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Discussion Starter · #1 ·
Hi guys iam new to this and had recently noticed that when i turn on my bike there is a little (barely noticeable) clanking sound on my engine header part and when i pull the clutch it disappears and on releasing the sound came back . Is this normal or is there any malfunction on my engine. PLEASE HELP iam really lost and dont know whether if this is normal or bad for my motorcycle. THANKS in advance
 

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That is 100% normal..... Every motorcycle does it. The sound you are hearing is the clutch plates moving around (slightly) in the clutch basket. That happens when there is no load/pressure on them. Enjoy you bike, and don't give it a second thought :cool:-
 

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Sequential motorcycle transmissions with straight cut gears rattle when warmed up with clutch lever disengaged. It's not the clutch discs and steels as some believe, since any time the clutch lever is out, the pack it clamped and tight. It is the gears rattling inside the trans, when in neutral, when none of them are locked together by the dog clutches, causing the gears rotating rattle a little in neutral. When you release the clutch (pull the lever), the gears slow or stop moving, and the noise goes away. As soon as you get the trans in a gear, the load on the gears, input and output shafts causes things to tighten up. In gear, the rattling is still there but to a far lesser degree at steady speeds, as any gear not connected by the dog clutches by the gear selection fork and spool is still spinning loose against its mate on the opposite shaft. However, under acceleration and deceleration, all of the gears are loaded against the leading or trailing faces, so the noise is pretty much gone. Motorcycles have their gearboxes exposed, without sound deadening or a floor to hide the noise. Sequential car transmissions make the same noise, you just don't here it. Lightweight gears will make more noise than heavier gears, so Japanese and Italian bikes exhibit more of this behavior than, say, Harleys or big English stuff that use big heavy cast gears, over smaller, thinner alloy gear sets. Also, quick shifting boxes are a bit looser to make shifting faster, so sport engines are the noisiest of the lot. 2 cylinder bikes make a more noticeable rattle than 4 bangers as well, due to lower harmonic frequency of vibration. Race prepped boxes can sound like a rock crushers, then create a new rattling of clutch pack when the lever us pulled in - ie the Ducati twin with dry clutches - that sound broken all the time.

So, what you are hearing is perfectly normal, and an indication the trans internals are doing their thing as designed. No worries.
 

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Discussion Starter · #4 ·
Sequential motorcycle transmissions with straight cut gears rattle when warmed up with clutch lever disengaged. It's not the clutch discs and steels as some believe, since any time the clutch lever is out, the pack it clamped and tight. It is the gears rattling inside the trans, when in neutral, when none of them are locked together by the dog clutches, causing the gears rotating rattle a little in neutral. When you release the clutch (pull the lever), the gears slow or stop moving, and the noise goes away. As soon as you get the trans in a gear, the load on the gears, input and output shafts causes things to tighten up. In gear, the rattling is still there but to a far lesser degree at steady speeds, as any gear not connected by the dog clutches by the gear selection fork and spool is still spinning loose against its mate on the opposite shaft. However, under acceleration and deceleration, all of the gears are loaded against the leading or trailing faces, so the noise is pretty much gone. Motorcycles have their gearboxes exposed, without sound deadening or a floor to hide the noise. Sequential car transmissions make the same noise, you just don't here it. Lightweight gears will make more noise than heavier gears, so Japanese and Italian bikes exhibit more of this behavior than, say, Harleys or big English stuff that use big heavy cast gears, over smaller, thinner alloy gear sets. Also, quick shifting boxes are a bit looser to make shifting faster, so sport engines are the noisiest of the lot. 2 cylinder bikes make a more noticeable rattle than 4 bangers as well, due to lower harmonic frequency of vibration. Race prepped boxes can sound like a rock crushers, then create a new rattling of clutch pack when the lever us pulled in - ie the Ducati twin with dry clutches - that sound broken all the time.

So, what you are hearing is perfectly normal, and an indication the trans internals are doing their thing as designed. No worries.
Thank you so much..
 

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Discussion Starter · #5 ·
That is 100% normal..... Every motorcycle does it. The sound you are hearing is the clutch plates moving around (slightly) in the clutch basket. That happens when there is no load/pressure on them. Enjoy you bike, and don't give it a second thought :cool:-
Thank you soo much..
 

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no synchro?
Motorcycle transmission do not utilize synchro rings or clutches, or bias cut gears. They utilize sequential straight cut gears. This is lighter, faster shifting, and more efficient (less friction), but comes with the price of noise and the tendency to like being shifted through the gears up and down, without skipping. A car trans with modern synchros can be easily shifted from 1-5-3-6-2-4-5-1-6, etc..., or in any order you wish up and down. Bike gearboxes are more 1-2-3-4-5-6-5-4-3-2-1 in character (design of the shift spool system), so no syncros necessary.
 

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If you are interested, this video shows how the gearbox works (video is a 5 speed, so there are only 5 gears - the R3 has one more pair for 6 total egars). Note the moving parts in neutral. These are the cause of any noise you might hear. Also note that a bike box has no synchro rings and clutches like a car box.

Thank you for the excellent video, as well as the education..... I'm not ashamed to admit that "I didn't know, what I didn't know". I appear to have received some bad information along the way? Your explanation, and video makes MUCH more sense than the mis-information I received decades ago. Thank you :cool:(y)-
 
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