Optimal shift points?

[Rob@TZP]

Howdy gang,
I've been doing some reading on riding technique and I'm curious to know your opinion on optimal acceleration shift points for the 750C3? Peak torque at 7300, Peak HP at 9500. So two theories I've read is change to hit peak torque (or peak HP) in the gear you're changing into? Seems silly to change straight into peak HP because where do you go from there? And you'd just be bouncing the red-line? Speaking of which, how firm is the red-line? Will it pop at 10k or is it just a guide to worn you against going to 12k? What about changing 5/600/1 gear-ratio-difference RPM below Peak HP?

For cornering is it better to hit the corners at peak torque to help with the change in direction? I know this is all kinda vague-and-by-feel, but I'd like to know your thoughts.

Does anyone here have a dyno sheet for a standard Zephyr 750? Tried googling but no luck..

[Freddy]

Howdy gang,
I've been doing some reading on riding technique and I'm curious to know your opinion on optimal acceleration shift points for the 750C3? Peak torque at 7300, Peak HP at 9500. So two theories I've read is change to hit peak torque (or peak HP) in the gear you're changing into? Seems silly to change straight into peak HP because where do you go from there? And you'd just be bouncing the red-line? Speaking of which, how firm is the red-line? Will it pop at 10k or is it just a guide to worn you against going to 12k? What about changing 5/600/1 gear-ratio-difference RPM below Peak HP?

For cornering is it better to hit the corners at peak torque to help with the change in direction? I know this is all kinda vague-and-by-feel, but I'd like to know your thoughts.

Does anyone here have a dyno sheet for a standard Zephyr 750? Tried googling but no luck..

If you wanted 'optimum' shift points in terms of maximum possible straight line acceleration, change at redline (10,000rpm). With peak HP at 9,500 the redline on a Zephyr 750 set at 10,000 is just about spot on. Redline is always set just above peak HP revs so that when you change up into the next higher gear and the engine drops in revs it will remain closer to the peak HP revs. And the reason for reving it out through the gears all the way to redline is because its the power at the drive wheels that is the important factor, not the engine. The transmission multiplies the engine torque, so staying longer in a lower gear all the way to redline will always be putting more power to the ground because of the increased mechanical advantage, than changing up into a higher gear even if the engine produces slightly more power at lower revs. Gearing is the key ingredient.

Ok, that's 'optimum' from a theoretical perspective. From a practical 'optimum' cornering perspective you want to be entering the corner in the gear that's going to give you maximum acceleration OUT of the corner (lowest practical) meaning engine spinning somewhere around 6,500 rpm when you start to roll on the gas, and punch it out to around 8,000 before shifting up again. The reason for this ....its called Freddies Law (invokes complex physics like the Theory of General Relativity etc so way to complicated to explain).

[Rob@TZP]

Thanks Freddy, I'll try that out on the asphalt dyno. FWIW I've followed your advice in another thread riding further up the rev range and it shocked the mate I was riding with how quick the old gal was.

[Freddy]

Thanks Freddy, I'll try that out on the asphalt dyno. FWIW I've followed your advice in another thread riding further up the rev range and it shocked the mate I was riding with how quick the old gal was.

Just to clarify, I'm not recommending you redline it every time. As you say they are an 'old girl and probably need just a little consideration. But your original question was what is the theoretical optimum acceleration shift points, and that answer is redline. As I hopefully explained in the previous email, because of the mechanical advantage of the transmission.

To me, working in the 6000-8000 rpm range gives a good balance of performance and engine longevity. Keep the momentum going, watch how Moto3 guys with 50hp approach the race. It's all about momentum, being smooth, and correct anticipation e.g. correct gear. Actually makes for a way better rider than someone why can just cheat and rely on HP to compensate for lousy riding skills. Most just rely on this 'crutch' and never really improve.

P.S. If you want to really make a performance improvement, focus on tires and suspension, and rider skill. I'll back a good rider on a humble SV650 (making 70hp?) with upgraded suspension to embarrass a typical Ducati Panigale 1299 (200hp) owner every time in the tight twisties.

[Rob@TZP]

No worries, that's how I took it. 90% of my riding is highway commuting or crusing along to get to the twisties. "Spirited rides" where I'll apply as much theory and technique as possible are rare - but it's those 10% that I want to shine best I can. Even then I try to hold back a little and not ride faster than my guardian angels can fly....

As for tyres I've got Michelin Road Pilots as she's an all weather bike. That's what the cops use (I know a few of them personally) and they ride much harder than I will. Suspension set-up is my next field of inquiry!