The Triumph Bonneville Bafflectomy

Welcome to the third episode in my series comparing my Triumph Bonneville vs my Royal Enfield Interceptor 650 vs my Moto Guzzi V7 where we are going to figure out what is the best mid-size retro motorcycle (for me).

In today’s video I’m going to be modifying the exhaust pipes on my Triumph Bonneville, aka performing the Triumph “Bafflectomy.”

I’m primarily doing this Bonneville exhaust mod in hopes of getting a little more character out of my Bonneville. Character is one area where the Bonneville is lacking in this competition against the V7 and even the Interceptor, and this modification should let a little more of the Bonneville’s personality ring out.

The second reason why I’m doing this modification is because I have a maximum budget that I’m allowed to spend on each motorcycle in this competition. I only have $220 left to spend on the Bonneville, and a bafflectomy is basically free!

Today we’ll be exploring:

• What is a Triumph Bonneville bafflectomy?
• How to do a Triumph Bonneville bafflectomy?
• How does it sound and run once done?

If you’re interested in retro motorcycles, Triumph Bonneville mods, or free motorcycle mods in general, this video is for you.

What is a Triumph Bonneville bafflectomy?

The Bafflectomy was is a common Bonneville exhaust mod designed to let more sound out of your Bonneville and give it a deeper tone.

Triumph used to make their own in-house performance exhaust pipe branded the TORS exhaust. People realized that the TORS exhaust were identical on the outside to the original exhausts. The significant difference between the two was that you could see right through the inside of the TORS exhaust, but with the original exhaust you couldn’t. That’s because the original exhaust had a system of inner walls, channels, and baffles designed to restrict airflow and silence the sounds of the motor.

Smart people realized instead of buying TORS pipes from Triumph, they could just hollow out their original exhausts and make their own homebrew version of the TORS pipes, by performing the “bafflectomy” mod that I’m about to show you.

The goal is to get a bit more noise, but more importantly a deeper tone, with more base, and maybe even more character, compared to the muffled sounding original exhaust, without having to spend any money.

If this doesn’t work, I can’t see the Bonneville making it through to the next round in my Bonneville vs V7 vs Interceptor competition. So let’s get started and I hope this works!

How do you do a Triumph Bonneville Bafflectomy

Let’s look at what you’ll need to do a Triumph bafflectomy, how to start cutting and remove the baffle, and all of the other things you can do from there.

What you’ll need for a bafflectomy

The first step is to make sure you’re well equipped. Here is what you’ll need to complete the bafflectomy:

• A good drill
• 1.25″ Hole saw (get at least two, maybe three)
• Drill bit extension set
• 5/8″ Dowel
• Other common shop stuff supplies
  • WD-40
  • Saw
  • Drill bits
  • Rubber mallet or hammer
  • Magnet
  • Pliers, etc.

How to start cutting and remove the baffle

Cut off a bit of the 5/8^th dowel.

Grab a drill bit that matches the size of the bit on your hole saw. It will go in your exhaust later.

And drill into the center of the cut off bit of dowel. The dowel will be a guide to keep your hole saw in place.

Add a little duct tape around the dowel to make it the perfect fit in your exhaust pipe outlet.

And gently tap the dowel into place, while bracing the rest of the exhaust so you aren’t damaging anything.

Apply a little WD-40 for lubrication and start drilling.

Once you’ve drilled through the outer chrome sell you may need to use a drill bit to help pull the dowel out.

You may want to use a magnet tool to pick up any loose metal shavings.

You may need to apply some more tape, turn the dowel around, and put it back in to help you pull the baffle out.

You may need to use pliers to pull the baffle out completely.

Repeat these steps for both exhausts.

Getting through the inner walls and channels

The first wall you’ll see inside the exhaust seemed to be the hardest to drill through… until I realized my hole saw was getting kind of blunt. Once I replaced it with a new blade things got much easier.

Everything from this point is up to you.

There are two more sets of walls in the mufflers, along with little tubes the exhausts pass through. You can choose to either drill a bunch of holes with a drill bit (using your drill bit extensions), or you keep pushing your hole saw down deeper through the exhausts.

Some people recommend not opening things up too much so you don’t have too much issue with a lack of back pressure, other people have gone completely wild with it since the TORS exhausts from Triumph are open from inlet to outlet anyway. Ultimately, it doesn’t matter what you do, someone will always tell you that you’re wrong.

My personal recommendation is to try drilling a little bit, and then go for a ride and see how you like it. You can keep drilling or cutting and then going for a test ride until you’re satisfied. You can always open the exhausts up more, but you can’t seal it back up again later. There’s no putting the geenie back in the bottle, so you’re better off making small steps until you’re satisfied.

You can even take off the exhaust pipes so that you can drill or cut from both sides. It’s really easy, my video (at the beginning of this article) will you show you how.

How does the Triumph Bonneville sound and run after a bafflectomy?

Overall I’m glad that I tried this and it did help. The bafflectomy does make the Bonneville sound better. It waks the motorcycle up and makes it a little less soft spoken and muffled. The Bonneville is still nowhere near loud, but it’s an improvement overall. Check out the video at the beginning of the article for a before and after comparison.

The Bonneville is running fine, however it has developed a deceleration pop, which I don’t mind. People who do this mod will often bring it to the Triumph dealer to have their motorcycles flashed with the TORS mapping. That’s something you should probably look into before doing this mod. Some dealers have been known to swap maps for free if your motorcycle is in for an oil change or other service anyway. Other dealers will charge half an hour of labor. You should call ahead and ask.

Was the bafflectomy worth it? Yes, but also no. If the Bonneville wins the competition, and I sell my Royal Enfield Interceptor and my Moto Guzzi V7, and keep the Bonneville, I’ll get rid of these exhausts and buy an aftermarket option. The bike sounds better now than it did before, and it sounds better than my Royal Enfield Interceptor 650. The Bonneville doesn’t sound better than my Moto Guzzi V7 though. That came with Mystral exhaust pipes and sounds fantastic. That being said, this mod was basically free, and I only have $220 left to spend on the Bonneville. That’s now $220 I can spend elsewhere. And the Bonneville does sound better, so overall, it was worth it.

If you found the content informative or entertaining, and you want to encourage me to keep on making content like this, I hope you’ll subscribe to YouMotorcycle on YouTube. It’s free and it lets me know I should keep on making content like this to help other riders out!

Adrian

Click the pic below for the next episode, where I show you the work I’ve gotten done fixing up a stolen Moto Guzzi V7: