School Senior Design project (need your help!) October 1st!

[95FZR600]

Sounds like a really cool project. Have fun with it and lots of beers in between the thought process.

[Luke-a-Tron]

The FZR flywheel is a solid piece. It has to be because the ignition timing is read from the flywheel. If there were any free play in the flywheel, the timing would bounce all over the place.

The problem with those clutch springs (I can't remember the technical name) is that they are completely undamped. Nearly all the energy that goes into compressing the spring comes right back out a fraction of a second later. The OEM clutch in my car had rubber blocks instead of springs that had a bit of natural damping action. I had the clutch replaced and the new one has springs. The clutch is far less forgiving as a result and much more prone to "bouncing" in slow acceleration situations.

An ideal solution would be to allow for some controlled slip in the drive train that would not have to return energy back into the drive train before it can perform it's function again. Think something along the lines of a slipper clutch. When sharp increase in back torque occurs, the clutch is allowed to slip a little so the amount of resistance the engine can apply to the rear wheel is capped. If that level is exceeded, the excess energy is just thrown out of the system.

[zero9243]

An ideal solution would be to allow for some controlled slip in the drive train that would not have to return energy back into the drive train before it can perform it's function again. Think something along the lines of a slipper clutch. When sharp increase in back torque occurs, the clutch is allowed to slip a little so the amount of resistance the engine can apply to the rear wheel is capped. If that level is exceeded, the excess energy is just thrown out of the system.

I like that idea. Sucks to have that excess energy just expelled though. It would be neat on the EE side to try to harness that energy to perhaps power some electrical monitoring system.

[megaloxana]

It's called "shaft drive", tell harley to get on board...

They can't afford to be any slower than they are

[ShogunTX]

Here's a real easy solution. Electronic rear caliper. Have it put a slight amount of pressure on the back rotor and release when getting up to 5 miles an hour or so... This keeps pressure on the rear tire until the belt pulls.

Done.

Why go through all this other mess?

Great idea but remember since it is a harley it has to be a complicated expensive failure prone device. Otherwise they won't see the value in it, and the riders will accuse them of selling out to the Japanese.

[haro504]

why spend your money modifying it and for accessories when you can spend it on repairs

[Luke-a-Tron]

I like that idea. Sucks to have that excess energy just expelled though. It would be neat on the EE side to try to harness that energy to perhaps power some electrical monitoring system.

I don't think it would be worth it. We're only talking about the potential energy stored in the drive train in the form of tension. Once that has been released, which will happen very quickly, you start tossing out spare horsepower coming from the engine. It's the equivalent of revving the engine with the clutch in. It's typically not going to last very long as the idea is gradually allow that power to transfer back into the drive train in a smooth manner. It would have to happen quickly or else throttle response would feel sluggish. It's debatable that any Harley rider would notice though.

[yamaha_george]

throttle response would feel sluggish. It's debatable that any Harley rider would notice though.

LT,
I have no love of Hardleys either but sluggish these days they ain't 0-60 in under 4 secs for the 1400 sportster.
is not to be sneered at.
Mind you my brother (the sportster in questions owner) though that 1400 cc would leave my "tiny" 600 well behind bit of a shock to not see me in his rear veiws but along side at 130mph on the hiway when i was testing my Plastex repair on the h/light fairing :-}

[YAM93]

Here's a real easy solution. Electronic rear caliper. Have it put a slight amount of pressure on the back rotor and release when getting up to 5 miles an hour or so... This keeps pressure on the rear tire until the belt pulls.

Done.

Why go through all this other mess?

Great idea but remember since it is a harley it has to be a complicated expensive failure prone device. Otherwise they won't see the value in it, and the riders will accuse them of selling out to the Japanese.

you took the words right out of my keyboard. oh yeah and............BURN!!!

This seems like a pretty cool project nonetheless, and it's already proving to be quite informative and entertaining, watching zero go back and forth with Luke and George is putting my brain on overload already. (hey, it's a weekend and the wife is making me go to an art museum in Washington DC tomorrow)

I look forward to seeing what you guys invent. Although one of the things that makes me not really want a 07+ bike is this slipper clutch idea, which I don't think should be allowed in AMA, FIM, MotoGP or whatever, as, it takes some of the skill out of racing these bikes, some say it takes a lot of skill and thinking out of it, seems to me on par with the "linked-braking-systems" Honda started years ago. I really don't want the bike doing any more thinking for me than it already does. Besides, if you think about it, it's just something else to break or go wrong to worry about.

[Luke-a-Tron]

I could see your point about not allowing them in racing but I think as far as street bikes go, I hope it becomes standard equipment. It's a pretty simple device without much opportunity for failure and it introduces a nice margin of safety right when the bike is in it's most unstable state, entering corners. All they do is stop the rear tire from skipping when you down shift hard. It's not really going to give you any performance advantage other than keeping you skin off the ground.

[zero9243]

Here's a real easy solution. Electronic rear caliper. Have it put a slight amount of pressure on the back rotor and release when getting up to 5 miles an hour or so... This keeps pressure on the rear tire until the belt pulls.

Done.

Why go through all this other mess?

god you would go through brakes so fast darrin!

[the_finch]

I'm definitely looking forward to seeing what you guys come up with. I don't have anything creative to add, other than I think the mini electric lockup torque converter sounds the most promising, from the smooth and torque limiting standpoint as well as the expensive, breakable, and unique standpoint.

As my MSF instructor said "the only reason to buy a Harley is to have that expensive badge on the tank and be able to say you spent twice what the other guy spent to buy your bike"

Most of the cruiser owners I know don't know a whole lot about their bikes, other than they take gasoline (or petrol, for the users accross the pond, LOL) and make them "look tougher". They let the dealership do everything for them. Maybe nobody else has the type of Harley riders we have in my hometown, or maybe I'm just off my rocker. But sometimes it seems like squids aren't just the guys wearing shorts and flip-flops on their gixxers; sometimes it seems alot of them wear sleeveless shirts and useless plastic "DOT approved" skull caps on Harleys.

I agree with YAM93 that I don't want a bike (or a cage, for that matter) that thinks for me. But for some people out there, a bike with traction controlled, torque-limited drive wheel, ABS linked brakes, 5000 kw emergency flashers, and quadruple side airbags are their only chances or survival on two wheels.
<<End Rant>>

Go give'em hell, and show them what you can make that rear wheel do.

[zero9243]

I'm definitely looking forward to seeing what you guys come up with. I don't have anything creative to add, other than I think the mini electric lockup torque converter sounds the most promising, from the smooth and torque limiting standpoint as well as the expensive, breakable, and unique standpoint.

As my MSF instructor said "the only reason to buy a Harley is to have that expensive badge on the tank and be able to say you spent twice what the other guy spent to buy your bike"

Most of the cruiser owners I know don't know a whole lot about their bikes, other than they take gasoline (or petrol, for the users accross the pond, LOL) and make them "look tougher". They let the dealership do everything for them. Maybe nobody else has the type of Harley riders we have in my hometown, or maybe I'm just off my rocker. But sometimes it seems like squids aren't just the guys wearing shorts and flip-flops on their gixxers; sometimes it seems alot of them wear sleeveless shirts and useless plastic "DOT approved" skull caps on Harleys.

I agree with YAM93 that I don't want a bike (or a cage, for that matter) that thinks for me. But for some people out there, a bike with traction controlled, torque-limited drive wheel, ABS linked brakes, 5000 kw emergency flashers, and quadruple side airbags are their only chances or survival on two wheels.
<<End Rant>>

Go give'em hell, and show them what you can make that rear wheel do.

thats part of our design constraint. Since this has a slim chance of going into production if its good enough, we have to make sure its 1) inexpensive to produce 2) easy to assemble and install (for assembly line workers) and 3) easy and cheap to service. AS much as i'd love to have some off the wall idea that is awesome, idk what our sponser would think. but hey! that doesn't mean we can't try!

[zero9243]

Ok guys I need your help now. Because this is for a "senior design" class we need to follow a lot of red tape. One of the big ones being separate reports for each step of the process. Our next step is customer needs and I need to get the opinions of people that ride.

What would you guys look for in a new system. It can be anything. What would you like to see out of a new application as a rider?

[reelrazor]

Why not move the slipper clutch to the rear wheel hub?

This could be done with good sized sprag, mount it in rubber in the wheel to cush the drive side load. This would be a pretty cheap retrofit to our bikes.

Could use the EE side of this to provide some regenerative braking/charging. ALL HD's have weak charging circuits-they often burn out stators and reg/rects within 3 years. I think the HD people would appreciate getting a little help there-esp since they are more and more forced to drive more electronics because of emissions issues.

Tho, all the harley guys I know just looove to downshift and engine brake for the backfires. Kinda like truckers who use the jakes on flat roads coming into towns ...it kinda says "I'm here, notice me!" (which, I think is a common 'need' among HD riders) .

And as far as the 'typical' HD riders? I think the_finch is spot on-it's not just the ones in your area. Nationwide m/c death/injury rates that are highest are age 45 and up, on a bike larger than 1200cc, with no formal training.