A reverse cam crossbow looks very similar to most other crossbows on the market. The difference is the string comes off the front of the cam(closest to the stirrup) on a reverse limb crossbow. On a standard forward draw crossbow, the string comes off the back of the cam.
By now many people have seen reverse limb crossbows. The Ten Point Nitro RDX was incredibly popular for us last year. It’s easy to tell the difference since a reverse limb crossbow looks completely different than a standard crossbow, it’s limbs are mounted at the center of the crossbow and face forward. But a reverse cam crossbow looks very similar to most other crossbows on the market. The difference is the string comes off the front of the cam(closest to the stirrup) on a reverse limb crossbow. On a standard forward draw crossbow, the string comes off the back of the cam.
This doesn’t seem like a big deal to the average set of eyes. But this simple design change makes a huge difference in performance. There are three ways to create speed in a crossbow; draw weight, power stroke, and the eccentric or cam. By utilizing reverse cam technology, the crossbow gains power stroke and thus more speed without adding more draw weight. Power stroke is essentially like draw length in a vertical compound bow. For example, if you take a 70 pound bow and set it up at 27” and then take the same bow and set it at 29”, the 29” bow will be faster.
Using the same principle in a crossbow, speed can be made with less weight. For example, the reverse cam TenPoint Eclipse RCX can hit 370 feet per second with just a 140 pound draw weight. The TenPoint Stealth FX4 also shoots 370 feet per second but needs 180 pounds of draw weight to hit the same speed. There are a few other differences but the main difference is reverse cam technology due in large part to a longer power stroke.
By building a crossbow that gets more speed with lighter draw weights, the crossbow generally has better string life and fewer limb problems. Every time a crossbow is shot there is stress placed on the limbs, strings, and other components of the crossbow. If you can decrease the amount of stress placed on the crossbow, you can increase the life cycle of the crossbow and it’s components.
Reverse cam crossbows also tend to be more narrow and have narrower string angles. This makes the crossbow easier to use in tight areas and with less space inside the string when cocked, there are fewer dangerous places to put your hands.
At this point, you’re wondering if there are any downsides to reverse cam crossbows. In my opinion, there are a few. The tight string angle mentioned in the above paragraph can lead to a couple of issues. First, crossbows with tighter string angles tend to have string serving problems faster than crossbows with wider string angles. This is magnified if the user overcocks the crossbow with a crank. A good proshop can rewrap the serving on your string if this occurs. It’s usually pretty inexpensive to have this done.
The other disadvantage is accuracy can sometimes be diminished as the string angle gets tighter. A lot of it really depends on the model you’re looking at. But you’ll often see premiere target archers using vertical compound bows that are very long axle-to-axle. Part of the reason they shoot big bows is to get a wider string angle. The nock may not be seated the exact same way on every shot when the string angle is tight. Accuracy is built by exact replication during the shooting process. We usually don’t see a lot of differences at close range but at longer ranges this becomes more apparent. Again, there are other factors that determine accuracy. A forward draw crossbow built with lower quality materials and lower tolerances will still be less accurate than a well built reverse cam crossbow.