Summary:IMO your first Rebel 300 mod should be a tachometer. The engine starts making a roar about 5,000 rpm and you have to overcome the tendency to shift up. Adding a tach let’s you see graphically that the engine is nowhere near blowing up, even though it sounds like it is. It makes riding the bike a lot more enjoyable and it makes you more comfortable exploring what the bike will do. Your second mod should be a 15 tooth front sprocket to reduce the revs. IMO your third mod should be to leave the stock muffler on – maybe drill one or two holes underneath or in the back. IMO the stock muffler has the best exhaust TONE for the Rebel 300 compared to aftermarket mufflers. I am talking about the tone quality, not loudness. For aftermarket mufflers, adding a Shorty GP baffle/catalyst to the header pipe will help a little.
•• 2017 Rebel 300, black, 4,228 miles, tachometer with voltage guage, Dart Marlin flyscreen, crash bars, larger front sprocket for less revs, added driving lights, exhaust upgrade for much better sound (muffler from Rebel 500), runs great ….. Just lubed/adjusted chain, comes with 2 keys
Voltage guage – add 1.2v to the reading. 11.7 on the guage is 12.9v at the battery
66.8 mpg average, 72.6 driving slower, 57.7 lowest when driving harder.
My wife agreed to let me get a second bike, so I now own a black Rebel 300. It’s a 2017, 3,600 miles, and has crash bars.
Why I bought a Rebel 300 – A lot of good and bad things have been said about this bike, and I want to find The Truth about the Rebel 300. I’m going to try things and learn about the bike. I want to learn how to better utilize it’s power. I want to better answer Rebel 300 questions from people in this forum – and hopefully they will learn, too, as we go along ….
Facebook group “Honda Rebel 300 500 1100″ https://www.facebook.com/groups/1098193840710040
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Rebel 300 mufflers – a great choice is a Rebel 500 muffler! It’s a little louder and has a great throaty tone. It is my favorite muffler for the Rebel 300.
If your stock Rebel 300 muffler is not needed for future emission/noise testing, you could drill out the catalytic converter. You need a drill bit extension since the cat is located 5.4 inches from the end of the muffler. You would also need a hole saw about 40mm wide.
1/11/23 42°F Rode both bikes. I have a 15T front sprocket and the 300 still requires more frequent gear changes than the 500 – I think the 300 requires 15 T front and 34T rear. The 300 needs a tach but especially with the stock muffler.
11/10/2022 60°F today so I went for a ride on the Rebel 300. Lately I’ve been riding my Rebel 500 (has low profile radials) – on my Rebel 300 you sit higher and it steers slower. Normally a Rebel 300 steers/turns lighter than a 500. Today I used a Black Widow BN35R with a Shorty GP baffle/catalyst added to the header pipe which definitely improved the sound. It was still too loud for me, but it was “acceptable”. I could ride through the neighborhood, but I didn’t rev it up. If your Rebel 300 aftermarket muffler is too loud, the Shorty baffle/catalyst is a good idea.
The Sound – Today on my Rebel 300, I tried a Black Widow BN35R muffler (it has the stock baffle plus a baffle I added). I liked it 40% and hated it 60%. It sounded decent at a constant speed, but it sounded raspy, hard, un-pleasant, and too loud when accelerating. The bike seemed to have less torque, but more high rpm horsepower. I added a Shorty GP baffle/catalyst to the header pipe which made it acceptable to me (I liked it 60% and hated it 40%).
…. “Tone” and “Loudness” are two different things – the stock unmodified Rebel 300 muffler has the best tone compared to other mufflers I tried. I would use the stock Rebel 300 muffler even if I lived out in the country with no neighbors. Here are the mufflers I tried: 1). Rebel 300 stock muffler, 2). Rebel 300 muffler with exhaust tip removed, 3). Rebel 500 shortened muffler with a $15 Shorty GP baffle/catalyst in the muffler, 4). Rebel 500 shortened muffler (with and without Shorty baffle in header pipe; also with Shorty baffle plus an in-muffler baffle) 5).Black Widow BN35R muffler (with and without Shorty baffle in header pipe).
Acceptable: 1, 4C, 5A. Not acceptable: 2, 3, 4A, 4B, 5B.
To me, the Rebel 300 sounds best with the stock muffler with maybe 2 holes drilled underneath. It sounded quite a bit better when I removed my large windshield/fairing.
Today on my Rebel 300, I tried a Rebel 500 shortened muffler with a $15 Shorty GP baffle/catalyst (which is like 1/3 of a catalytic converter). I liked it 30% and hated it 70%. It is louder than a Rebel 300 muffler with exhaust tip removed, and has a little better tone, but it sounds raspy, hard, and un-pleasant when accelerating. When holding a steady speed, it sounded “OK”. This is nowhere near as loud as a Shorty GP muffler. I think a single Shorty GP baffle/catalyst does not provide a full catalytic converter function.
Today I removed the Rebel 300 muffler outlet tip using a hole saw. Overall I did not like it, so I am putting it back in. I liked it 20% and hated it 80%. At low / medium speeds it sounds raspy, hard, and unpleasant. The nice throaty old Triumph sound it made when accelerating sometimes is completely gone. The noise did hide about a third of the 5,000 rpm roar. It is maybe half as loud as a Shorty GP muffler. I do not recommend this mod for the Rebel 300, but keep in mind some people like it. This mod brings out the worst of the single cylinder sound.
Thoughts after 10 days with a Rebel 300 – The Rebel 300 is faster than I expected. It is smoother with less vibration than I expected. It accelerates quickly enough to keep up with traffic even without revving it up. I think this is because it has excellent torque even at low rpm. The engine sounds more revved up than it actually is (someone needs to work on an engine damper 😉). It starts sort of screaming around 55 mph, yet 80 mph is 8,000 rpm, which the bike seems like it could maintain for a long while on the highway. Rev-limiter engages at 10,900 rpm. A 15 tooth front sprocket would reduce the revs some but it DOES NOT make a large difference – 8,000 rpm would be 85 mph instead of 80. I think a loud muffler would all of make this a LOT worse, but I haven’t experimented with that yet – waiting for my wife and daughter to be gone for a few hours. The Rebel 300 needs a tachometer, much more than the 500 does. edit …. Sometimes it does sound like “just a single cylinder”, but if you accelerate around 4,000 or 5,000 rpm, it has a throaty sound a little like an old Triumph twin. You can hear it better if you lean your head to the right. (I’m not making this up – in parallel twins, the pistons go up and down together, so it can sound somewhat like a single cylinder.) I will be doing “Step C” of the muffler mod soon, and I hope I don’t lose that sound. …. The transmission in my 300 shifts easier and more positive than my 500 – both upshifts and downshifts. …. The sound of the bike encourages short-shifting (shifting early) 
and low rpm riding, which will prevent you from knowing what the bike will do. It starts making a roar about 5,000 rpm and you have to overcome the tendency to shift up. I would encourage people to put a chart on the gas tank cap showing speeds at 4,000 and 8,000 rpm. Make yourself do 26 mph in 1st, 40 mph in 2nd, and 55 mph in 3rd. (The rev-limiter on the 300 is 10,900 rpm or 75 mph in 3rd gear.) …. After you get used to it, you won’t have to watch the speedometer anymore – when you hear the engine start to roar, you know it’s 5,000 rpm, so you can shift up. Or wait for it to wind up more and shift up at 6 or 7,000 rpm.
Rebel 300 eBay fairing – I tried this for a while and then removed it – NOT plug & play – medium difficulty to install. For $78 USD shipped, it’s a great fairing. It looks great, looks nicer than my higher priced Rifle fairing. The windshield has optical distortion. The fairing amplifies the 4,000 rpm whine like any large fairing would do (easily fixed with sound deadener) – the sound gets better around 5,000 rpm. It makes the ride much quieter and the wind hits me at forehead level which is perfect. The bonus is 490 cubic inches of storage – you just need to add a bottom tray. ….. Installation – The turn signals need to be slid down 5 inches – loosen the screw and remove the rear bolt. The most difficult thing is you need two 1/4 inch thick brackets with holes with 1.5 to 1.75 inch center spacing – this is to move the headlight mount forward. If you are short, use a longer bracket with 2.5 to 3 inch center spacing – this will angle the windshield more. Then the fairing fits over the headlight and fastens at the lower rear with a 5″ bendable bolt or zip-tie. Then you need to come up with top brackets – I just used bungee cords temporarily.
eBay windshield – $77.90 USD shipped – 25″ (63.5 cm) https://www.ebay.com/itm/133888246071?var=433415861645
Rebel 300 Day 6 – Put fairing on (will post review later). For $78 USD shipped, it’s a great fairing. It looks great, looks nicer than my higher priced Rifle fairing. The windshield has optical distortion, medium difficulty to install, it amplifies the 4,000 rpm whine like any large fairing would do (easily fixed with sound deadener) – its gets much better around 5,000 rpm. Besides the whine it makes the ride much quieter and the wind hits me at forehead level which is perfect. …. I’ve gone 170 miles on the bike so far. Had it 83 mph yesterday – if I had less traffic, I could have tried top speed. … Driving at night tonight made me see how bad the stock tires are at tar strips – the headlight made the movements much more noticeable.
Rebel 300 fourth Ride – Handlebar vibration actually adjusts the mirrors – it might help if I get new riser rubber washers – the original ones are 5.5 years old. …. I’m really impressed with the low rpm (3,000 rpm) torque of this bike. …. Sometimes it does sound like “just a single cylinder”, but if you accelerate around 4,000 or 5,000 rpm, it has a throaty sound a little like an old Triumph twin. It helps if you lean your head to the right. (I’m not making this up – in vertical twins, the pistons go up and down together, so it can sound somewhat like a single cylinder.) I will be doing “Step C” of the muffler mod soon, and I hope I don’t lose that sound.
For my Rebel 300, I ordered this one. It is $22 USD – much cheaper than a Daytona tach ($125). Hopefully it will work. It is for cars so I will need to seal it for wet weather. https://www.ebay.com/itm/164022590621
Rebel 300 Second Ride – when I hear the engine start to roar, it’s 5,000 rpm so I can shift up. Or wait for it to wind up more and shift up at 6 or 7,000 rpm. I don’t have to watch the speedometer anymore. If you have a Rebel 300, go 30 mph in 3rd gear and then, staying in 3rd gear, accelerate hard to 60 mph. It won’t hurt the bike. It is definitely quicker than I expected. (OK, the 500 accelerates 32% faster.) …If you’re keeping the stock muffler, all you can do to improve what YOU hear is 1) large windshield, 2) muffler sound reflector, and 3) more induction noise. I’m trying the 3rd one tomorrow – leaving the air cleaner cover off to see it it adds induction noise. The filter still filters the same, but I shouldn’t go on any dirt roads. (This is just an experiment – I do not recommend this.) ((( edit for #3 – it did seem a little faster, but the intake roar/honk is louder than the muffler with the cover off – I will test just a gap in the cover later. ))) …. .. I’m already driving the 300 just as fast as I ride the 500, then tonight I found out the tires are only 15 PSI 🙁 Maybe with the correct air pressure, I’ll be able to push a little harder tomorrow. … The transmission in my 300 shifts easier and more positive than my 500 – both upshifts and downshifts.
Rebel 300 First Impressions (I just got it today): The bike is a little faster than I thought. It has less vibration than I expected. It seemed less bumpy than my 500. My 500 has radials and steers and turns-in very light, so I thought I would have trouble with the 300’s harder steering, but it just took a few miles to become accustomed to it. The sound of the bike encourages short-shifting (shifting early) 🙁 and low rpm riding, which will prevent you from knowing what the bike will do. It starts making a roar about 5,000 rpm and you have to overcome the tendency to shift up. I would encourage people to put a chart on the gas tank cap showing speeds at 4,000 and 8,000 rpm. Make yourself do 26 mph in 1st, 40 mph in 2nd, and 55 mph in 3rd. (The rev-limiter on the 300 is 10,900 rpm or 75 mph in 3rd gear.) The Rebel 300 needs a tachometer, much more than the 500 does. It sounds better than I expected. My opinion is that the 300 sounds best with the stock exhaust – so I will stick with that for now. One benefit is that if you rev it up, you will attract less attention. Sixth gear has plenty of power, so a 15 tooth front sprocket is a great choice if you are on the highway a lot. This would raise the gearing 7.1% – 60 mph indicated would be 64 mph actual. With the 15T sprocket, you would be going 64 mph at the same rpm as 60 mph with the original 14T sprocket. Going from 36/14 to 33/15 is 16.8%. 60 mph same rpm would be 70 mph. 6th gear is 12.1 % higher than 5th gear
Rebel 300 gearing
36 14 2.571
36 15 2.400 1.071
34 15 2.267 1.134
33 15 2.200 1.169
Virago 250 gearing
45 16 2.813
40 17 2.353 1.195
38 17 2.235 1.258
Rebel500 