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[MostlyBonkers]

[Part 2 of 2]

In addition to the points I've already made, here are some compelling reasons to start demanding g-force figures from our favourite bike reviewers:

1. G-force is actually a term that most of the general public can relate to.  Have you ever been in a rollercoaster or simply just jumped off a wall? 1G is an extremely effective way of getting fast very quickly!
2. G-force can easily be made more interesting by plotting the results on a graph against other well-known bikes, either in the same category or otherwise, or both!  This would reveal a lot about different gear ratios, aerodynamic efficiency, engine or motor characteristics, weight and so on.
3. I think most readers would happily adjust the figures for themselves if told the rider's weight, height and body shape.  Not in a complicated way; just in terms of thinking that the test rider was heavier than them, a bit taller and quite stocky, therefore they could expect slightly better figures.
4. G-force directly measures what we often refer to as oomph, which directly relates to the fun factor.  G is for Giggles!
5. Modern traction control systems often offer the rider some adjustment as to how intrusive they are.  It would be interesting to see how g-force is affected by the different settings. 
6. Likewise with power modes.
7. I'd like to see g-force figures for deceleration too.  Breaking figures would give an indication of tyre grip and breaking power.  It's nice to know how well a bike can slow down.  Engine breaking could be shown in different gears too.  Some like it, some don't.
8. G-force certainly gets the juices flowing, much like certain parts of the male and female anatomy.  It's a bit of fun, if a little naughty... ;-)
9. PC magazines have been comparing various stats using sliders, dials and benchmarks for years.  It's a great way of comparing kit and even easier with g-force because 1G will always be 1G.  The benchmarks for computers keep changing as each new generation eclipses the last.  G-force benchmarks for bikes would last decades and be meaningful to different generations of bikers.
10. G-force could really help to illustrate the appeal of a lightweight 2-stroke bike versus a thumping Harley.  How and where they provide the thrills.
11. G-force might help prevent riders from choosing sportsbikes for the road, when they realise they're going to have have more fun with a bike that provides more fun at legal speeds. I've fallen victim to that recently...

I could go on and perhaps you can think of some other compelling reasons? There must be more reasons why we don't see g-force starts very often, although the ones I've mentioned are probably enough...

Anyhow, I've spent much longer on this reply than I anticipated.  Perhaps it's worthy off it's own topic.  Please let me know your thoughts and I might just rewrite it a little and post it separately if the feedback indicates so.

[Jarrett]

Did you mean to post that in this thread?  I don't see what it has to do with the topic.

[MostlyBonkers]

Erm, you do have a good point there Jarrett.  I think it was inspired by all the talk of gear ratios earlier on in the thread.  However, it is rather off topic so apologies for that.

I'm glad you went for a DSR, by the way.  A great choice.  Just take extra care in situations that could catch you out, like diesel spills on the road in the dark.

[Jarrett]

Erm, you do have a good point there Jarrett.  I think it was inspired by all the talk of gear ratios earlier on in the thread.  However, it is rather off topic so apologies for that.

I'm glad you went for a DSR, by the way.  A great choice.  Just take extra care in situations that could catch you out, like diesel spills on the road in the dark.

No worries, its cool info, I just wanted to make sure I wasn't missing the connection.

I only just recently encountered my first diesel spill in the dark in a light rain.  Thankfully, I was not on my bike but rather in my truck.  Even then, it was crazy.  ABS and TC were going on instantly and major loss of control.  Can't imagine trying to handle that on a SR or DSR.

[remmie]

Ok bonkers, you wanted G-forces, tou got it

As i am from the mainland of Europe (Netherlands) i am more familiar with the metric system so i'll just use that. Good thing about G-force is that it is irrespective of metric or imperial or other conversions. (not 100% as the G-force is different around the globe but not by much)

lets take the SR and the SR/F (i have the first and the latter is on order

SR 2018 :
157 Nm at the motor
final drive ratio 90 : 20 = 4.5 (belt)
Tiresize 140/70/17
Weight : 188 kilos
Rider weight : 80 kilos (could vary among riders
1 G = 9.8 m/s^2

156 Nm * 4.5 = 707 Nm at the wheel (2% loss of the belt not calculated)
tire radius = 0.314 m

707 Nm / 0.314 m = 2250 Newton at the wheel exerted to the ground
2250 N / (188+80 kg) = 8.39 m/s^2
8.39 m/s^2 / 9.8 m/s^2 = 0.86 G

And also a nice thing about G's is that the 0-100 km/hr figure can be calculated. (100 km/h = 27.77 m/s)
the THEORETICAL 0-100 km/h then equals to 27.77 (m/s) / 8.93 (m/s^2) = 3.31 seconds.
mind that this figure is with a lineair acceleration and no wind resistance and no losses in the drivetrain. So faster than that should never be possible.

Same for the SR/F
190 Nm at the motor
final drive ration 90 : 20 = 4.5
Tiresize 180/55/17 (tire radius is the same as a 140/70/17
Weight : 226 kilos (premium version)
Rider weight : 80 kilos (could vary among riders
1 G = 9.8 m/s^2

190 * 4.5 / 0.314 = 2722 Nm
2722 / (226+80) kg = 8.90 m/s^2
So the G-number is 8.90 m/s^2 / 9.8 m/s^2 = 0.91 G
0-100 km/h time is at optimum 3.12 sec

By using lbs for all weights and lbs/ft and tire radius in feet should generate the same numbers for G and 0-100 km/h (0-62 mph)

Weight can have a very profound effect. For example riding with my girl (at 60 kgs) slows the acceleration of the SR from the theoretical 3.3 secs to 4.1 seconds (0.70 G)
All theoretical off course but as bonkers says very comparable.

Final comparison is to a 2010 Street triple that i used to own (Great bike and very similar riding position but noisy as hell
torque is around 60 Nm throughout the rev range (very flat from around 2000-10000 rpm)
primary ratio is 85/46, first gear is 34/13 and final drive (chain) is 47/16 totaling a ratio of 14:1 (vs the 4.5:1 of the Zero)
Tire radius is the same at 180/55/17
60 * 14 / 0.314 = 2675 N (almost identical to the SR/F)
weight is 189 kilos + 80 kgs rider (lots less than the SR/F)
acceleration is 10.1 m/s^2 = 1.02 G => 2.75 sec 0-100 kph
Again, totally without consideration for losses in the gearbox and chain etc. which should be a lot higher due to the gears, oil and the chain (15% loss ??)

So while the MOTOR of an electric has loads more torque compared to an ICE bike. The total drive ratio is much smaller and therefore the force exerted to the ground is comparable (600-750 CC bikes) or even lower (litre or greater bike) for an electric motorcycle.

[Jarrett]

That's interesting info, thanks.

Makes me want a Street Triple

Which is about 1/2 the cost of a new Zero.

[remmie]

hahaha yeah, it was a very nice machine.

But noisy as hell, having to shift (although the quickshifter was very smooth). It literally eats tires (< 5000 km) while the zero does 16.000 km with a much cheaper set.
And the chain maintenance was the most annoying of all. every ride (or every 300 km) having to grease the chain and grease splattering all over the backside (and my backside)
oil changes, valve clearance adjustment etc , ugh.

Although the triple cylinder engine was also smooth as butter, pulling lineair like a zero from as low as 2000 rpm al the way up to 12000 rpm. Very similar to the SR. No waiting at all for it to go up the rev range.

But when i bought my 2018 SR which went a lot further on a charge than my 2014 SR it was done with the Striple. I sold it to have additional funds to justify the purchase of the SR/F and i have no regret about it (I rode it only once on a 3 day gettaway since i got the 2018 SR)

[Jarrett]

That's good to know.  I've been considering trading my DSR on a Street Triple.

Need to go test ride one, maybe its not all its cracked up to be.

[Yamanatc]

" Just search for Zeros on (salvage) auction site and run the numbers against actual sales <1000 annually. "
Wonder how many crashes are the result of 'learning curve-itis?' Most of salvage Zero wrecks out there are bump-and-dumps rather than high-speed-high-sides; retraining the right wrist after years and years of caressing throttles is not instantaneous.

Traction control may give a rider time to get things under control after unintentionally and unconsciously sending 100HP to the rear wheel, but not if sitting 10 feet behind a garbage truck waiting for a light or some such nonsense. Can you imagine the trouble converted H/D riders will have with their new Livewires? How much sheer determination and self control will be required for a life-long Harley ICE'r to never blip the throttle ever again?

Warren   
 

[Jarrett]

Well... it happened tonight

I was in a Harley group ride of all things.  Group got caught at a light and split.  Light turns green, left hand turn, Sport mode, I give it juice and the back tire starts to step out on me as I make my way around the corner.  I chopped the throttle, brought it back in line and hammered it again.  A dude on a (I guess faster) Harley wanted to test the DSR at that moment, so I had to get back into it once I straightened up.  It waved bye bye to the Harley easily

I swear after the last firmware update, this thing is accelerating harder.  I spun the rear tire coming out of my garage this morning.  It's never done that before.  Then I spun it out at that red light tonight.  All the sudden, the torque seems to be there now.  Not sure why, but I dig it.  Whatever the dealer did to it on the last trip was nice and appreciated.

[MostlyBonkers]

Ok bonkers, you wanted G-forces, tou got it

As i am from the mainland of Europe (Netherlands) i am more familiar with the metric system so i'll just use that. Good thing about G-force is that it is irrespective of metric or imperial or other conversions. (not 100% as the G-force is different around the globe but not by much)

lets take the SR and the SR/F (i have the first and the latter is on order

SR 2018 :
157 Nm at the motor
final drive ratio 90 : 20 = 4.5 (belt)
Tiresize 140/70/17
Weight : 188 kilos
Rider weight : 80 kilos (could vary among riders
1 G = 9.8 m/s^2

156 Nm * 4.5 = 707 Nm at the wheel (2% loss of the belt not calculated)
tire radius = 0.314 m

707 Nm / 0.314 m = 2250 Newton at the wheel exerted to the ground
2250 N / (188+80 kg) = 8.39 m/s^2
8.39 m/s^2 / 9.8 m/s^2 = 0.86 G

And also a nice thing about G's is that the 0-100 km/hr figure can be calculated. (100 km/h = 27.77 m/s)
the THEORETICAL 0-100 km/h then equals to 27.77 (m/s) / 8.93 (m/s^2) = 3.31 seconds.
mind that this figure is with a lineair acceleration and no wind resistance and no losses in the drivetrain. So faster than that should never be possible.

Same for the SR/F
190 Nm at the motor
final drive ration 90 : 20 = 4.5
Tiresize 180/55/17 (tire radius is the same as a 140/70/17
Weight : 226 kilos (premium version)
Rider weight : 80 kilos (could vary among riders
1 G = 9.8 m/s^2

190 * 4.5 / 0.314 = 2722 Nm
2722 / (226+80) kg = 8.90 m/s^2
So the G-number is 8.90 m/s^2 / 9.8 m/s^2 = 0.91 G
0-100 km/h time is at optimum 3.12 sec

By using lbs for all weights and lbs/ft and tire radius in feet should generate the same numbers for G and 0-100 km/h (0-62 mph)

Weight can have a very profound effect. For example riding with my girl (at 60 kgs) slows the acceleration of the SR from the theoretical 3.3 secs to 4.1 seconds (0.70 G)
All theoretical off course but as bonkers says very comparable.

Final comparison is to a 2010 Street triple that i used to own (Great bike and very similar riding position but noisy as hell
torque is around 60 Nm throughout the rev range (very flat from around 2000-10000 rpm)
primary ratio is 85/46, first gear is 34/13 and final drive (chain) is 47/16 totaling a ratio of 14:1 (vs the 4.5:1 of the Zero)
Tire radius is the same at 180/55/17
60 * 14 / 0.314 = 2675 N (almost identical to the SR/F)
weight is 189 kilos + 80 kgs rider (lots less than the SR/F)
acceleration is 10.1 m/s^2 = 1.02 G => 2.75 sec 0-100 kph
Again, totally without consideration for losses in the gearbox and chain etc. which should be a lot higher due to the gears, oil and the chain (15% loss ??)

So while the MOTOR of an electric has loads more torque compared to an ICE bike. The total drive ratio is much smaller and therefore the force exerted to the ground is comparable (600-750 CC bikes) or even lower (litre or greater bike) for an electric motorcycle.

Thanks for doing that remmie, very interesting and much appreciated! [emoji4]

[alko]

Well... it happened tonight

I was in a Harley group ride of all things.  Group got caught at a light and split.  Light turns green, left hand turn, Sport mode, I give it juice and the back tire starts to step out on me as I make my way around the corner.  I chopped the throttle, brought it back in line and hammered it again.  A dude on a (I guess faster) Harley wanted to test the DSR at that moment, so I had to get back into it once I straightened up.  It waved bye bye to the Harley easily

I swear after the last firmware update, this thing is accelerating harder.  I spun the rear tire coming out of my garage this morning.  It's never done that before.  Then I spun it out at that red light tonight.  All the sudden, the torque seems to be there now.  Not sure why, but I dig it.  Whatever the dealer did to it on the last trip was nice and appreciated.

I haven't done a firmware update yet and I purchased my 2017 dsr used in June 2018, with only 1200 miles on it. Ive heard bad things happening with certain updates, so as long as my bike is working, why fix it?
But if your update improved performance, maybe I'll take a chance with it.

[Shadow]

...I swear after the last firmware update, this thing is accelerating harder.  I spun the rear tire coming out of my garage this morning.  It's never done that before.  Then I spun it out at that red light tonight.  All the sudden, the torque seems to be there now.  Not sure why, but I dig it.  Whatever the dealer did to it on the last trip was nice and appreciated.

Sport mode? Eco? Custom?  Flashing the firmware can have effects on the mode profiles. Custom mode is always overwritten. If you gain access to the MBB the other two profiles can (I think?) be set differently.

[Richard230]

...I swear after the last firmware update, this thing is accelerating harder.  I spun the rear tire coming out of my garage this morning.  It's never done that before.  Then I spun it out at that red light tonight.  All the sudden, the torque seems to be there now.  Not sure why, but I dig it.  Whatever the dealer did to it on the last trip was nice and appreciated.

Sport mode? Eco? Custom?  Flashing the firmware can have effects on the mode profiles. Custom mode is always overwritten. If you gain access to the MBB the other two profiles can (I think?) be set differently.

I had a couple of firmware updates to my 2018 S about a year ago and my custom mode was not affected. 

[NoMoreIdeas]

That's good to know.  I've been considering trading my DSR on a Street Triple.

Need to go test ride one, maybe its not all its cracked up to be.

I have a '14 Street Triple and it's going up for sale soon since I got the FX. In 2013 they widened the ratio in 1st gear and it just doesnt seem to have the punch you hear about in older triples. My FX feels faster below 60mph. The motor is fantastic though, very nice torque all through the rev range and like has been said, just buttery smooth even at 2000 rpm. The 765 though.. thats another beast and I want to check one of those out.