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Six Simple Rules For Designing My Bike (loong!)

Discussion in 'General Motorcycling Discussion' at netrider.net.au started by RacingTurtles, Jan 22, 2007.

  1. This is what happens when I get bored... I sat down and wrote my manifesto, Mein Kampf of how bikes should be... according to me, anyway. Variety is a great thing because we all have different ideas and different needs. Here are mine:

    Six Simple Rules For Designing My Bike

    As the story goes, early space flights hit an unexpected snag: it turned out that ball pens did not work in low gravity. This made things like taking notes and recording the results of experiments a bit awkward, so NASA assembled a team of engineers to come up with a fix. Given a couple of months and a couple of millions of dollars they produced a 'space pen' that did in fact work quite well.
    Russians, faced with the same problem, used pencils.

    This little story ilustrates two possible approaches to engineering: high tech or simplicity? Given a choice, I will always, always, always chose simplicity. The industry tends to go the other way, I feel largely because the industry is run by the business and marketing types rather than true engineers. Twenty-valve nano-injected multi-this computer-that makes for impressive marketing material... it doesn't always mean the gizmo will perform any better than the simple solution, and even if it does, at what cost? And for how long? Was it really worth it? Which leads to the next point...

    (did we take the wrong turn at turn one?)
    Yamaha R6 revs to a silly 16,000rpm... or 17,500 if we were to trust their early promotions. The fact Yamaha would *lie* about a bit of technical specification for the sake of marketing is telling in itself - how screwed up are their priorities? - but that's not what I want to talk about here, it's just an example of your average race-bred highly stressed engine.

    Q: why does it rev so high?
    A: to squeeze more power from the available 600cc (and to provide over-rev, so the rider doesn't need to waste miliseconds shifting gears in between corners - which is really of value only when racing)

    Q: if they need more power, couldn't they just use a bigger engine?
    A: No, because this bike races in a 600cc category.

    Q: what's that got to do with ME?!?
    A: Nothing! None of this has absolutely anything to do with the real world. The connection between development, racing and road use is fiction devised by the marketing types because neither the design brief, or the technology used to achieve it are in fact optimal for the road. In practice, OF COURSE they could use a larger engine and let it provide the same output at half the revs, and if they put the same efort into making it lighter and simpler instead it would not even have to be that much heavier than a 600cc. But just about every bit of engineering invested into the modern engine is aimed at one thing: getting it to work at ever higher levels of mechanical stress, more heat, more revs, higher g-forces... when a simple engine of larger capacity would provide the same output for a lot less effort. We don't think of water cooling as a high-tech solution, but even that is overkill when you get down to it. In fact my ideal bike is air-cooled because all that plumbing is one of those things I had in mind when writing point 1 - just adding complexity, weight and vulnerability when in fact they shouldn't be required at all. My CB250 is air cooled and it never gets too hot...Well OK, I would like a bit more 'go' than what CB250 provides... Fine. Suzuki GSX750F air/oil cooled engine produces something like 106hp. Air-cooled 1200cc engines used by Buell produce somewhere around 100hp as well, give or take a few. It is my belief a real-world motorcycle doesn't need any more power than that, especially if you manage to keep the weight down...

    Leaving aside the argument whether bikes are getting too powerful for the roads and for most riders, I'm just concerned because this quest for more power results in more complexity, possibly more weight and definitely more cost. Yes, more power is good up to a point, but we reached that point long ago. So, it's no longer about power - but it is still about the power/weight ratio! Given a choice of more power or less weight I will always take less weight... it's easier on the tyres, too.
    My ideal bike would leave the engine alone at around 100hp and concentrate on steering and keeping the weight down - I'd aim at somewhere around 140kg, and on making use of what it's got on actual roads, not race track. I don't want my bike to be designed for the track, or by the stopwatch or any of that nonsense. I want it designed by real engineers, for the real world - because that's where it will live.

    Things break, or get damaged. Even not counting accidents, bikes fall over - it's a fact of life. Sooner or later the owner will drop it, or a car will back into it, or someone will just push it over for the heck of it. Bikes should be designed to handle this and to minimise the damage. But the fact is, this is not even on the radar. What do they care? They are perfectly happy to sell more parts... Take the Buell: the principle of mass centralisation and low gravity centre is great, I'm fully behind it - but if you are going to carry the fuel in the frame, how can you allow the frame to be the first thing to come in contact with the ground when the bike falls over?!? Clearly, that possibility was either not considered or ignored. On my ideal bike, the principal design goals would be protection from simple damage and accessibility of everything for ease of maintenance and repairs. I imagine a bike that the owner can easily maintain and repair themselves. 'Who cares, that's what mechanics are for', you say? Well, I'm the first to admit I'd rather leave these things to mechanics myself, but even so, this means lower labour costs, which means cheaper service... and we all like to hear that.

    Now don't get me wrong. I want a bike that is fun to ride, engaging and responsive, with an attractive styling. If that's what you mean by 'soul' then fine, we're on the same page. What I am talking about here is 'soul' as used by certain people to explain things like false neutrals or no neutrals, bikes falling off the sidestand, not starting in the cold or wet or.... you get the picture. People - this is not a soul, this is not character - this is only poor design and shoddy manufacturing!!! Don't be so gullible, for God's sakes. It is possible to develop a gearbox that will select *all* of its gears, including the neutral. It simply has to be possible, given that it is a problem long solved on all cars, even the cheapest ones. And on some bikes as well... certainly it would be a high priority on my ideal bike.
    I want a bike where utmost attention was paid to the detail, both in design and in the assembly process. I can sacrifice some performance, but I am not willing to compromise on quality control.
    I am perfectly capable of enjoying a vice-free machine. I am the one with the soul; all I expect from the machine is that it should WORK.

    This is just to cover the little peeve of mine - instrumentation and mirrors. They are there for a reason, and the reason is not to make a fashion statement, it is to provide the rider with vital information. That's why I object to digital displays (harder to read than a dial), LCD displays (hard to read in some lighting conditions) and mirrors that show little more than the elbows. Crappy mirror might be OK on a race track, but it is absolutely vital in traffic and I allow no excuses here. As for digital displays, I consider them a novelty for novelty sake only worse, because they are actually inferior to the solution they replace. My ideal bike will have regular analogue dials, thank you very much. Also, the speedo will be calibrated from 0 to the actual maximum speed it can reach, not another 100k/hr beyond that. What purpose does that serve? None - it just makes it less accurate, since everything is squished closer together... On the other hand, the speedo will be calibrated correctly. If it shows 100km/hr, you can be assured you're in fact doing 100 km/hr. Well, within the tolerance limit of course, but that is around 2%, not over 10% seen on some speedos. Small things? Yes, but it's the principle. The purpose of the speedo is to tell you how fast you're going, not to make you feel good about yourself... My ideal bike might not be power crazy, but it is a serious, purposeful and focused machine.

    So... who is going to build my ideal bike? It doesn't exist - I suspect it never will, because market forces are against it. But if it did get built, I guess it would be some cross of supermotard (light and streamlined, but not a single and not so high) and Buell (incorporating some of their ideas, but not some of their quirks, and not the Harley engine, either), built with attention to detail and dedication to quality now almost unknown in the world based on outsourcing to the lowest bidder... I think it would be a pretty cool bike. And if you made it this far, I thank you for reading!
  2. I disagree, reduced weight often comes at the expense of reduced strength - or in the case of alloy components the issue of fatigue life. Personally I'd much rather have an overstressed engine fail than an overstressed frame. Otherwise though agree entirely with what you're saying, bikes should be designed for everyday riding and doing so should only make them cheaper to buy and cheaper to run. There are some nakeds designed this way (ie the Sachs 650, Honda CBF500 and CBF600, Suzuki 650 Bandit, etc.) but unfortunately many are either unavailable or overpriced here.
  3. I read every bit... and I agree on some spots, on others, mine would be slightly different

    I wouldn't mind a touch more, (like 60% more than that) :)

    Bikes are pretty light as it is. I'm a definite car fanatic and, well, maybe light is good for manouverability, but you've still gotta push only a couple hunj kgs or less

    could mean extremely inflated parts prices due to a lack of other income, but otherwise agreed.

    agreed to an extent.

    They are there for a reason, and the reason is not to make a fashion statement, it is to provide the rider with vital information. I consider them a novelty for novelty sake only worse, because they are actually inferior to the solution they replace. [/quote]


    but me personally..... i'll just have a KTM superduke, completely pulled apart and reassembled by the best and i'll be happy.
  4. Would you like more? Really? Bear in mind the specs I am talking about - 100hp/140kg weight are already in the teritory of such bikes as the SuperDuke - a certified hooligan machine, except the Duke is actually considerably heavier at 180kg... and you'd STILL like more? Hmmm.... I think I can live with this much.

    Fair enough - of course, we don't want overstressed frames falling apart. I just mean in general principle I am more interested in reducing weight than increasing power, of course not to the point where the integrity is compromised. This is one area where I am all in favour of bringing the newest and the best technology can produce and the progress in materials, while not flash, is quite dramatic. So go ahead - give me the strongest, lightest, least fatigue-prone materials your nanobots can produce! :)

    I just want to stress that I am not against technology as such. Far from it! It's just that my sense of what constitutes the appropriate use of technology might be not totally mainstream - I am far less obsessed with gadgets for gadget sake, and far more interested in streamlining, and in simplifying.

    That's interesting that you should bring up SuperDuke because KTM does have a fair bit of that design sensibility that I grope for in my inept way... but they still come up a bit short on the quality issue, and they still fall for some of the trinkets: their engine is water cooled, and they use EFI... yeah, I know - regulations force them to go that way... still it doesn't mean I have to like it.
  5. Great thread - the perfect bike eh, good luck :wink:

    And useable power as well - right from low in the rev range :cool:

    More than enough for me would be the SXV 550 - read of dyno'd 70hp and under 120kg. Super moto, VTwin, watercooled and fuel injection - not your preference, but you aren't going to get weight reduction without water cooling those light metals. And fuel injection just gives plenty of options in regards to where you want the power - especially on this high end technology.

    Service is too crazy for me - 60 hours and need to replace the piston :shock:

    Well done on at least drawing a line
  6. Fair enough. It's just that I reckon designers now are going that little bit too far to try and save weight. I mean hollow bolts are great for race machines but for the road does it really matter if the 07 model is .5kg lighter than the previous given the variation in rider weight. All these weight saving measures cost money to design and incorporate - personally I'd be much happier with a simpler, tubular steel bike that costs thousands less (and won't fall apart should you decide to drill some holes to mount crash knobs, luggage etc.).
    As for engines I reckon torque is far more important than outright power, just like I consider acceleration far more important than top speed (who cares if you can do 300+kph if scooters can beat you up to 60 ;)).
  7. Sounds to me like you want a Ducati Monster 900, or perhaps the Japanese/German equivalent thereof (Yamaha TRX850? BMW F800?).
  8. All very nice bikes, but if your budget doesn't go that far then perhaps ER6, Sv650, GT650 may also be options. I can see bikes like these starting to take more sales away from the supersport 600's over time. If not just for their suitability to 'real life' riding but price tag, running costs and insurance. Of course the recent addition of a racing class to suit these machines will only help their popularity.
  9. Don't know - but probably wouldn't have mass appeal.

    I would buy it - I would call it a triumph of function over form.

    But the fashionistas would shun it - because then they wouldn't be individual enough.

    As I get older, I find myself buying lower stressed bits - witness my 800 cruiser.
    My cars get older, my daily driver is an FJ holden (yeah, with a 202 and triple carbs), but not even a heater.. Simple and fixable.

    Fit for purpose is underratted. A bike should not suffer $3k damage when it falls of the sidestand. A part should be able to be replaced without replacing 20 other parts, broken while removing it.
  10. Believe me, I considered those, but when the OP started knocking on about how 600cc was not enough, and wanted closish to a lazy 100hp, I didn't consider them for long as being relevant to him.

    Sounds to me like he's after a 800-1200cc air-cooled 2 cyl naked or semi-naked.
  11. Hmm, try the Hornet 900. It's a bit heavier than your ideal bike, but it's cheap, hardy, comfy, powerful enough for serious fun and as no-frills as they come.

    Of course, I'm biased by the memory of my recently departed one...
  12. Sounds like you need to start yourself a custom streetfighter project, gsxr 7/11 to be precise.
  13. LOL. You're probably right - that would be the surest way of getting exactly what I want, wouldn't it? Problem is I have minimal aptitude for such projects, no garage, no tools...

    Anyway, this wasn't meant to be another of those 'which bike is right for me?' threads, that's why I posted it in 'general discussion'... This was meant more as a mental exercise, and a general, almost philosophical question along the lines of : "What design principles would you implement in your ideal bike?"

    On a practical level, as I stated from the start, that bike doesn't exist. I also admit that bike is unlikely to exist, or at least, be created in any kind of volume, and at a price level I'd be able to afford it. But if anyone is going to pull this off, I'd be looking to Buell. For one thing, they are about half-way there already but more importantly, they are the only bike manufacturer of any kind of significance I can think of that is still run by an actual engineer rather than a hive of marketdroids.

    At this time, there are three bikes that represent similar philosophy to mine: one is Buell, with its 'lazy engine in sharp handling body' combination... they are half way there, they would just need to work on the practical aspects of the design, quality, reliabilty, crash protection...

    Second one is VUN which tries to keep the weight down to 130kg, but it is powered by a 650cc single of 'only' 68hp, while I'd prefer a large twin with a bit more oomph.

    The third, and perhaps the closest, is French Wakan - powered by an S&S 1640cc twin, weight of some 176kg.

    Now the thing about both Buell and Wakan is that being relatively small manufacturers they don't have resources to develop their own engines, and are forced to use what they can get - Harley in case of Buell and S&S on the Wakan...

    But I'm talking about the ideal, so I don't have to worry about practical details. I think given some resources it should be possible to develop a much better, lighter V-twin engine of about 1200cc capacity that could remain air-cooled, be bullet-proof, produce about 100hp (and that V-twin torque we all love) and weight a bit less than the current ones, all while not shaking like an epileptic in a fit and losing oil... Now, stick it into a lightweight, sharp-handling chassis, pay a lot of attention to quality and practical details like crash protection... and there you are: my ideal bike.
  14. Well, it is a "What bike is right for you?" thread though. Everyone has different priorities. You're identifying a hole in the marketplace that you think can be filled with a bike that has qualities that match your stated set of priorities.

    For myself, my (road) bikes are recreational vehicles. I rarely commute. They'll double-up with track-day and weekend-fang cross-duty. They don't get left where people can knock them over. They don't go on gravel/dirt except to connect winding road sections. The few times I need mirrors to really work could be replaced by a head-check anyway. The actual numbers on a tacho are meaningless except to indicate when I should shift up. The speedo, while digital, is somewhat irrelevant half the time (track days), and when on the public road, displays nice large digits well enough in all conditions except when the sun is directly reflecting off the plastic - which would be a problem with a dial speedo anyway. With a digital speedo, I don't have to worry about "digit cramping". Since different tyre profiles affect a speedo's accuracy, I installed a $100 electronic speedo-corrector which allows me to calibrate the speedo to within 1% either way so I'm no longer at the mercy of speedometer inaccuracies when diverging from OEM manufacturer spec tyres.

    On the engine though, our goals are somewhat similar. My 998cc engine has been further tweaked to deliver power like a big V-twin. Near linear, 95-110Nm torque across the bulk of the rev-range, and puts out more power than I ever need to use (~150rwhp), but boy is it fun using it! The bike weighs about 168kgs dry after replacing the exhaust system and other items, and pulling off bits and pieces that I don't need.

    My needs are different to yours, by a country mile, so of course this is a "What bike is right for me?" thread. If there's no bike that's presently right for you, then it sounds to me like you need a project bike to work on to make it all your own.
  15. Yes, that is exactly what I am doing. I am trying to identify the design principles that would result in a bike that is right for me... and possibly for some other people. But if you are not one of them, hey - that's fine. There's plenty of room for everybody.

    Good... good! So, some of the things that matter to me are not important to you. No problem :) Tell me then, what *design principles* would be important to you? In the sense they would produce the bike YOU want?
  16. eh? Thought I just did say what were priorities to me.

    I want a race bike with a comfortable seat (no wooden planks thanks), the minimal mirrors/lights and indicators required to pass ADR, and an engine that has a flat torque curve. The exact engine config doesn't really matter.

    Oh, and it should have an oggy knob mount point to prevent damage to the ducktail and pegs if it falls on its side.
  17. Heh, not really - so far you just told me which things that I care about don't matter to you: mirrors, digital instruments, damage protection... although you *do* seem to want oggy knobs :)

    So, you use your bike for recreation, on the road or track. You still have to maintain you bike though - does the ease of maintenance matter to you, or are you happy to let the garage look after your bike? Or are you interested in looking after your bike yourself (and if so, are you able to do that?) How do you feel about various computer/electronic-based solutions creeping into the design of your bike - for, against, indifferent? It seems you'd be happy enough with one of the bikes currently on the market because what they make caters to your needs just fine... so if you could get anything you want, what would it be?
  18. Anyone with an ounce of self-confidence, a manual, and half a brain can maintain their own bike. The only real computer gadgetry involved is in EFI remapping, but that's best left to a tuning shop with a dyno bench, which is no different to carburettion rejetting anyway. It's a tool that they need, but doesn't really impact the ability of the owner to maintain their bike.

    Keeping it clean, torquing the bolts, checking and changing the fluids, plugs, pads, electricals, and so on are all basic maintenance items common to all bikes. If you're concerned about the costs of a faired bike for servicing, take the fairing off prior to dropping it off, and put it back on yourself. No problems. Takes as much time to service (at the shop) then as a naked.

    What else is there to discuss other than what it is that makes a bike something that you want. I don't have a problem with digital speedos. I don't have a problem with wringing an engine's neck (within reason). I don't have a problem with doing much of the ongoing servicing myself, faired or not. So long as the frame isn't flimsy, nor is it a tank. So long as the rims are good for road use. So long as I can tweak and modify the base bike (whatever that may be) to be more like what I want as I evolve myself, then that's good. Unsure what your gripes about the gearboxes are about. Might be a very few bad examples about, but overall most gearboxes I've sampled work just fine.

    i.e. Give a bike a basic framework that works well, turns well, stops well, and goes well, I'm happy to work with it and evolve it into something that suits my needs.

    Which bike would that be specifically? Heck, I couldn't tell you. Probably about 80% of the bikes on the market I reckon.
  19. Why do you need 100+hp? You stated you're not interested in track work but more road riding. How fast do you want to go? My current bike has about 60hp & that seems to be plenty to keep me entertained, break the open road speed limit by over double & keep 99% of litre sport bikes honest in the twisty bits :) From what you're saying an SV650 -the naked variety, sounds about perfect. About 65-70hp, cheap to buy, insure & maintane. Pretty damn quick in the twisties. Hang on a minute, that sounds about perfect for me as well :LOL:
  20. About as fast as SuperDuke and Buells can go, and they all have about 100hp... You've got to understand, I am not a bike engineer. I have some definite ideas about what it is that I'd like to see, but when it comes to the actual figures, I basically pull them out of my arse :) That's also how I arrived at the 140kg weight figure - VUN bike I mentioned above aims at 130kg, so I figure it sounds good, plus about 10kg for a bigger engine... it well might be that 140kg is simply not feasible for the current state of technology. Wakan weights around 176kg, SuperDuke 180kg... maybe I should settle for 160 kg or so? Don't worry about the details, keep the eye on THE CONCEPT.

    Yes, in reality I am most likely going to get either SV650 or ER6 - these bikes provide a compromise I can sort-of live with at the price I can sort-of afford... but they do not embody the design ideas I am talking about here... so what? reality is one thing... but his... this is just tossing around some ideas, nothing more.