Should I convert to 15 front sprocket?

[Momo1970]

I have 600 miles on my Duke and I will do the 600 miles service this Saturday.
The plan is to remove 2,3 restrictions, loose the California specific emission crap, and perhaps replace the front sprocket to 15.
Basic mathematics shows that if you go from 16/40 to 15/40 thats ~ 6.6% lower gears. Currently I find the highway cruising speed ~ 75MPH, so should I assume ~70MPH post switch?
My main use for the bike is weekend rides in twisty single roads (some call them goat roads...), but I still need to get there which means 0-50 miles ride.

[kopfjager]

Originally Posted by Momo1970

I have 600 miles on my Duke and I will do the 600 miles service this Saturday.
The plan is to remove 2,3 restrictions, loose the California specific emission crap, and perhaps replace the front sprocket to 15.
Basic mathematics shows that if you go from 16/40 to 15/40 thats ~ 6.6% lower gears. Currently I find the highway cruising speed ~ 75MPH, so should I assume ~70MPH post switch?
My main use for the bike is weekend rides in twisty single roads (some call them goat roads...), but I still need to get there which means 0-50 miles ride.

I say yes. It is an in-expensive mod and you can always change it back.

[bajadog]

Why do you want to run your bike at higher RPMs?

You could always add few more teeth on the rear which would not be as drastic
a change.

[Tmd]

I have 2 extra teeth larger rear sprocket and find it works very well, very slightly less aggressive than going 15 tooth on front.

[kopfjager]

Originally Posted by bajadog

Why do you want to run your bike at higher RPMs?

You could always add few more teeth on the rear which would not be as drastic
a change.

The Duke needs all the help it can get down low, quite frankly it is a pig without this mod and 2 up in the rear or 1 down in the front is darn close to the same thing.

[Momo1970]

6.6% vs. 5% different ;-)

[kopfjager]

Originally Posted by Momo1970

6.6% vs. 5% different ;-)

Which one are you gonna try?

[Momo1970]

I have 40 miles ride to the dealer shop. That type of distance is about the max mileage I normally ride before I hit the twisties. I will try to ride using 5th gear. If it will be OK I will go with 15 in the front, if it will be not great but tolerable I will go with 42 in the back. If it will be complete disaster I will stick with th stock set up.

[WoodsRiderParts]

I would go with the 42 in the rear before dropping to a 15 up front. Try that out for a decent distance and see how you like it first.

Luke

[Momo1970]

My 40 miles to the dealer proved that stock gearing is probably best. Going on 5th gear was slower then traffic which I do not like. The 6th gear is not really and overdrive on the duke and allows 70-75 mph cruising speed . I think the duke requires different riding style then most single keeping it high on the revs.
Now that the break in period is over, 2nd and 3rd gear restriction is off I should be able to push the bike harder, and see how goes. Thank you all.