Motorcycle testing and measurement: Difference between revisions

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{{Short description|Motorcycle technology and verification}}

{{refimprovemore citations needed|date=December 2009}}

[[File:2008 Sprint ST on the dyno at Ducati Seattle.jpg|thumb|upright=1.35|A [[Triumph Sprint ST]] on a chassis dynamometer]]

[[File:Suzuki Hayabusa at the Bonneville Salt Flats Speed Week.jpg|thumb|[[Suzuki Hayabusa]] at [[Bonneville Speedway|Bonneville Speed Week]].]]

'''Motorcycle testing and measurement''' includes a range of more than two dozen statistics giving the specifications of the [[motorcycle]], and the actual performance, expressed by such things as the output of the engine, and the top speed or acceleration of the motorcycle. Most parameters are uncontroversial and claims made by manufacturers are generally accepted without verification. These might include simple measurements like rake, trail, or wheelbase, or basic features, such as the type of brakes or ignition system.

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==Top speed==

[[File:Dragrace01.JPG|thumb|Two motorcycles at a ¼ mile (402 m) [[dragstrip]].]]

Motorcycle speed tests, especially at high speeds, are prone to variation due to human error, limitations in equipment, and atmospheric factors like wind, humidity, and altitude. The published results of two otherwise identical tests could vary depending on whether the result is reported with or without industry standard correction factors calculated to compensate for test conditions. Rounding errors are possible as well when converting to/from miles and kilometers per hour.<ref name=Ford2003>{{citation |last=Ford |first=Dexter |title=Grudge Match |magazine=[[Motorcyclist (magazine)|Motorcyclist]] | issn=0027-2205 | publisher=Source Interlink Media |date=August 2003 |pages=34–35 |url=http://www.motorcyclistonline.com/features/122_0308_kawasaki_zx12r_suzuki_hayabusa/index.html }}</ref>

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Ford |first=Dexter |title=Grudge Match |magazine=[[Motorcyclist (magazine)|Motorcyclist]] | issn=0027-2205 | publisher=Source Interlink Media |date=August 2003 |pages=34–35 |url=http://www.motorcyclistonline.com/features/122_0308_kawasaki_zx12r_suzuki_hayabusa/index.html }}</ref>

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==Engine power and torque==

{{See also|Dynamometer}}

With power typically being the product of [[force]] and [[speed]], a motorcycle's power and [[torque]] ratings will be highly indicative of its performance. Reported numbers for [[power (physics)|power]] and [[torque]] may however vary from one source to another due to inconsistencies in how testing equipment is calibrated, the method of using that equipment, the conditions during the test, and particularly the ___location that force and speed are being measured at.<ref name=Searle2009>{{citation |last=Searle |first=Dave |magazine=[[Motorcycle Consumer News]] | ___location=Irvine, California |publisher=Aviation News Corp |issn=1073-9408 |title=Measures |page=2 |date=October 2009 |volume=40 |issue=10 |url=http://www.mcnews.com/mcn/editorials/2009OctOpenRd.pdf |accessdateaccess-date=2010-04-29}}</ref> The power of the engine alone, often called crankshaft power, or power at the crankshaft, will be significantly greater than the power measured at the rear wheel. The amount of power lost due to friction in the [[Motorcycle transmission|transmission]] (primary drive, gearbox and final drive) depends on the details of the design and construction. Generalizing, a chain drive motorcycle may have some 5-20% less power at the rear wheel than at the crankshaft, while a shaft drive model may lose a little more than that due to greater friction.

<gallery>

File:Mobile bike dyno run prep.jpg|Preparing for a dyno test &ndash; note the fan used for engine cooling

File:Mobile bike dyno run.jpg|Motorcycle rear wheel on a dyno roller.

File:Boxsterdyno-en.pngsvg|Graph of power and torque.

</gallery>

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While the crankshaft power excludes these transmission losses, still the measurement is often made elsewhere in the drive-train, often at the rear wheel. A correction for the transmission losses is then applied to the measured values to obtain the crankshaft values. For motorcycles, the reported power and torque numbers normally pertain to the crankshaft. In directive 92/61/EEC of 30 June 1992 relating to the type-approval of two or three-wheel motor vehicles,<ref name="eur-lex.europa.eu31992L0061">http:{{CELEX|31992L0061|text=Council Directive 92/61/eurEEC of 30 June 1992 relating to the type-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31992L0061:EN:HTMLapproval of two or three-wheel motor vehicles}}</ref> it is referred to as "maximum engine power", and manufacturers use similar terms. Historically, this convention may have come from the pre-[[unit construction]], wherein the crankshaft was directly accessible for measurements, and the gearbox might have come from a different manufacturer. However, when the engineering details of the transmission are known, the losses therein can be accurately quantified & corrected for. Explicit guidance on the homologation measurements and transmission corrections is given in directive 95/1/EC.<ref>http:{{CELEX|31995L0001|text=Directive 95/1/eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:EC of the European Parliament and of the Council of 2 February 1995:052:0001:0040:EN:PDF on the maximum design speed, maximum torque and maximum net engine power of two or three-wheel motor vehicles}}</ref>

A main source of ambiguity and differences comes from the conditions the test was done at. These conditions include details like atmospheric conditions (temperature, pressure, humidity), tire pressure, how the motorcycle is secured against the dyno drum, but most importantly: the conditions of the motorcycle itself. Examples thereof are: was the alternator fitted?; was the air filter fitted?; what exhaust system was fitted? One would hope that manufacturers would test their motorcycles in normal running order, so the condition that they are sold in, and for which they obtained type-approval, but this is not always the case. Ducati, for instance, has chosen to publish more positive values, stating that "Technical data referring to power and torque was measured on an engine test stand at Ducati".<ref>{{cite web |url=http://ducati.com/bikes/superbike/1199_panigale_r/tech_spec.do |title=Ducati Superbike 1199 Panigale R - Ducati |access-date=2013-06-09 |url-status=dead |archive-url=https://web.archive.org/web/20130704053908/http://www.ducati.com/bikes/superbike/1199_panigale_r/tech_spec.do |archive-date=2013-07-04 }}</ref> Their published values are typically 5% higher than the [[homologation]] values, in normal running order.

==Weight==

Motorcycle weight is expressed in three ways: ''[[gross vehicle weight rating]]'' (GVWR), ''dry weight'' and ''wet weight''. GVWR is the maximum total weight of the motorcycle including all consumables, the rider, any passenger, and any cargo. It is generally well-understood and standardized, being defined by law and overseen by agencies such as the [[US Department of Transportation]].<ref>[{{cite web|url=http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=0901633480023892%7CPart|Parttitle=Search 390Regulations|website=dot.5:gov}}{{dead Definitions,link|date=July Federal Motor Carrier Safety Administration]2025|bot=medic}}{{cbignore|bot=medic}}</ref> In contrast, wet and dry weight are unstandardized measurements that refer to the weight of the motorcycle without rider, passengers or cargo, and either with (wet) or without (dry) a varying set of fluids such as fuel or lubricants, and the battery.

Wet and dry weight are often used to make comparisons between different motorcycles, because all else being equal, a lighter motorcycle will generally perform and handle better than a heavier one.

The difference between GVWR and wet weight is how much the motorcycle can safely carry, including the rider, and any passenger and their cargofuel, and other accessories. This is especially of interest in [[touring motorcycle]]s because when comparing motorcycles ridden by the same operator and passenger, clad in the same [[Motorcycle safety clothing|safety clothing]], the machine with the greatest difference between its GVWR and wet weight can safely bear the most additional weight; for instance, camping food and gear, extra fuel, or spare partsload.

===Dry weight===

As its weight changes during riding, the dry weight of a motorcycle typically excludes the [[gasoline]] (or other fuel). Dry weight, in this sense, can directly be used for comparison with (FIM) weight limits, which pertain to the motorcycle in operating condition. It is also part of the homologation tests,<ref name="eur-lex.europa.eu31992L0061"/> and it is found on the EC Certificate of Conformity as unladen mass.<ref name="31993L0093">http:{{CELEX|31993L0093|text=Council Directive 93/93/eurEEC of 29 October 1993 on the masses and dimensions of two or three-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31993L0093:EN:HTMLwheel motor vehicles}}</ref> This dry weight could also be useful in comparing different models, with different fuel tank capacities. However, manufacturers may also exclude some or all of the following: [[engine oil]], [[coolant]], or [[brake fluid]], and this makes such a comparison difficult. Obviously whenWhen any of these is excluded, the specified dry weight no longer pertains to the motorcycle in running order, and thereby becomes misleading. Some manufacturers even exclude the [[Car battery|battery]], but asnotwithstanding the weight of the battery is mainly in thesolid components (usually lead), this is evennot moreliquid misleading(electrolytes).

So there is no standardized way to test the dry weight of a motorcycle. Inconsistencies may be found between a motorcycle manufacturer's published dry weight and motorcycle press and media outletoutlets's published dry weight. This is due to different testing techniques, mainly differences in what is being excluded, and a lack of defining how the test was done. A battery is typically included in the dry weight by manufacturers (with the exception of at least one), but it may not be included by media outlets. On the other hand, some press and media outlets only exclude fuel to define their dry weight. For a typical [[sport bike]], the difference between wet weight and manufacturer claimed dry weight is around {{convert|70|lb|kg|abbr=on}}.<ref>[{{cite web|url=http://www.amadirectlink.com/news/2006/cbr600rr/|title=American RiddenMotorcyclist &Association Reviewed:> 2007Home|first=American Honda CBR600RR<!-- Bot generated title -->]Motorcyclist|last=Association|website=www.amadirectlink.com}}</ref> This difference includes around {{convert|30|lb|kg|abbr=on}} of gasoline, {{convert|7|lb|kg|abbr=on}} of engine oil, {{convert|7|lb|kg|abbr=on}} of coolant, and {{convert|9|lb|kg|abbr=on}} of battery. These weights are even larger for bigger motorcycles with higher capacities, andcomplicating attemptingcomparison to compare the dry weights ofbetween [[air-cooled]] versusand [[water-cooled]] motorcycles' candry be even more misleadingweights.

While its weight is quite small, andcompared [[hydraulicto fluid]]the isother notfluids strictlydiscussed speakingabove (a few ounces), [[lubricanthydraulic fluid]], it is a liquid that might be excluded during shipping. It is not safe to assume that it is either included or excluded in the reported dry weight. Hydraulic fluid might be found on a particular bike's front brake and reservoir, plus maybe a rear brake with a reservoir, and maybe also in a hydraulic clutch with its own reservoir. It may add a few ounces to the uncertainty.

[[Ducati]] has in the past used the term "Ducati weight", pertaining to a value excluding the battery as well as all fluids, but have since begun using "dry weight" for this.<ref>{{cite web |url=http://ducati.com/bikes/monster/1100__evo/tech_spec.do |title=Ducati |access-date=2013-06-08 |url-status=dead |archive-url=https://web.archive.org/web/20130511070711/http://ducati.com/bikes/monster/1100__evo/tech_spec.do |archive-date=2013-05-11 }}</ref>

Beginning in 2009, the four[[Japanese majorBig JapaneseFour]] manufacturers and BMW, began publishing the wet weight rather than dry, usually providing some explanation for what this means. Since then most other manufacturers have followed, in order to comply with EC directives that explicitly state that the values pertain to the vehicle in running order. Honda describes it as curb weight (aka kerb weight) and says this means the bike is "ready to ride." Others say all fluids are included and the fuel tank is at least 90% full. [[Erik Buell Racing]] gives "Wetwet Weightweight (Nono Fuelfuel)" for the 2012 1190RS motorcycle,<ref>[{{cite web|url=http://www.erikbuellracing.com/motorcycles/1190rs/ |title=1190RS « Erik Buell Racing]|website=erikbuellracing.com|access-date=2012-02-09|archive-date=2012-03-14|archive-url=https://web.archive.org/web/20120314231429/http://www.erikbuellracing.com/motorcycles/1190rs/|url-status=dead}}</ref> while [[KTM]] gives a "Weightweight without fuel approx."<ref>{{cite web |url=http://www.ktm.com/us/superbike/1190-rc8-r-usa/highlights.html#.UbLgxpz4KoY |title=Highlights - KTM |website=www.ktm.com |url-status=dead |archive-url=https://web.archive.org/web/20110512004258/http://www.ktm.com/us/superbike/1190-rc8-r-usa/highlights.html |archive-date=2011-05-12}}</ref>

===Wet weight===

The wet weight of a motorcycle includes, but is not limited to fuel, engine oil, coolant, brake fluid, and battery.

There is no global standardized way to test the wet weight of a motorcycle. In the EU, Council Directive 93/93/EEC specifies wet weight as "mass in running order", which includes all equipment normally fitted to a bike such as windscreen, tool kit and at least 90% of its fuel capacity.<ref>{{cite web | urlname= http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:"31993L0093:EN:HTML | title= Council Directive 93/93/EEC of 29 October 1993 on the masses and dimensions of two or three-wheel motor vehicles | work=EUR-Lex | accessdate= 14 December 2009}}<"/ref> Motorcycle manufacturers will rarely publish wet weight measurements and inconsistencies will almost always be found between different motorcycle press and media outlets. This is due to different testing techniques, differences in what is being included, and by the organization doing the testing omitting an explanation of how they weighed the motorcycle.

''[[Cycle World]]'' has published wet weights with all consumables on board, but only half a tank of fuel, while [[Honda]] has recently published specification tables that use the typically automotive-oriented term ''curb weight'', and stated that it included full fluid levels and the bike was "ready to ride."

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===Gross vehicle weight rating===

{{main|Gross vehicle weight rating}}

Gross vehicle weight rating (GVWR) is the manufacturer's stated maximum safe mass of the motorcycle, including its own mass and everything it carries, taking into consideration the tire profile and load capacity; brake, suspension and frame capacity. It is printed on a motorcycle's [[VIN Plate]]. The difference between GVWR and wet weight is how much the motorcycle can safely carry, including fuel; the rider, passenger and their clothing; cargo; and other accessories. Using this calculation, a typical large [[Cruiser (motorcycle)|cruiser]] might have a maximum useful payload of {{convert|400|lb}}. This is especially of interest in [[touring motorcycle]]s because when comparing motorcycles ridden by the same operator and passenger, clad in the same [[Motorcycle safety clothing|safety clothing]], the machine with the greatest difference between its GVWR and wet weight can safely bear the most additional weight; for instance, camping food and gear, extra fuel, or spare parts. It also indicates that a large rider and passenger might overload the machine even without carrying any additional load, in which case they might need two vehicles for a planned tour.<ref>{{citation|author=Art Friedman|title=Getting Loaded: How Much Weight Can Your Motorcycle Handle?|date=October 2000|journal=Motorcycle Cruiser|url=http://www.motorcyclecruiser.com/getting-loaded-how-much-weight-can-your-motorcycle-handle}}</ref>

==Aerodynamics==

[[Automotive aerodynamics]] of motorcycles are not as frequently measured by third parties or reported by manufacturers as other figures like power.{{sfn|Anderson|1999|p=41|ps=&nbsp;"Most motorcycle companies resist quoting drag coefficients of their products because the numbers look poor compared to cars..."}} The dimensionless measure of [[drag coefficient]], C_d, varies from .55 to .65 (comparable to a pickup truck), vs C_d .29 for many sports cars and even .20 for high efficiency cars. However a more relevant figure of merit, C_dA, factors in the vehicle's frontal area, and thus actual power required to overcome wind resistance.<ref>{{sfnharvnb|Reeve|2010|ps=}}&nbsp;"The best measure of aerodynamic drag is the parameter known as the drag area, C_dA, which has units of square feet."}}</ref> A typical projected frontal area for motorcycles is in the neighborhood of {{Convert|2.9|-|3.9|sqft|abbr=on}}. When the C_dA figure is reported, it is sometimes in nonstandard units making it hard to compare between motorcycles and automobiles.{{sfn|Anderson|1999|pp=40-41|ps=&nbsp;"...Not to mention the popularity of giving out the CdA in square meters while forgetting to mention the units..."}}

C_d 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.{{sfn|Robinson|1994|p=132|ps=&nbsp;"[T]here is little chance of developing a fully streamlined machine (FIM regulations forbid streamlining...)"}} The adherence to "styling aerodynamics" (as opposed to measurably improved aerodynamics) and ergonomic considerations have affected production motorcycle design.<ref>{{sfnharvnb|Reeve|2010|ps=}}&nbsp;"Motorcycles, even racing designs, continue to feature what Cooper calls "styling aerodynamics" ... styling conventions and comfort demands make this sort of [rigorous] approach [to streamlining] impractical."}}</ref>

Another factor making aerodynamic measurements relatively uncommon in the popular press is the lack of access to research-quality [[wind tunnel]]s by journalists.{{sfn|Reeve|2010}}

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{{colbegin}}

* Class ''see [[types of motorcycle]]''

* Engine ''see [[motorcycle engine]]''

** Power ''see above''

** Torque ''see above''

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** {{convert|0|to|1/4|mi|km|abbr=on}} ''See [[dragstrip]]''

** Braking {{convert|60|to|0|mph|km/h|abbr=on}}, {{convert|100|to|0|mph|km/h|abbr=on}}

** Fuel consumption ''See [[Fuel economy in automobiles|Fuel economy]] & [[World Motorcycle Test Cycle|WMTC]]''

** Range

** Emissions ''see [[Vehicle emissions control]] and [[World Motorcycle Test Cycle|WMTC]] (global), [[New European Driving Cycle|NEDC]] (EU), [[FTP-75]] (USA)''

* [[transmissionMotorcycle (mechanics)transmission|Transmission]] number of forward gear ratios, and the type of transmission (e.g. "6-speed [[manual transmission|manual]], 5-speed [[automatic transmission|automatic]]")

* Final drive

* Suspension ''See [[Motorcycle suspension]]''

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==Notes==

{{reflistReflist|colwidth=30em}}

==References==

{{commonsCommons category|Motorcycle testing}}

{{refbeginRefbegin}}

*{{Citation |url= httphttps://books.google.com/books?id=igONw5YZvEUC&pg=RA6-PA40 |title= Aerodynamics 101; What looks fast isn't |magazine=[[Cycle World]] |date= June 1999 |last = Anderson |first= Steve }}

* {{Citation |last=Coyner |first=Dale |title=The Essential Guide to Motorcycle Travel: Tips, Technology, Advanced Techniques |publisher=Kogan Page Publishers |year=2007 |ISBN=1-884313-59-0 |url=http://books.google.com/books?id=0KAXtdNSj-4C&pg=PA136&lpg=PA136#v=onepage&q=&f=false}}

* {{citationCitation |last= Canet |first= |date=Don |title=Packing:Tach WhatTruths; toTall take,tales howof tothe take ittachometer |magazine=American Motorcyclist[[Cycle World]] |publisher=[[AmericanHachette MotorcyclistFilipacchi AssociationMedia U.S.]] {{Subscription required|___locationvia=Westerville,[[Bondi OhioDigital Publishing]]}} | issn=02770011-9358 4286 |volume___location=44Newport Beach, California |issuedate=4July 2006 |pagevolume=4645 |urlissue=http://books.google.com/books?id=F_YDAAAAMBAJ&pg=PA46#v=onepage&q=&f 7 |page=false51}}

* {{Citation |last=Coyner |first=Dale |title=The Essential Guide to Motorcycle Travel: Tips, Technology, Advanced Techniques |publisher=Kogan Page Publishers |year=2007 |ISBNisbn=978-1-884313-59-02 |url=httphttps://books.google.com/books?id=0KAXtdNSj-4C&pg=PA136&lpg=PA136#v=onepage&q=&f=false}}

* {{Citation

|last=Stermer* |year=2006{{Citation |firstdate=BillApril 1990 |title=StreetbikesPacking: EverythingWhat Youto Needtake, how to Knowtake it |magazine=American Motorcyclist |publisher=MotorBooks/MBI[[American PublishingMotorcyclist CompanyAssociation]] |___location=Westerville, Ohio |isbn issn=0277-9358 9780760323625|volume=44 |issue=4 |page=46 |url=httphttps://books.google.com/books?id=NMokiWY6E00CF_YDAAAAMBAJ&pg=PA37#v=onepage&q=&f=false |page=37PA46}}

*{{citation|first=BruceCitation |last=Reeve |first=Bruce |date=June 30, 2010|journal=Cycle Canada|via=Sport Rider|url=http://www.sportrider.com/tunnel-vision|title=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}}

*{{Citation |url= http://books.google.com/books?id=igONw5YZvEUC&pg=RA6-PA40 |title= Aerodynamics 101; What looks fast isn't |magazine=[[Cycle World]] |date= June 1999 |last = Anderson |first= Steve }}

*{{citationCitation|url=httphttps://books.google.com/books?id=l2Zizg8I8p8C&pg=PA129|title=Motorcycle Tuning: Chassis|first=John|last=Robinson|publisher=Butterworth-Heinemann|year=1994|ISBNisbn=075061840X}}

* {{Citation|last=Stermer |year=2006 |first=Bill |title=Streetbikes: Everything You Need to Know |publisher=MotorBooks/MBI Publishing Company |isbn= 9780760323625 |url=https://books.google.com/books?id=NMokiWY6E00C&pg=PA37 |page=37}}

*{{citation|first=Bruce|last=Reeve |date=June 30, 2010|journal=Cycle Canada|via=Sport Rider|url=http://www.sportrider.com/tunnel-vision|title=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}}

{{refendRefend}}

{{Motorcycles}}

{{DEFAULTSORT:Motorcycle Testing And Measurement}}

[[Category:Motorcycle technology| *]]