For a recent TL4 game, I wanted an array of crossbows available for purchase, broken down by ST and performance, with commensurate weight, cost, etc. Thrust damage has breakpoints at odd-numbered ST values, so I skipped the even numbers.
|Weapon||Damage||Acc||Range||Weight||Min ST||Eff ST||Draw ST||Bulk||Cost||Notes|
|Crossbow ST 9||1d+2 imp||3||180/225||5 lbs||7||9||9||-5||$125|
|Crossbow ST 11||2d-1 imp||3||220/275||6 lbs||7||11||11||-6||$150|
|Crossbow ST 13||2d imp||3||260/325||8 lbs||8||13||13||-7||$175|
|Crossbow ST 15||2d+1 imp||3||300/375||11 lbs||9||15||15||-8||$200|
|Composite Crossbow ST 15||2d+2 imp||4||375/450||9 lbs||8||15||15||-6||$1000||Includes Goat's Foot|
|Steel Crossbow ST 15||2d+2 imp||4||375/450||15 lbs||11||15||30||-7||$750|
|Steel Crossbow ST 17||3d-1 imp||4||425/510||19 lbs||12||17||34||-8||$850|
|Steel Crossbow ST 19||3d imp||4||475/570||25 lbs||13||19||38||-9||$950|
|Steel Crossbow ST 21||3d+1 imp||4||525/630||33 lbs||14||21||42||-10||$1050|
Min ST - Lifting ST required to simply wield the crossbow's mass in combat, independent of its draw strength.
Eff ST - Strength of the crossbow for range and damage purposes.
Draw ST - Lifting ST required to draw the crossbow. Use one of the drawing mechanisms from Low-Tech p.79 to increase your effective Lifting ST.
Composite Crossbow - Has a nomad-style prod of laminated horn and sinew construction. This example includes a Goat's Foot drawing aid (Low-Tech p.79), allowing a man with Lifting ST 11+ to draw the crossbow while in the saddle.
Steel Crossbow - A steel prod can be much stronger, permitting higher tension and striking power, but cannot be drawn as far. This requires additional mechanical advantage to cock the crossbow.