It was actually a grant, but yes, the purpose was to educate and train because 20-29 sport bike riders account for BY TWICE, the number of motorcycle deaths in the state. A big part of the discussion was "how much would you pay for this" and "would a payment program work".

interesting combination of nanny state and people trying to make a difference.

i had a 900 CR. i found it harder to ride than my 600. i had a F4i at the same time. the motor dragging down on the decel was very hard to get used to. i didnt keep it long enough to get proficient on the twisties. it did pull wheelies easier.

I had the same trouble with dirt bikes, vash. The transition to four strokes, after having grown up on two strokes, was hard. I just wan't used to compression braking. Once I got used to it, I actually prefered it.

I guess lots of guys put slipper clutches on the big twins just for this reason. It makes them feel more like their familiar small bore multi's. I've debated doing the same, but in the end decided I rather like the compression braking. A well executed downshift, rev-matching perfectly, is a lot of fun. The trailing throttle popping and banging is kind of cool.

my 620 monster had a slipper clutch...it was like riding a 2 stroke. My 1000ss did not...and having grown up racing 2 strokes (and started on the street with rz350's) i still prefer the two strokes...the slipper was a huge improvement for me

Nick, can you describe the difference between the two?

I never got comfortable riding the twisties with my previous Aprilia Mille. There were times the engine compression would affect my line in the entry to a turn. Bottom line I didn't know how to ride a big twin very well. Loved the torque but disliked the handlebar vibes the big twin put out. My fingers/hands would go numb, throttle hand most, on every ride. The newer big twins come with a slipper clutch and think it would have helped greatly. Vibes could be addressed with bar/grip changes I guess but that's a hit or miss too.

Best of both worlds is a triple ;)

Cannot believe I'm the first one posting eye candy... Triple your pleasure!

http://forums.pelicanparts.com/uploa...1243446709.jpg

when you let off the gas on the two stroke bikes, there was little to no engine braking...with a four stroke, when you let off the throtttle, there is immense engine braking . On my 1000ss, it was so strong that it would roll the weight forward very agressively. The monster 620 with the slipper clutch was unique, when you rolled off the gas, it had some brake effect, but if you really wound the bike up or downshifted then let the clutch out (especially mis synched ), it would almost freewheel; like a 2 stroke on decel. I have ridden a few of the bigger duc's with a slipper and they are great! it lets you control the braking with your hand/brake rather than with throttle, it is hard really to describe...the newer 4 stroke sport atv's are VERY pronounced with engine brake compared to a two stroke

a twin has more engine braking than a 4-cyl. i had the same experience as david.

I can certainly understand the principle of widening a power band via high-rpm cams, etc. But it is NOT true that horsepower is work done over time. Work done over time.......the power actually generated......is torque. HP is a made-up, calculated number using torque as the principle input.

Let's say a DUC can make 60 lb-ft of torque at 4000 rpm going 70 mph. Let's say a Suzuki is alongside this DUC, going the same speed, engine speed is 12,000 rpm, and capable of making 40 lb/ft of torque at that engine speed. Guess which bike makes the most power when they crack the throttles open.

For a time I rode a 2-cylinder 500cc two-stroke street bike. When it hit the power band, I had to be gripping the handle bars tightly.

Thanks Nick. My clutch will last the summer (it's pretty noisy now but works well) but will add a slipper to the punchlist for this winter. Going through the entire bike when I take it off the road.

The guys I'm getting to know in this offbeat little niche of the old Ducati are unanimous in their assesment of the slipper clutch: They are for folks who don't know how to ride a big twin properly - a crutch.

Now, please don't shoot the messanger. I have no experience with a slipper, and no experience with a high-reving multi. Like I said above, my transition from two to four cycle dirt bikes left the same impression on me - the compression braking really threw me off at first. But, I learned to use it, then to love it.

I bet riding a slipper equiped bike, or a high reving multi, would throw me off. I would subconciously be expecting that compression braking, and when it didn't happen, I bet I could find myself in trouble. At least until I got used to it.

Anyway, the consensus among old Duc riders (or riders of old Ducs) is that they take a good deal of the personality away from the bikes, and reduce the skill needed to ride one well. I can relate to that. I like early 911's, too, for many of the same reasons. If you drive one well, you have accomplished something. Many don't see that, and think trying to shift a recalitrant 901 or 915 is just a pain in the ass. The propensity for snap oversteer frightens them. They don't see the appeal; more modern is more appealing. To each his own - there is room on the road for all of us. I'm just not going to "modernize" a classic to make things easier. If I wanted that, I would just buy newer.

Dave said it right, when you cornered, especially, if you rolled off the gas, the braking would stand you up.
If it helps, I have had REALLY good luck with fred at Yoyodyne (he is right around the corner from my job) He sells GREAT stuff...so does Moto wheels or BCM
There is an early 900ss/sp by me for sale for like $3000, i will have to go look at it

Fred is a great guy. I have his slave which makes the bike usable in the city. When the first one was destroyed by a bad PP bearing (rod becomes a drill), he replaced it for 50% off.

Hoping that refreshing my brake fluid this weekend will help with the grabby front brake.

hope all goes well with the ss/sp.

thanks!

Ah, there is the thing though...

If you are going 70mph, at 4k rpm vs 12k rpm, you have a vast different in how much gearing you're using.

Let's say that you have tires that are just the right size so that the Duc is using a 1:1 gear ratio. That 60lb/ft at the engine is 60lb/ft on the ground.

On the other hand, the Suzuki has a 3:1 gearing reduction, so it's 40lb/ft is being multiplied to the ground as 120lb/ft.

(This would be why the HP rating of the Suzuki would be higher @ 12,000rpm than the HP rating of the Ducati @ 4,000rpm)

Another example I found on the web:

How does gear ratio affect Torque?:

Simply put, torque at work (such as at a wheel) is your motor's torque times your gear ratio.

Motor Torque x gear ratio = torque at the wheel

Lets say we have a 10rmps motor that is capable of 5 oz Torque (we know this from our motor spec.)

Lets say we have 2 gears. Our input gear (attached to our motor) has 10 teeth Our output gear has 50 teeth

Our Gear ratio is 5:1

Motor Torque x gear ratio = torque at the wheel

5oz x 5:1 = 25 oz

What if our gear ratio were 1:3 ?

5oz x 1:3 = 1.6oz



I'm not an engineer and didn't stay at a Holiday Inn, but this is the reason I've always understood for having a high revving engine.

Am I completely off the deep end? Should I pick up a diesel motor for my 911 because it'll be a torque monster. ;)

So is a "slipper clutch" the same sort of thing as what they call the "sprag" in my shifter cart?

Basically it prevents you from overrevving the motor because if the wheels are spinning faster than the engine it won't engage.

Or is that something different?

A slipper clutch engages and feeds power from the motor to the tranny when on the throttle but slips when you are coasting and the forces are from the other direction. In other words, it slips when the rear wheel tries to turn the engine crankshaft as you are decelerating.

Racers use them on high compression engines so they can start backshifting early in the braking zone without much thought given to rev-matching. You don't really need them on the street, in my opinion, because you are supposed to corner a motorcycle on the throttle, not coasting. If you find yourself chopping the throttle in a corner, you need to rethink your approach to corners. You're doing something wrong.

JR

Ah, okay, sounds like it is the same basic thing as the sprags we use then, they send power from the engine to the wheels but mostly ignore it coming the other direction.