Jump to content

Gas up - Let's Go!

YOC Member
  • Posts

    1,238
  • Joined

  • Last visited

Everything posted by Gas up - Let's Go!

  1. It doesn't matter about the outline shape, the issue is the manner in which air would pass over/through this shape. Even a brick shaped Cortina whould have less air disruption than any bike. Despite it's shape a car has a smooth surface alowing the air to pass over it faily undisturbed. A bike will have holes for the air to get into, whether that is around the engine, riders legs, under the visor, around the arms and torso, the area around the wheels, under the muguard, around the pipes, the list is endless, but the fact remains that a bike is a mass of items that disrupts the flow of air and has massive drag. Look ath the race bikes, they cover them in farings to reduce the air drag, riders have state of the art smooth leather, speed humps, buckle-less boots all to improve the drag. Figures, it is important because overall, taking end-to-end economy the car has highs and lows, manufacturers will use whatever 'statistics' to improve these figures. Some cars ever kill the engine when stopped, because this improves the statistics they can quote nad even impacts the road fund licence value. Kinetic energy is hugely important, it has to be a constant, so if a car has a low drag coefficient, low rolling tyres and higher weight than a bike then there are less places for this energy to be dispelled, so the energy pushes the car further. On a bike this energy is dispelled by the ineffiecient tyres, high drag, noise etc. About the only place a bike has the advantage over a car in respect of energy loss is in turning. A car will loos energy to turnign forces, where in a bike the turning forces are so efficient we (the rider) has to force the bike to expel energy during the turn (counter steering), otherwise we'd turn to fast and lose controll. The kinetic energy isn't all that's important here, there are many other forces at play, but to put it in simple terms, an oil tanker travelling at 10 mph will take much longer to stop than a rowing boat.........
  2. Oooooo This looks interesting.... Nope, now you've gone and quoted the noddy guide to motorcycling. Now where's the Jaffa Cakes and the Beano. PS - Your physics is flawed. You are looking at power to weight, but you are not considering the Kinetic energy you get from a 1000Kg car moving forward, this means you don't require as much effort from the engine to maintain constant movement. On a bike, you have much less kinetic energy and therefore the engine has to do more work. If you were to look at the fuel required to project a car from 0 to say 50 mph, and the same fuel required to propell a bike from 0-50, with the same rate of acceleration then you would find the bike is much more efficient. Once a cruising speed has been reached the car will use less fuel to maintain it's speed because it is less sucptable to influencing factors, and has the added energy generated from it's proppelled mass. Also, a car is a much more contained vessel, with smooth lines and lots of wind tunnel development. A bike is full of holes causing lots of wind turbulance and drag/resistance, not to mention the rider ! And another point, you quote figures for a car at optimum speed, whereas a bikes optimum speed is much more fluid. In that you will never get your 1000Kg Micra/fiesta/mini/whatever to get anything like 30mpg in stop/start city traffic, but a bike can opperate pretty close to optimum efficiency in the same traffic.
  3. Thats a good bit of riding, pity his mate kept stopping though - I'd have left a big gap between us too!! Kinda reminds me of my Portugal trip last year....... and I've nowt planed this year, which makes me sad
  4. 100mpg....... Hmmmmmm Dunno, never worked out the mpg. However. The tank is 22 litres (23 if you fill the expansion space), and, if you ride realy smooth, keep the speed under 70, on long runs 220+ miles before the F-Trip is fairly easy to achieve. You then have around 70 miles on the f-trip. Now, when I say 70, this is what I've made before deciding it's time to fill up..... Loaded ot unloaded doesn't really make much difference to the mpg. The fuel gauge however is a lies, it couldn't tell the truth if it's life depended on it... I've had it flashing F-Trip before and only managed to squeeze 10 litres of fuel in it. A point the salesman didn't tell you, you can actually ride the bike, non-stop from full to empty without the need to have your spine re-aligned. There have been a couple of times I've ridden places with guys on sportsbikes, sports-touters and Naked bikes. In every case I arrived before them, not because I ride fast (but I do keep a good average)or take stupid risks, but mainly because of the bikes range and ability to ride non-stop. So over 300 miles I would make one stop to top up, the other riders would take 3 stops but would need to stretch or have physio before moving on again. I have a mate with a XT1200Z, the range is about the same, but with more power and greater comfort (and double the price tag!). These bikes aren't for everyone. They are tall, very tall and it's less about the length of your leg and more about your skill and ability on the bike. I have a mate who is a short arse, he manages fine. I've spoken to others who are around the 6 foot size and they claim it's to high.... I've a 29" leg, perfect for me. They are also a single, so if you don't like Thumpers, you are never going to gel with this bike. For a Thumper it is smooth, but compare it to a Fazer and it's a bone shaker. A good opportunity for some pictures I think -> This is Finland, about 70Kms south of the arctic circle Northern Greece a week later Where do you want to go today? At the end of the rainbow is the pot of gold, Northern Racing Gold! THere's always a Donkey around somewhere....
  5. Ah, the conclusion is correct, but I might have made some errors in my workings....
  6. I was just trying to break it down into some calculatable options, yep a rope around the wheel would have hurt. But the palms of the oinks would still suffer some serious burns. There are lots of what-if factors, angle of the bike, the rop hitting your neck, the pressure the rope applies (depending on the diameter etc) to whatever it hits before the other forces are taken into account etc etc. It's all academic now, and easy to talk about afterwards, the fact remains you react how you react, you don't start doing calculations in your head !! more like "Oh sh1t, brake, brake, fall off with style" .....
  7. I've been thinking about this, two kids one either side of the road, asume they realy did have a rope. So a bike is what ? 200Kg ?? and traveling at speed, dunno what the momentum would have been and I'm not sure of the calculations, but I'm pretty sure 2 kids would weight less than the bike, rider and combined velocity of the bike. Is it something like Mommentum = Mass x Velocity, so at 30MPH = 48Km/h or 48,000 meters per hour or 13.3 Meters per second. So your mommentum would have been 2660Kg-m/s (200 x 13.3) theirs would have been Zero! In order to stop you dead, they would need to excert a force equal and opposite to you, 2660Kg to stop you, or the weight of a Landrover Discovery ! Given that thier effort was pulling the rope tight, their effort was not opposing yours, so the reality is they probably had about 10Kg?? of force opposing you. Think about it, if you and a mate were to put 2 gallos of water in a bucket and put a rope through it, do you think you could pull on the rope and lift the water up ? IF there had been a rope, and IF id wasn't raised enough to clear your screen (and it takes a fair bit of effort to pull a rope taught over 20feet), It couln't have stopped the bike. In fact I think the kids would be following the bike down the street, or at least the palms of their hands would.. Certainly you would have come off the bike, but because of your own reaction rather than what they did, and no worse than you are now ?? So, this is easy after the fact, and I think I'd have probably acted the same as you, looked for the soft option. But worth thinking about if anyone comes across this again ? and if you were to hit the rope closer to one person than the other then you are tipping the odds in your favour even more as the oink closest to you would get the full force of your mommentum. ** there will be other factors involved in the physics, I'm just trying to demonstrate the forces involved, and I'm no Physicist!
  8. I'm struggling with this word..... what does it mean ?
  9. It's simple. The price of Oil goes up, so does the price of fuel - Becasue they have to buy it at the market price....... When the price of Oil goes down, they have to keep the price of fuel up until the reserves are used up, because they bought it at that price..... The Gas companies have been getting away with it for years..... The ironic thing about this, it's all down to the bwankers buying and selling on the markets, and sod all to do with supply. I guess they will be invading Libya next, crackpot dictator and oil, if he had no oil 'they' wouldn't give too hoots about him.
  10. No, it isn't. It's an awful part of the world, if you come here you will be gang raped, and your bike will get nicked. Stay away until the locals have made it safe. Hi Dave - from a fellow Northerner.
  11. Did you look at her ? no amount of make up would have changed that!
  12. Bang on! It's after the test you start to learn....
  13. It shouldn't stick, but it cold be something as simple as your clutch needing adjusted, or the gearbox could be in meltdown!!!. It is important to get these things checked out as soon as possible, the last thing you want is to have the dealer/Yamaha saying you should have brought it in sooner.
  14. I'm never sure what they teach folk these days in order to pass the test. But out here in the real world, where staying alive is a full time job, you should always split your hazards, passing parked cars would be at least a door width, if you can safely ride down the middle of the road (so no oncomming traffic) then do that (not sure how they would take this during a test though) Whenever you ride, ask yourself "What if ?" What if; That door opens, that dog runs out, that car pulls out, that puddle is a pot hole my wife gave the examiner a BJ.... The list goes on... then think about what you would do if it did.......
  15. Yes, do nothing to the bike. Take it back to the dealer and let them sort it out.
  16. I was in Locarno the week before last, blooming lovely! I've to go back there in the summer, about August time. I'm trying to convince work to let me take the bike!
  17. This is the most important thing, let me elaborate on it some; When you set off, and you've done your lifesavers, start your turn and look over your shoulder, your head should be looking at right angles to your body. fix your eyes on something, a tree, a post, sign - anything! as you turn move your focus around so you keep looking over your shoulder. Pay absolutally no attention to the lines, cones or front of the bike, none at all. when you have completed about 3/4 of the turn look at where you want to stop. ---- The same is true for the figure-of-eight - always look past where you want to go. The second you look forward, you will bollox it up! ---- Practise in a car park, it's possible to turn your bike in the distance between the lines of one large space, it takes lots of practise but it's possible. If you are in any doubt as to how tight you can turn, do it in an open space, keep going round and round. It is only when the lines get put there it becomes hard! One of the favourite tests our IAM SO does at BikeSafe is to get riders to ride a perfect circle, stoping in the same place they started from, very few riders can do it, and all the ones that could ride off-road bikes!
  18. I watched my Soup Bowl for an hour last night. I just don't get it, all I was left with was some pretty 'orible Chicken soup and the bowl did nothing! I'll never understand American sports...........
  19. I know lots of people who have fitted these, but alas I'm not one of them. The best place to get this information is over on XT660.com, pop over & join up, make an introduction in the Newbies Lounge and ask away with your questions. BTW - Whilst you are over there you'll find out how to give these bikes more Uuumph as the pipes just don't do it, the engine needs to breath.
  20. Finally, another decent bike on the forum.... Did you ever see so many Ten's in one spot ?
  21. Drewps, you are a ham slice short of a full butty..... where, sorry, why would you ever find such a site ?
  22. I'm going to echo Leatherat, in that would you trust a second hand tyre that has been repaired ? I've had tyres plugged in the past, but I know they have been done right. This cannot be the case with ones from eBay, you can only trust the sellers word. I would look for a new, cheaper tyre if costs are important - unless you are just using it for burn-outs!!! in which case, no problem.....
  23. I come from a long line of bikers...... My great Grandad was a cavaly rider in the 'Great War', then progressed to bikes, My grandfather had bikes (and a Bren Carrier!) My old man was a '60s biker (I was carried around on a mixture of BSA's and Bonny's before I was born), as was my uncle, How could I not follow ? I learn't to ride a 125mx bike, following my step brother around Moto-X meets at weekends, had dirt in my face ever since. On my 16th birthday, I rode to school on my first crappy 50cc, at 17 I progressed to my 'first' bike a Honda MTX125R,,,, lots of bikes, miles, £££££'s and years later and I'm still on a trailie !!
  24. Come Ttsk.... We agree on this topic ! Nothing wrong with recycling, better to re-use than make new
×
×
  • Create New...