IS41 headset standard (integrated vs ZS44 headset standard (zero stack: specs compared
Updated 05 September 2026.
3
specs differ
IS41 headset standard (integrated and ZS44 headset standard (zero stack differ on 3 specs: shis designation, cup / bearing outside diameter, crown race.
| Spec | IS41 headset standard (integrated | ZS44 headset standard (zero stack |
|---|---|---|
| SHIS designation | IS41 (integrated (IS)) | ZS44 (zero stack (ZS)) |
| Cup / bearing outside diameter | 41.0 to 41.1 mm bearing outside diameter | 44.0 mm cup outside diameter, 43.9 to 43.95 mm head-tube bore |
| Steerer diameter | 28.6 mm (1 1/8 in) | 28.6 mm (1 1/8 in) |
| Crown race | 30.0 mm crown race, or machined into the fork | 30.0 mm crown race seat |
Questions and answers
How do IS41 headset standard (integrated and ZS44 headset standard (zero stack compare?
IS41 headset standard (integrated and ZS44 headset standard (zero stack differ on 3 specs: shis designation, cup / bearing outside diameter, crown race.