Why Do Motorcycles Make More Power Than They Did 40 Years Ago?
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- Опубликовано: 24 сен 2017
- The great advance in horsepower is possible because today’s engines are strong enough to remain reliable at higher rpm.
Rob Muzzy's Kawasaki Superbike of the early 1980s made something like 152 horsepower at 10,250 rpm. The current factory Kawasaki Superbike raced in the world championship by Jonathan Rea and Tom Sykes is based on the ZX-10R and makes more like 220 horsepower at 14,750 rpm.
That classic Z-based engine was a real transitional design. It had an all ball-and-roller crankshaft pressed together out of pieces. And that pressed-together crankshaft set a limit, so things started to go bad in a hurry at 11,000 rpm.
But the ZX-10R has a forged steel crankshaft made in one piece with durable multi-layer bearings. It has split and bolted connecting rods. And it has a reliable oil system designed so that the oil pump does not get air-the enemy of plain bearings at high rpm.
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Been reading the articles for decades, but if I could sit and talk all night about motorcycles, I'd want this man to be there.
..Agreed...!
hell ya! I also have been reading his articles for many, many years. Mostly on dynotechresearch
Enough about your sexual fantasies mate
Kevin DOES NOT need background music.
...Yeah, music usually ruins a video....but this is tolerable, barely.....
Eric...This music is perfect for getting your brain ready for input. It calms you and masks ambient sounds then fades to the background as you learn.
Yeah, I've got to agree. If there were music, it should be less of a carnival freak-show tune as it is currently... I would enjoy listening to him without the annoying and distracting music. His voice is one people would listen to on end already.
Yeah just distracting.
When Kevin explains it, it seems so simple you wonder why it was ever a mystery to begin with.
I've always looked forward to reading Kevin's articles in Cycle World. Thank you for these, too.
This dude needs to make more of this type of vids
Man! He has knowledge gems stotred within him!
Great stuff as usual!
Loving these!
What's more amazing that despite petrol / gasoline having less than 80% of the calorific energy content than it did 40 years ago, modern bikes still make more power!!
Of course 40 year old bikes make far less power than they did when they were new when running on unleaded ethanol crap, but they weren't designed to run on the stuff or cope with the damage the stuff does either.
That’s a great point! I do hate ethanol myself.
You got me hook and it was getting more intreasting
Kevin always looks like he's yelling at my kids.
Love all your tech articles I have been reading for 30 years. Glad to see you here sir!
I just now found my way here to Cycle World's channel. Hearing Kevin brought back memories of reading Cycle World magazine as a youngster in the 90's. I have now subscribed.
Kevin used to write for Cycle Magazine. When Cycle disappeared, he started to write for Cycle World.
I used to straighten up and then TIG weld the cranks to build a 1485cc top end with a huge turbo running at 30 psi with very soft cams to make it all stay together for a "Breakfast Run" cycle.
Bryan Kirk "Bitchin" speakin my lingo. I'm sure you've breathed on a few things
Not a pretty sight.
Great line.
I have seen a few of those myself.
I remember a YZ360 from way back, broke the rod at the wrist pin, the rod went through the cylinder sleeve, the crankcases, the motor mount bolt too. The clutch and transmission were the only things undamaged.
TX750's did much more damage when they blew up.
Cameron why haven't I seen 2 strokes with single piece cranks with planed bearings? is it because of lubrication problems? i.e. mixed fuel alone or even with oil lines to the bearings isn't enough these types need to bathe in oil?
A perfect example of a impressive engine,,,,. VF 750 Honda Magna,,,, Cruiser,,,. 87 horsepower,,, 10,000 RPMs,,,, 135 miles per hour,,,,,,,.
More KC vids every day please
Might be nice to include a mention of digital engine management and EFI as well. Both things account for a bump in horsepower--although not as dramatic as a jump of 4,000 rpm at the top end. With the added plus of lower emissions and better mileage. Just saying.
Who Woulda thunk it I thought it was just better technology
Engine designs like much higher compression ratios bigger bores shorter strokes lighter internal parts variable valve timing better fuel system (efi) etc etc
Some more "etc etc" stuff... Electronic ignition timing, thin piston rings, optimized head, intake, and exhaust designed using fluid-dynamics simulations.
I like Kevin but why is he always only talking about Kawasaki in his examples?
Because riders keep on getting fatter and heavier 🤣
I disagree with the notion the old and new designs have the same volumetric effeciency.
A modern sports bike engine has race proven technology as opposed to the older engines.
Because you haven't done the math. Kevin is saying that at 10,500 rpm the old K was filling it's cylinders just as well as the modern K bike. The difference is the modern bike is capable of doing that at 4000 rpm more-it's rate of work ( power) is therefor proportionately greater.
Lots more advancements.....not just bearings and oil pumps
Virtually everything is engineered better, more efficient.
Whilst far from expert on this topic, I think it is obvious that he is referring to what was responsible for the biggest leap in development which was responsible for a transition to a new way of thinking. Your analysis is obvious and so not really insightful, because all manufacturers will look to improve as many aspects of the vehicle as possible. But few will set the trends that lead to a real leap in performance. For example, the standardisation of Traction Control could be said to have a similar effect. Someone took the risk to go with it and now it's developed so much that the voice of the die hard old school "I don't need no computers to make me go faster" has all but evaporated to a whisper. So, yes. Bearings. Just like in F1 the advancement of Piston technology was a real gamechanger in generating significantly more power.
Please ditch the annoying background music.
Can you answer this question? Why are motorcycle magazine road tests today so much gibberish? All they are is advertising for the brand in question. There has not be an honest motorcycle road test since Cooke Neilson and Phil Shilling retires from Cycle twenty years ago. Their test gave you all the statistics , quarter mile time top speed at the end of a half mile run, they gave you every good thing a bike had and every bad thing! You could read their test carefully and know what your getting before you set foot in a show room! As an example , when they tested a Harley, and said for the most part what shit they are, Harley would pull the advertising from the mag for a few months, but the magazine was there to serve the buyer and not manufacturer ! All Cycle world does is say they are all wonderful and the buyer gets screwed. I have been riding bikes and buying motorcycle magazines for 52 years but I am not renewing my subscription to Cycle world.
i.imgur.com/tcidhQU.png
Everyone ignore this guy
These are really great but that darn music! PLEASE STOP!!! 8-)