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Hi All,
have recently purchased a 2019 cb500f and gave my older 2017 one to my brother who is currently learning. Im having issues where its almost impossible to shift from gear 3 and lower unless i really kick the shift leaver. Even if i roll the bike a little or try and release clutch, it just wont budge unless i kick down hard. On my 2017 model I could literally pull in the clutch and shift from 6 to 1 smoothly as long as the speed was right, but on this bike i have to really think about shifting and put me in a few akwards situations where i need to pull away after stopping hard but cant as its still stuck in 3rd gear.

Its not the clutch freeplay as ive played around with that and the shifter pedal is in the same position as on old bike so its not that im not pushing it low enough. One thing ive noticed is that when i do get it into first gear, if i try push down again, its almost like it goes into 1st gear the 2nd time. I thought it may be something to do with the slipper clutch but i doubt they would design it that way? Where could I start looking to try and resolve or improve it slightly.
 

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It has to be an issue with your bike. Is it under warranty, if so take it to a service dealer. I've never had such issues with my 2019F and I think the slipper clutch is one of the best things with this bike.
 

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Discussion Starter #3
No its out of warranty unfortunately. I may just take it so they can do a test ride and perhaps point me in the right direction as to what it may be. Thought I would ask in case anyone might have an idea.
 

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They modified the 19 model year shifting mechanism to improve shifting better than the previous model. The shift on this model is so so slick. If clutch adjustment is ok., Check the adjusting rod isn't bent or loose, and just check the gear lever height with the other bike. If all is ok then it's possible it is a shift drum or shift drum lever fault. The bike hasn't been dropped on to the gear lever by any chance has it.
 

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Change to the recommended 30W oil to see if there's any improvement, particularly if it is still factory oil from new.

Never kick the shift lever in anger. There are internal shift forks that can bend. Hope it is not; it is a big job to fix (and should be last on the list of possibilities).

Check all the other smaller, easier items first; shift link (that vertical rod), shift lever position (usually set too high), etc.
 

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This can happen if the gear lever height is wrong, try moving the lever a little bit at a time up and down and I think you will find it will be ok ,it happen'd to me when I first had my bike.

Good luck

Plasma1.
 

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Suppose you're at a stop-light in N and the light turns green; you pull in the clutch and snick it into first gear. What is the response of the bike to that? Specifically, does the gear select with a hard clunk, does the bike jump more than a bit when it the gear engages?

Suppose you're ready to pull away; clutch lever is pulled to the bar and you're in gear. How far from the bar does the lever need to move before you get drive at the back wheel? Do you sense there's already driving force there, even with the lever to the bar and the bike starts moving with authority immediately upon the lever moving a mm from the bar?

Put the bike up on a paddock stand (or get the back wheel in the air some other safe way.) Make sure the bike is secure and stable. Start and the engine, pull the clutch and select 1st; then cycle up through the gears and back down. How difficult is shifting under this condition?

You say "when i do get it into first gear, if i try push down again, its almost like it goes into 1st gear the 2nd time "; do you feel this when the engine is off and the bike is still? You might have to rock the bike back and forth a bit to select first but when you do, do you still feel this weirdness?

What type and grade of oil are you running? If it's very thick it may cause drag on even a properly adjusted clutch leading to loading of the gearbox which can make shifting difficult. If you sense drag when stopped (clutch pulled in, in gear) and clutch probably isn't fully releasing. Play is one thing you seem to have ruled out but there could be others (oil viscosity or type, damaged or swollen friction disc(s) in the pack etc.

A weird feeling in the shift lever is, unfortunately, more sinister. I drew a crude drawing of the gearbox to get an idea of the shift forks involved in each gear. Cheesy drawing below:



This is a top-down view of the trans. Gears are rectangles with the counter ("secondary") shaft labeled "SEC" and the main shaft labeled "MAIN". They are labeled 1-6 for each shaft and their numbers in brackets are the number of teeth on each. Some gears are splined to their shafts (represented by shaded in center bits in those gears) and some ride on bushings (non-shaded center bits.) The sprocket to the back wheel is at the top right. The clutch is the big rectangle on the left with the primary drive represented by the slashes.

There are three shift forks in this transmission. They act on 5S (5th gear, secondary shaft), 6S (6th gear, secondary shaft) and 34M (main shaft, 3-4 gear.) Note that 1M (1st gear, main shaft) is shown in the drawing as being splined to the shaft; in actuality that particular gear is machined into the main shaft. It's not removable like the other gears.

Gears are selected by moving these three parts -- 5S, 6S and 34M using the shift forks and drum. When you press the lever down the drum rotates and little pins, following slots in the drum, move left or right or not at all depending on the shape of the slot in that part of the drum. To select 1st gear, 5S is moved over to 1S; side dogs on 5S engage slots in 1S locking 1S and 5S together. Since 5S is splined to the secondary shaft, so is 1S. As 1M is splined/part of the main shaft so now torque is transferred through 1M -> 1S -> 5S (splines) to the output shaft.

When you want 2nd gear, you pull up on the shift lever. The 5S fork is moved back to its "center" position and the fork for 6S is moved "right" so its dogs engage the slots in 2S. Since 2M is splined to the main shaft and now 2S is connected to the secondary shaft through 6S's splines, you're now in 2nd gear.

For 3rd gear, 6S is moved back to its center position and 5S is moved so its dogs engage 3S. 4th gear is 6S moving "left" so its dogs engage 4S. 5th is 34M moving left to engage 5M and 6th is 34M moving right to engage 6M.

This is described in the little legend off to the bottom right.

The upshot of all this is the following: For gears 1, 2 and 3 the forks for 5S and 6S are used. (5S moves left (1st), center (2nd), right (3rd) and back to center while 6S moves right (2nd) and left (4th.) For gears 4, 5 and 6, forks 6S and 34M are used.

You mentioned that "...impossible to shift from gear 3 and lower . What's common to 1, 2 and 3? It's the fork for 5S:

  • 1st gear: 5S moves left, 6S remains centered, 34M remains centered
  • 2nd gear: 5S returns to center, 6S moves right, 34M remains centered
  • 3rd gear: 5S moves right, 6S returns to center, 34M remains centered

For 4th, 5th and 6th:
  • 4th gear: 6S moves right, 34M remains centered, 5S returns to center
  • 5th gear: 6S returns to center, 34M moves left, 5S remains centered
  • 6th gear: 6S remains centered, 34M moves right, 5S remains centered

When coming down the gears, 6-5-4, 5S does not move; it remains centered. When you go to 3 and then 2-1, 5S moves for each of these gears. It is also what selects 1st gear... If 5S is bent or otherwise damaged, it might explain why you have trouble downshifting from 3 down and why it feels goofy trying to select 1st; 5S is involved in all of those operations. Because 5S also moves when going from 3 to 4 (it returns to center) there may also be some shifting trouble shifting up from 3 to 4 but the shift from 4 to 3 would feel normal since 5S is already centered and doesn't move.

It's not a pleasant prospect to think that a shift-fork may be bent or damaged and it's not cheap or easy to fix. These bikes don't have cassette gearboxes so I'm pretty sure the whole thing has to be torn apart to get to the bits in question here. Because it's not going to be cheap I'd get a 2nd & 3rd opinion and double check the low-hanging fruit first before committing to what some random dude on the Internet thinks.
 
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Suppose you're at a stop-light in N and the light turns green; you pull in the clutch and snick it into first gear. What is the response of the bike to that? Specifically, does the gear select with a hard clunk, does the bike jump more than a bit when it the gear engages?

Suppose you're ready to pull away; clutch lever is pulled to the bar and you're in gear. How far from the bar does the lever need to move before you get drive at the back wheel? Do you sense there's already driving force there, even with the lever to the bar and the bike starts moving with authority immediately upon the lever moving a mm from the bar?

Put the bike up on a paddock stand (or get the back wheel in the air some other safe way.) Make sure the bike is secure and stable. Start and the engine, pull the clutch and select 1st; then cycle up through the gears and back down. How difficult is shifting under this condition?

You say "when i do get it into first gear, if i try push down again, its almost like it goes into 1st gear the 2nd time "; do you feel this when the engine is off and the bike is still? You might have to rock the bike back and forth a bit to select first but when you do, do you still feel this weirdness?

What type and grade of oil are you running? If it's very thick it may cause drag on even a properly adjusted clutch leading to loading of the gearbox which can make shifting difficult. If you sense drag when stopped (clutch pulled in, in gear) and clutch probably isn't fully releasing. Play is one thing you seem to have ruled out but there could be others (oil viscosity or type, damaged or swollen friction disc(s) in the pack etc.

A weird feeling in the shift lever is, unfortunately, more sinister. I drew a crude drawing of the gearbox to get an idea of the shift forks involved in each gear. Cheesy drawing below:



This is a top-down view of the trans. Gears are rectangles with the counter ("secondary") shaft labeled "SEC" and the main shaft labeled "MAIN". They are labeled 1-6 for each shaft and their numbers in brackets are the number of teeth on each. Some gears are splined to their shafts (represented by shaded in center bits in those gears) and some ride on bushings (non-shaded center bits.) The sprocket to the back wheel is at the top right. The clutch is the big rectangle on the left with the primary drive represented by the slashes.

There are three shift forks in this transmission. They act on 5S (5th gear, secondary shaft), 6S (6th gear, secondary shaft) and 34M (main shaft, 3-4 gear.) Note that 1M (1st gear, main shaft) is shown in the drawing as being splined to the shaft; in actuality that particular gear is machined into the main shaft. It's not removable like the other gears.

Gears are selected by moving these three parts -- 5S, 6S and 34M using the shift forks and drum. When you press the lever down the drum rotates and little pins, following slots in the drum, move left or right or not at all depending on the shape of the slot in that part of the drum. To select 1st gear, 5S is moved over to 1S; side dogs on 5S engage slots in 1S locking 1S and 5S together. Since 5S is splined to the secondary shaft, so is 1S. As 1M is splined/part of the main shaft so now torque is transferred through 1M -> 1S -> 5S (splines) to the output shaft.

When you want 2nd gear, you pull up on the shift lever. The 5S fork is moved back to its "center" position and the fork for 6S is moved "right" so its dogs engage the slots in 2S. Since 2M is splined to the main shaft and now 2S is connected to the secondary shaft through 6S's splines, you're now in 2nd gear.

For 3rd gear, 6S is moved back to its center position and 5S is moved so its dogs engage 3S. 4th gear is 6S moving "left" so its dogs engage 4S. 5th is 34M moving left to engage 5M and 6th is 34M moving right to engage 6M.

This is described in the little legend off to the bottom right.

The upshot of all this is the following: For gears 1, 2 and 3 the forks for 5S and 6S are used. (5S moves left (1st), center (2nd), right (3rd) and back to center while 6S moves right (2nd) and left (4th.) For gears 4, 5 and 6, forks 6S and 34M are used.

You mentioned that "...impossible to shift from gear 3 and lower . What's common to 1, 2 and 3? It's the fork for 5S:

  • 1st gear: 5S moves left, 6S remains centered, 34M remains centered
  • 2nd gear: 5S returns to center, 6S moves right, 34M remains centered
  • 3rd gear: 5S moves right, 6S returns to center, 34M remains centered

For 4th, 5th and 6th:
  • 4th gear: 6S moves right, 34M remains centered, 5S returns to center
  • 5th gear: 6S returns to center, 34M moves left, 5S remains centered
  • 6th gear: 6S remains centered, 34M moves right, 5S remains centered

When coming down the gears, 6-5-4, 5S does not move; it remains centered. When you go to 3 and then 2-1, 5S moves for each of these gears. It is also what selects 1st gear... If 5S is bent or otherwise damaged, it might explain why you have trouble downshifting from 3 down and why it feels goofy trying to select 1st; 5S is involved in all of those operations. Because 5S also moves when going from 3 to 4 (it returns to center) there may also be some shifting trouble shifting up from 3 to 4 but the shift from 4 to 3 would feel normal since 5S is already centered and doesn't move.

It's not a pleasant prospect to think that a shift-fork may be bent or damaged and it's not cheap or easy to fix. These bikes don't have cassette gearboxes so I'm pretty sure the whole thing has to be torn apart to get to the bits in question here. Because it's not going to be cheap I'd get a 2nd & 3rd opinion and double check the low-hanging fruit first before committing to what some random dude on the Internet thinks.
Hi All,
have recently purchased a 2019 cb500f and gave my older 2017 one to my brother who is currently learning. Im having issues where its almost impossible to shift from gear 3 and lower unless i really kick the shift leaver. Even if i roll the bike a little or try and release clutch, it just wont budge unless i kick down hard. On my 2017 model I could literally pull in the clutch and shift from 6 to 1 smoothly as long as the speed was right, but on this bike i have to really think about shifting and put me in a few akwards situations where i need to pull away after stopping hard but cant as its still stuck in 3rd gear.

Its not the clutch freeplay as ive played around with that and the shifter pedal is in the same position as on old bike so its not that im not pushing it low enough. One thing ive noticed is that when i do get it into first gear, if i try push down again, its almost like it goes into 1st gear the 2nd time. I thought it may be something to do with the slipper clutch but i doubt they would design it that way? Where could I start looking to try and resolve or improve it slightly.
 

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Just to explain a bit more, we have two cb500f's and whan we first bought them we both found the gear lever was too low to get your foot under comfortably, so i did what i always do when i get a new bike, i adjusted the gear lever up a bit using the connecting rod and thought no more of it because i had always done this on my bikes previously, however when we come to use the bikes we both found difficulty when changing down, this surprised me as i couldnt explain why it would happen, what i eventually did was to put the bike on the center stand and marked the height of the gear lever on a piece of wood, i then progresivley lifted the height of the lever about half an inch at a time till i found the gear change was back to normal.

Plasma1
 
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