V Star 250 Sprocket Upgrades

[ShootingVStar250]

I own a 2008, Yamaha V Star 250 that I upgraded with a tachometer and a wind-deflector. I went ahead and changed my front and rear sprockets from 16/45 to 17/38. The change is hard to believe. There is no clutch slippage in 1st gear and great acceleration in all gears including 1st. I had it at 75 mph at 5,900 rpm in 5th gear. If I had done this with the stock sprockets the rpm's calculated would have been 7,500 rpm. I am 5 ft 10. inches and weigh 200 lbs, yet this bike has a lot of torque and acceleration even with the 17/38 change, and best of all riding on the interstate is now very possible. I have just over 500 miles on the bike now, and still in the break in 1000 mile period. So I did not try to max out the speed, but it has a lot of punch and throttle left after 75 mph. I list below the actual road data and theoretical calculations for the benefit of others.

Road Data 16/45 in 5th gear

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RPM MPH

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2,500 25

3,100 30

3,600 35

4,475 45

5,400 55

Road Data 17/38 in 5th gear

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RPM MPH

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3,100 40

3,500 45

3,900 50

4,300 55

4,700 60

5,100 65

5,500 70

5,900 75

Theoretical Data - RPM vs MPH in 5th gear

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RPM 16/45 17/45 17/44 17/43 17/42 17/41 17/40 17/39 17/38

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2,400 24 25 26 27 27 28 29 29 30

3,200 32 34 35 35 36 37 38 39 40

4,000 40 42 43 44 45 46 48 49 50

4,800 48 51 52 53 54 56 57 59 60

5,600 56 59 61 62 64 65 67 68 70

6,400 64 68 69 71 73 74 76 78 80

7,200 72 76 78 80 82 84 86 88 90

8,000 80 85 87 89 91 93 95 98 100