I now understand that the Standard Driver Sprocket on the Phantom has 13 T
Will the gearbox accommodate a 14T alternative? ie no foul condition occurs between the chain and gear box casing.
Is 15 T out of the question?

I have no knowledge of anybody changing the front sprocket on a Honda Phantom TA200. The Honda Phantom is just not powerful enough to do that.

It's said that 1 teeth on the front sprocket equals 4 teeth on the rear sprocket, with that in mind I want to advice you against changing the sprocket more than 2 teeth.

Quote by: ThaiDesign

I have no knowledge of anybody changing the front sprocket on a Honda Phantom TA200. The Honda Phantom is just not powerful enough to do that.

It's said that 1 teeth on the front sprocket equals 4 teeth on the rear sprocket, with that in mind I want to advice you against changing the sprocket more than 2 teeth.

Changing to 14 T is the equivalent of changing the driven from 41T to 38 T

Based on what u say it has never been tried

I will have to go it alone

Keep us informed about your findings. We love to hear how it worked out.

Personally I have my doubts that you find what you're looking for, some friends who changed the rear sprocket 2 teeth down and found themselves without power. They then invested in alternative camshafts and eventually one did a 250cc bore-up. The other sold the Phantom and bought a Tiger Boxer 250 RS.

Quote by: ThaiDesign

Keep us informed about your findings. We love to hear how it worked out.

Personally I have my doubts that you find what you're looking for, some friends who changed the rear sprocket 2 teeth down and found themselves without power. They then invested in alternative camshafts and eventually one did a 250cc bore-up. The other sold the Phantom and bought a Tiger Boxer 250 RS.

Experience such as that to which you refer cannot be ignored.

However my calculations tell me:

Every 100 revs of the crank produces 4.03 revs of the rear wheel in 1st gear(STD) and 6.08 revs in 2nd gear (STD)
With a rear Driven sprocket of 37(reduced from 41T STD) then the 4.03 value increases to 4.46.Still way below the 6.08(2nd gear STD ) value
The bike will currently accelerate from rest , 2-up (130kg combined weight), in 2nd gear STD

As a precautionary measure I will order 3 sprockets 37T 38T and 39T

I purchased a sample STD sprocket and that is currently on its way to the UK
I expect to know something by mid June
Will keep you posted