Wednesday 25 April 2018

Weights and Measures

I'm always mindful of how heavy a motorcycle is, but there is a lot of static in the way. Between the splits Canadians do between the metric and imperial systems and the games played by motorcycle manufacturers, I'm often left second guessing what I think I know.

I've owned everything from feather weight KLX250s (278lbs/126kgs) to light weight Ninja 650s (393lbs/178kgs), heavy weights like the Concours (‎671lbs/305kgs) and middle weights like my current Tiger (474lbs/215kgs), but even those statistics are suspect because manufacturer's will share a dry weight (no fluids) if it's a bike that is bragging on its lightness and a wet weight (ready to ride with fuel) if it doesn't matter so much or the bike has a tiny tank and lousy range.  There is no consistency at all in this other than the marketing angles being played.  I have no idea if those numbers published on the bikes I've owned above are even equivalent.  Are they wet weight?  Dry weight?  Something else?

To try and get my head on straight I've gone looking for some stats, and found montesa_vr's work on ADVrider.com (great site!  Check out their epic ride reports if you like to get lost in a long distance adventure).  

I took that exhaustive list of street legal dual sports and dumped them into a spreadsheet, sorting them by comma separated values.  Then I added in some handy metric/imperial connections and stats on weight of a tank of fuel, so you can see them all in one place.

one gallon of gasoline weighs 6.2 lbs.
One litre is equal to 0.264172 gallons (US liquid).
So, 1 litre = 1.6378664 lbs.
1lb = 0.453592 kgs
1 litre of gasoline = 0.7429237021194 kgs




It ain't heavy, it's my Tiger. It's obviously lighter than
the Concours I rode before it, but much heavier than
the Ninja before that. I just wish the stats were
consistent and comparable
The Tiger 955i is listed as a 215kg dry weight.  With a full tank of gasoline it's loaded up with almost 18kgs of fuel, putting it at about 233kg, yet it's listed as a 257kg wet weight.  So, that must be 18kgs of fuel and 24kgs of oil and coolant?  That seems like an awful lot of oil and coolant (and brake fluid? and what, fork oil?  How asinine does dry weight get?).  I've since been told that some manufacturer's don't include batteries in the dry weight of a bike - this is getting silly.

At 566lbs, my old Tiger would be 7th in the current crop of heavy weight adventure bikes.  I don't think it's exceptionally heavy for what it is, but it's hard to tell with the smoke and mirrors.

Dry weight is virtually meaningless, I'm astonished that it's even given as a statistic.  When would you ever need to know what a bike weighs without any fluids in it?  I couldn't run, so it's an academic statistic verging on pointless.  I also get montesa_vr's point that bikes shouldn't be punished on weight comparisons for being able to carry a reasonable amount of fuel.  Putting a peanut sized tank on a bike so you can brag about the weight seems disingenuous.

At least a wet weight comparison offers up a bike that is actually operational.  A wet weight with an empty tank seems like the obvious standard if you don't want to punish long distance capable machines, but no one seems to do it.

Case in point:  the picture on the left is from UK BIKE Magazine.  Don't expect a comparable standard in motorcycle weights.