Hydro-peneumatic hybrid drivetrain and brake system

Mehrdad Wieske

3 words !!!

get a job !!!

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davebee

Mehrdad,

What do you think is the major advantage of a hydraulic drive system over a traditional metal chain?

Cost: There are a numebr of issues that I would note.
I would expect your design will be a lot more expensive than a traditional drive system even if you take into account both mechs and the two sets of cogs, so for your product to be viable it would have to be a LOT better than the current products. In what ways will this be so?

Maintenance: Current systems can be readily repaired on the trailside for the most part. Mountainbikers crash, it is part of mountainbiking. Even if i bend a mech hanger in a crash i can usually knock back into shape with a rock or something to make it good enough to get me home. In the event of a crash would yuor system be more or less durable than (say for example) a hydraulic disk brake set? How easy would it be to repair on the trailside (it may be a case of carrying a spare olive rather than a spare powerlink). How easy would your design be to repair at home or would you need to take it to a dealer to protect the warranty?

weight: The current drive systems are not especially light (probably come in at 1.5-2kg or thereabouts for a complete good quality lightweight set (the whole shaboodle). How heavy would your design be?

efficiency: Hydraulic systems tend to be rather inefficient due to the inherent nature of heat build up which causes energy losses in the system. How do you plan to mitigate this. Hydraulics also tend to be quite high pressure. what will yours run at?

Sorry that there are mroe questions than answers and you may have already addressed some of the questions so my apologies for that.

Mehrdad Wieske

davebee: lot more expensive than a traditional drive system

M.: Yes that is true. But, wenn you need "Rentable bikes" for "Bike Parks" they will cost more but also making money.Have you ever "Performed" on an existing Rental- Bike. I am not even mentioning the poor begginers and thair problems with HI- TECH. Discouraging !!! I am racing, training, tour- Guiding and teaching cycling NOW FOR ALMOST 20 YEARS and I think that, by itself qualify me to talk shit, if I wanted. But I do not.....I know exactly what I am talking about. Only problem,....I am not an engeneer.

davebee: your design be to repair at home or would you need to take it to a dealer to protect the warranty?

M:Think Bigger, think Skiing.

davebee: weight: How heavy would your design be?

M: How heavy are your skies......does it really matter?

davebee: Efficiency: Hydraulic systems tend to be rather inefficient due to the inherent nature of heat build up which causes energy losses in the system. How do you plan to mitigate this. Hydraulics also tend to be quite high pressure.

M: The winnig point !!!..... What Heat? Through what pressure?wir are not talking about tons of power here and everyone seems to ignore this fact.

Light metal (Alu.) low speed, low pressure hyro-pumps on the market return over %97. And I do not want to us "PUMPS", or anything with Piston Aktion....Pistos are dead, so the combustion engienes, the so called, last Bastion of the Ingnorants.

TIMES CHENGES, DINASORS DIE !!!

For a Car/Emmission free future

M.

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dabac

Look, for someone asking for help you're really coming on pretty strong. Cut down on the preaching and maybe people will be more inclined to listen to your ideas.

So, someone designed a variable-volume hydraulic pump, good for him.

But despite going over the website I can't see how the variable stroke is achieved. I've seen the pics of the crank in the full stroke position and in the zero stroke position-but how is the transition achieved?
What is the degree of adjustability in the system - can it match the span of gearing that a MTB can offer?

Production costs - an ordinary drive train has quite few high precision components, apart from the bearings and freewheel/freehub clutch the rest can be pretty much stamped out from sheet metal. I suppose you'd need far more precision engineering in a hydraulic system.

Seals/ bearings/losses
On a bike seals for the rotating parts are fairly basic, which is OK since they only have to be splash proof. For a hydraulic design they would have to deal with both rotation AND pressure, which in all probability would make them drag more.


davebee: your design be to repair at home or would you need to take it to a dealer to protect the warranty?

M:Think Bigger, think Skiing.

dabac: ??? I don't get it, how would a bike compare to a set of skis? Are you saying it would be as maintenance-free as a set of skis? That comparison is way too lopsided to make any sense.

davebee: weight: How heavy would your design be?

M: How heavy are your skies......does it really matter?

dabac: Weight IS frequently important, first if you're riding in the hills, second it affects the feel and the handling of the bike.
This means there is a strong imperative to keep the size down(as a means of keeping the weight down) - but smaller size also means that the pressure will have to go up in order to achieve the same power transfer. For a car it doesn't matter much, but for a HPV you really want to keep the weight down.

davebee: Efficiency: Hydraulic systems tend to be rather inefficient due to the inherent nature of heat build up which causes energy losses in the system. How do you plan to mitigate this. Hydraulics also tend to be quite high pressure.

M: The winnig point !!!..... What Heat? Through what pressure?wir are not talking about tons of power here and everyone seems to ignore this fact.

dabac: You will get pressure, see above. And heat is not only a function of power transmitted, but also about the size of the power converters. It's all about power-to-weight ratio. Think brakes: the power dissipated during a descent by a drum/coaster brake is the same as the power dissipated by a rim brake for the same descent. Yet overheating the drum brake is quite easy while overheating a rim is quite rare. Discs are sort of intermediate, they are small, can run really hot, and cool off efficiently.

For a cyclist we're looking at maybe 300 W in sustained output, which isn't that much. But it has to be handled by gear weighing in at only a few pounds. And I'm far from certain that this is an easier task than what a car has to handle.

But if one were to use the chain stays as conduits it sure would be a step towards an ultra sleek bike...

Mehrdad Wieske

Hi,
thanks for your interest. To my Tone,.......I do not care, what people think !

A couple of points:

------------------Are you saying it would be as maintenance-free as a set of skis? YES!

Production costs - an ordinary drive train has quite few high precision components, apart from the bearings and freewheel/freehub clutch the rest can be pretty much stamped out from sheet metal. I suppose you'd need far more precision engineering in a hydraulic system.

M.: This is the difference, I am not talking about ordinary anything.......where have bin Disc Brakes for Bikes 10 -20 years- 30 -40 years ago ? Now days I am not gona hit the trails without!

I blieve, Gears (Gearbox) are passed, Hydlaulic gears are light and don't brake, no warring out, no Chain SUCK, no Dirty Chains...broken gears, brocken chains etc. resulting broken Colar bones and no fun.......

BAD News to Shimano and the co., no not really, because as you said it, it is going to be more expensive then a DH-Bike....but....

Seals/ bearings/losses
On a bike seals for the rotating parts are fairly basic, which is OK since they only have to be splash proof. For a hydraulic design they would have to deal with both rotation AND pressure, which in all probability would make them drag more.

M.: have you ever had a "Rolof Gearhub" in your hands ? Turn that B..ch.this is not sealed...this is braked. People still love that shit! And the Hub is far from perfect.

I don't get it, how would a bike compare to a set of skis?

M.: I am only comparing the two activities (not the equipments), sommer and winter time ski-slope bikking becomming more and more popular the only missing link to get that really masively going is a mainanence free rentable begginer friendly "RENTAL-BIKES".

Hydraulic drive is DA Solution, Man ! Don't you think?

Bye bye

Mehrdad

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dabac

That, frankly, is stupid. People are generally quite conservative when it comes to big changes, and switching from chain-drive to hydraulic drive would definitely be a big one. So selling people a huge new idea is hard enough even if you're slick, well-funded and likeable, and you're trying to do it while being abusive, that's a seriously bad move.
You're setting yourself up for failure by setting people up to ignore your idea because the way you're treating them.


So you want a bike as maintenance free as a pair of skis-

1) they already exist. The single-speeds with coaster brakes that was all I rode until I was 15 never saw any other maintenance than flat fixing and the yearly oiling of the chain and saddle adjustment.
2) rental skis aren't mainteance free. Between each customer they get waxed and the edges checked over. Between every 5-10 customer they get the edges honed. At least once every season they get planed, floated and scratches seen to.
3) it's an unfair comparison. The ski itself is a purely passive piece of equipment, all its environmental interaction is dictated by its inherent materials properties. The ski binding as compared to the bike is ridiculously simple. It has no rotating parts, almost no seals and a very simple task - clamp down and release. Basically they consist of a set of springs, hinges and a few cams.





But for there to be a market there has to be a demand. Brakes were easy to develop and sell because there were so many obvious shortcomings in the earlier systems. Drum brakes - overheated at long descents, rim brakes - poor performance in wet, wore the rims out, needed reasonably true wheels. Current drive systems WORKS, so you're facing a far tougher sell.

Apart from the bits about chains you don't know any of this. Switching to hydraulic is not a guarantee against things breaking, or wearing out, or ending up at a low weight. To make things rugged and reliable you need careful design and wide margins. To make things light designers tend to skimp on the margins, use lighter materials and more complicated production processes. A requirement for light weight is very often in direct conflict with a requirement for ruggedness and durability.

Besides, how many accidents are caused by equipment failures as compared to those caused by user error?





But the rohloff is aimed at a very specific market segment - those who want a low-maintenance (commuter/touring) bike with a decent span of gear ratios. They know the tradeoff and accepts it.
The rest of the bike-riding population prefers the tradeoff between higher performance and a certain amount of maintenance instead.



Ah, so you're not looking for a replacement for the average bike, you're looking for a special rental bike version. That's a quite different proposition.

OK, you have a complete rookie who wants to start riding bikes downhill, do you really think the drive train design will be his biggest difficulty? How would the hydra-drive help him? It can't tell him to shift his weight rearwards before applying the brakes, the difference between a firm and a panicky grip on the bars, or when to bail out or when to ride it through.

Something that does seem to cause rookies some trouble is switching gears, particularly if they have a triple front together with a 7-9 rear. But a way around that which would require far less engineering would be to use electronic servo-shifting systems. You could have a two-button user interface and the bike would keep track of cross-chaining and all that. Heck, stick a cadence counter in there and you'd have an auto shifter.

Or is it just meant to help the guys in the rental shed? They're not concerned with maintenance as such, their concerns are payoff time, the MTTR (Mean Time To Repair) and average repair cost. If your design is 50% more expensive it has to make up for that somehow. Either by breaking down less often , or by being faster to repair. Cheaper to repair would be nice too, but I think that it would be hard to beat the current systems.




Not really. If you're thinking of summertime ski-slope biking I assume most will take the lifts/cable cars uphill, and then do some light DH-ing back down. That reduces the span of gear ratios required considerably. I think a bike with a rohloff/nexus hub (perhaps with a beefed up axle, or a tandem version?), disc brakes and a fully enclosed chain guard would do just fine for that purpose.

If mud is a serious issue internally geared hubs could be combined with shaft drive for a "completely" sealed drive train.

I think a more probable customer segment for a hydra drive bike is a tourer who is looking for the ultimate durability from his bike even if it comes at a cost.

Mehrdad Wieske

You know what? I think "frankly" That Something about my idiea is hurting you where the sun does not shine, and you do not have the balls to call me stupid in my face!!!.....I do not use Falls names! Komm on don't hide your sorry a...

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dabac

Your idea HAS some merit, as doing away with the chain would be a nice thing. But spreading insults around at every hint of criticism when trying to introduce a new idea IS plain stupid. And I would do it to your face too, if need be.

But since you're probably just as unpleasant IRL I'm well content that this is as close as you and I are likely ever to get.

YOU are your own greatest enemy as long as you keep acting like this. Heck, with this rude behaviour (which you so handily demonstrated) you wouldn't even be able to sell a fully operational tailwind generator, something every cyclist have dreamed about at some point.

davebee

Ah I see this thread has risen from the dead and the mr Mehrdad is being just as ofensive as ever. Anybody would think he was trying NOT to sell his product.

As for the tailwind generator, any idea where I can get one? It sounds like something I could use.

dabac

You know, in hindsight there are a couple of parts from the OP that I find rather entertaining "...I need an engeenier to caculate my designs...I have thougt of everything.....
If he really HAD thought of EVERYTHING, would there really be anything left for the engineer to do?

Besides, throwing some crude math at the problem quickly shows that the objections pointed out earlier in this thread, pressures, flow rates etc certainly aren't as insignificant as he thinks they are.



Yeah, why settle for the trifling obstacles of precision engineering and a conservative industry when one can have a compound challenge by adding an abusive personality to the mix as well

There is a crude DIY version which is basically a table fan strapped to the rack and powered by a pickup from the wheel, but the one you really want is usually found on the shelf to the right of where they keep the variable gravity front wheels, you know, the ones with the built-in permanent descent

Psychopete

This reminds me of something I read not too long ago, I deal with this in software more frequently than I'd like to.

http://worsethanfailure.com/Article...7_s_Gloves.aspx

IMHO, you want someone to engineer this thing? Make a prototype and prove that it has an advantage over chain. Otherwise you have no credibility.

One thing I've learned (just tinkering out in my garage), you might think you have the greatest idea since bread, but the bottom line is that it might be junk once it's built. Your "design" has no merit. I've had quite a few disasters, but that's how I generally learn, from my own and other's mistakes.

Chain has been standard for years, pneumatics have been around for years. If it had any advantage as drive train for a bike, I imagine that most high end bikes would be hydro-pneumatic today.

Later,
Pete

Mehrdad Wieske

Just a simple Q. ? Is everyone working for "Shimano" & the co.?

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dabac

Just because we're not "with" you doesn't necessarily mean that we're actively against you.

You have to ask yourself, what is more probable:

a) The big manufacturers are so worried about you and your idea that they have recruited a world-wide network of people commited to putting you down wherever you pop up.

OR...

b) Your idea simply hasn't enough merit to anyone else but you.

And until you learn to accept criticism gracefully and to evaluate your own ideas in a wider perspective you're not going to be an economical threat to anyone but yourself.

JohnO

I have long thought about a better way to handle the gearing on a bike, and am convinced that a CVT style transmission might be the best approach. Fairly lightweight, infinite gearing, and relatively cheap to implement. They are widely used on snowmobiles and atv's, and have begun to appear on cars.

The real downside of CVT is that it depends upon friction - the friction of the belt on the cones. Splash a bit of water or mud on the belt or one of the cones, and you're stationary. Perhaps a V shaped chain with ridges on the side to engage ridges on the cones...