Shifting (normal vs. aggressive)

[JSP]

I don't doubt that those numbers you posted are accurate, although I am interested to see the graphs and hear your explanation. What I do doubt though is that any non professional can hit those exact RPM's on a consistent basis and keep full focus on the road.

I go partly by engine sound while shifting with a quick glance at my tach. I'm not going to sit and watch my tach to make sure I hit the exact perfect RPM before shifting, while the scenery is whizzing by. I usually get it between 10.5 and 11K, which is close enough for government work as they say.

I have a big ass bright programmable shift light on mine . Staring straight out at the road and you can still see it out of the corner of your eye so you can focus on riding and shift right when you want to, to stay in the meat of the power band. I dont use it for every day riding. (obviously since its programmed to light up right about 15,000 RPM) .

 

[UselessPickles]

What I do doubt though is that any non professional can hit those exact RPM's on a consistent basis and keep full focus on the road.

I go partly by engine sound while shifting with a quick glance at my tach. I'm not going to sit and watch my tach to make sure I hit the exact perfect RPM before shifting, while the scenery is whizzing by.

I agree. Trying to shift at (or as close as possible) to the absolute best RPM shift point only really makes sense when drag racing in a straight line. When there are curves and/or any kind of possible distractions that require mental focus, then it's most important to be in a gear that will allow you to accelerate as desired without hitting the rev limiter before you are physically/mentally ready to pay attention to shifting.

For example, shifting (or potentially forgetting to shift and hitting the rev limiter) while aggressively cornering should be avoided, as well as when merging into heavy traffic on a freeway. In either situation, accidentally hitting the rev limiter could cause some big problems. Shifting while cornering aggressively could upset the suspension, or even injure your left foot if leaned over far in a left turn. It's better to upshift early as you approach situations like this for a safety margin.

That said, I think it's good to understand what determines the ideal shift points for max acceleration. Knowing the exact ideal shift points allows you to make an informed decision on where you will generally aim to shift, even if you're not going to try to shift at the exact ideal points.

Sneak preview of my explanation: It has nothing to do with what RPMs the peak TQ or HP occurs at, but rather the overall shape of the torque curve combined with the gear ratios.

 

[UselessPickles]

As promised, I'm back with an explanation and charts to show where the ideal shift points are...

It doesn't matter at what RPM the engine makes peak TQ or HP. What matters is at what point the next higher gear will start to cause the bike to accelerate faster than the previous gear.

Acceleration is a direct result of the engine's torque output at any given moment. The torque is multiplied by the reduction ratio of the entire drive train, including the reduction ratio of the currently selected gear. Divide that multiplied torque by the radius of the rear tire, and you've got a linear force. Subtract the force of the drag caused by air resistance at the current speed, and now you've got a net force on the bike. Divide that net force by the mass of the bike + rider, and you've got acceleration.

Using data from the torque curve of a dyno chart, you can create a graph of the bike's acceleration vs. speed for each of the 6 gears:

That data assumes a rider weight of 155lbs and assumes that the FZ6R 's top speed is limited by aerodynamics to 132mph (actual; not indicated). If my top speed assumption is wrong, it would not affect the shift points at all, so don't whine about that .

Where the lines intersect, that's when you shift. Rather than just eyeballing it, I actually calculate all the intersections, so I can get exact shift points.

1 -> 2: shift just before redline (11500 rpm?)
2 -> 3: 10660 rpm (I would aim for 10500)
3 -> 4: 10297 rpm (I would aim for 10250)
4 -> 5: 10119 rpm (I would aim for "just over 10000")
5 -> 6: 10055 rpm (I would aim for 10000)

Here's a graph of RPM vs. speed when shifting at the ideal points:

And for fun, I can create charts to compare the maximum acceleration of different bikes if they are all shifted ideally:

Note that this is max theoretical acceleration, assuming that the rear tire does not slip and that the front stays on the ground. That ZX10 probably starts to wheelie at some point under full throttle in 1st gear, so you would have to back off the throttle and not actually reach that max acceleration of 1.2 Gs

 

[onegin]

This is very interesting analysis, thanks! I like it when somebody else approaches the problem with proper analysis (I am an engineer by practice).

BUT...

Have you ever heard our bike redlining in the 1st gear? I mean... I got "Hearos" and it still makes my ears bleed a lil bit

 

[UselessPickles]

This is very interesting analysis, thanks! I like it when somebody else approaches the problem with proper analysis (I am an engineer by practice).

I'm glad someone appreciates my geeky analysis. I actually started writing a program that would allow you to define vehicles (torque curve data, weight, gear ratios, drag area, etc) and graph all kinds of stuff about them, compare vehicles, experiment with changing sprocket sizes, etc. I have all the important math stuff done that calculates all the data, including intersections between the per-gear torque curves to find shift points. I just haven't been able to decide how to design the user interface. For now I just dump the results into a spreadsheet and make charts.

BUT...

Have you ever heard our bike redlining in the 1st gear? I mean... I got "Hearos" and it still makes my ears bleed a lil bit

I wasn't aware that the FZ6R made any sound . It's my wife's bike, and I can't even hear it when riding next to her on my FJR.

 

[Nastybutler]

I wasn't aware that the FZ6R made any sound . It's my wife's bike, and I can't even hear it when riding next to her on my FJR.

You should install a TBR or other exhaust on it. Then you'll definitely be able to hear it.

 

[onegin]

You should install a TBR or other exhaust on it. Then you'll definitely be able to hear it.

Oh no, not the exhaust I was talking about... that high, whining, screaming, please-let-off-the-throttle... noise!

Maybe I am missing something, but other than "safety" why would u want to be the "loud" kid by installing something. I actually like how stock exhaust sounds... the performance reasons I understand, but the sound that comes with it is a negative in my book.

Also, check out gear commander, it's a website that generates curves similar to urs with different mods applied to them to give u more idea on UI (or lack of it)

gearingcommander.com/

 

[Nastybutler]

Oh no, not the exhaust I was talking about... that high, whining, screaming, please-let-off-the-throttle... noise!

Maybe I am missing something, but other than "safety" why would u want to be the "loud" kid by installing something. I actually like how stock exhaust sounds... the performance reasons I understand, but the sound that comes with it is a negative in my book.

Also, check out gear commander, it's a website that generates curves similar to urs with different mods applied to them to give u more idea on UI (or lack of it)

gearingcommander.com/

Better than the "angry weed whacker" sound the stock exhaust makes, imho. Maybe it has something to do with riding snow mobiles most my life, but the rumble at lower RPM's and the "brrraaap!" at the higher revs is music to my ears. Besides, it's not really THAT loud. Even my dad and wife think it sounds good without being too loud.

 

[jocampo]

For max acceleration, the shift point depends on which gear you are in:

1st -> 2nd: as close to the rev limiter as you can get without hitting it
2nd -> 3rd: 10660 rpm
3rd -> 4th: 10297 rpm
4th -> 5th: 10119 rpm
5th -> 6th: 10055 rpm

I'll post pretty graphs later that show where these numbers come from.

Can you (or someone else) provide a similar post for normal/easy riding? I don't usually ride aggressive, lol ... also, bike is in the break in period, still.

I'm coming from a Ninja. I remember the forum admin has a wiki with ideal shifting under normal riding conditions, without driving aggressively.

As a side note, I've noticed that when I shift, revs drop to 2k really fast, shifting between 4.5k and 5k. Is that normal or maybe I need to improve my technique? I fully disengaged the clutch (totally pulled) when shifting.

I don't know what are those rev limits on the fz6r ...

 

[Briguy453]

To be completely honest, in order to get the absolute fastest/aggressive upshift, I preload the shifter, and shift without the clutch, and blip the throttle just fast enough. Its fast as hell, and no matter how good I get with the clutch its always faster, and I hardly ever drop rpms on the upshift. Normal riding I always use the clutch, as well as downshifting. But to get the fastest most aggressive upshift, learn how to do it without the clutch.

 

[UselessPickles]

Can you (or someone else) provide a similar post for normal/easy riding? I don't usually ride aggressive

Nope. There's no way to calculate the best shift points for "normal" riding, because there is no clear goal. The shift points I calculated were for a very clear and specific goal: max acceleration.

For "normal" riding, the only thing I can say is to be in the gear that is best for the current conditions.

Don't lug the engine (excessive load at low RPMs), which can't be clearly defined as a minimum RPM because it depends on what gear you're in, how much throttle you're giving it, whether you are going uphill, downhill, flat, etc. People can suggest minimum RPMs all day long, but it all depends on so many factors that you just need to be aware of what "lugging" feels like and avoid it. When the engine makes louder noises as you open the throttle, vibrates more, but doesn't really accelerate you much, you're probably definitely lugging. At some point near that feeling, but not quite there, you're probably still lugging it, so just stay away from that feeling (downshift to stay in higher RPMs with lower gear ratio for higher torque multiplication, or back off the throttle).

Stay in a low enough gear so that instant acceleration is available as necessary, or stay in a high enough gear for better fuel economy and more "comfortable" lower RPMs (but without lugging). Choose somewhere in between based on your current situation and desires/goals.

It's really easy to avoid exceeding the max safe RPM on the bike while accelerating, because the bike won't let you accelerate past that point. Beware of downshifting too soon though. It's possible to downshift such that you are now exceeding the max safe RPMs.

Speaking of max RPMs, does anyone know for sure (with backing evidence such as a shop manual, technical document, etc.) what the actual max RPM (redline) of the FZ6R is? Google search results come up with 10k, 11.5k and 12k.

 

[jocampo]

Nope. There's no way to calculate the best shift points for "normal" riding, because there is no clear goal. 12k.

1st time I heard that.

My car has suggested rpms points for shifting. My Ninja 250 had. on most vehicles you can suggest or manufacturer can give numbers about which rpm you should shift.

So, I'm sorry but I don't agree with your comment.

My question was about knowing those rpms points on the fz6r. I knew them on my previous Ninja: 4k when riding smoothly, 5k when riding normal to aggressive and avoid dropping rpms below 7k on city. Of course, those are suggested values, but if followed, I was able to get good torque on most riding conditions.

 

[Kdubb223]

Are you talking about these listed in the owners manual?...

 

[jocampo]

Are you talking about these listed in the owners manual?...

Hmmm ... kind of, but the manual talks about speed, not revs.

Mine is on break in period, so I can't ride aggressive. But based on what I've felt so far, it looks like 5k is that point where we should shift?

 

[UselessPickles]

Mine is on break in period, so I can't ride aggressive.

That's not true. Break-in period means you should be especially careful to allow the engine to fully warm up before accelerating hard (this is a good thing to do after break-in; just more important during break-in), you should vary your engine speed and load often (don't cruise at a steady speed in a single gear for a long time), and you should not sustain RPMs above the manual's recommendation (that doesn't mean you can't accelerate through the higher RPMs then upshift).

But based on what I've felt so far, it looks like 5k is that point where we should shift?

Like I already said. Shift when you want to, when it feels good to you, and when you need to be in a different gear based on what you want at the time, but don't lug the engine, and also follow the break-in recommendations. As a general recommendation, somewhere in the middle of the RPM range or a bit lower is great when you're maintaining a steady speed. You probably don't want to cruise near idle or redline.

All owner's manual recommended upshift points I've seen have been ridiculously low, probably assuming VERY economical driving (slow acceleration, prefer MPG and low emissions at all costs over acceleration). All owner's manual recommended downshift points I have seen have been equally ridiculous (example: 15mph is the recommended downshift point for ALL gears on my FJR). I really don't know what the manufacturer's motivations are for coming up with those numbers, but I'm guessing it has something to do with the EPA.

 

[jocampo]

That's not true. Break-in period means you should be especially careful to allow the engine to fully warm up before accelerating hard

Let me clarify.

When I used the word "aggressive", I meant not passing 5k! ... under 600 miles, or 7k, under 1000 miles. Anything above, I consider it aggressive. Basically, the same that Yamaha recommends, it's on the manual.

I know we can rev above that for a second or so, but not frequently or sustained.

So not sure why you said is not true.

All owner's manual recommended upshift points I've seen have been ridiculously low, probably assuming VERY economical driving

I think is a semantic thing! The speeds that sound ridiculously low for you, are not for me or maybe others. I actually don't like to rev really high or speed with my bike or car. I know several folks at work with really expensive and fast bikes that ride really, really conservative but enjoy riding on curves.

Yes, it has something to do with EPA, I believe you're right on that, plus manufacturers must adhere to local laws when printing manuals; for instance, in terms of speed, anything above 65 or 75 mph is usually illegal in USA.

 

[Kdubb223]

Pretty sure this has already been posted but here is a different take on break in
Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

as far as rpms go, when I'm cruising to school everyday I usually up shift around 4-6k depending on what's ahead of me. If no traffic I'll shift at 4k even though the bike bogs down a bit it's not a big deal with no cars to avoid and helps on gas mileage for me atleast, which is a main reason why I got the bike... 350z is a thirsty premium gas car that doesn't like street driving all that much.

 

[UselessPickles]

Let me clarify.

When I used the word "aggressive", I meant not passing 5k!

...

So not sure why you said is not true.

I guess my "aggressive" is different than yours. I consider large throttle opening and quick acceleration to be "aggressive" you can ride "non-aggressively" at high RPMs (steadily cruise at 10k RPMs, for example), but that's exactly what you shouldn't do during break-in. Accelerating hard (large amounts of throttle) through high RPMs is perfectly fine during break-in (as long as the engine is fully warmed up), therefore "aggressive" riding is fine during break-in. Some theories even claim that aggressive acceleration and engine breaking during break-in is beneficial, and that avoiding purely avoiding high RPMs during break-in is detrimental.

If you read the exact wording of the owner's manual, it only says to avoid prolonged full throttle and prolonged operation abover certain RPMs.

I think is a semantic thing! The speeds that sound ridiculously low for you, are not for me or maybe others. I actually don't like to rev really high or speed with my bike or car.

I guess my point (which I forgot to make) was that the manufacturer recommended shift points are probably more like lower limits. You should generally probably not shift at lower speeds/RPMs than recommended, because that will probably be lugging territory. However, you should not treat it as "this is the best way to shift when riding normally".

Like I've already said, no one can tell you what the best shift points for "normal" riding are, because it all depends on the situation and your preferences. You have all the information you need in the posts above (both mine and the picture of the manufacturer recommendations in the owner's manual) to help you decide when to shift.

If you really just want someone to tell you what RPMs to shift at, then how about 6000 RPMs? Then after break-in, always shift at 11000 RPMs. That's just as correct as any other specific shift point that could be recommended to you.

 

[Sander Koop]

Try up-shifting without clutch - just roll off the throttle, load the shifter, and roll on again - it'll slip into gear effortlessly! It won't hurt your gearbox, either!

 

[Chucker]

Try up-shifting without clutch - just roll off the throttle, load the shifter, and roll on again - it'll slip into gear effortlessly! It won't hurt your gearbox, either!

Not completely true. There is excess wear on your gearbox, you just may not necessarily notice it, for a while. There isn't really an advantage to not using the clutch, unless you're running a quarter mile and 1/10s of seconds count.

I use my clutch, preload the shifter, only give about 1/2 pull from 2nd up, and I can hardly feel the transmission shift. I'm usually shifting around 7K and will jump that up to 10-11K when riding agressively.