Sprockets - More Teeth On Rear = Faster Acceleration+ Top Speed?

Can't do both, higher top speed gearing slows acceleration, and vice versa, with very few power band exceptions.

 

More teeth = bigger sprocket = more torque at the wheel for any motor RPM, as torque = Force * Radius of sprocket. Torque means acceleration. However, higher ratios at the motor maximum RPM means less RPM at the wheel = lower speed at any given motor RPM. The surface speed of the chain is the same. Your sprockets with more teeth give you a higher ratio, which gives more acceleration, but less top speed. Less teeth go the opposite direction. Ratio is generally calculated as rear teeth / countershaft teeth.

 

Hard to say, change the sprocket for top speed bragging rights at the pub. Sometimes requires a length change for the chain. May or may not provide better fuel economy. Maybe somebody else can chime in.

 

If you are not horsepower limited, drop a tooth if you want to go faster. My Sprint RS hits 100 mph with plenty of RPM left. Stock 2000 RS comes with a 43/19. Daytona has 42/19. I think I added a tooth when I last changed the rear sprocket. Bikes are generally stopped by aerodynamics, as they present the same as a barn door, when compared to a race car.

 

On my Speed Triple I've got three teeth up from stock - it accellerates like a bat out of hell, and still easily does 140 mph.

 

Overtaking a bus on Skye last year I inadvertently wheelied past it - fortunately I was wearing brown underpants...

 

The best way to understand what's happening is to ride a push bike with derailleur gears (the type with exposed workings) and watch and experiment with the various ratios. You'll soon get the hang of what makes for easier (i.e. faster) acceleration but less top speed, and vice versa.

You'll also understand why we ride motorbikes and not push bikes!

 

For what it's worth here's my two pennyworth.

Most bikes are over geared for the road as standard, I have not found one yet that didn't ride better by changing the front sprocket for one tooth less than standard, or three teeth more extra on rear, this has exactly the same effect.
So 1 tooth less on front = 3 teeth more on rear.

My preference for road is to change front sprocket as it is cheaper & the one tooth change has less effect on chain length, but for racing I have a wide range of sprockets both front and rear.

To give an insight, recent testing at Cadwell with 14 front 46 rear meant that I was not getting top until too late in the straights, also coming out of corners in 2nd gear it was trying to wheelie while still cranked over, 3rd gear was better but not quite urgent enough, so gearing changed by one tooth to a 47 rear.

 

This thread has got a few of us thinking, it seems. I don't need a top speed of 120+ on my Street Triple that doesn't have any fairing. The fun has always been in the acceleration and handling. Might be time to experiment with a tooth off the front sprocket.

 

Presumably there's a margin for the chain and as Billy said, the front sprocket has a smaller impact. Not that I'm any sort of expert.

 

One tooth plus or minus on the front sprocket is not going to have an effect on chain length.

 

No Duck, one tooth will not mean taking a link out of the chain, it will just need adjusting but will be well within adjustment levels available.

 

That's what I did on my 675R, made it accelerate much better and if honest when I did test the top end it just meant it pulled all the way to the red line in top, to an indicated 153 mph (probably more like 140 in reality).
Strangely the 765RS I owned afterwards never felt like it needed gearing down?

 

No, you'll find just one tooth on the front sprocket can be taken up by the chain adjusters.

 

Let us know what sort of difference you think it makes.

 

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