Rear Axle Ratios

[vtwins4life]

Does anyone know what the rear axle ratio is on our V11 bikes ? Are any of them different or are they all the same for all V11s? I'd love to get something shorter on my EV as it's absurdly tall for the riding I do around here. I never use 5th as you don't even shift into it until 85mph. 

 

VT4L

[Lucky Phil]

7 hours ago, vtwins4life said:

Does anyone know what the rear axle ratio is on our bikes ? Are any of them different or are they all the same for all V11s? I'd love to get something shorter on my EV as it's absurdly tall for the riding I do around here. I never use 5th as you don't even shift into it until 85mph. 

 

VT4L

I dont think I use 5th until around 80-90kph.(50mph) If your bike wont pull 5th until 85mph then there's an issue with your bike. Probably needs a tune up and throttle sync.

All the V11's are the same final drive ratio. Sounds like you may have the same issue as others that have migrated from Japanese 4 cylinder bikes to twins like Ducati's esp and feel they need to be in 5th or 6th gear at moderate speeds. Around town my Guzzi and Ducatis spend most of their life in 3rd gear.

The issue with shorter gearing is then you have an absurdly low 1st gear.

 

Ciao

[fotoguzzi]

Your EV, you could replace the 8x33 rear drive to a 7x33 from an older Tonti frame bike, all the 850's and the G5, SP and Cal 2 had the 7x33, I did that swap on a Bassa (same drive train as an EV), really livened up the fun factor.

[LowRyter]

Gary Scott installed the shorter gearing on his EV and really likes it.  He pulls a camper on occasion.  

[docc]

I've seen this 8x33 and 7x33 thing before. I realize it the tooth count on the pinion and ring, but do not recall what this is for the V11 (?)

[Lucky Phil]

1 hour ago, docc said:

I've seen this 8x33 and 7x33 thing before. I realize it the tooth count on the pinion and ring, but do not recall what this is for the V11 (?)

Its 11/32 docc. 2.9 to 1.

Ciao

[vtwins4life]

Thanks All. My bike runs very well and is not in need of a tune up. I think some may not be aware of the very different transmission in the EV as compared to the Sports and similar models. It's a very wide ratio 5-speed (which feels more like a 4-speed plus OD). We all know not to lug the motor on these, and 80mph in 4th is a little over 4000rpm. Shifting into 5th under 80 puts the motor down below 3500. Couple that with the larger throttle opening you need at highway speeds and it just doesn't feel terribly happy to me. 

 

I'll investigate the older ring/pinion setup of the previous gen bikes.

 

VT4L

[docc]

Just trying to wrap my head around the practical math . . .

So, as the V11 11/32 is 2.9:1, the others are both much "taller" ratios? 8/33 = ~4.1, and 7/33 + ~ 4.7 (even "taller", yet)?

And "taller" would lower the RPM at a given speed? And a lower (?) gearing, like the V11, makes for more aggressive take-off?

[vtwins4life]

A "taller" rear gear (lower/smaller number numerically) decreases revs in each gear (for a given road speed), lowers revs on the highway, increases MPG and makes for less aggressive take off. 

A "shorter" rear gear (higher/larger number numerically) would be the opposite of all those, and what I want. The gearing on the EV is absurdly tall and could use to be shortened for better take offs, and being able to actually use 5th gear at legal speeds. It reminds me of some wide-ratio 3-speed car transmissions from back in the day. Sporty, the gearing is not. 

 

VT4L

[GuzziMoto]

Yeah, it is odd. But as mentioned a shorter gear is a higher number and a taller gear is a lower number. 

Another aspect to the math is how the gear ratio works. In a sense the gear ratio in the rear end is multiplying the power output from the transmission. So a shorter gear being a taller number is actually multiplying the power output from the trans more, any given amount of power multiplied by 4.7 is going to be more than the same power multiplied by 4.1. So while an EV with the 4.7 gear set in it will not have the higher top speed of the same EV running the 4.1 gear ratio it is putting more power, more acceleration down to the pavement at the rear tire.

[luhbo]

2 hours ago, docc said:

Just trying to wrap my head around the practical math . . .

So, as the V11 11/32 is 2.9:1, the others are both much "taller" ratios? 8/33 = ~4.1, and 7/33 + ~ 4.7 (even "taller", yet)?

And "taller" would lower the RPM at a given speed? And a lower (?) gearing, like the V11, makes for more aggressive take-off?

Docc, that says 2.9 rotations of the engine for one at the tyre. We call that a long one. 4.7 at the engine for one at the tyre means a short one. The definition works the other way round. One turn of the crankshaft can move the bike a long distance - or a short one.

But the figures above are for the rear drive only. The chain goes from the crankshaft through the gearbox through the rear drive 'through' the tyre radius resp. circumference. Check the manual, it gives overall numbers.

[docc]

Thank you, gentlemen! I appreciate the tuition!

So it is that the V11 has a tall reardrive and short cogs in the gearbox?

[gstallons]

4 hours ago, luhbo said:

Docc, that says 2.9 rotations of the engine for one at the tyre. We call that a long one. 4.7 at the engine for one at the tyre means a short one. The definition works the other way round. One turn of the crankshaft can move the bike a long distance - or a short one.

But the figures above are for the rear drive only. The chain goes from the crankshaft through the gearbox through the rear drive 'through' the tyre radius resp. circumference. Check the manual, it gives overall numbers.

At the rear , the driveshaft will rotate 2.9 Xs for every wheel rotation .  You can verify rear axle ratio by marking ( with a dot or mark ) on the driveshaft and the rear wheel . Rotate the rear wheel one revolution while counting the driveshaft rotations . If you get 3 driveshaft revolutions for 1 wheel revolution you have 3/1 ratio .

[Lucky Phil]

2 hours ago, gstallons said:

At the rear , the driveshaft will rotate 2.9 Xs for every wheel rotation .  You can verify rear axle ratio by marking ( with a dot or mark ) on the driveshaft and the rear wheel . Rotate the rear wheel one revolution while counting the driveshaft rotations . If you get 3 driveshaft revolutions for 1 wheel revolution you have 3/1 ratio .

This is correct.To get the overall gearing and relationship to the engine speed you need to add the gearbox gear ration of whatever gear you're looking at assuming the tyre circumference is the same. 

Ciao 

[luhbo]

7 hours ago, docc said:

Thank you, gentlemen! I appreciate the tuition!

So it is that the V11 has a tall reardrive and short cogs in the gearbox?

Could be so. Quicker spinning cogs have to bear less load, can be smaller and lighter, see less pulsing