flywheel dh bike

[bcd]

just thought we could have a thread about this.
here is some thoughts to start.


Originally Posted by bizutch:

OK...jsut thought of this conspiracy theory! What if the gearbox on Minnar's bike contains a "inertia wheel". Stick with me here. If you've ever ridden a Schwinn Spinner, you know what I mean. Once it gets rolling...it will roll by itself for 10 minutes.

What if inside there, the rear wheel is attached to some sort of "inertia wheel" that spins on some sort of freehub when he's not pedaling...but engages the rear wheel when he pedals? Not a fully FIXED hub like on a spinner...but one that clutches off when the cranks don't turn.

Essentially, the inertia wheel gets cranked up by his first few pedal cranks and then freehubs inside while the pedals aren't turning. When the pedals turn forward again, it clutches the inertia wheel into action and powers the chain and rear hub.

Each time the rider goes to torque on the pedals, the inertia wheel engages and makes the bike snap forward like it's got an engine.

Wouldn't this be a FANTASTIC explanation for Honda's R & D of the gearbox. It would make a motorcycle gets 80-85 miles to the gallon, or a bicycle pedal like nothing. >


Originally Posted by bcd:

i would tease my frend about a bike like that i thought of making.

so you sit in the gate waiting to start. you disingage a clutch and start cranking your flywheel 5-4-3-2-1- GO. whizzzzzzz - click snap out of the gate! you could also spin it up by using it as a brake then pop it coming out of the turn. might surprize you what a 5 lbs wheel could do for you.

[buildyourown]

I'm sure the UCI has some rule in that fat book of theirs that says you can't do it.
If it were legal, how would you engage and disengage the clutch? You could make it disengage when you apply the brakes, but there would be lots of times when you would just want to coast. No flywheel or brakes.
Add a 5# flywheel plus several pounds of clutch and housing. Would it be worth adding 7-10# to your bike.

I just had another idea. Figure out somekind of regenerative braking mechanism contained in the hub. I'll think about that one for awhile.

[RhinofromWA]

I just had another idea. Figure out somekind of regenerative braking mechanism contained in the hub. I'll think about that one for awhile.A big spring that winds up......and then lets go with the release of brakes......a little boost. :rolleyes: :D

[dump]

nice... a frame that's 5lbs heavier :) (i can hear the whining now) It would be interesting to see the calculations though.

The real consideration is maximizing the distance that 5lbs is from the axle it revolves around.

[KleinMp99]

so you sit in the gate waiting to start. you disingage a clutch and start cranking your flywheel 5-4-3-2-1- GO. whizzzzzzz - click snap out of the gate! you could also spin it up by using it as a brake then pop it coming out of the turn. might surprize you what a 5 lbs wheel could do for you.


HAahahahha what a sweeeeet idea! :thumb:

[zedro]

i just put lead weights on my rims for the extra inertia....

[dw]

Only problem with a flywheel is that in order to store any significant amount of power, and also fit inside the box on that bike, it would have to be insanely heavy.

Im talking hundreds of pounds.

Dave

[HRDTLBRO]

Way to ruin a perfectly good thread of speculation amoung us monkeys who don't know what the hell we are talking about, Dave. You engineer types always have to speak the facts. :mumble: :D Will Iron Horse any kind of trade in program? I'm loving my new SGS, but the new DW DH is, eh...er...wow. :thumb:

[AR_]

so you sit in the gate waiting to start. you disingage a clutch and start cranking your flywheel 5-4-3-2-1- GO. whizzzzzzz - click snap out of the gate! you could also spin it up by using it as a brake then pop it coming out of the turn. might surprize you what a 5 lbs wheel could do for you.


Ever remember those little plastic bikes with the lead flywheel in the rear wheel? You would put them in some little plastic holder, crank it up, get the flywheel spinning to some insane rate, then disengage the locking mechanism, and off it shot. Wouldn't like to try and hold onto my bike if it did something like that! :D

[Sir_Crackien]

gyroscopic effect!! you would not be able to steerer the bike well if it all!

[Toshi]

gyroscopic effect!! you would not be able to steerer the bike well if it all!
mount it in a gyro! :D

dw, how did you come to the (paper napkin?) calculation of flywheel mass? a sketch of your thoughts would be much appreciated

[dhtahoe]

just thought we could have a thread about this.
here is some thoughts to start.


Originally Posted by bizutch:

OK...jsut thought of this conspiracy theory! What if the gearbox on Minnar's bike contains a "inertia wheel". Stick with me here. If you've ever ridden a Schwinn Spinner, you know what I mean. Once it gets rolling...it will roll by itself for 10 minutes.

What if inside there, the rear wheel is attached to some sort of "inertia wheel" that spins on some sort of freehub when he's not pedaling...but engages the rear wheel when he pedals? Not a fully FIXED hub like on a spinner...but one that clutches off when the cranks don't turn.

Essentially, the inertia wheel gets cranked up by his first few pedal cranks and then freehubs inside while the pedals aren't turning. When the pedals turn forward again, it clutches the inertia wheel into action and powers the chain and rear hub.

Each time the rider goes to torque on the pedals, the inertia wheel engages and makes the bike snap forward like it's got an engine.

Wouldn't this be a FANTASTIC explanation for Honda's R & D of the gearbox. It would make a motorcycle gets 80-85 miles to the gallon, or a bicycle pedal like nothing. >


Originally Posted by bcd:

i would tease my frend about a bike like that i thought of making.

so you sit in the gate waiting to start. you disingage a clutch and start cranking your flywheel 5-4-3-2-1- GO. whizzzzzzz - click snap out of the gate! you could also spin it up by using it as a brake then pop it coming out of the turn. might surprize you what a 5 lbs wheel could do for you.

Ok just talked to my father (a R&D guy for the Honda Road Race program for 20 yrs) says that you guys are not TOO far from the truth.

[prophet6]

hey DW:

I was under the impression that you could rock either a stupid heavy flywheel, or a light flywheel spinning really, really fast.

In fact, last I heard, cutting edge research in flywheels was using carbon fiber wheels rotating at extreamly high speeds... it was leading to interesting research on bearing methods, from what I recall...


or am I drunk?




p6

[dhtahoe]

[QUOTE=prophet6]hey DW:

I was under the impression that you could rock either a stupid heavy flywheel, or a light flywheel spinning really, really fast.

Oh crap there it is!!!

[Transcend]

Only problem with a flywheel is that in order to store any significant amount of power, and also fit inside the box on that bike, it would have to be insanely heavy.

Im talking hundreds of pounds.

Dave

oh way to ruin it Dave. :dead: :p

[dhtahoe]

Anybody remember that REEEEEAAALLL high pitch whine the Honda made at Big Bear??? Flywheel??? I looked into it a little more and the rules state that if the rider turns it... It is 100% legal. Honda just had the money and the R&D to find the Holy Grail of DH! Getting the damn Road Grouppo off of our bikes. IMO this little R&D project is more about that gearbox than anything. Just like Indy Car or F-1... Honda builds the drive, and someone else builds the chassis. Think about it. :evil:

[dw]

hey DW:

I was under the impression that you could rock either a stupid heavy flywheel, or a light flywheel spinning really, really fast.

In fact, last I heard, cutting edge research in flywheels was using carbon fiber wheels rotating at extreamly high speeds... it was leading to interesting research on bearing methods, from what I recall...


or am I drunk?




p6

p6 my MAN! where have you been!?

You could build a somewhat light one, but in order to spin fast enough to store any real energy, you would need to run it on air bearings at the minimum, but most likely, superconducting magnetic bearings. Otherwise parasitic power losses just kill you.

Those dont like shock loads so much, so I would have to rule those out.

I happen to have a little thing for energy conservation and flywheels in general, only reason I know anything about them. :D

dw

[dhtahoe]

Gotta watch them sneeky little guys over there... There getting us back for the H-Bomb. Oh for got to ask... DW what if this was more about keeping the bike rolling through the rough. Also what if they killed two birds by using the already rotating gears as the flywheel. The Honda RC 211 V-5 Motor counter rotates 2 cylinders from the opposing 3 cylinders to counter balance each other. Thus, needing no counter balancers on the crankshaft. Result 998cc, 225hp, 18,000rpm redline. Honda does some freaky s*it i tell ya.

[bizutch]

Ok just talked to my father (a R&D guy for the Honda Road Race program for 20 yrs) says that you guys are not TOO far from the truth.
so....wait. What exactly you saying? he knows what they've got in there?

I totally understand the gyroscopic effect (spin a wheel by the axle and then try to turn it on it's side...doesn't wanna go)...but I'm not talking a ton of torque here. If it generates even a small amount of added momentum as you go to crank on the pedals, it will add up each time you sprint.
A. Less effort to pop out of turns
B. More power with every crank (skinny guys get sprint power)

What got the idea going in my head was...well...mopeds.

Plus, if the spinning mass of the internal wheel is located at the exact center of the frame's balance point, you would have plenty of leverage to lean the bike over.

If anything, the gyroscopic effect of it would act almost the same as a Hopey damper does for forks. When you lean the bike over, the resistance would make it more controllable in stutter bumps and roots, etc....b/c it would resist tiny deflections from trail obstacles and in a lean the bike would be less twitchy and skittish! :sneaky:

[dhtahoe]

Watched Minnar at Idaho go thru rocky section that would hang EVERYONE up, and he would just coast right thru and loose no forward speed whatsoever. Somethings going on in there. When it come to engineers honda is serious. My father was going to sign with Suzuki this year. Honda said no way gave him a S*it load of money, and then TOLD him to retire. So he gets 75k a year for the next five years to sit at home.

[Toshi]

75k a year for the next five years to sit at home.
that's just about my dream job! :monkey:

[Transcend]

Watched Minnar at Idaho go thru rocky section that would hang EVERYONE up, and he would just coast right thru and loose no forward speed whatsoever. Somethings going on in there. When it come to engineers honda is serious. My father was going to sign with Suzuki this year. Honda said no way gave him a S*it load of money, and then TOLD him to retire. So he gets 75k a year for the next five years to sit at home.

Now that sir, is a job I can appreciate!
I agree as well. I did a long interview with Martin and Greg, there is some definite monkey business going on in that gearbox. They obviously would not say a peep, but there was a twinkle in their eyes. :thumb:

I think it's probably not so much monkey business, as much as it is a VERY efficient system. The UCI did actually go over the bike at the beginning of the season (signed a NDA i assume), and I believe is supposed to every race.

[dhtahoe]

NDA= Non Disclosure Agreement. (Only because you know that one's coming Transend)

Had to sign one once for running Carbon Fibre Wheels on the Superbike I rode one year. You brake one with Honda your done... no matter how fast you are.

[crashing_sux]

It's all fun and games until a flywheel explodes and throws shards into your nads. The problem with spinning really light flywheels really fast (besides the bearing issues dw mentioned) is that the material can't cope with the force and explodes. Between your legs no less.

To get an idea think about a good heavy flywheel on your bike with a decent amount of weight, like your rear wheel when you're doing 30mph. Ever lock up your rear wheel going that fast? Didn't take much effort did it? Ever lock your rear wheel up while in the air at that speed? It will make the front of the bike drop a foot but it isn't exactly awe inspiring power being stored there.

As for the rules saying if it's powered by your legs then it's allright to run, I thought that they were more specific than that and that is why Minaar had to run a shifter with a set number of speeds instead of having it be infinitely variable. Was that just a rumor?

[dhtahoe]

Yes it is correct. The rules say that you must have at least five working gears.

[dhtahoe]

I believe there is a NORBA rule that states a bike must have at least 3 working gears.

You might have the right number... sorry. I'll look.

[Transcend]

You might have the right number... sorry. I'll look.

it's 3.

[zedro]

it's 3.

yay! break out the 3 speed coaster hubs!!!

[Smelly]

Only problem with a flywheel is that in order to store any significant amount of power, and also fit inside the box on that bike, it would have to be insanely heavy.
Im talking hundreds of pounds.


yeah, but dude, it'd be near the bb and stuff, so that's an ok place to have weight. :rolleyes: :thumb:

[SuspectDevice]

Come on now folks... Go pick up the UCI technical regulations and you'll see that devices that store energy are clearly illegal, and should be. It would change the fundamental nature of cycling competiton (mano a mano, or man V nature), which, IMO DH has already strayed a little bit too far from.

[DHanamal]

I don't think it's possible. The torque from a flywheel that's storing a substantial amount of energy would be tremendous. Two flywheels could cancel out each other, but only on one axis, so it would still have a drastic effect. You could put the flywheel in a gyro, but then how would you mechanically get the energy off of the flywheel. Another thing is a DH bike is constantly getting a beating, flywheels loose their momentum when they are acted apon by an outside force. There's probably other mechanical issues, bearings, etc.

[dhtahoe]

Come on now folks... Go pick up the UCI technical regulations and you'll see that devices that store energy are clearly illegal, and should be. It would change the fundamental nature of cycling competiton (mano a mano, or man V nature), which, IMO DH has already strayed a little bit too far from.

HONDA FOUND A LOOPHOLE!!!

[Westy]

The Honda Gearbox is actually a little electronic device that rips a hole in the time space continuum. Where the driveshaft seems to enter the gearbox is actually a cosmic wormhole. The drive shaft does not go into the gearbox but to the output shaft of a CBR600 that is running on a remote island off the coast of Japan. The rider controls the throttle psychokinetically by thinking "Braaaaaap". The louder he thinks Braap, the faster he goes.

[-BB-]

Only problem with a flywheel is that in order to store any significant amount of power, and also fit inside the box on that bike, it would have to be insanely heavy.

Im talking hundreds of pounds.

Dave


Yeah... that and the fact that this isn't a magic Dynamo... If it was Pedal powered, you would still loose some energy while cranking it up.


What about a spring though, that was wound tighter by Brake energy?
Then, you would use energy that you were trying to disapate anyway, it wouldn't weigh as much, and it would still give you a nice "snap" out of corners or on short uphills.

[zedro]

What about a spring though, that was wound tighter by Brake energy?
Then, you would use energy that you were trying to disapate anyway, it wouldn't weigh as much, and it would still give you a nice "snap" out of corners or on short uphills.


hey why not just have regenerative brakes which can return some energy into motive forces? i mean, if you started with a zero charge in a large capacitor, this wouldn't be any different than using flywheels and springs to store and return energy. See what a slippery slope this can be...

[Jm_]

hey why not just have regenerative brakes which can return some energy into motive forces? i mean, if you started with a zero charge in a large capacitor, this wouldn't be any different than using flywheels and springs to store and return energy. See what a slippery slope this can be...
Ugg...there's a guy in town that buys electric bikes, he thinks they are the greatest thing ever. They all seem to break, but one of them has regenerative braking (it also weighs about 70-80lbs)...

The battery and generator are all "in" a massive hub at the wheel too, it's like 12" in diameter, and you no nothing about rotational momentum untill you try to pedal one of these beasts, it's simply insane.

[dhtahoe]

Come on now folks... Go pick up the UCI technical regulations and you'll see that devices that store energy are clearly illegal, and should be. It would change the fundamental nature of cycling competiton (mano a mano, or man V nature), which, IMO DH has already strayed a little bit too far from.

For example: One year my father look at the rules about fuel injection. The rule stated that no fuel injection was allowed in the combustion chamber. Well that rule says nothing about port fuel injection which is OUTSIDE the combustion chamber. The result was a port fuel injected RS 750 flat-track bike that won all but two Nationals that year piloted by Bubba Shobert. Nobody and I mean nobody has EVER come to Dh with this kind of money and R&D. They have people who's job it is to find the "Grey areas" of the rule book. My father used to be one of those guys. Wait till the F-1 ceramic composite engine come out... Ferrari will tremble!

So like I said before. If you used already spinning planetary gears AS YOUR FLYWHEEL that would skirt alot of that rule. Go spin up a Rohloff hub real fast and you will see what I mean.

[Kornphlake]

While it's a neat idea to use a flywheel, do you really think Honda would patent one design which would actually work with such a detailed patent application only as a disguise for the true inner workings of the gear box? The whole idea seems a little too much like science fiction to me.

[RhinofromWA]

Yeah... that and the fact that this isn't a magic Dynamo... If it was Pedal powered, you would still loose some energy while cranking it up.


What about a spring though, that was wound tighter by Brake energy?
Then, you would use energy that you were trying to disapate anyway, it wouldn't weigh as much, and it would still give you a nice "snap" out of corners or on short uphills.See my post, 3rd one in the thread, for that same idea....pretty much. :D

[-BB-]

See my post, 3rd one in the thread, for that same idea....pretty much. :D

Yeah... Same idea pretty much. I just wanted to clarify that it makes less sense to have it "charge" via the cranks b/c you are still using energy. (not that you were saying that)

When you brake, you are turning inirtia into heat. Why not store it?

[buildyourown]

See my post, 3rd one in the thread, for that same idea....pretty much. :D

Hey, that was my idea first. I mentioned it in the 2nd post in the thread. I already applied for the patent at the internet speculative engineer patent office.
No really, I went ot engineering school. Sort of.....




I don't have the book in front of me, but I'm pretty sure the UCI says you can't have any device that stores energy. Having a flywheel spin up to speed isn't any different than charging a battery that runs a motor.

[dante]

so wait a second, you mean to tell me that the kid who won the 2003 NORBA series also won the 2004 NORBA series?? OH MY GOD IT MUST HAVE BEEN THE BIKE HE WAS RIDING IN 2004!!!! We already saw that he's a fat, out-of-shape DH'er who spends more time smoking weed and gorging himself on Krispy Kreme's when the munchies set in than actually training or even riding bikes for that matter!! So Honda took this poor street urchin who was huddling on door steps to stay out of the rain, handed him this magical bike and he went from zero to HERO?? Oh my god, I can't talk anymore, must go secure film rights to this story so I can sell it to Disney!!!

:evil:

(saw minaar at mt snow. he was pedaling when other people were braking. he's f'ing fast, and custom tuned gearing, shock setup and geo only make him go faster. oops, sorry about that, back to discussing the bike... :p )

[zedro]

When you brake, you are turning inirtia into heat. Why not store it?

store the heat? like to make hot-dogs after the race?

[zedro]

I don't have the book in front of me, but I'm pretty sure the UCI says you can't have any device that stores energy. Having a flywheel spin up to speed isn't any different than charging a battery that runs a motor.

oh now your stealing my argumentative ideas!

[RhinofromWA]

I don't have the book in front of me, but I'm pretty sure the UCI says you can't have any device that stores energy. Having a flywheel spin up to speed isn't any different than charging a battery that runs a motor.Would that make a bike that exhibits brake squat (storing energy in compressing the suspension), illegal? :D

[dhtahoe]

Ok again... This gearbox thing is not about storing energy. Kinetic Energy is energy in motion and not stored. This would be "skirting" such a rule. A flywheel is kinetic energy... not stored energy.

[zedro]

A flywheel is kinetic energy... not stored energy.

thats not true, a freewheeling flywheel which is not producing any work (or imparting its energy for that matter) is potential energy, just like a paper weight thats actually flying over 25,000km through the universe isn't considered kinetic.

bah its all relative....

[bcd]

i don't think the gyro efect would be any more than a big dh wheel.
the radius would be a lot less making it have less gyro efect.
if it does have one it seems like there is no problem whipping it.

http://164productions.com/diatribe/greg_5846.jpg

or mabey the gyro is still in this pic and he just spins it up when he is trying to hold a strait line.

[Toshi]

i don't think the gyro efect would be any more than a big dh wheel.
the radius would be a lot less making it have less gyro efect.
if the flywheel was small and light, then it would have to spin very fast to store a useful amount of energy. my intuition is that for a single flywheel the gyroscopic effect would be only dependent on the energy stored, and independent of the flywheel radius.

[RhinofromWA]

You guys want to see a gyro effect crack the throttle on an old 500cc 2 stroke dirt bike and try to change direction. :eek: :D

I had my fathers out and tried to jump over a rise and turn as I left the the lip like I did on my 250cc and my brothers 125cc to set up for the landing. Fathers bike shot straight out and for the life of me I couldn't get that thing to turn. I ended up landing off the trail and stopping about 15ft into a field. :eek: I learned to respect the effect of alot of metal spinning at high speed. :D Actually kinda scared me. :) It was amazing how power full it was.....it jsut wanted to hold it's direction no matter how big my eyes were and how much my arse puckered.....I ended up in that field. Damn Gryos......

LOL

His bike was a 1986 Maico(M Star) 500 the enduro version that was air cooled(the motoX one was watercooled) It was similiar to this one I found on the internet....1985 MStar 500 ;)
http://www.maicomadness.com/baca.jpg

Closer to teh 1986 CrossCountry model seen below and to the left:
http://www.maicobrothers.com/mstarmodels.jpg

[dhtahoe]

thats not true, a freewheeling flywheel which is not producing any work (or imparting its energy for that matter) is potential energy, just like a paper weight thats actually flying over 25,000km through the universe isn't considered kinetic.

bah its all relative....

But still not stored... right.

Damn I always get those two confused :think:

[XpeteX]

store the heat? like to make hot-dogs after the race?
Like this fella here with a hotdog boiler (don't ask, Norwegians are weird cooking their meat -hence me beeing a veggie :) )
http://www.kustom-x.net/skeikampen04/DSCN1131web.jpg

also: I think people need to take notice to Westy's explanation more carefully, that's the one I'm buyin' :P

[zedro]

But still not stored... right.



you mean the paper-weight right? that has stored (potential) energy. Any mass acted on by gravity has potential energy....but could be considered kinetic under another reference.....ok forget i said anything

[BRacing]

Very interesting thread. Are monkey's supposed to be capable of this type of thought?

With the flywheel effect, remember that you'd have to spin it up to speed - which is going to take MUCH more effort off the starting line. And if you go to sprint out of a corner faster than the flywheel is spinning, then you're also accelerating the flywheel - which will require more effort.

The flywheel would act like heavy DH wheels/tires. Only if it was mounted to the main frame, then it would be sprung weight (unlike the unsprung weight of wheels/tires). Additional sprung weight would probably make the bike more stable by resisting changes in direction. This would cause the suspension to work harder to cope with the bumps.

I don't know where this is going, but it sure is interesting.

-B

[bizutch]

Blame DHTahoe...he's teh one telling us all this amazing stuff they've pulled off before. I just keep hearing my science teacher saying "If you can dream it...you can do it!"