Chopped cans - The Pros & Cons

What… you thought I was giving you a list? LOL:D I am hoping that you all might contribute to compiling a list. I’ll start:


  1. Short cans LOOK much better

  2. Short cans sound louder and deeper

  3. Possibly increase in power?

  4. Simple inexpensive mod


  1. They were Not designed that length for a reason, which is?

  2. Might cut them too short and they look stupid (I couldnt think of anything else to write)

I know there are some very knowledgable people on LB so please chip in, it may be very helpful to someone considering this ‘free’ mod.

my mate did it on his bandit, cut it about an inch after the bracket. loud pipes saves lives and all that, but his was far too loud. he left work early and woke up his wife, baby daughter and half the street. plus riding near him caused a serious ear ache. he kept it for about a fortnight.

that said, i have a dented can that im thinking of chopping up, but ill just put it on for rallies and runs out, not every day use.

If you cut your can, AND re jet your carbs or remap fuel injection profiles, it MIGHT give more power. As it is, most motorcycles are not noisy enough because drivers are being insulated from roads noise to a greater extent these days. And if you are driving down the road and some dim-bulb fails to see you, makes a lane change because he expected the motorcycle to be louder, or you to be further away that would be bad. I prefer to fit a louder HORN for that purpose rather than going deaf.

It also gives the narrow-minded and bigoted drivers the chance to say “those d*mned expletive-deleted motorcycle riders modifying their motorcycles, there ought to be a LAW”.

And sooner than you can say “huh?” there will be.

standard slip on race cans are ‘usually’ below the 105db mark.

cut down ones may well put you over (and defo for evening sessions which are 102dbs) so you’d need a spare exhaust to put on for track days, or work up some baffles to be able to insert

if you misjudge it and they’re obnoxious loud you’re more likely to get sh*t from cops

i actually put extra packing in my exhaust as was fed up with my head resonating. sound tested at brands they’re now 98dbs at 7k rpm, and its not like i’d say the bike is quiet

Maybe chunks can confirm, and maybe its more to do with two strokes, but would shortening the can mess up the exhaust pulses?

I had my arrow can cut down. Sounded lovely, no issues with ther police. All good really :slight_smile:

Shortening a can has very little or no impact on performance other than give you earache:D

As E rightly says, it’s more critical when it comes to two strokes to get the resonating pulses synchronized to give the correct amount of back pressure in the expansion chamber.

There’s a fascinating story of industrial espionage behind the development of 2 stroke expansion chambers.

In 1961 an East German MZ rider Ernst Degner defected from East Germany in the boot of a car to join Suzuki . He took with him the drawings for the expansion chamber and the rest is history:w00t:

The year before that during the TT he and Suzuki riders kept breaking down at exactly the same spot on the course. Strange eh?;):smiley:

Got this little bad boy on mine:

Sounds like a Ferrari, only 113 BHP out of a possible 120 - but thats only cos’ the system is short, not the can.:smiley:

Have been thinking about cutting down the Akras on my Tuono as they are a little too long for my liking but not sure that , after my " inept f**king about " with them , whether the power pulses from the Twin would blow them apart ?

Not cutting them down for noise reasons as they sound nice as they are just purely for aesthetic reasons :wink:

what was the reading on the 1st march?

Some cans are too long as they come, but I’ve also seen a lot of chopped cans which are too short and look silly, like a can of baked beans, totally mis-matched with the bike. Still, it’s a matter of personal taste so each to their own.

Great responses:)Allways good to read differant view points to help make a decision. As I said I am cutting my can’s down, they are way too long and my bike sounds like a scooter at the moment. I do not want them to be too too short as i think that looks silly but a nice stubby can under my seat instead of this big exhaust will put a smile on my face:D

What about Gazza’s can (he posted the pic up a couple of weeks ago) :w00t:

Personally I reckon you could chop em’ in half at most, but at least 6 inches.

I think just under 6 inches or there abouts will do. Just past the ‘quill’ sign plate.

It’ll run in line with the tail tidy, is that your thinking?

THat’s where I would chop them to - just so the strap is about 1/4 inch away from the Quill sticker - Not too short but short enough :wink:

Erm, not sure but they didn’t stop me going on track and I do have a rather rude shaped baffle for it :slight_smile:

THAT’S supposed to go in yer " muffler " Sherrie :wink:

had you slipped it in? :wink: