juddery wet clutch, what can it be ?
Discussion
Hello BanterHeads,
my little Dax with 175 Nice engine runs good, but has one annoying feature :
When moving from standstill in 1st gear, the clutch does not engage smooth and evenly,
but judders a bit, which makes the coordination between revs and clutch gripping a bit difficult.
Combined with a low rotating mass and long-ish 1st gear, I stalled the bike twice in traffic *shame*,
and now get moving with more revs than I should have, which sounds and feels not correct.
Lever and cable are new and easy-going, what could be the culprit there ?
my little Dax with 175 Nice engine runs good, but has one annoying feature :
When moving from standstill in 1st gear, the clutch does not engage smooth and evenly,
but judders a bit, which makes the coordination between revs and clutch gripping a bit difficult.
Combined with a low rotating mass and long-ish 1st gear, I stalled the bike twice in traffic *shame*,
and now get moving with more revs than I should have, which sounds and feels not correct.
Lever and cable are new and easy-going, what could be the culprit there ?
Thanks for the answers so far, I have taken the clutch apart, and found :
No warped or overheated ( colored ) steel discs or springs,
3 of the friction discs were worn minimal and equal, 2 had very miniscule differences in wear ( 4/100mm)
Bolts and bearings also OK.
I have recieved new friction discs and new springs, seems the old springs were a bit tired,
29 <> 32mm and went "on block" earlier if clamped together in a vise.
Oil is semi-synth "BEL-RAY Thumper" :
https://www.belray.com/product/thumper-racing-synt...
There also was a bit of "grooves worn in basket", more like "shiny spots",
will it be enough to file them down to level again ?
No warped or overheated ( colored ) steel discs or springs,
3 of the friction discs were worn minimal and equal, 2 had very miniscule differences in wear ( 4/100mm)
Bolts and bearings also OK.
I have recieved new friction discs and new springs, seems the old springs were a bit tired,
29 <> 32mm and went "on block" earlier if clamped together in a vise.
Oil is semi-synth "BEL-RAY Thumper" :
https://www.belray.com/product/thumper-racing-synt...
There also was a bit of "grooves worn in basket", more like "shiny spots",
will it be enough to file them down to level again ?
I had this on my CBF500. It was driving me absolutely insane.
I'd already replaced the plates at about 65k (not at 85k). I recently pulled it all apart again and found the aforementioned grooves in the basket.
I spent a few hours filing them all down and cleaning it up. It seems to have sorted it so far but will no doubt become a problem again at some point.
I'd already replaced the plates at about 65k (not at 85k). I recently pulled it all apart again and found the aforementioned grooves in the basket.
I spent a few hours filing them all down and cleaning it up. It seems to have sorted it so far but will no doubt become a problem again at some point.
Don't know anything about Dax but, the basket on my Monster was badly worn/notched, along with plates where over half the tang had worn away.
Take a look at the state of it, considering the official wear limit for the plate tangs to basket is 0.8mm or some such ridiculous number, mine had 7mm;
But despite being a 'tad' noisy it was still working fine and there was still plenty of friction material left.
Now it's a dry clutch but, if anything I'd expect that to be worse?
Does your clutch hub have any cush drive/damping in it?
Take a look at the state of it, considering the official wear limit for the plate tangs to basket is 0.8mm or some such ridiculous number, mine had 7mm;
But despite being a 'tad' noisy it was still working fine and there was still plenty of friction material left.
Now it's a dry clutch but, if anything I'd expect that to be worse?
Does your clutch hub have any cush drive/damping in it?
catso said:
Don't know anything about Dax but, the basket on my Monster was badly worn/notched, along with plates where over half the tang had worn away.
Take a look at the state of it, considering the official wear limit for the plate tangs to basket is 0.8mm or some such ridiculous number, mine had 7mm;
But despite being a 'tad' noisy it was still working fine and there was still plenty of friction material left.
Now it's a dry clutch but, if anything I'd expect that to be worse?
Does your clutch hub have any cush drive/damping in it?
Jeez you got your money out of that !Take a look at the state of it, considering the official wear limit for the plate tangs to basket is 0.8mm or some such ridiculous number, mine had 7mm;
But despite being a 'tad' noisy it was still working fine and there was still plenty of friction material left.
Now it's a dry clutch but, if anything I'd expect that to be worse?
Does your clutch hub have any cush drive/damping in it?
Reply to Catso´s question :
Does your clutch hub have any cush drive/damping in it?
Yes it has, two small springs
Could they be the reason for juddering ? Replacement seems to be loads of work,
maybe something for an external machine shop, because rivets have to be opened.
Then I could find & fit stiffer springs and get the cutch bell re-riveted ( and balanced ) ??
OEM part from Thai HONDA scooter of the 90s is no longer manufactured.
I would s
t bricks if I had ran THAT worn clutch, that could have "exploded" under load if all tangs had gone to lunch.
Does your clutch hub have any cush drive/damping in it?
Yes it has, two small springs
Could they be the reason for juddering ? Replacement seems to be loads of work,
maybe something for an external machine shop, because rivets have to be opened.
Then I could find & fit stiffer springs and get the cutch bell re-riveted ( and balanced ) ??
OEM part from Thai HONDA scooter of the 90s is no longer manufactured.
I would s
t bricks if I had ran THAT worn clutch, that could have "exploded" under load if all tangs had gone to lunch.Benni said:
As they look to be intact, I doubt it. I was more wondering if they were broken or missing.As for the wear on the Ducati clutch, it's not uncommon. The upside of the Ducati dry clutch is that it's an easy job to service/replace, the downside being that it needs doing often, hence them going to wet clutches on the newer bikes.
As has been mentioned earlier, if the plates aren't showing signs of heat or warping, then the most likely culprit is the plates hanging up on the basket as the clutch is released. This results in the plate skewing in relation to it's neighbours and causing a juddering when drive is taken up. If so, this will eventually cause heating to the steel plates as they aren't being engaged evenly.
Check the inner and outer baskets for signs of the friction or steel discs possibly hanging up on one of their tangs , make sure the openings for the disc tangs are smooth and even and with the clutch installed but visible, actuate the clutch to see if the plates are moving evenly around the inner and outer baskets. Obviously, double check the obvious suspects like plate flatness and eveness of wear, signs of heat spots, clutch bearing wear etc as well as the basket bearings. If these are wearing, you might find the inner or outer clutch baskets are moving unevenly in relation to the other basket, again, skewing the plates against eachother.
Unfortunately, clutches work on very small tolerances so it's often a game of replace a part and retry if there isn't an obvious issue.
Check the inner and outer baskets for signs of the friction or steel discs possibly hanging up on one of their tangs , make sure the openings for the disc tangs are smooth and even and with the clutch installed but visible, actuate the clutch to see if the plates are moving evenly around the inner and outer baskets. Obviously, double check the obvious suspects like plate flatness and eveness of wear, signs of heat spots, clutch bearing wear etc as well as the basket bearings. If these are wearing, you might find the inner or outer clutch baskets are moving unevenly in relation to the other basket, again, skewing the plates against eachother.
Unfortunately, clutches work on very small tolerances so it's often a game of replace a part and retry if there isn't an obvious issue.
catso said:
Don't know anything about Dax but, the basket on my Monster was badly worn/notched, along with plates where over half the tang had worn away.
Take a look at the state of it, considering the official wear limit for the plate tangs to basket is 0.8mm or some such ridiculous number, mine had 7mm;
But despite being a 'tad' noisy it was still working fine and there was still plenty of friction material left.
Now it's a dry clutch but, if anything I'd expect that to be worse?
Does your clutch hub have any cush drive/damping in it?
Wow, you did well with them! That's impressive!Take a look at the state of it, considering the official wear limit for the plate tangs to basket is 0.8mm or some such ridiculous number, mine had 7mm;
But despite being a 'tad' noisy it was still working fine and there was still plenty of friction material left.
Now it's a dry clutch but, if anything I'd expect that to be worse?
Does your clutch hub have any cush drive/damping in it?
Out of curiosity how many miles had this done?
To the OP as Steve mentioned make sure you check the centre hub too - as this is ally with the steel clutch plates running it on they wear too.
MK3 Dan said:
Wow, you did well with them! That's impressive!
Out of curiosity how many miles had this done?
To the OP as Steve mentioned make sure you check the centre hub too - as this is ally with the steel clutch plates running it on they wear too.
The only way to really prove disc flatness btw is to lay them on a small mirror or piece of glass. Like this you can immediately see the smallest deflection of the plate from being flat which may not be visible by just looking at them in the hand.Out of curiosity how many miles had this done?
To the OP as Steve mentioned make sure you check the centre hub too - as this is ally with the steel clutch plates running it on they wear too.
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