Talk:Motorcycle testing and measurement

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Merge[edit]

I'm seeing a number of articles have been merged into this one article without following any of the merge procedures. Although I may not disagree with the merge, this type of merge definitely required some sort of discussion. Dbratland, it looks as if you may have been the user championing the merge. What was the reasoning behind this merge? What data has been lost or added with the merge? roguegeek (talk·cont) 21:21, 8 December 2009 (UTC)[reply]

The reasoning is primarily that WP is not a dictionary. That Flammability and Inflammability don't require separate articles. And that the questions over errors, fudging, exaggeration and misunderstanding in motorcycle weight, horsepower, speed, etc, are one topic, not several topics. The articles merged were generally rambling essays, and uncited. I kept everything with a source, and added more sources. --Dbratland (talk) 21:35, 8 December 2009 (UTC)[reply]
So I guess I'm just looking to see how to pick up editing this article. The stuff that didn't have a source, was it tagged or just removed? roguegeek (talk·cont) 21:40, 8 December 2009 (UTC)[reply]
All we're talking about is Dry weight (motorcycle) and Wet weight (motorcycle) being merged into Motorcycle weight on 1 October, and then that, plus this bit about speed tests, merging into the current article. I kept even woolly, unsourced speculation like "This difference includes around 30 lb (14 kg) of gasoline, 7 lb (3.2 kg) of engine oil, 7 lb (3.2 kg) of coolant, and 9 lb (4.1 kg) of battery. These weights are even larger for bigger motorcycles with higher capacities" which probably ought to go.

It isn't so much that anything was lost, it is that I didn't delete nearly enough.--Dbratland (talk) 21:50, 8 December 2009 (UTC)[reply]

Specially prepared press vehicles[edit]

Consumer Reports just had a blog post about car manufactures providing specially prepared vehicles for press reviews, free of charge, often with travel and lodging thrown in as well. Some press cars have blueprinted engines, different fuel mapping, extra sound deadening, and more. Ash on Bikes has mentioned in some reviews over the last few months that the press bikes were equipped with better tires than the one you can buy, and hinted at other optimizations, such as better suspensions. Motorcycle Consumer News is known for not selling advertising, but unlike Consumer Reports, they do review press bikes rather than buying them anonymously at the dealership. We should try to highlight this issue more if we can. --Dennis Bratland (talk) 04:05, 22 November 2011 (UTC)[reply]

Agree. We should put something about it into this article, but otherwise unless specific evidence is obtained it will be really difficult to put anything into individual bike articles. --Biker Biker (talk) 09:44, 22 November 2011 (UTC)[reply]

Another ref.

On the screen popped up a graph of power and torque curves, with lines for what looked like three bikes. And there were, sort of… "These are the curves for the Tiger Explorer, and here are the curves for the customer BMW R1200GS. And here, just above those, are the curves for the R1200GS press bikes…"

Pause while jaws hit floor… But these aren't Triumph's own findings, the Hinckley factory is merely reproducing what was published by German magazine Motorrad, which put its press demo bike and showroom versions of the GS on the same dyno, and found smoother curves with more peak power and less low rev torque on the press version, pandering to typical journalist tastes clearly.

We should track down the Motorrad magazine article this is based on. --Dennis Bratland (talk) 21:21, 26 February 2012 (UTC)[reply]

Susan Carpenter wrote on her website "in my role as a motorcycle critic, the only handout I take from manufacturers is the vehicle itself and whatever gas happens to be in the tank when I take possession for a short-term loan and test ride. I do not accept any gifts or swag, no matter how minute, i.e. a baseball hat. I do not accept free travel or accommodations. I do not accept free gear. I do not accept free accessories or gadgets. I pay for all the gas myself. This is all in an effort to remain unbiased and true to the task at hand, which is an honest assessment of what I'm riding." Note that that most motorcycle reviewers including Motorcycle Consumer News but not Consumer Reports, normally accept travel and accommodations from manufacturers. --Dennis Bratland (talk) 03:16, 9 December 2013 (UTC)[reply]

Beginning in 2009, the four major Japanese manufacturers, and BMW, began publishing the wet weight[edit]

Would it be reasonable to move this to the end of the wet weight section? Fotoguzzi (talk) 17:17, 7 March 2012 (UTC)[reply]

Need section on Cd and CdA[edit]

Using source: Anderson, Steve (June 1999), "Aerodynamics 101; What looks fast isn't", Cycle World, pp. 40–41. We need a new section saying:

  • Sportbike motorcycles generally have a Cd of .55 to .65 (comparable to a pickup truck), vs Cd .29 for many sports cars and even .20 for high efficiency cars. Motorcycle projected frontal area is in the neighborhood of 2.9–3.9 sq ft (0.27–0.36 m2). The Hayabusa's Cd is .56 with a CdA of 2.9 sq ft (0.27 m2)
  • With dustbin fairings, motorcycles could have Cds as low as .45 to 50, but these were banned in racing in the 50s and so are out of fashion among street motorcycles. Rounded, smooth shapes are also out of fashion, in favor of less efficient, pointed, jet-fighter like shapes.
  • Manufacturers don't publish bikes' Cds, or else try to confuse the public by advertising CdA in meters, because the figures, like 0.31, sound comparable to a car's Cd. Cd is dimensionless, while CdA is dimensioned but marketers often fail to reveal the dimension. --Dennis Bratland (talk) 19:51, 8 July 2014 (UTC)[reply]
Good idea, here are some more sources -- Brianhe (talk) 22:46, 8 July 2014 (UTC)[reply]
  • Aerodynamics, Tony Foale Designs, 1986-1997.
  • Tunnel Vision - What makes the Suzuki Hayabusa faster than the more powerful Kawasaki ZX-12R? A visit to the National Research Council wind tunnel provides the answer, Sport Rider, 2010
  • Motorcycle Tuning: Chassis, John Robinson, 1994: "[T]here is little chance of developing a fully streamlined machine (FIM regulations forbid streamlining...)" (p. 132)
Here's a start on text...
Automotive aerodynamics of motorcycles are not as frequently measured by third parties or reported by manufacturers as other figures like power. The dimensionless measure, Cd, varies from of .55 to .65 (comparable to a pickup truck), vs Cd .29 for many sports cars and even .20 for high efficiency cars. However a more relevant figure of merit, CdA, factors in the vehicle's frontal area, and thus actual power required to overcome wind resistance. A typical projected frontal area for motorcycles is in the neighborhood of 2.9–3.9 sq ft (0.27–0.36 m2). When the CdA figure is reported, it is sometimes in nonstandard units making it hard to compare between motorcycles and automobiles.(Anderson 1999)
Cd could be reduced through the use of "dustbin fairings" or fully enclosed and streamlined fairings (like the Vetter Streamliner prototype) to reduce wake turbulence and flow separation, but these were banned in racing in the 50s and so are out of fashion among street motorcycles.(Robinson 1994)
Looking forward to feedback. Especially feel that we need a source saying that the Cd and CdA measurements aren't often reported -- Brianhe (talk) 22:53, 8 July 2014 (UTC)[reply]
It's in the link I gave above: "Most motorcycle companies resist quoting drag coefficients of their products because the numbers look poor compared to cars... Not to mention the popularity of giving out the CdA in square meters while forgetting to mention the units..." --Dennis Bratland (talk) 04:01, 9 July 2014 (UTC)[reply]
Started Motorcycle testing and measurement#Aerodynamics. — Brianhe (talk) 04:55, 9 July 2014 (UTC)[reply]

Need to add Speed in Gear definition Suggestion[edit]

We need to define speed in gear, aka top speed in gear. It's not the same as top speed. Speed in gear is the hypothetical top speed at redline based on drive ratios and nominal tire size. Actual top speed takes into account real world variation in tire circumference, and rolling resistance/air resistance vs. horsepower. Many publications list speed in gear as a reference, but it is sometimes misunderstood to represent top speed. Most vehicles can't reach redline in top gear because they can only go as fast as air resistance allows. --Dennis Bratland (talk) 20:47, 25 August 2014 (UTC)[reply]

A quick web search suggests that the phrase "top speed in gears" is more common. Top Gear has a good explanation[23] using the terms "drag limited" and "rev-limited" top speeds. It would weave well with the aerodynamics section, too, which ain't bad. —Brianhe (talk) 22:51, 25 August 2014 (UTC)[reply]

Need to incorporate this source[edit]

This is an excellent source for us here. It doesn't really matter that it's from 1977, because we have large numbers of citations from tests in that period, so we need a source like this to describe what the methodology was then. --Dennis Bratland (talk) 00:02, 11 December 2014 (UTC)[reply]

Good find. Summarized source with other summaries at Talk:Motorcycle testing and measurement/Dumping ground. Brianhe (talk) 01:55, 11 December 2014 (UTC)[reply]

Speedometer error example[edit]

See Motorcyclist Kawasaki ZX-12R Consumer Information John Burns quote "Heck, if not for us you'd have to take it from your ZX-12R's speedo, which reads 210 when you're only doing 180. How embarrassing." --Dennis Bratland (talk) 19:31, 5 November 2015 (UTC)[reply]

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