JezB
New member
- Location
- Scarborough
These are not marked with any ref numbers or names. There is a short pipe that goes into the silencer for abou 6 inches,and nothing else. Sound wonderful.
Anyone recognise these 1000 180 pipes?
- Thread starter JezB
- Start date
These are not marked with any ref numbers or names. There is a short pipe that goes into the silencer for abou 6 inches,and nothing else. Sound wonderful.
Jo
Hero member
- Location
- Cologne, NRW Germany
Usually the protruding end tubes characterize the (more open and louder) Jota dampers.
No idea which manufacturer made this replica though.
No idea which manufacturer made this replica though.
JezB
New member
- Location
- Scarborough
Laverdalothar
Hero member
- Location
- Germany
Are you sure it's 6 inches? That's about 15 cm... surprisingly long for "Jota" cans...
Don't know that exact type, but they were re-produced by many. The ones on my bike were made and stamped with Campbell. They had 32mm inner diameter of that pipe and roughyl 2,5 cm/1 inch length of the pipe at the outer side, roughly 5cm inside the "damper". HTH
Don't know that exact type, but they were re-produced by many. The ones on my bike were made and stamped with Campbell. They had 32mm inner diameter of that pipe and roughyl 2,5 cm/1 inch length of the pipe at the outer side, roughly 5cm inside the "damper". HTH
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Andy
Hero member
- Location
- Auckland, roughly
Yeah, I’ve been told that too
Laverdalothar
Hero member
- Location
- Germany
Reunited Chris
Senior member
- Location
- Sydney
I agree with Lothar, I seem to remember 1.25 inches internal dia and 4.5 inches long. The key to performance was the length of the small pipe.sorry - 15 I meant to say
Laverdalothar
Hero member
- Location
- Germany
It might also have to do with performance, but the sense of this tube is to reduce noise in a certain frequence. It's called a "Helmholtz" resonator tube. The tube makes most of the noise to be reflected at the end of the muffler where it can't exit. this causes waves to go backwards and - if done right - kill the next waves comming. The length of the tube has an impact on the frequency it is aimed to eleminate. dB-Eaters are a combination of that effect with other reflections. They are more effective in reducing the noise, but also a bit more restrictive in flow.
HTH
HTH
Standing waves theory, not so sure Helmholtz effect is an underlying principal Lothar, my opinion of course, not a certain given.
Standing wave theory is endemic through electronics, when understood ( taught it in college/TAFE ) very powerful tool. More so in musical instruments, woodwinds a notable. Had my difficulty explaining to a pro flautist of some 60 years playing, that the combination of pads/keys when one is open it does not look open to a standing acoustic wave, in his mind if a hole was open it was open, dependent on the standing wave maxima or minima at that hole position it will look closed even when open ( flute 3rd register a notable example ).
Did start to play with a tunable/removable "stub" on spare "mufflers" here ie "Jota" cans with tunable inner small diameter pipe. Outcomes were interesting though no significant gain noted over the clever ( as mentioned ) originals, whatever they were in the day. Factory 3c cans were very deflating in performance and living sound output, dare i say horrible... at the extreme, a poorly engineered jota can that cause discomfort while riding, headache a common outcome, hence the tunable stub episode. Hope i make sense with a simple explanation... yes i know simple is complex... a smile here. j
Standing wave theory is endemic through electronics, when understood ( taught it in college/TAFE ) very powerful tool. More so in musical instruments, woodwinds a notable. Had my difficulty explaining to a pro flautist of some 60 years playing, that the combination of pads/keys when one is open it does not look open to a standing acoustic wave, in his mind if a hole was open it was open, dependent on the standing wave maxima or minima at that hole position it will look closed even when open ( flute 3rd register a notable example ).
Did start to play with a tunable/removable "stub" on spare "mufflers" here ie "Jota" cans with tunable inner small diameter pipe. Outcomes were interesting though no significant gain noted over the clever ( as mentioned ) originals, whatever they were in the day. Factory 3c cans were very deflating in performance and living sound output, dare i say horrible... at the extreme, a poorly engineered jota can that cause discomfort while riding, headache a common outcome, hence the tunable stub episode. Hope i make sense with a simple explanation... yes i know simple is complex... a smile here. j
JezB
New member
- Location
- Scarborough
Well they are similar to a 900ss I had a few years back - they are an interference fit. I'll pop them off and chop the tube off.
Max
Full member
FWIW I have a Keihan system on my Jota, still happy with it after 34 years. The inserted pipe is 65mm long, with 45mm inside the can and 20mm sticking out.