Bike goes into gear, but needs high rpm for clutch to engage

Last week I was riding and after an hour or two, my clutch stopped working correctly. At low rpm, it acted like the clutch was slipping. You could release the clutch all the way in first gear with no movement. With the clutch released, and throttle at approximately half, the bike would lurch forward then feel normal until engine braking, where it coasted as if it was in neutral or the clutch was pulled in.

I assumed this was an issue with the clutch, so I replaced it and it felt normal at first, then after about 30 minutes of riding it went back to doing the same thing.

I should also note that letting it cool down seems to help the issue (not totally resolve it however).

Additionally, I swapped the rear tire a few days before the issue started. I installed a tusk D sport which is a heavy tire. I’m curious if this could be the cause of the issue, since the issue started after the new tire was installed.

Any advice? TIA

Speedymaru wrote:

You could release the clutch all the way in first gear with no movement. With the clutch released, and throttle at approximately half, the bike would lurch forward then feel normal until engine braking, where it coasted as if it was in neutral or the clutch was pulled in.

I presume the lever play was adjusted correctly?

What do you mean by "...feel normal until engine breaking"? Where was the engine breaking coming from?

Speedymaru wrote:

I assumed this was an issue with the clutch, so I replaced it and it felt normal at first, then after about 30 minutes of riding it went back to doing the same thing.

You mean you replaced the entire clutch plate pack? Did you inspect the old plates? Were they burned? Were the friction plates completely scrubbed?

No, the tires have nothing to do with this.

johnkol wrote:

Speedymaru wrote:

You could release the clutch all the way in first gear with no movement. With the clutch released, and throttle at approximately half, the bike would lurch forward then feel normal until engine braking, where it coasted as if it was in neutral or the clutch was pulled in.

I presume the lever play was adjusted correctly?

What do you mean by "...feel normal until engine breaking"? Where was the engine breaking coming from?

Speedymaru wrote:

I assumed this was an issue with the clutch, so I replaced it and it felt normal at first, then after about 30 minutes of riding it went back to doing the same thing.

You mean you replaced the entire clutch plate pack? Did you inspect the old plates? Were they burned? Were the friction plates completely scrubbed?

No, the tires have nothing to do with this.

Correct, I adjusted the clutch level to the correct adjustment after installing the clutch.

What I mean by it feeling normal until engine braking is that when throttle was applied, it would accelerate as normal, but then when the throttle was released, rather than decelerating the bike, it coasted at idle as if it was in neutral (it was still in gear).

Correct, I replaced all of the fiber and steel plates and installed new springs. I inspected the old clutch plates, and they looked great (no signs of burning and still had plenty of clutch material left). I believe the clutch was definitely not the issue, and I misdiagnosed it.

Thanks for the clarification on the tire not being the issue. I’m kind of baffled on what it could be, so I’m thinking of everything I changed from before the issue occurred. Could a chain that’s too tight cause the issue? I adjusted it to be slightly tighter than I had it beforehand.

Thank you for your help, I really appreciate it.

Let's eliminate the crazy things first:

1. Countershaft sprocket has fully functional teeth
   
2. Apparent clutch slipping happens at multiple gears, not just first, right?
   

Assuming the above, re-adjust the clutch lever for double the play, put the bike into gear and release clutch; still slipping?

Chain tightness is not a factor.

The sprocket teeth look good from the outside, but I’ll go ahead and pull it off and confirm that it’s good.

Correct, the issue occurs in all gears.

Just to confirm, you’re saying to adjust it to start to engage further from the handgrip then normal?

You don't have to take the sprocket out, just rotate the wheel to visually confirm the teeth are intact.

Speedymaru wrote:

Just to confirm, you’re saying to adjust it to start to engage further from the handgrip then normal?

No, the opposite: it should engage closer to the handlebar.

So bizarre! Many replies are addressing the opposite issue of clutch slipping at HIGH rev's not like yours, slipping at low rev's. Sorry I cannot help but to have people focus on low RPM slipping and engaging on high rpm's.

Looking forward to learning what is going on

I worked on the bike for a while yesterday. I took off the clutch cover and removed all of the plates. Everything looked to be in great shape, including the clutch basket. I reinstalled everything, and adjusted the actuator rod on the pressure plate. I also changed the oil and loosened the chain.

Went for a 100 miles ride afterwards and it seemed to be working correctly, no slippage. Still baffled as to what the issue was. I’ll post back here if the issue reoccurs. Thanks for everyone’s help