Motorcycles Inside KTM’s 890 Duke R
Dovetail Workwear Effie Moto Pant Review
As a labor of love between Portland, Oregon-based women’s workwear company Dovetail Workwear and engines-and-coffee retail/café See See Motor Coffee comes the women’s Effie Moto Pant. Let’s begin by starting with the name of the pant because it was inspired by a significant woman in female riding history: On May 2, 1915, aboard a Harley-Davidson Effie Hotchkiss, along with her mother Avis in the sidecar, went on a grand motorcycle tour—a round trip from Brooklyn, New York, to San Francisco, California—which made her and her mother the first women to ride a motorcycle across the US. An impressive backstory that is likely causing you to daydream about your next road trip.
Okay, folks, here are the figures from the CW dyno, comparing thewith this year’s complete redesign with increased bore and stroke. , and torque is boosted 3.7 percent. To get these increases, had to give this engine a new crankcase, and new crankshaft, con-rods, pistons and valves, a new cylinder head, new balance shaft, and new cam profiles with greater lift.
, and compression jumps from 12.7 to 13.5—two changes that normally have a big effect in boosting peak torque. But when I got out my colored pencils and graphed CW’s 790 and 890 power and torque curves on the same sheet of graph paper, the torque curves were so close that they crossed each other in three places. Close.
TV program Wednesday May 20: Wonder Wheel and Inside Man
Every day, find the program of films and series to see on TV. Today: a case full of twists and turns, a bittersweet dramatic comedy, the weight of family traditions and a breathtaking biopic on Lance Armstrong. © Mars Films / United International Pictures TV program Wednesday May 20: Wonder Wheel and Inside Man Inside Man by Spike Lee with Clive Owen, Denzel Washington (TCM Cinéma, 2:15 p.m.): "A priori, the idea that Spike Lee could get on with the staging of this thriller might seem strange g
I thought the above was an expensive list of engine changes to gain just 3.7 percent in peak torque, so I asked if we could run a retest. I didn’t want to write something that made KTM look like it had paid big bucks for new die-casting molds and production programming to get so little return without a confirmation of results.
A few weeks later I heard from our test rider andguy Michael Gilbert that he’d rounded up another 890, and shortly he sent me two more runs. But instead of the hoped-for (or expected) big step-up in torque, the new curves were pretty close to what we’d measured before. Mind you, the torque curves are lovely and flat from 5,500 to 9,000 rpm, as well as impressively high from 3,000 rpm, where torque is close to 80 percent of peak. That’s a great gas-it-and-go torque curve of the modern type. But I had expected a torque increase that just wasn’t there.
2020 KTM 890 Duke R First Ride Review
2020 KTM 890 Duke R First Ride ReviewBut, of any company, KTM’s developmental program has truly focused on seeking absolute performance. So the Austrian brand went to work analyzing every component of the 790, then re-engineering it for improved capability. Enter the all-new KTM 890 Duke R—faster, lighter, and fitted with more premium components, all at a reasonable additional cost.
That jolted me out of an obsolete perspective: A hot-rodder’s reasonable expectation that major engine changes will bring a big jump in performance. Sorry, we now live in the Euro 5 world, so what KTM has cleverly done is make all those expensive changes to keep and even somewhat increase the performance of this motorcycle while making it pass Euro 5.
Euro 5, scheduled for introduction in January 2020, tightens carbon monoxide (CO) by 12 percent, unburned hydrocarbons (UHC) by 41 percent, and oxides of nitrogen (NOx) by 33 percent. It also sets standards for particulate and evaporative emissions, requires OBD-II self-diagnostic capability, and raises the system durability requirement from 20,000 kilometers to vehicle lifetime.
We would normally expect this 890′s boost in displacement and compression ratio to give it not 60 pound-feet of peak torque but more like 65 to 67 pound-feet. Where is that missing torque? I believe we could find it in the mapping of the ECU. To pass Euro 5, engineers have to avoid the highest-temperature combustion that generates NOx, and they have to lean out fuel-air mixture where possible to meet UHC. This is now the cost of making the motorcycle compatible with wider social goals such as cleaner air in urban areas.
2020 KTM 890 Duke R First Ride Review
For 2020, KTM shows off a new top-shelf version of its original 790 Duke middleweight in the 890 Duke R ($12,439 as tested). This hot-rodded parallel-twin-powered 890 expands the basic formula of the 790 by infusing a vastly higher level of engine, chassis, and electronic countermeasures. We wrote about its technical improvements in the 2021 KTM 890 Duke R First Look Preview article and gave an in-depth evaluation of its road performance during the 2020 KTM 890 Duke R Review MC Commute article. In this ancillary review we expand on its sporting pedigree after spending a day melting Michelin Power Cup rubber through our favorite stretch of Southern California back roads.
And there’s more. Engineers are saying that we can expect to see fewer supersport four-cylinder engines in future because Euro 5 is so difficult for them to meet.
Here is a major reason why—as the mixture is ignited, turbulent flame roils radially outward from the central spark plug. Burning releases heat, causing a steep rise in combustion chamber pressure. That pressure, which may peak as high as 1,200 psi at peak torque, occurring at about 11 degrees ATDC (after top dead center), forces unburned mixture into the crevice volume defined by the top piston ring land and the ring’s vertical and back clearances in its groove. As much as 2 percent of the charge can be compressed into those tiny volumes. When combustion ends and piston motion expands and cools the combustion gas, that unburned mixture comes streaming up out of the crevice volume. Dramatic Schlieren photography made with MIT’s square quartz cylinder test engine shows this gas—a major source of UHC, continuing to emerge through the whole exhaust stroke. That unburned mixture stays unburned.
2020 Ducati Streetfighter V4/V4 S
2020 Ducati Streetfighter V4/V4 S Reviews, Comparisons, And CompetitionIn Cycle World’s first ride review, Road Test Editor Michael Gilbert stated, “At first touch of the throttle, the Streetfighter offers a crisp and tractable power delivery as it comfortably transfers weight rearward for supreme confidence at corner exit. But hit the 7,000 rpm mark, and you’ll witness the V4 in all its glory as it lofts the front end skyward and sends your glutes into the rear cowling under hard acceleration.”Sign up here to receive our newsletters.
One way to minimize ring crevice volume is to move the rings up as high as possible on the piston, and to minimize the clearance above and behind the rings. That has already been done. To get further reductions we have to reduce the total length of piston ring sealing, which is the circumference (distance around) of one piston, times the number of cylinders.
Why not just eliminate this crevice volume by tightening clearances? Rings must have enough vertical and back clearance for combustion pressure to press them out to seal against the cylinder wall, and downward to keep them on the bottoms of their grooves. Make clearance too tight and ring sticking may occur, destroying ring seal.
I did the arithmetic to compare the seal length of a Honda CBR600 with that of this new 890 KTM. Result? Thetwin, despite having 48 percent more displacement, has almost 50 percent less total seal length. That has to translate to a useful reduction in HC—just by building a twin instead of a four.
And there’s more. I see more and more outstanding torque curves like these in recent engines, and I suspect they are not just the result of simple-minded “more torque is more better” thinking. They are also what happens when Euro 5 or similar limits apply pressure to reduce valve overlap. Overlap is the period around TDC at the end of the exhaust stroke, during which the intakes have begun to open but the exhaust valves have not yet completely closed. Overlap is important to emissions because it is the major “window” through which some fresh charge, entering the cylinder through the intake valves, can get short-circuited straight out the exhausts to be detected as UHC in emissions test cycles.
2020 Triumph Speed Triple S/RS
The Triumph Speed Triple has a 25-year history in the United States and has seen a couple boosts in displacement since then to the 1,050cc in-line three-cylinder standard/naked bike we see today. Within this quarter century it has claimed not one, but two awards in Cycle World’s annual Ten Best for its rational, everyday riding personality with sportbike shredability. If you are looking for a bike with an upright riding position, gobs of torque across the rev range, and a stripped-down appearance, then keep your eyes on the Speed Triple.
It just so happens that the shorter valve timings that result from reduced overlap can also produce extremely broad and very rideable torque curves. How much overlap is a lot, and how much is a little? Back in the days of two-valve engines, greater valve weight needed more time for valve springs to control it, so engines were built with as much as 80 degrees of overlap. By contrast, some Harley engines have been given zero or negative overlap, and engineers at Ducati have called their “Diavel” engine “the eleven-degree” because of its very short overlap.
Not so long ago, the 13.5-to-1 compression of this new 890 was considered radically high, and very likely to cause engine knock on ordinary pump gasoline. How do modern engines avoid knock (a.k.a. “detonation”) with such high compression? Years ago, before we had the luxury of digital mapped ignition timing and fueling, a 13.5 engine would have knocked itself silly the first time the owner took a big handful down at 3,000 revs (lugging can lead to detonation) but today the combination of fast combustion and electronic knock detection/prevention make knock a thing of the past. Then why so much compression if it’s not to boost torque? High compression doesn’t just make torque—it also reduces fuel consumption and therefore carbon dioxide emissions (motorcycle CO2 emissions are not regulated in Euro 5 but must be reported).
Looking at the power and torque curves we see that the new 890 makes its peak power of 106 up at 9,870 rpm, up 660 revs from the 790′s peak. Why rev a bigger engine higher than a small one? If we compare the net, stroke-averaged combustion pressures of these two designs, we find they are reduced almost 10 percent in the new design. If you need more power for a new model but Euro 5 is making it harder to achieve high combustion pressure, to get it you have to boost one or both of the other two major variables in engine power: cylinder displacement and rpm.used both to realize the 890′s gain of 11.7 percent in peak power.
The Last Of Us 2 Training Manuals Guide: Where To Find Every Upgrade
In the world of The Last of Us Part 2, finding supplements can help you build new skills to do all kinds of things, from developing more efficient crafting to improving your stealth capabilities. But earning those skills first requires that you first unlock them by discovering Training Manuals, books that impart new knowledge to Ellie so she can start to hone her new abilities. The thing is, many of those Training Manuals require some scavenging to discover, and are often hidden off the beaten path. To help you out, we've tracked down every Training Manual in The Last of Us Part 2, to help you grab every skill and earn a variety of Trophies. Check out the full list below.
The journal insert plain bearings most used in modern automotive practice consist of a thin layer of aluminum-silicon alloy on a steel backing. In increasing cylinder bore by 3 percent and stroke by 4.7 percent, the 890′s inertia loads from bigger pistons, moving through a longer stroke at higher peak rpm told the engineers they needed to make some changes. They redesigned the pistons to be 10 grams lighter than those of 790, not 6 percent heavier as you’d expect from their larger bore. And to handle the added loads of the longer stroke and higher peak revs, they adopted con-rod bearing shells with copper-based rather than aluminum-based bearing material, in all-new con-rods.
Probably because idle can be a problem at high compression ratio, crankshaft rotating mass has been increased 20 percent.
To further refine mixture control, each throttle body has its own manifold pressure sensor and operating variables are separately mapped for each cylinder.
Motorcycling is changing to adapt, both to Euro 5 emissions limits and to riders who want a more natural upright riding position. The sportbike era was exciting, but the sudden rush of high-rpm four-cylinder power is now being replaced with Euro 5-compatible short valve timing that gives strong rideable torque across a wide range. To control costs in our post-2008 and COVID-19 economy, engines have fewer parts. That means twins like this 890. Enjoy your ride.
2020 Triumph Street Triple R .
2020 Triumph Street Triple R