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05-17-2025, 11:09 AM
(This post was last modified: 05-17-2025, 11:13 AM by YellowNimbus.)
Hey everyone,
I'm back again with another question about the CB1100, in hopes that someone has the time to teach me more about the mechanical aspects of the great CB1100.
I recently came across a video comparing a modern CB1100 and a 1970s CB750 K Series. Both bikes are running what appear to be Wyvern-style exhausts, and visually, they’re quite similar. But when it comes to sound, there’s a clear difference: the CB750 has a raw, wild tone that I find incredibly appealing, while the CB1100 sounds more refined and subdued.
https://www.youtube.com/watch?v=ckJwYVSpegk
This got me thinking:
What determines the sound characteristics of a motorcycle exhaust?
Besides fitting a reproduction Wyvern exhaust, is there a way to tune or modify the CB1100 to more closely match the CB750’s aggressive tone?
In the video comments, someone said:
"Sounds like a hotter cam to me. It would be cool to hear a 1100 with a similar cam profile."
Can anyone here explain: - What exactly is a hotter cam?
- How does it affect the exhaust note, and engine behaviour overall?
- Would it be practical (or worthwhile) to fit a more aggressive cam on the CB1100 for sound and performance?
It also seems to me that the commenter is implying a hotter cam can be installed, based on how they phrased it. Or am I misunderstanding?
Looking forward to hearing your thoughts — especially from those who’ve done performance or exhaust work on these bikes. Thanks a lot! 
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(05-17-2025, 11:09 AM)YellowNimbus Wrote: Hey everyone,
I'm back again with another question about the CB1100, in hopes that someone has the time to teach me more about the mechanical aspects of the great CB1100.
I recently came across a video comparing a modern CB1100 and a 1970s CB750 K Series. Both bikes are running what appear to be Wyvern-style exhausts, and visually, they’re quite similar. But when it comes to sound, there’s a clear difference: the CB750 has a raw, wild tone that I find incredibly appealing, while the CB1100 sounds more refined and subdued.
https://www.youtube.com/watch?v=ckJwYVSpegk
This got me thinking:
What determines the sound characteristics of a motorcycle exhaust?
Besides fitting a reproduction Wyvern exhaust, is there a way to tune or modify the CB1100 to more closely match the CB750’s aggressive tone?
In the video comments, someone said:
"Sounds like a hotter cam to me. It would be cool to hear a 1100 with a similar cam profile."
Can anyone here explain:- What exactly is a hotter cam?
- How does it affect the exhaust note, and engine behaviour overall?
- Would it be practical (or worthwhile) to fit a more aggressive cam on the CB1100 for sound and performance?
It also seems to me that the commenter is implying a hotter cam can be installed, based on how they phrased it. Or am I misunderstanding?
Looking forward to hearing your thoughts — especially from those who’ve done performance or exhaust work on these bikes. Thanks a lot!
its port size cam profile and 2 valvbe vs 4 valve mine sounds pretty close to my dads 750 i built a custom exhaust the cat also takes away lout of beautiful noise
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(05-17-2025, 01:02 PM)1973cb750 Wrote: (05-17-2025, 11:09 AM)YellowNimbus Wrote: Hey everyone,
I'm back again with another question about the CB1100, in hopes that someone has the time to teach me more about the mechanical aspects of the great CB1100.
I recently came across a video comparing a modern CB1100 and a 1970s CB750 K Series. Both bikes are running what appear to be Wyvern-style exhausts, and visually, they’re quite similar. But when it comes to sound, there’s a clear difference: the CB750 has a raw, wild tone that I find incredibly appealing, while the CB1100 sounds more refined and subdued.
https://www.youtube.com/watch?v=ckJwYVSpegk
This got me thinking:
What determines the sound characteristics of a motorcycle exhaust?
Besides fitting a reproduction Wyvern exhaust, is there a way to tune or modify the CB1100 to more closely match the CB750’s aggressive tone?
In the video comments, someone said:
"Sounds like a hotter cam to me. It would be cool to hear a 1100 with a similar cam profile."
Can anyone here explain:- What exactly is a hotter cam?
- How does it affect the exhaust note, and engine behaviour overall?
- Would it be practical (or worthwhile) to fit a more aggressive cam on the CB1100 for sound and performance?
It also seems to me that the commenter is implying a hotter cam can be installed, based on how they phrased it. Or am I misunderstanding?
Looking forward to hearing your thoughts — especially from those who’ve done performance or exhaust work on these bikes. Thanks a lot!
its port size cam profile and 2 valvbe vs 4 valve mine sounds pretty close to my dads 750 i built a custom exhaust the cat also takes away lout of beautiful noise
Oh it sounds amazing! This is one of the best sounding exhausts I've ever come across! Close to this comes the Pipemasters but nonetheless amazing! Do you see any rooms for improvement or your future plans for your bike?
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05-17-2025, 02:25 PM
(This post was last modified: 05-17-2025, 02:33 PM by 1973cb750.)
(05-17-2025, 02:20 PM)YellowNimbus Wrote: (05-17-2025, 01:02 PM)1973cb750 Wrote: (05-17-2025, 11:09 AM)YellowNimbus Wrote: Hey everyone,
I'm back again with another question about the CB1100, in hopes that someone has the time to teach me more about the mechanical aspects of the great CB1100.
I recently came across a video comparing a modern CB1100 and a 1970s CB750 K Series. Both bikes are running what appear to be Wyvern-style exhausts, and visually, they’re quite similar. But when it comes to sound, there’s a clear difference: the CB750 has a raw, wild tone that I find incredibly appealing, while the CB1100 sounds more refined and subdued.
https://www.youtube.com/watch?v=ckJwYVSpegk
This got me thinking:
What determines the sound characteristics of a motorcycle exhaust?
Besides fitting a reproduction Wyvern exhaust, is there a way to tune or modify the CB1100 to more closely match the CB750’s aggressive tone?
In the video comments, someone said:
"Sounds like a hotter cam to me. It would be cool to hear a 1100 with a similar cam profile."
Can anyone here explain:- What exactly is a hotter cam?
- How does it affect the exhaust note, and engine behaviour overall?
- Would it be practical (or worthwhile) to fit a more aggressive cam on the CB1100 for sound and performance?
It also seems to me that the commenter is implying a hotter cam can be installed, based on how they phrased it. Or am I misunderstanding?
Looking forward to hearing your thoughts — especially from those who’ve done performance or exhaust work on these bikes. Thanks a lot!
its port size cam profile and 2 valvbe vs 4 valve mine sounds pretty close to my dads 750 i built a custom exhaust the cat also takes away lout of beautiful noise
Oh it sounds amazing! This is one of the best sounding exhausts I've ever come across! Close to this comes the Pipemasters but nonetheless amazing! Do you see any rooms for improvement or your future plans for your bike? ![[Image: GK80Mjm.jpeg]](https://i.imgur.com/GK80Mjm.jpeg)
i want to go to a 2.5 from header back this is 2", also id like to use a larger tip. i have packing in this one. i plan on some day building a 2013 drag bike with cams porting and high compression pistons the whole nine with nitrous, or a turbo low compression build i been playing with the tune on this one it runs pretty stong
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(05-17-2025, 04:12 PM)Cormanus Wrote: There's a long discussion about cams here, https://cb1100forum.net/forum/showthread.php?tid=4994
That has been very helpful Cormanus! I've yet to read the rest of the pages I left unread. Thanks! ?
I will surely bring this topic up again in the future.
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