dream super bike

[dan_bo]

This thread is absolutely hillarious. I blame Wiggle .

OK enough of being polite. The original poster is wasting his time 'designing' a new bike with a mahoosive gear if he's not fit enough to power a conventional bike at more than 10-12 mph over 40 miles.

I would suggest you start riding your bike more - this works mirracles. Try riding 100 miles at about 20 mph - then you'd be considered as reasonably fit cyclist - takes lots and lots of training. It's like an inverse pyramid - lots of quality miles to get that little peak of performance.

Please listen to the folk here, they are some very experienced cyclists. You are either a spotty teenage boffin who knows nothing about bikes/aerodynamics or dillusional.

Get training, and you can compete in the National Time Trials - those folk can do a sustained 30 mph on a TT bike, with conventional gearing. Even HPV's (bikes built into a giant egg shape ) don't have gears that huge !

say what you see Foss, say what you see.....

 

[fossyant]

say what you see Foss, say what you see.....

Like OMFG !

 

[Licramite]

oh dear I see your missing the point somewhat.

yes young (ish) fit people can do that - and may I ask what % of the poulation are we including here?

This is about bike design, - if we flew aircraft to the same design evolution as your average racing bike
we would be flying fabric covered biplanes.

ok I,m new to bikes but I already know theres an automtic gear change system based on rpm, - (just don,t know who makes them) - so why aren,t these standard on all bikes?

are you saying you would be happy to drive in a model T ford because you can,t be arsed to design something better ?

and finally - I,m 56 with a heart condition and most routes round my way involve a least one hill of 20% gradient - and I,m riding a hybred,
Of course I want a bike that goes faster with less effort - who wouldn,t - except some cycle nut!.

If you have ever worked in design expressions like - "It,s never been done decause so it can,t be done" is the starting point for Doing it.

 

[Rob3rt]

oh dear I see your missing the point somewhat.

yes young (ish) fit people can do that - and may I ask what % of the poulation are we including here?

This is about bike design, - if we flew aircraft to the same design evolution as your average racing bike
we would be flying fabric covered biplanes.

ok I,m new to bikes but I already know theres an automtic gear change system based on rpm, - (just don,t know who makes them) - so why aren,t these standard on all bikes?

are you saying you would be happy to drive in a model T ford because you can,t be arsed to design something better ?

and finally - I,m 56 with a heart condition and most routes round my way involve a least one hill of 20% gradient - and I,m riding a hybred,
Of course I want a bike that goes faster with less effort - who wouldn,t - except some cycle nut!.

If you have ever worked in design expressions like - "It,s never been done decause so it can,t be done" is the starting point for Doing it.

Because we don't farking want them because it is a stupid idea!

 

[fossyant]

Oh my..

It's not going to happen.

Bikes don't have a magic power source. It's really simple. The only really quick bikes are recumbents because of the lower aerodynamic drag, and the really fast ones need a shell.

Bikes are something like 97% mechanically efficient. Aerodynamics are your enemy to going fast - simple.

If you aren't fit (medical condition aside) (like most of the UK population) then there is no way on earth that you'd make a bike that can do 30 mph (on a flat windless road or even an indoor test track) with the same effort needed to do 10 mph. Think about it. Just go and buy a recumbent HPV !



Oh and automatic gear change based on RPM is a 'test bed' application - absolutely no use in real life. There is a human on top of it, not an engine !

 

[Saundie]

Of course I want a bike that goes faster with less effort - who wouldn,t - except some cycle nut!.

If you have ever worked in design expressions like - "It,s never been done decause so it can,t be done" is the starting point for Doing it.

There's nothing you can do to overcome the laws of physics, though. You're not going to be able to design your way around gravity and wind resistance.

ok I,m new to bikes but I already know theres an automtic gear change system based on rpm, - (just don,t know who makes them) - so why aren,t these standard on all bikes?

As Rob3rt says, nobody would want such a thing, and would just remove it in the same way they remove reflectors and bells, despite them being a legal requirement on new bikes sold in the UK.

 

[fossyant]

PS I'd recommend importing an electric bike from overseas where they aren't restricted, if you want to do 30 mph with no effort.

 

[Zakalwe]

It's not about designing something "better", people still ski even though we have skidoo's, people still walk even though we have Segways, people still hot air balloon even though we have planes.

For whatever reason, people like cycling on a two wheels, diamond framed bike, it's a convenient position and efficient enough. Gearing is suited to the task at hand. If you want other ways of propelling yourself at higher speeds look at fairings and recumbents, that's how you tackle the challenges high speeds present. The guy doing 126mph on rollers is proof enough - there's no way you could get the bike up to that speed with 126mph headwinds, regardless of what chainring he's got on there.

 

[fossyant]

No-one is missing the point Licramite, I am afraid you are not grasping the basic laws of physics, these you can't change unless in a sci-fi movie or cartoon.

My 9 year old daughter understands if you want to go faster you have to pedal harder, what ever gear she is in, and the faster you go the harder it is. She also understands that in a head wind it's much harder to pedal at 10 mph than it is to pedal at 10 mph with a tail wind. Aerodynamics apply whether on a bike, a super fast HPV recumbent or indeed a £1m super car. You are still limited by the "engine", more so with a pedal bike.

The world record on rollers - there is relatively little aerodynamic drag other than that from the wheels/spokes and of course mechanical efficiency.

 

[dan_bo]

I get it. Bonj's back isn't he.

 

[fossyant]

If you want other ways of propelling yourself at higher speeds look at fairings and recumbents, that's how you tackle the challenges high speeds present..

Or chuck yourself down a hill at 50-60 mph on your 'old fashioned' bike - I can let you know some good ones !

 

[fossyant]

I get it. Bonj's back isn't he.

Think so !

 

[Licramite]

why wouldn,t you want an automatic gear that put you in the right gear for the speed your doing. ?

the intersting point about power required to turn the pedal, - have you ever seen a man push a train, once its moving its own weight and momentum carries it along
all you need is a lesser ratio to get you get going and the bigger ratios can be engaded

 

[fossyant]

why wouldn,t you want an automatic gear that put you in the right gear for the speed your doing. ?

Because

A human is not an engine, therefore we have a better torque range for delivering power. For example, RPM and power needed to climb a 20% hill is different to that needed to pedal flat out on the flat, or down hill - hence why lots of folk ride fixed gear bikes where we can easily vary our efficient RPM from say 60 to almost 130 - lots of flexibility.

Man pushing a train - very little aerodynamics involved, so you lose ! Momentum on a bike will not carry it forward at 30 mph for very long, aerodynamic drag will stop you rather sharpish.

 

[dan_bo]