Are all slipper clutches "jerky"?

[mcmurray]

My 'busa is the first bike I've ridden with a slipper clutch.

Sometimes my gear changes aren't as smooth as I'd like them to be and I'm pretty sure this is because of extra drivetrain lash due to the two-piece clutch hub design.

Some 'busa owners have their clutch hub welded to eliminate the play especially for drag racing applications.

Are all slipper clutches like this?

Is there any other way to reduce play short of welding the hub?

[Munkers]

Is it a Mk1 or a MK2 Busa?

[Desmo]

The Duc slipper clutches can be very juddery off the line, but this is generally on non-open clutched bikes that have a large build up of clutch dust in them (due to the way the back-torque limiter works) and due to inadequate cooling.
If you are experiencing lash due to a slipper clutch then I would hazard a guess there is something wrong with the clutch.

[I Fancy Holidays]

≠

[g0zer]

do you have a parts drawing of the plate arrangement? is it fitted with an anti judder spring?

i just went through this exercise with my 2010 r1 slipper which was horribly juddery. involved installing an anti-judder spring (courtesy of an earlier model r1 which happens to have the same geometry as the 2010 basket). it is a very simple thing just a concave steel ring which sits in-between and applies a small separating force between the rear most steel and the back of the basket releasing the rear most fibre first and evenly to eliminate the judder harmonic when slipping the clutch at high rpm.

for some reason yamaha decided the anti judder spring wasnt necessary in their new bikes the difference was night and day.

[Big_Dave]

Never had an issue with the one in the cbr1000.

As most have said it sounds likes something's a bit off in your bike.

Is it always jerky or only with things like downshifting with high rpm.
Are you dumping the lever or letting it out smooth ?

[BusaSteve]

I would be very interested in what happens...mine is a 2010 gen II with the slipper clutch and my changes are clunky and sometimes I have to double clutch to get first at a standstill. having said this mine has less than 7500 k's so may loosen up with use. I changed the oil recently so it isn't likely to be that. I am thinking of changing the fluid to see if that helps. from others experiences the clutch/gear changes can be a little clunky before 20 thou or so on these.

[Hornet]

I've never had a problem with the '06 R1 or the K9 Gix thou'.

A slipper works by letting the clutch slip slightly when the rear wheel is trying to turn the engine faster, rather than the engine turn the wheel. Little ramps reduce the clamping force on the clutch allowing for slip. This only works when the force is coming from the wheel, not when it's coming from the engine.
I don't see how this would make a difference in acceleration but how things are made and put together can have varying effects in other areas. I would lean more to the clutch not having the best tolerances when built rather than it being a slipper clutch, or the plates needing replacing or something similar. Or maybe it's the Busa's gearbox? More power needs stronger, beefier gears, etc. It might just be a characteristic of the gearbox.

Perhaps an aftermarket slipper of decent reputation?






As an aside, a slipper clutch was the reason Casey couldn't be push started last year when Vale took him out. Honda produced a new clutch not long after that to allow for push starts.

[Sonik]

I haven't had any problems with my ZX6's factory slipper aside from n00b moments on the track causing a little compression lockup from heavy breaking and uncoordinated downshifts. It feels smooth even with some pretty hard drag launches but I don't use it to shift up at all so I can't really say much about gear changes other than as long as I don't do anything too rough with downshifting it's sweet. Might just be your bike

[mcmurray]

Thanks for the comments guys.

I've been reading about "judder" associated with slipper's and I don't think that's the problem I've been having.

Is it a Mk1 or a MK2 Busa?

Mk2.

I got the bike with 21000kms on it. From the start smooth gear changes (upshifts) have been tricky compared to my previous bikes, there was a lot of drivetrain lash (felt like a very loose chain). To address this I've adjusted the throttle cable to eliminate play, adjusted and lubricated drive chain, and replaced the cush drive with much firmer aftermarket parts (Sensei cush drive - recommended). This work has made a world of difference in addressing the problem and now it's just the odd upshift that is jerky.

When I release the clutch slowly in first gear there's a noticeable "clunk" as it begins to grab, the same "clunk" occurs when gently rolling on and off throttle whilst in gear without touching the clutch.

I think if it continues to bother me, what I might do is try the one piece hub and see fixes it. I always blip on downshifts so the slipper might be wasted on me for everyday riding anyway.

I would be very interested in what happens...mine is a 2010 gen II with the slipper clutch and my changes are clunky and sometimes I have to double clutch to get first at a standstill. having said this mine has less than 7500 k's so may loosen up with use. I changed the oil recently so it isn't likely to be that. I am thinking of changing the fluid to see if that helps. from others experiences the clutch/gear changes can be a little clunky before 20 thou or so on these.

Does yours behave like what I've described?

Can Munkers or any other 'busa owners chime in?

[mcmurray]

do you have a parts drawing of the plate arrangement? is it fitted with an anti judder spring?

I found a parts drawing here: Clutch clunk&#33

[g0zer]

yeah it has the anti judder spring arrangement parts 9 and 10, a quick skim of that thread your problem is not the same as mine was. also looks like there is are options to mod it out if you want.

[mcmurray]

Some interesting posts in the linked thread over at hayabusa.org;

"My 01 did it and my 08 does the same thing. It feels like a sloppy chain and more noticable when shifting at lower RPMs. Without a doubt my biggest complaint about the bike."

"There's not much to complain about with the busa, but I am with you; that's my only real complaint. I wouldn't tell any of my riding friends about it because I was embarassed. I thought my bike was broken...I must have adjusted my chain 100 times in the first month that I owned it. Really freaked me out! So I did some research about the busa clutch and found it. Man was I relieved to find that my bike wasn't all screwed up. The day I installed the billet mod that 'lash' went away!"

"Yes, it feels alot like a loose chain....it's classic back torque limiter 'lash'. Normal stuff and the only way to eliminate it is going to a one piece limiter."

This pretty much confirms my suspicions. Looks like I'll be ordering a one-piece hub.

I wonder if this is a Hayabusa only problem.

[Munkers]

I have just over 50,000 kms on my gen 2 Busa from brand new, and can honestly say that I have not had a single problem with the machine at all, what I did find was that after a shop service, and this has happened on several occasions, the shop always fill the engine oil to a certain level, normally just under half way up the oil window. When the bike came back from a regular service at the shop, the gear change would be a bit clunky and the clutch would drag when selecting first gear. I top up the oil level to 2/3rds of the window, and for some reason this fixes both problems. Running gear wise, my Busa is stock standard.

[BusaSteve]

Thanks for the comments guys.

I've been reading about "judder" associated with slipper's and I don't think that's the problem I've been having.



Mk2.

I got the bike with 21000kms on it. From the start smooth gear changes (upshifts) have been tricky compared to my previous bikes, there was a lot of drivetrain lash (felt like a very loose chain). To address this I've adjusted the throttle cable to eliminate play, adjusted and lubricated drive chain, and replaced the cush drive with much firmer aftermarket parts (Sensei cush drive - recommended). This work has made a world of difference in addressing the problem and now it's just the odd upshift that is jerky.

When I release the clutch slowly in first gear there's a noticeable "clunk" as it begins to grab, the same "clunk" occurs when gently rolling on and off throttle whilst in gear without touching the clutch.

I think if it continues to bother me, what I might do is try the one piece hub and see fixes it. I always blip on downshifts so the slipper might be wasted on me for everyday riding anyway.



Does yours behave like what I've described?

Can Munkers or any other 'busa owners chime in?

Mine does exactly the same but I am more concerned about the double clutching at a standstill to get into 1st. As for the gens 1s doing it they didn't they had no slipper clutch and the gear change on my 22thou klm was sweet so in my case I reckon a clutch bleed is needed and I'm going to forget about the post engagement clunk who cares?

[BusaSteve]

I did the clutch bleed...took longer to get at the nipple than the actual job. I topped the master cylinder up four times so that probably means a total fluid swap. I took it for a spin and the action is sweet...no more trouble getting into 1st and no after engagment clunks...almost silent action too well worth the effort. Will do the brakes next.

[mcmurray]

Good to hear. I sometimes have trouble finding first from neutral also. Clutch fluid looks pretty dirty so I'll do what you did and change it.

[gravy]

Hi mcmurray, mate i sold my K8 Busa not long ago and always had gear issues from new. I had huge trouble changing from 5th to 6th and would go into a false neutral quite regularly. I too had the loud clunk when putting into 1st at the lights and generally wasn't too happy with the gearbox as was pretty rough through most gear changes. Maybe just a Busa trait?? Was still a great bike though !!!!

[Dragunov-21]

Nothing like that on my 636, though it's worth noting that I also occasionally have trouble getting it into first and have to let out the clutch slightly and try again before it'll mesh.

[BusaSteve]

Just an update...I found the clutch lever to be binding at the pivot bolt...when moving the lever out past the return point to reset the sweep the lever would stick a bit. I took the bolt out...was tight as a nuns you know what...had to use WD40 to get it to come out. I also removed the brass trunnion that operates the MC push rod. I found the pivot bolt to be crudded up...a quick light rub down with wet and dry and WD40 for lubricant worked wonders there and on the trunnion which had binding marks on it too. The lever action is now smooth and I wonder if it had some effect on the actual clutch action...I have yet to take it for a run to see. I did both levers and found them to be stiff...mine is from being left for long periods by the original owner who did less than 6K klms in two years.