Gear: Arrow Thunder Titanium on a Honda CRF300 Rally Noise Test

Gear: Arrow Thunder Titanium on a Honda CRF300 Rally Noise Test

The stock exhaust on the Honda CRF300L and CRF300 Rally, is great. It looks good and is quiet. It is also heavy, so I've been trying to find an aftermarket exhaust which is both quiet and also lightweight.

This is the exhaust that I have (Affiliate link): https://ebay.us/nDCTqS
I nearly bought this version in black: https://ebay.us/uVUnCu
or this (I think this is the cheapest, stainless, black coating and stainless end cap): https://ebay.us/kBXumH

The Arrow exhaust is definitely light, but comes at a price. In this video I see just how loud, (or quiet...) it is using the same tests I did for the Honda OEM exhaust and also the MotoX Titanium silencer exhaust.

The two tests I'm using are the ACU static rpm test and the 2 metre max test, and the technical descriptions of these can be found on:
https://www.acu.org.uk/Uploaded/1/Doc...

I'm also aware that there are sometimes claims that new exhausts increase power, and though this can be shown on a Dyno, I don't have one and don't plan to get my bike on one, so this is a noise test only. If anyone has a Dyno and is near the Peak District, please let me know, and I'd be happy to do a video with one!

If you don't want to watch the video (and let's face it, it's not of interest to everyone!), the results are:
Test: Stock/MotoX standard/MotoX Baffle removed/Arrow Thunder Titanium
Idle: 72.6dB/69.1dB/72.0dB/72.1dB - Quieter than stock
Static RPM: 83.4dB/80.1dB/81.3dB/82.1dB - Quieter than stock
2m Max: 96.2dB/97.7dB/99.0dB/99.4dB - Louder than stock

So it's quieter at idle and at medium revs but louder at 10,500 rpm. This latter number may appear problematic, but after a few hours of trail riding on various terrain, it feels quiet. Very quiet. I passed a few groups of horses on roads, and it didn't bother any of them, so if you're looking for a light, quiet, road legal and emissions compliant exhaust for a CRF300, this might be it.

If you're unfamiliar with dB's, I'll not go into the detailed explanation as it's a long time since I had to know it and it's probably not that useful to understand the mathematics if you understand the scale. Essentially it's a logarithmic scale which means that for an increase of 10dB the sound level doubles and this scales up so taking 70dB as a starting point, as this is a useful baseline, roughly equivalent to a vacuum cleaner or traffic.

80dB is twice as loud as 70dB
90dB is four times as loud as 70dB
100dB is eight times as loud as 70dB
110dB is sixteen times as loud as 70dB

For additional context, exposure to sound levels over 85dB for sustained periods (8h+) can cause permanent hearing loss. Sound levels of 90dB+ can cause damage after 30 minutes and levels of
120dB+ damage after 30 seconds.

The upper limit set by the ACU does vary but is around 112dB for racing and 105dB for track days (though lower limits can apply) Max noise for an enduro bike is 112dB and for a trials bike 100dB.

I hope this has been interesting and useful, and if it has I'll see you next time!