TBR Pipes

[SteveNZ]

Just got back from my annual vehicle Warrant Of Fitness inspection for the Valkyrie. (in New Zealand all vehicles must have a WOF to be on the road, big fines if you do not)
She has had TBR 6 into 6 pipes for about 10 yrs now, and for the first time they said she was too loud.
Was a new inspector, not seen my bike before. Everything else about the bike passed with flying colours. I told him I have been bringing the bike to his establishment for about the last 7 or 8 years and she had passed everytime. So what gives?
He went to find one of the previous inspectors. This previous inspector said she was definitely louder than when he inspected it a year ago, that he would never have passed it if she were this loud last year.


New Zealand road code says multi-cylinder bikes over 125cc can be a maximum of 97db when measured 500mm behind and at 45 degrees to each exhaust outlet at half their redline rpms. (for some reason twin cylinder bikes are allowed to go up to 103db when measured the same way?!?) When the pipes were fitted 10 yrs ago the inspector measured 95db. Then a couple years later that inspector died and so did his little garage business, so I started using this big-chain inspection company. In the last 10 years, today is the first time someone has measured the sound level, and this new inspector is claiming 116db!


So my question. Do TBR pipes have anything inside them that can break down over time? any kind of baffling or sound absorbing material? I had always thought they were just six big beautiful straight pipes. Maybe I have been wrong all these years.

If there is such a material inside them can it be replaced?

worst case I still have the stock pipes and can put them back on, but then she loses the "hear me roar" part of "I am a big beautiful beast, hear me roar!" equation.

[Leathel]

Make a Lolly pop baffle for each pipe bolted from under the pipe, put it in for WOF tests

I take it you are talking VTNZ?

What area are you from?

116db is pretty loud, was he strait behind the bike right at the exhaust?

[SteveNZ]

Thanks for the input. What is a lollipop baffle?

Yeah was VTNZ, been using the Whangarei branch for several years with no problems, new guy today, young guy, probably in late 20s.

I wasn't present when they tested it, didn't expect any problems, was drinking their coffee in the waiting room. Says he was 500 behind and 45 degrees port and starboard. Didn't think to check his meter, hope he used a proper meter and not just an app on his cellphone.

Been thinking about the stock pipes... My daughter is 13 and she loves coming for a ride. We getting out seeing the countryside a lot more than I used to. Doing some 3 and 4 day rides. I must say, as much as I like the roar and the looks it gets, after 4 or 5 hours I do wish I could turn it off.

[Leathel]

Lolly pop baffle is eventually a washer with a nut welded to the bottom, Drill a hole under each pipe and bolt it in place

the larger it is the quieter it is

[Leathel]

I have stock pipes on mine (with pigtails removed) and it has a drone type noise down low but cruising its quite and its nice compared to my old bike

My Daughter loved being on the bike, I didn't need to ask if she wanted to go..... Just check with the wife and son if they wanted to go and if they didn't want to go it was OK then your up....but she now has her own bike now and enjoys riding still but not so much as pillion 

[SteveNZ]

That looks simple enough, are they effective? Reckon I could lose 20db with 6 lollipops?

[WintrSol]

That looks simple enough, are they effective? Reckon I could lose 20db with 6 lollipops?

Volume is directly related to how much open area is around the lollipop.
If your inspectors balk at what is clearly easily removed, you can, with a bit more work, make this:
Gas pipe end caps, drilled and tapped around the sides in 3 places for socket-head set screws. You can drill the center hole to a size that sets any volume you wish, and mounting just takes a hex wrench, ground down to just fit onto the screws. Grinding the three lobes around the sides, as shown, also increases volume. Once mounted in the pipes, they appear like included baffles, so fool many inspectors.

The screws shown have heads, but I've since decided headless ones work, and look, better. I used 5mm screws, BTW.

[Leathel]

if you start with a larger masher with a smaller hole (panel washer) you have the option to drill the center out if its too quiet, even a Rivet in the hole to block it

I know of some that have had the mounts break going to big because pressure and flex.... but they were on a big V Twin with 900cc per pipe not 250cc per pipe like the Valkyrie

[Wayn-O]

I have cobra pipes and I am running no baffles because I love the tone.  Noticed a flat spot as a result and a slight stumble at about 2100 rpm.  I made some lollipop baffles using eye-bolts and bolting in a fender washer through the eye.  Regained some horsepower, eliminated the stumble, and still have a nice tone (only barely quieter).  Good cheap fix.

[old2soon]

Remind me of the snuff or nots my Brother had in his 305 Honda Scrambler. Gal I used to run around with probably Still has the scars on her inner thigh from the hot pipes.  RIDE SAFE.