Topic: Considering gearing changes on the Interceptor.

[DarkRider]

My bike is pretty much overdue for a chain and sprocket swap. I am considering altering the gearing when i do this however im not sure how much it will impact the bikes low end power. The combination im looking at running is 17/39 which with a stock size rear tire would net me about 257 km/h top speed in 5th. But im not sure how much low end power im giving up in the process of which...i know that if i give up too much low end it will make any gains up top worthless since the bike wouldnt have the power to take advantage of it.

The stock gearing is 17/45
To regain stock performance with a CBR wheel upgrade i would need to use a 17/41. with the CBR wheel i can see how changing gears would help performance since the bike looses about 30 lbs with that upgrade.

[ekim98]

The 30 lbs weight gain sounds great but will the engine have enough guts to pull that gear ratio in the upper gears and still keep you within the power band. 6 teeth smaller seems like a big change, may be a little to much.

[DarkRider]

it would be a 4 tooth smaller sprocket with the smaller wheel to restore performance...however i suspect i will be redoing the heads and adding cams before i do the CBR upgrade which would give the bike the power it needs to make use of the smaller part.

[ekim98]

Oops, your right 4 teeth. I didn't read it properly. Even without the up grades it should pull ok, and the mods will put you ahead of the game. 

[kirkn]

Let's see now....

Stock is 17/45

With the wheel swap, you need 17/41 to stay 'stock'.

You're proposing a 17/39.

My opinion is, if you put the 17/39 combo on the stock wheel, you're going 6 teeth less, which is a pretty big jump.  IMHO, you're going to be slipping the clutch a lot to get going, and you'll just be running around in 4th, say, rather than 5th all the time.

The 17/39 combo on the wheel swap will be much less severe, dropping only 2 teeth from 'stock'.  Much more livable.

My two cents.   

Good luck with it, whatever you do.

Kirk

[DarkRider]

well since a 39 T sprocket isnt avalable without going to custom sprockets i did a bit more calculations with the gearing site i have been using for reference. I suspect a combination of 17/42 may be a lot more livable since its only 3 teeth less then stock on the stock wheel. As it is in town i barely get out of 2nd let alone get to 4th. same usually goes on the longer rides as well...i barely ever touch 5th during those. however since 5th is essentially an OD thats a probably a good thing..