spark
- ❌ Not interchangeable with IS52 bottoms
Practical insight (this is where people get caught)
This standard (IS41 / IS46 with 1 1/4") is:
- Common on older or mid-generation road bikes
- Less common today (modern bikes moved to IS52 bottoms)
- Sometimes harder to find replacement bearings
When this is correct
Use this headset only if:
- Your frame is a Scott Addict or Solace designed for 1 1/4" taper
- Your current bearings are marked:
Quick identification tip
If you’re unsure which one you need:
- Measure bottom bearing seat
- ~46 mm → this one
- ~52 mm → NOT this one
- Or check fork:
- 1 1/4" lower steerer = this headset
