Clutch slip/losing drive

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Beancounter
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Clutch slip/losing drive

Post by Beancounter »

The bike is a Ducati Scrambler Icon 800 with circa 10k miles on the clock. We've owned the bike for the last 3.5k miles IIRC.

This started yesterday. When opening the throttle, the engine is very willing and you get some immediate drive but then the engine revs climb with no increase in wheel speed. The more aggressive you are with the throttle, the worse the problem is and is more noticeable in lower gears. If you are careful with the throttle you can get the bike up to and hold a steady 70-75mph. Considered use of the clutch and throttle allow you to pull away from a stop like there isn't a problem.

Bike goes into gear and changes gear without any problem. The engine runs without any problem and feels healthy.

I've never experienced a slipping clutch but I would imagine the symptoms above are what I would get.

The chain and sprockets will need changing in the next 1k-1.5k miles but there's plenty of meat on both sprockets so I think it unlikely these are slipping.

Thoughts please?
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weeksy
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Re: Clutch slip/losing drive

Post by weeksy »

Sounds very like it mate yes. Hydraulic or cable ?
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Re: Clutch slip/losing drive

Post by KungFooBob »

Sounds like clutch slip.

Put the front wheel up against a wall and try to pull away, if it revs up rather than stalling, the clutch is shot.

If it's just worn plates it's an easy fix.

I had an R6 that developed a similar problem and it was one of the clutch friction plates had snapped in half, other than that they all had plenty of meat on them.
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Re: Clutch slip/losing drive

Post by Beancounter »

weeksy wrote: Thu Jul 20, 2023 11:11 am Sounds very like it mate yes. Hydraulic or cable ?
Cable - sorry, should have mentioned.
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dern
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Re: Clutch slip/losing drive

Post by dern »

Definitely sounds like the clutch. Any slip on the chain/sprockets would be hideously noisy and when cables go slack or hydraulic clutches need new fluid or leak then you tend you have issues disengaging the clutch, not engaging it.

Changing it is easy enough if you're confident and have access to the procedure for your bike. Otherwise getting a garage to do it shouldn't cost too much.
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weeksy
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Re: Clutch slip/losing drive

Post by weeksy »

Beancounter wrote: Thu Jul 20, 2023 11:16 am
weeksy wrote: Thu Jul 20, 2023 11:11 am Sounds very like it mate yes. Hydraulic or cable ?
Cable - sorry, should have mentioned.
How floppy is the lever ? make sure there's a bit/decent amount of wiggle in there at the pivot point.
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Re: Clutch slip/losing drive

Post by Le_Fromage_Grande »

Is there any free play at the lever, the end of the clutch lever should move by about 10mm before you feel any pressure on the lever.

If it's not the clutch, it's very shagged sprockets, or the front sprocket retaining nut has come undone.
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Re: Clutch slip/losing drive

Post by Beancounter »

KungFooBob wrote: Thu Jul 20, 2023 11:12 am Sounds like clutch slip.

Put the front wheel up against a wall and try to pull away, if it revs up rather than stalling, the clutch is shot.

If it's just worn plates it's an easy fix.

I had an R6 that developed a similar problem and it was one of the clutch friction plates had snapped in half, other than that they all had plenty of meat on them.
Thanks. This was pretty sudden - I used the bike on Tuesday morning around town, no issues. Missus used the bike yesterday to go to the office and was complaining of over-revving, I then used the bike last night and noticed what she was complaining about. No idea if anything actually happened whilst she was riding the bike yesterday morning, I suspect not because she would have shouted at me through the intercom.
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weeksy
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Re: Clutch slip/losing drive

Post by weeksy »

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Re: Clutch slip/losing drive

Post by porter_jamie »

job one check the lever adjustment. has it just had an oil change?
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Re: Clutch slip/losing drive

Post by Le_Fromage_Grande »

If it's suddenly happened I'd be looking at the front sprocket nut, though they normally loose drive completely if they undone.
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Re: Clutch slip/losing drive

Post by Beancounter »

Le_Fromage_Grande wrote: Thu Jul 20, 2023 11:20 am Is there any free play at the lever, the end of the clutch lever should move by about 10mm before you feel any pressure on the lever.

If it's not the clutch, it's very shagged sprockets, or the front sprocket retaining nut has come undone.
Fairly sure it's not the front sprocket, checked it this morning and it looks like I'll have a job to remove it.
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Re: Clutch slip/losing drive

Post by Beancounter »

porter_jamie wrote: Thu Jul 20, 2023 11:38 am job one check the lever adjustment. has it just had an oil change?
Nope, no recent oil change, it's on the to-do list.
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Re: Clutch slip/losing drive

Post by porter_jamie »

ah - if someone has fitted the wrong oil - car stuff for example without friciton modifiers, it could make the clutch slip, if it was a wet clutch. being a ducati it could be dry i suppose
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Re: Clutch slip/losing drive

Post by Beancounter »

weeksy wrote: Thu Jul 20, 2023 11:27 am Lever adjustment video
porter_jamie wrote: Thu Jul 20, 2023 11:38 am job one check the lever adjustment. has it just had an oil change?
Le_Fromage_Grande wrote: Thu Jul 20, 2023 11:20 am Is there any free play at the lever, the end of the clutch lever should move by about 10mm before you feel any pressure on the lever.

If it's not the clutch, it's very shagged sprockets, or the front sprocket retaining nut has come undone.
Just checked the lever, bugger all free play. I've sorted that and will take the bike for a spin later to see if that has changed anything.
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weeksy
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Re: Clutch slip/losing drive

Post by weeksy »

it certainly won't do any harm to give it some play.
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Re: Clutch slip/losing drive

Post by Beancounter »

Every day is a school day - giving the lever some free play seems to have cured it. Only took the bike on a short ride on the dual carriageway near to our house but a definite improvement. Just as well it doesn't need a new clutch because I FUBAR'd the garage door when putting the bike away.

Thanks all.
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Re: Clutch slip/losing drive

Post by dern »

If you’ve had it for a while, who adjusted the clutch to take all the free play out of it? Cables don’t contract by themselves.
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Re: Clutch slip/losing drive

Post by Beancounter »

dern wrote: Fri Jul 21, 2023 9:35 am If you’ve had it for a while, who adjusted the clutch to take all the free play out of it? Cables don’t contract by themselves.
I *think* my missus might have adjusted the cable instead of adjusting the lever to suit her small hands - obviously this is just a guess and she maintains she did nothing so there could still be an underlying issue to resolve.
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Re: Clutch slip/losing drive

Post by weeksy »

Beancounter wrote: Fri Jul 21, 2023 9:48 am
dern wrote: Fri Jul 21, 2023 9:35 am If you’ve had it for a while, who adjusted the clutch to take all the free play out of it? Cables don’t contract by themselves.
I *think* my missus might have adjusted the cable instead of adjusting the lever to suit her small hands - obviously this is just a guess and she maintains she did nothing so there could still be an underlying issue to resolve.
I think the odds are then that the cable has always been 'tight' but the condition of the clutch means that it wasn't an issue. As the bike is used and the clutch is wearing, it's now become an issue. So you may have taken a bit of the life off the clutch overall as a consequence. But assuming it's not slipping now, i'd just keep riding it until it starts slipping again, that may be 300 miles or 30,000 miles, hard to say. Just make sure the play is correct now and you'll be golden.

If she wants a level that's closer to the bars, get a set of ASV adjustable levers which will give that facility.