Honda CRF300 Rally Stock Exhaust Noise and Power Test 4K

Honda CRF300 Rally Stock Exhaust Noise and Power Test

Ask any enduro or older dual sport rider about the Honda CRF300L/Rally and they will tell you it's too heavy. They may have a point, even if you don't notice it as much when riding. One component which weighs a lot, in an inconvenient place on the bike is the exhaust system, and in particular the silencer/muffler/end can depending on where you are in the world!

In the UK, having a quiet exhaust on a trail bike is ideal, as the lanes are shared with other users, of which some groups are looking for opportunities to limit access for motorcycles. Loud pipes that scare livestock and intimidate other trail users are not great, and only strengthen the case for the trails to be shut.

Accordingly, whenever there is talk of exhaust replacement, one of the first questions is 'how loud is it'? The answers are entirely subjective and range from not too loud, to the ever helpful 'it sounds much better' (for what I always wonder!).

So, to this video... I have a MotoX exhaust from Thailand, and before I fit it, I want to know how loud the stock exhaust is. I've not seen it anywhere else on the internet, so I'm doing my own test.
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 instead I picked a nearby hill and timed acceleration from 15-30mph in 3rd and then 30-40mph in 4th, both at the same points, multiple times.

Both the sound and acceleration numbers have given me a base with which to compare other exhausts, which will begin with the MotoX once fitted.

00:00 Introduction
02:15 Idle and Static RPM setup
03:01 Idle Test
04:33 Static RPM Test
06:13 FIM 2 Metre Max Test
08:53 Acceleration Intro
09:58 Acceleration Test
12:55 Conclusion

If you don't want to watch the video (and let's face it, it's not of interest to everyone!), the results are:

Idle test: 72.5dB, 72.6dB, 72.7dB Average 72.6dB
Static RPM test: 83.5dB, 83.4dB, 83.3dB Average 83.4dB
2m Max test: 96.0dB, 96.2dB, 96.3dB Average 96.2dB

Thanks to Suzette Shipman who suggested it would be useful to explain dB's (decibels) to people who might not be familiar. 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)

15-30mph in 3rd 3.9s, 4.4s, 4.8s Average 4.4s
30-40mph in 4th 3.0s, 3.8s, 3.2s Average 3.3s
The noise readings are pretty consistent, the acceleration is all over the place and not particularly useful, mainly due to the challenges of starting at the right point on the road and the reaction times. I'll still do them again with the new exhaust, but not sure if it'll be a compelling answer on power, and more likely that I'll perceive it to be better or worse...

Next videos will include the fitting of the MotoX exhaust, followed by another noise comparison.
I'll do a weight comparison in that video too as it's a lot easier to weigh the exhaust when it's off the bike!

I hope this has been interesting and useful, and if it has, please like and subscribe.

See you next time!