Preamble Most of my riding is done at highway speeds. Even with a windshield and earplugs I find the noise fairly wearing after a full day. I wear a good Arai full-face helmet and I’m used to the feel of it but I dislike the inconvenience.
With a little free time yesterday I set out to do a helmet noise comparison. I was interested in seeing whether there were dramatic differences between a 3/4 and a full face and whether there was much difference between two full-face helmets.
I had my day-to-day lid: a silver Arai Signet GT(full face), my old red Shoei full-face, and a black 3/4 helmet sourced at an auto parts store – DOT approved but hardly high end. The key difference between the Arai and Shoei that I wanted to know about was that the Arai has fairly prominent top vents that I thought might be contributing some noise.
Conditions Odd as it may seem, I wore earplugs for most of the tests. I was trying to duplicate my own riding experience. I wore the helmets the way I usually do, visor up on the street, visor open a bit on the highway (10-25%). The top vents on the Arai were closed because I know from experience it’s noisier with them open.
Trials I tried each helmet without earplugs sitting on the idling bike. I tried each on a 30 mph street loop, I tried each on a 10 mile highway run with speeds from 60-80 mph.
Observations. • With all three helmets the dominant noise on the street run and up to about 65mph on the highway was my engine. The bare helmet does essentially nothing to block engine noise except for closing the visor on a full face which has a dramatic effect.
• At about 65 a low frequency flutter or booming takes over. Again, much the same with the three helmets. The 3/4 might have been a bit worse but I would have started to close the visors by this point. The low frequency noise is not much affected by ducking behind the screen but (of course) it’s way louder if I stand up out of the windscreen’s shelter. The character of the noise is the same whether behind the windscreen or not. It’s just much less down in the windscreen’s shelter.
• At 75 mph the Arai has a very prominent high pitched whistling from the top vents even when they’re closed – this is the dominant noise even with the visor well open. The Shoei has a much lower volume whistle that’s only noticeable with the visor fully closed. The 3/4 helmet had no high frequency noise (or I couldn’t hear it with no visor).
Conclusions re Noise • Bikes are noisy, even mine with stock pipes.
• Helmet padding around the ears does essentially nothing to block noise.
• The full face helmet with visor closed blocks engine noise where the 3/4 doesn’t. With it open even a bit they’re about the same.
• All the helmets exhibit the low frequency noise at 65+ mph. It’s not helmet or style specific and certainly not brought on by any kind of resonance in the full-face helmets.
• The most annoying noise on my Arai is the high pitched whistling at highway speed. This is helmet-specific rather than 3/4 vs full face. Neither the shoei nor the 3/4 had the problem.
Specific conclusions re the 3/4 helmet • The 3/4 is a wonderful thing to put on and wear. This one was not the quality of my other two but it was light, easy, and gave wonderful visibility.
• The 3/4 with no visor is pretty hard to take at 75 mph – especially in the rain.
Next Steps for me • I’m going to throw out my 10 year old Shoei. The black granular stuff that fell out of it probably used to be important.
• I’m going to try popping off and filling in the vents on top of my Arai helmet.
• I’m going to look for a better 3/4 helmet for use around town.
