My sincere apologies to nitrosatya for inadvertently hijacking his thread in this manner. Since it seemed inappropriate to leave things hanging in mid-air, I take the liberty of this one last post which attempts to clear the confusion.

I guess there has been confusion over the forces involved in turning the handle. It is difficult to visualize in three dimensions what one sees on paper i.e. 2D. The figure below should help with that comprehension.



The difference between case 1 and case 2 is the height of the handle above its point of rotation. A raised handlebar (stock) is in effect a longer lever arm than a straight handlebar (clip-ons). The Resultant force that actually turns the steering head is the resultant of two force vectors in case 1 compared to just one force in case 2. So the rider in case 1, for applying a certain torque at the steering axis, needs to apply a smaller force than he would need in case 2. In short, all things being the same including the linear handlebar length, the handle would feel lighter in case 1 and heavier in case 2.

OF

i am sorry but your explanation is flawed.

provided the handlebar is sufficiently stiff, there is not going to be any difference in the steering effort for the same width of the handlebar.
the resultant length of lever arm you show in the picture cannot be right. thats because the resultant lever arm will always be perpendicular to the axis of rotation, no matter its location.

at this point we need to separate static and dynamic steering effort.

static steering effort is the effort required to turn the steering when the bike is not moving (or moving very slowly). friction of the tyre is the biggest contributor to this effort. the tyre friction is caused by the size of the contact patch, compound of the tyre and load on the tyre.
a lower handlebar will increase this effort because it will cause more weight to be placed on the front wheel, increasing friction.
a fatter tyre will have the same effect as lower handlebar on the static steering effort.

dynamic steering effort is the effort required to turn the steering when the bike is moving. the steering effort is the result of the self correcting tendency of the bike thanks to the trail. the handlebar has no effect on this effort.

but static steering effort does not vanish once the bike is motion but reduces gradually to a negligible value with increase in speed.

a human factor that we can consider is that maybe a person perceives the steering effort to be more if there is too much load on the wrists.
perceptions are not necessarily the truth.

cheers all

@@nitrosatya - Sorry to have asked more questions on handlebars that deviates from this topic altogether.

I've a request to OF - can you create a new thread on handlebars? Probably, we can all ask the Mods to move the appropriate replies to the new post & still keep discussing on styling here & handle bar discussion there?

People who have been following this thread would be aware that the discussion there has taken an additional tangent about handlebar shapes/lengths vis a vis steering force they exert.

So as to keep the original thread true to the purpose as deemed by the thread starter, all posts related to the 'Handlebars' discussion have been moved to this new purpose-made thread 'Handlebars and Steering torque'. All posts relating to this tangent have been copied into the new thread. Lets switch to this new thread for discussions on this topic and its related tangents (ergonomics, relation between seating/foot pegs and handlebars, compoarison of clip-ons vs conventional bars etc).

Old Fox sir! It was great to have have inputs from you! Now i understand handles better! I would like to have styling inputs from you guys! Plz do contribute! As to what design bits you like in a particular bike!

I like to see this topic getting hotter & hence bumping it

Let me begin by asking some preliminary questions. What exactly goes into the design of a motorcycle? What're the most complex parts in a motorcycle? IMO, I would say most of the parts, however to name a few of them lets say the engine, the frame, the gears, brakes, clutches & so on.

So what exactly is a design of motorcycle? Putting all these components together? Or just the frame design? Or is it the aerodynamics or fairings?

What i realised is that engineers interpret the word 'design' mechanically! And the artistically inclined take it as styling!

Basically it is the hiding of all mechanical parts in a clever way. Attracting customers as you go along!

What i mean to say here is, why a particular styling bit, for eg. a tank scoop was fitted on the bike? Does it serve any mechanical purpose? Or is it just to make the bike look good?

Bikes are styled to make you respond with an emotion. And that is why i want you guys to know how it is done.

Next post will describe the aggression in a design.

Sorry @nitrosatya, IMO, there's some real engineering goes into motorcycle design more than attraction or emotion. I could be wrong here, but this is what I've observed. I think motorcycle design goes very much hand in hand with a frame design. If the frame is not designed properly, it affects the design of the bike completely. However, I'm unable to differentiate between design of frame & design of motorcycle here; that's the reason I said, I could be wrong. However, I strongly feel its some engineering or some technical stuff that is more than emotion or attracting a customer.

PS - Waiting to read more on the "aggression in design" followed by other designs. Pls keep them coming up

My take:- It is developing a solution in line with a requirement. I don't think you just develop components individually, like say carb, clutch etc.

You build something around a requirement. For example, urban commuter, sporty commuter, cruiser, etc. Any and every effort to give shape to this effort will be design activity, i.e until you develop a prototype. So that will start right from deciding upon engine capacity, frame design, transmission mechanism, etc. It ends up being somewhat deductive process till a final prototype is made.

I know, not that articulate, this is all I could manage

That @aargee is a typical 'what came first - chicken or egg' question . And so no straight answers possible I guess. But still plenty of chickens and eggs around to confuse us all. Though what Nitin says below does make sense.
A 'design' is a creative process first and foremost and being able to accommodate all the required technical elements into it is a part of the creativity. Very difficult to discern the hierarchy of the thought process involved here.

And the 'requirement' could arise from any number of triggers.....market demand, need for a variant, availability of new/path-breaking technology, or a myriad of other reasons. Of course, the first move is to define 'what class of motorcycles' would the design address. But then, isn't that what nitrosatya's thread is all about? Making 'designs' easier to understand by classifying and organising the different schools of thought.

^ From market/marketing perspective that would mean 'positioning' and exterior styling (design in this thread's parlance) would be one of the elements.

Well, I got what you're trying to say & yes probably this could be a reason too.

Yes, I agree, this could be the reason too; actually I strongly agree with "need for a variant, new/path-breaking technology". Reason being that I can quote few models that are failure not because they're bad, but bad at certain point in time. RD350 & India is a classic example; Another positive example being is Bajaj that changes with time.

Hello guys!
Right now i am surrounded by work. Will post more asap.

The next point which i want to explain was aggression in design. It is generally enforced by lines slanting down towards front. The more they are slanting the more they are aggressive. But the lines at some point become vertical and loose aggression. The same concept also apply to headlights. More on that later.

You mean, the street bikes can be thought of having vertical lines? Or is it the fairings in them cause the aggressiveness? This is provoking a thought in me that, if the fairings are removed, then the bike should not look aggressive.

^Good question there.
I will tell you an interesting story.
For years on,Honda's CB900F Hornet ruled the big streetbike market. In many countries. But then came the new Z1000 in late 90s and early 2000s. This bike redefined the streetbike design. And it did put a dent in CBF's sales. Honda then asked Boxer design of France to design some aftermarket kits for CBF. Tried to make it agressive. But it was not much of an impact. Hence Honda developed an all new CB1000R.
And then Kawasaki with new Z1000!
It goes on and on!









Notice how the lines get agressive. Even without a fairing the lines are sloping downwards. And how the headlight went down.