A motorcycle fork has an upper tree; a lower tree; a steering neck; and a steering stem. The steering stem is connected to the upper tree at a steering stem upper end, and is connected to the lower tree at a steering stem a lower end, and passes through the steering neck. The steering stem is oriented to a steering neck centerline in a first mode. A neck upper bearing race seat is formed on an upper portion of the steering neck. A neck lower bearing race seat is formed on a lower portion of the steering neck. An upper bearing race receives an upper bearing. The upper bearing race is mounted in the neck upper bearing race seat in the first mode. A lower bearing race receives a lower bearing. The lower bearing race is mounted in the neck lower bearing race seat in the first mode.

A motorcycle fork has an upper tree; a lower tree; a steering neck; and a steering stem. The steering stem is connected to the upper tree at a steering stem upper end, and is connected to the lower tree at a steering stem a lower end, and passes through the steering neck. The steering stem is oriented to a steering neck centerline in a first mode. A neck upper bearing race seat is formed on an upper portion of the steering neck. A neck lower bearing race seat is formed on a lower portion of the steering neck. An upper bearing race receives an upper bearing. The upper bearing race is mounted in the neck upper bearing race seat in the first mode. A lower bearing race receives a lower bearing. The lower bearing race is mounted in the neck lower bearing race seat in the first mode.

A bicycle bearing system comprising: an integrated cup, the integrated cup having a non-flanged outer diameter; a plurality of rolling elements configured to abut and rotate against an inner surface of the cup race; an inner race configured to abut and rotate about the plurality of rolling elements, the inner race having an inner diameter; wherein the rolling elements do not have a separate outer race, but rather the inner surface of the integrated cup acts as the outer race to the rolling elements; wherein the rolling elements' sizes are maximized to the limitation that the non-flanged outer diameter is smaller or equal to a first maximum diameter, and wherein the rolling elements sizes are maximized to the limitation that the inner diameter is greater or equal to a first minimum diameter.

A bicycle bearing system comprising: an integrated cup, the integrated cup having a non-flanged outer diameter; a plurality of rolling elements configured to abut and rotate against an inner surface of the cup race; an inner race configured to abut and rotate about the plurality of rolling elements, the inner race having an inner diameter; wherein the rolling elements do not have a separate outer race, but rather the inner surface of the integrated cup acts as the outer race to the rolling elements; wherein the rolling elements' sizes are maximized to the limitation that the non-flanged outer diameter is smaller or equal to a first maximum diameter, and wherein the rolling elements sizes are maximized to the limitation that the inner diameter is greater or equal to a first minimum diameter.

A bearing seat suitable for receiving a bearing includes an annular body, a first outer-radial flange and a second outer-radial flange. The annular body includes a peripheral wall. The peripheral wall has a first end, a second end, an inner matching surface and an outer surface. A thickness difference of the peripheral wall from the first end to the second end is within 30%. A portion of the inner matching surface is suitable for contacting and matching with an outer matching surface of the bearing. The first outer-radial flange protrudes from the outer surface adjacent to the first end and extends to the first end. The second outer-radial flange protrudes from the outer surface adjacent to the second end and extends to the second end. The overall structure of the bearing seat is uniform, which can reduce warpage and deformation caused by uneven shrinkage during the injection process.

A bearing seat suitable for receiving a bearing includes an annular body, a first outer-radial flange and a second outer-radial flange. The annular body includes a peripheral wall. The peripheral wall has a first end, a second end, an inner matching surface and an outer surface. A thickness difference of the peripheral wall from the first end to the second end is within 30%. A portion of the inner matching surface is suitable for contacting and matching with an outer matching surface of the bearing. The first outer-radial flange protrudes from the outer surface adjacent to the first end and extends to the first end. The second outer-radial flange protrudes from the outer surface adjacent to the second end and extends to the second end. The overall structure of the bearing seat is uniform, which can reduce warpage and deformation caused by uneven shrinkage during the injection process.

A headset assembly system for a bicycle is provided having a handlebar stem (1), radially fastenable by tightening to a fork tube (2), rotatable by headset bearings (7) with respect to a head tube (3) wherein the headset bearings are fastened (7); a retaining flange (4), radially fastenable by tightening to the fork tube (2); a thrust ring (5), axially movable along the fork tube (2); such that the retaining flange (4) and the thrust ring (5) are configured to contact each other by a ramp (6) which relates a rotation with a movement relative to each other; the thrust ring (5) is arranged such that, when the thrust ring (5) is rotated around the fork tube (2) with the retaining flange (4) fastened to the fork tube (2), the thrust ring (5) moves with respect to the retaining flange (4) pushing the stem (1) against the headset bearings (7).

There is provided a steering shaft modifier, capable of fundamentally preventing distortion generated in a new steering shaft, being easing aligned, and being simply assembled, including: a frame having a steering shaft penetrating portion formed in a front surface thereof and having a contact surface covering a portion of the steering head and disposed to be in contact with an upper bearing installation portion of a steering shaft installation portion; a shaft including a head portion caught by a lower bearing installation portion of the steering shaft installation portion of the steering head, a body portion passing through the steering shaft installation portion, and a connection portion connected to the frame; and a frame block including a lower contact surface tightly attached to a lower surface of the steering head in the rear of the lower bearing installation portion and coupled to the frame when installed.

There is provided a steering shaft modifier, capable of fundamentally preventing distortion generated in a new steering shaft, being easing aligned, and being simply assembled, including: a frame having a steering shaft penetrating portion formed in a front surface thereof and having a contact surface covering a portion of the steering head and disposed to be in contact with an upper bearing installation portion of a steering shaft installation portion; a shaft including a head portion caught by a lower bearing installation portion of the steering shaft installation portion of the steering head, a body portion passing through the steering shaft installation portion, and a connection portion connected to the frame; and a frame block including a lower contact surface tightly attached to a lower surface of the steering head in the rear of the lower bearing installation portion and coupled to the frame when installed.

A handlebar stem connection mechanism for connecting a handlebar stem with a front wheel fork comprises a steerer tube connectible with the front wheel fork. Further, a handlebar stem tube connectible with the handlebar stem is provided, the handlebar stem tube surrounding the steerer tube. Using a clamping element arranged between the steerer tube and the handlebar stem tube, the steerer tube is clampingly connected with the handlebar stem tube. For fixing, in particular a screw is provided in the clamping element as the fixing element.