Extralite UltraBottom Headset Lower Assembly
This is our new lineup of modular headsets. Extremely light and easy to configure on virtually any frameset. Just measure upper + lower headtube bore diameter then find your model on the chart.
HD (Heavy Duty) versions features 2 stainless bidirectional bearing cartridges that can handle double crown forks and manage Freeride abuses. Stainless and fully serviceable.
Improvements are on every single element of our original headsets, our new headsets are slimmer, lighter and trickier: a real concentrate of Extralite's high-quality engineering.
Reduced vertical dimensions allow more efficient bike layouts, as example you can use a longer travel fork while keeping your actual bar and BB level.
Japanese MX technology shows how to divide upper bearing (micro-radial) and lower bearing (stainless, bidirectional) steering functions; an ultra tricky layout that reduces weight and improves your race trim shrinking headset stack height.
Consistent weight reduction even if out of sight!
|Model||Head tube bore||Tolerance||SHIS||Weight||Headset style||Fork standard||Stack Height|
|UltraBottom 34||34mm||33.90-33.95mm||EC34/30||30.3g||Press Fit - External Cup||Straight Fork 1-1/8”||9.5mm|
|UltraBottom 41||41 to 42mm||41.00-42.50mm||IS41/30 or IS42/30||19.9g||Integrated - Bottom||Straight Fork 1-1/8”||1mm|
|UltraBottom 44||44mm||43.95-44.00mm||ZS44/30||23.8g.||Press Fit - Internal Cup||Straight Fork 1-1/8”||1.8mm|
|UltraBottom 44 T||44mm||43.95-44.00mm||EC44/40||38.3g||Press Fit - External Cup||Tapered Fork 1-1/8”-1.5”||10mm|
|UltraBottom 51||51 to 52mm||51.00-52.50mm||IS51/40 or IS52/40||25.3g||Integrated - Bottom||Tapered Fork 1-1/8”-1.5”||1mm|
|UltraBottom 55||55mm||54.90-55.00mm||ZS55/40||31.6g||Press Fit - Internal Cup||Tapered Fork 1-1/8”-1.5”||2mm|
|UltraBottom 56||56mm||55.90-56.00mm||ZS56/40||32.3g||Press Fit - Internal Cup||Tapered Fork 1-1/8”-1.5”||2mm|