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Discussion Starter · #1 ·
Its happened to me twice so far, I had to do some moderate emergency braking, and for some reason I didn't just pull in the clutch...I instead tried to downshift quickly (which is weird, because that should be an automatic response now)...anyway, the next thing that happens is I feel and hear a racket coming from my rear wheel, feels like the chain is coming off or something...I don't ever remember this happening on my 600R.

A little research revealed that because its a big motor on a light bike, it doesnt like to engine brake as much as my last ride (small motor on heavy bike), and I was locking up the rear wheel because of the engine didn't want to rev up when I down shifted.

Reading more I learn about the slipper clutch that is normally reserved for track bikes, but wouldn't this be good for all bikes?? Has anyone ever retrofitted a street bike with a slipper clutch? Is this even possible? Anyone considering it on the FZ?
 

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Wikipedia:

They are designed to partially disengage or "slip" when the rear wheel tries to drive the engine faster than it would run under its own power. The engine braking forces in conventional clutches will normally be transmitted back along the drive chain causing the rear wheel to hop, chatter or lose traction. This is especially noted on larger displacement four-stroke engines, which have greater engine braking than their two-stroke or smaller displacement counterparts. Slipper clutches eliminate this extra loading on the rear suspension giving riders a more predictable ride and minimize the risk of over-revving the engine during downshifts. Slipper clutches can also prevent a catastrophic rear wheel lockup in case of engine seizure. Generally, the amount of force needed to disengage the clutch is adjustable to suit the application.
 

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I do clutch-less down shifting... your right wrist and left foot must be in sync to work properly. You have to already be engine braking, micro throttle blurp + downshift. Works smooth.

It is tricky, but if you can't get right after a couple attempts then quit trying. The throttle - shift maneuver has to happen in a split second, your limbs and mind have to be connected to the bike. If you cannot make that commitment then don't try it or your tranny will suffer.
 

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Discussion Starter · #7 ·
Actually, it wasn't a clutchless shift, I dont actually know what the heck I did to be honest, just that I was in gear, was braking, and my rear wheel locked up and made a heck of a racket...it wasnt because of rear brake because the force was going through the chain. my understanding is that a slipper clutch will prevent this phenomena during engine braking
 

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sounds like your rear wheel was trying to slow down the engine too fast...

I don't know if anyone makes slipper's for the FZ-09, but I do know on a Ducati a slipper clutch is very pricey.
 

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Luke, that makes sense, you did use the clutch but after the down shift had more engine braking than the situation could handle.

Hmm, it's been 10 years so my description won't be the freshest lol. My SV650 had enough engine braking that it needed practice to downshift smoothly. Basically, don't close the throttle all the way. But that was a carbed first gen SV.



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There is nothing quite like banging a gear down and getting a little chatter back there, only had it happen a few times on my CBR and spooked me every time. Never had it happen on a fast stop though, I usually yank the clutch in immediately during those.

As far as a slipper on this bike I would consider it more of a luxury than a need, but of course couldn't hurt. Other things I'd rather spend the money on personally though
 

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Discussion Starter · #12 ·
I thought I lost my chain or something the 1st time this happened, and its only happened on this bike for me. I guess I need to get in the habit of not engine braking so much on the FZ.
Never got squirrely btw, so at least that part is good
 

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I do it by feel, plus we have a gear indicator, which is the first bike I have owned that has one out of about 30 streetbikes.
 

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Someone once told me that slipper clutches are for riders who don't take the time to practice the art of clutch-less downshifting. Slipper clutches are usefull if you do not how to downshift correctly and want to do so without over-stressing the drivetrain / engine. Although most racers run Slipper's, you never really want the clutch to slip unless your too hot into a corner or make a mistake while shifting. Ideal for a track day when your trying to improve your cornering and laptimes.

Slipper clutches are more of a safety cushion for your drivetrain to protect it from your riding mistakes.
 

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Discussion Starter · #16 ·
Great info, looks like more practice is in order...damned winter!
Yet another reason that the FZ is less forgiving to a new rider than a smaller cc bike.
 

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For fear of sounding like the old man who always screams at the kids about "Back in my day..."...

I think a rider should learn clutch manipulation as one of their advanced riding techniques, then if they feel the need for whatever reason - be it racing or whatever, then retrofitting a slipper or buying a bike that has an OEM one is cool.

Personally, of the last few bikes I've raced, 2 have had a slipper, and 2 haven't. Initially I had reservations about buying a race bike without one as when racing, the last thing I need is one more thing for my itty bitty brain to have to process while I'm 4 bikes wide braking into a hairpin playing chicken with three raving lunatics such as myself. But, after my '05 750 (no slipper) and I came to grips with clutch modulation on downshifts and my engine tuner jacked my idle up from 1450rpm to about 3600rpm, I actually preferred to "Be" the slipper instead of relying on a slipper to control rear wheel hop/spin into corners and actually found I could begin the turn in better myself by initiating the rear wheel slide, or backing it in as some people call it.

It's very easy to learn, you just have to change your habit of dumping the clutch on downshifts to instead release to your engagement point only, then lightly feather it out as much and as quickly as needed once you feel the rear begin to lock up or chatter. Any rider with supermoto experience can relate to this skill I'm sure as those guys are masters at it.

I haven't ridden my FZ in anger yet so I can't comment on what it's like to control but I'm guessing it's like every other bike with a clutch - it ain't rocket surgery! :)

Here's a little how-to video of a fellow racer from a few years back up here in the PNW area. Mitch is a former top level flat tracker - can ya tell!

 

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Yeah Doug, but in racing etc do they do clutchless down shifts?
In the upper echelon of road racing....the blip and the downshift are electronically aided. In other words ...yes..no clutch.
 

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Someone once told me that slipper clutches are for riders who don't take the time to practice the art of clutch-less downshifting. Slipper clutches are usefull if you do not how to downshift correctly and want to do so without over-stressing the drivetrain / engine. Although most racers run Slipper's, you never really want the clutch to slip unless your too hot into a corner or make a mistake while shifting. Ideal for a track day when your trying to improve your cornering and laptimes.

Slipper clutches are more of a safety cushion for your drivetrain to protect it from your riding mistakes.
You're 100% correct. Slipper clutches and traction control {on the street} are marketing advantages for the normal guy that can't ride fer shit. And never learns to ride fer shit. And never wants to learn how to ride.
Like others said....it takes a bit of practice to blip the throttle and match the engine speed to the rear wheel rotation RPM. Most riders never master it.
 

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Its all about the blip, you have to visualize in your mind the gear syncro's are spinning slower than they need to for the next gear down. The 'blip' speeds them up just enough so that when you grab the next gear down the wheel speed, final drive speed, syncro speed and engine speed are all matched up. This is the perfect window for shifting down, you know it when you feel that gear grab seamlessly, no noise, just 'click'.. you feel it in on the bottom of your toe. At this point, you know you can either ease off the throttle some more, or twist it wide open.

Once you perfected this, you'll never reach for the clutch again... unless of course your at full stop or cruising around casually.
 
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