dragonbusa
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Just got my shinko reactor mounted up, its about an inch and a half taller than the 008s I was running, I"m gonna need a bigger sprocket, how many teeth to make for the diff?
how many teeth?
- Thread starter dragonbusa
- Start date
That should give you a good contact patch 
1 should do it, but no more than 2.
Not to start an argument but I dont feel that 2 is near enough... What is the circumference of the new tire compared to the old tire? What are are attempting to accomplish? What gear and rpm do you want to be at when you cross the finish line? How heavy of a rider are you?
Well a 55 series is between 1 and 2 rear teeth difference than a 50 series tire.
+3 is too much just for the difference in tire heigth.
The question needs to be asked, exactly what tire size did you have before and what was your gearing? Do you want to keep it exactly (or as close to) or do you want to have more torque and drop the top speed? I am a heavy rider and for me to overcome - I am running a much larger rear gear to increase the bottom end power on the line. If the Reactor is anything like the MT, its is MUCH larger than the stock tire size. If the diameter of a stock tire is 24 (guessing because i dont have mine here to measure), the difference in circumference is 5 inches (at 1.5 inches taller)...
The first post says he just wants to make up for the difference in tire heigth.
I do not know the heigth of either tire. The op says it's about an inch and a half taller.
I say it's between 1 and 2 rear teeth(probably closer to 2) to make up the diffence in tire heigth.
Not having exact numbers I cannot say, but I would bet on +3 being too much.
I'm not argueing or making this more than it is either, times, rider weight, speed vs rpm, ect.
Just the difference in heigth vs sprocket like he asked.
I do not know the heigth of either tire. The op says it's about an inch and a half taller.
I say it's between 1 and 2 rear teeth(probably closer to 2) to make up the diffence in tire heigth.
Not having exact numbers I cannot say, but I would bet on +3 being too much.
I'm not argueing or making this more than it is either, times, rider weight, speed vs rpm, ect.
Just the difference in heigth vs sprocket like he asked.
dragonbusa
Registered
I was running a shinko 008 with 16/47 sprockets 1/8ml catching 4th about second before the line, I dont know the diam of the 008 but the reactor is 1-1/2" taller I"d like to say in that range and dont want to kill my 60s
Do you still have your stock front 17t?
Brain fart, wrong way...goin to bed on that one.
Brain fart, wrong way
...goin to bed on that one.
dragonbusa
Registered
yea, you need it? you can have it,
Trust me here and this will work without guessing but using math but you need to measure the exact circumference of both tires, old and new. You already know what tooth you have now but want to know what the new one needs to be. Using a calculator, multiply the tooth count on the old sprocket times the new circumference and take that total and divide it by the old circumference and that answer is the exact tooth new rear that you want. I knew algebra would pay off some day! It's cross multiplying two fractions. You can get the circumference by measuring around the tire with a tape measure or use string and measure it or mark the garage floor and measure out one complete revolution. So for instance.... if the rear sprocket is now say 46t and the old tire measures say 78 inches around and the new tire measures say 84 inches....46x84=3,864....3,864 divided by 78=49.538461 S0 you would use either a 49 or a 50 cause there obviously no half sizes. This may sound overly complicated but if you do it exactly like i said and don't mix up the numbers it will be right.Old tooth count times new cir divided by old cir equals new tooth count.
It's cross multiplying two fractions. You can get the circumference by measuring around the tire with a tape measure or use string and measure it or mark the garage floor and measure out one complete revolution. So for instance.... if the rear sprocket is now say 46t and the old tire measures say 78 inches around and the new tire measures say 84 inches....46x84=3,864....3,864 divided by 78=49.538461 S0 you would use either a 49 or a 50 cause there obviously no half sizes. This may sound overly complicated but if you do it exactly like i said and don't mix up the numbers it will be right.Old tooth count times new cir divided by old cir equals new tooth count.
dragonbusa
Registered
thanks for the help, I"m gonna go to the track and make a few passes as is and see were I"m at, My gut thought was three teeth, I may have some sprockets for sale in a week or so
09BUSA73
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I have 2009 gen2 busa my bike use to pull like hell when i was running 17t front 43t rear with a 190 50 r 17 in rear.I upgraded to a 190 55r17 in the rear and raised the rear 1 inch for handleing she corners great but a bit slugish.So i put a 44t rear thinking it would be back the way she was but still not the same has anyone ran a 190 55 r17 and has the magic combo i would be very greatful!I just want her pulling hard love acelleration the top end as long as i can hit the 170 180 range is fine i want to beat alot of bikes off the line can anyone help thanks......
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