Narrow crossbow with large power stroke

1. A crossbow comprising:

a main beam;

a riser:

1) supported to the main beam;

2) having a first end with a first limb attachment surface;

3) having a second end opposite the first end with a second limb attachment surface; and

4) having a U-shaped opening;

a first bow limb that has:

1) a first end supported to the first limb attachment surface of the riser;

2) a second end opposite the first end; and

3) a length L 1 ;

a second bow limb that has:

1) a first end supported to the second limb attachment surface of the riser; and

2) a second end opposite the first end; and

3) a length L 2 ; and

a bowstring:

1) adapted to propel an arrow;

2) received on the second end of the first bow limb; and

3) received on the second end of the second bow limb;

wherein:

1) the first and second limb attachment surfaces are separated such that a minimum distance between them is:

(a) at least as wide as a user's foot; but

(b) not greater than about 5 inches; and

2) the U-shaped opening:

(a) extends between the first and second limb attachment surfaces; and

(b) is designed to receive a user's foot;

3) L 1 is less than 15 inches; and

4) L 2 is less than 15 inches.

2. The crossbow of claim 1 wherein:

L 1 is less than 13 inches; and

L 2 is less than 13 inches.

3. The crossbow of claim 1 wherein:

L 1 is about 12 inches; and

L 2 is about 12 inches.

4. The crossbow of claim 1 wherein:

L 1 is about 11 inches; and

L 2 is about 11 inches.

5. The crossbow of claim 1 wherein:

the riser includes a first limb pocket defining the first limb attachment surface; and

the riser includes a second limb pocket defining the second limb attachment surface.

6. The crossbow of claim 1 wherein:

a first wheel is mounted to the second end of the first bow limb;

a second wheel is mounted to the second end of the second bow limb; and

the bowstring operatively engages the first and second wheels.

7. The crossbow of claim 1 wherein:

a foot stirrup extends between the first end of the riser and the second end of the riser.

8. A crossbow comprising:

a main beam;

a riser:

1) supported to the main beam;

2) having a first end with a first limb attachment surface;

3) having a second end opposite the first end with a second limb attachment surface; and

4) having a U-shaped opening;

a first bow limb that has:

1) a first end supported to the first limb attachment surface of the riser;

2) a second end opposite the first end;

3) a hinge point; and

4) a thickness that varies along the length of the first bow limb from the first end to the hinge point;

a second bow limb that has:

1) a first end supported to the second limb attachment surface of the riser;

2) a second end opposite the first end;

3) a hinge point; and

4) a thickness that varies along the length of the second bow limb from the first end to the hinge point; and

a bowstring:

1) adapted to propel an arrow;

2) received on the second end of the first bow limb; and

3) received on the second end of the second bow limb;

wherein:

1) the first and second limb attachment surfaces are separated such that a minimum distance between them is:

(a) at least as wide as a user's foot; but

(b) not greater than about 5 inches; and

2) the U-shaped opening:

(a) extends between the first and second limb attachment surfaces; and

(b) is designed to receive a user's foot.

9. The crossbow of claim 8 wherein:

the hinge point of the first bow limb is at least 6 inches from the first end of the first limb; and

the hinge point of the second bow limb is at least 6 inches from the first end of the second limb.

10. The crossbow of claim 8 wherein:

the first bow limb is a dual limb; and

the second bow limb is a dual limb.

11. The crossbow of claim 8 wherein:

the riser includes a first limb pocket defining the first limb attachment surface; and

the riser includes a second limb pocket defining the second limb attachment surface.

12. The crossbow of claim 8 wherein:

a first wheel is mounted to the second end of the first bow limb;

a second wheel is mounted to the second end of the second bow limb; and

the bowstring operatively engages the first and second wheels.

13. The crossbow of claim 8 wherein:

a foot stirrup extends between the first end of the riser and the second end of the riser.

14. A crossbow comprising:

a main beam having an axis of elongation;

a riser:

1) supported to the main beam;

2) having a first end with a first limb attachment surface;

3) having a second end opposite the first end with a second limb attachment surface; and

4) having a U-shaped opening;

a first bow limb that has:

1) a first end supported to the first limb attachment surface of the riser; and

2) a second end opposite the first end;

a second bow limb that has:

1) a first end supported to the second limb attachment surface of the riser; and

2) a second end opposite the first end;

a first wheel:

1) mounted to the second end of the first bow limb; and

2) pivotal with respect to the first bow limb about a first pivot axis;

a second wheel:

1) mounted to the second end of the second bow limb; and

2) pivotal with respect to the second bow limb about a second pivot axis; and

a bowstring:

1) adapted to propel an arrow;

2) movable between a cocked position and an un-cocked position; and

3) operatively engaged to the first and second wheels;

wherein:

1) the first and second limb attachment surfaces are separated such that a minimum distance between them is:

(a) at least as wide as a user's foot; but

(b) not greater than about 5 inches;

2) the U-shaped opening:

(a) extends between the first and second limb attachment surfaces; and

(b) is designed to receive a user's foot;

3) when the bowstring moves between the cocked position and the un-cocked position it moves along the axis of elongation a power stroke distance (PD);

4) the first pivot axis and the second pivot axis are separated by a wheel distance (WD) when the bowstring is in the un-cocked position; and

5) the ratio of WD to PD (WD/PD) is less than 2.0.

15. The crossbow of claim 14 wherein:

the ratio of WD to PD (WD/PD) is less than 1.8.

16. The crossbow of claim 14 wherein:

the ratio of WD to PD (WD/PD) is less than 1.6.

17. The crossbow of claim 14 wherein:

the power stroke distance (PD) is at least 10 inches.

18. The crossbow of claim 14 wherein:

the first wheel includes a first cam; and

the second wheel includes a second cam.

19. The crossbow of claim 14 wherein:

the first wheel includes a pair of pulleys; and

the second wheel includes a pair of pulleys.

20. The crossbow of claim 14 wherein:

a foot stirrup extends between the first end of the riser and the second end of the riser.