So being a follower of Lancaster Archery on social media I just had a video pop up for the new Elite hunting flagship bow of 2018...and one thing caught my eye: bow efficiency. I've never really ever heard this shared/discussed with anyone myself before today (either by complete ignorance or sheer luck). Does anyone have a link or chart of bows rated by their efficiency? I found it sad that they said at 88% efficient the bow should be the best on the market or right up there...
That has been around for a long time. Norb Mullaney used to do a ton of bow reports and dynamic efficiency was one of his tests. "Bow efficiency is calculated in the following manner... One must measure the entire draw force curve and figure the amount of Stored energy the bow holds. This is done by measuring each inch of draw and weight. When each data point is logged they are added up then divided by the number of data points then by 12 to get ft/pounds. Now shoot an arrow and calculate the KE of the arrow. Divide the KE by the SE and WALLA you have efficiency."
As Scott said - bow efficiency has been around for a long time it's just not something that has really come up in a larger scale until just recently. IMO this is because until the last decade or so there was still some pretty big enhancements in compound bows in terms of speed, size, weight, noise, vibration, etc. Now that we've reached a bit of a plateau when it comes to major improvements the manufacturers are looking at additional ways to market their product against the competition. Since everyone makes a bow that measures anywhere from 28 to 34 inches long, weighs 3.5 to 4.5 pounds, and shoots 330 to 350 fps how can you decide which one to buy? Well efficiency of course! A bow that is more efficient generally has less noise and vibration, is more "pleasurable" to shoot and who doesn't want something that's more efficient? We buy vehicles that are more fuel efficient, furnaces and air conditioners that are "high efficient" models, and the list goes on. To your point, no mechanical device is ever 100% efficient. There is always energy lost in various places - whether it's the resistance of the wind holding the string back, friction within the cable guard or cam system, or just energy lost through the various moving parts of the bow as it's shot. Bow's pushing the 90% efficiency mark are about as good as they get in today's world, and my guess is they will continue to get incrementally better in coming years as companies focus more on this new benchmark. Here's a good read of an interview with Matt McPherson from a year or so ago where he talks about bow efficiency - https://www.bowhunting.com/blog/2017/07/27/mathews-bows-25-years-innovation/ The one part of this article I like the most is this quote here:
Marketing. Efficiency is just the current buzz word. That said the bow looks great however it in all honesty it most likely isn’t measurably significantly different, in any meaningful way then anything they have made in the last 10 years. It would be nice to see the Archery industry evolve into a more sustainable model. Right now modest new offerings bring little to table in so far an advancements in technology or performance. The current model of totally “new “ releases yearly and bi yearly really hurts the dealers by devaluation of the current inventory. At one time, talking 15 plus years ago, the yearly advancements might ...maybe ...have warranted that type of turnover in models from year to year. However that no longer isn’t the case. In a contacting market the industry needs to correct itself.
When the No Cam was introduced, that was the first I had heard of bow efficiency. I definitely agree to it being used as a buzz word in marketing to help sell a bow or add another feature to it.
