I know that it gives you a stronger pull at lower RPM's, but overall, on a 1/4 mile track, would you actually pull a quarter mile faster? According to Sport Rider, the stock F4i did a 1/4 mile at 10.74 which is pretty quick.

I know that you would have more response and torque at a lower RPM, but you also have more trouble keeping the front end down, and you also have to shift more frequently, which costs you time.

The reason I ask, is that I did the -1/+2 gearing and I liked the midrange punch. But off the line, if I wanted to really get on it, I could not keep the front end down unless I backed off on the throttle, so any extra power wass wasted in my mind. I am 6'4" and 225 pounds, and a hard launch sends the front end flying up every time, due to the power and the shortened wheelbase from the rear tire being all the way forward to accomodate the stock chain. And last night I was on the highway with about 15 other bikes and we were riding along at 90-100mph(traffic was doing 85mph), and my tach was screaming away at about 10 grand, which is really annoying. And last, my gas mileage sucks. The reserver light consitantly comes on before I hit 100 miles on a tank of gas.

So I was thinking about this all day today, wondering how much extra acceleration you really get from the regear, and if that initial lunge is offset by having to moderate the power in 1st and second and the more frequent shifting.

I am almost convinced that on a 1/4 mile track, the times would be almost identical. The regeared F4i would launch a little faster, but the more frequent shifting would negate that over a certain distance, correct?

I wonder if the perception that it is faster is due to the fact that if you take the two bikes at 6000rpm and hit the gas, the regeared bike will pull harder. But what I never considered was that the regeared bike runs out of gear faster while the other one comes into it's power band and can pull longer without shifting.

I dunno, just some things I was thinking about today. I guess that regearing should be done in such a way as to get the lowest gearing possible while still managing to keep the front end planted when you need it to.

So tonight I went back to the stock front sprocket and a +1 Vortex on the back and tomorrow I will see how it rides.

Thoughts?

 

I hear what you are saying, I about 6' and 220 lbs and I have stock gearing on my bike and at full on acceleration from a roll in 1st gear the front will float about an inch or 2 off the ground if I tuck down on the tank. The other day I took off hard from a stop and kind of set up or leaned back a little and the front came right up and scared me a little. I have a -1 front sprocket hanging in my shop right now, but I don't plan on changing that for a while. The gearing that you have is more for stunting, I would mabye go to a -1 or -2 front sprocket to stretch your wheelbase a little and still get the better acceleration that you are looking for and you won't be turning so many rpms at speeds. Good luck and keep us posted on what you come up with from your changes.

-Jesse-

 

Your 220 with stock gearing and your bike walks up on you, lucky!!...theres either something wrong with my bike or m4 exhaust really adds some power...I weight 185, bikes completely stock and my nose stays down unless i get off the throttle then jump back on it

 

See, my main problem was that launching hard from a dead stop was damned near impossible. Front end would fly right up, so I would end up launching softer and then pouring on the gas as I picked up speed.

Then when you added the high rpm on the highway and poor fuel economy, that was when I decided to rethink this and switch back...

 

There was an issue of Motorcyclist where they tested 3 or 4 bikes in the 1/4 mile with different gearing. With a professional rider all the bikes had much better times with lower gearing. They did point out that there is a point in gearing where you'll get diminished results. The results with the regear, although lower times, were kinda misleading because they admitted that the rider had a handful keeping the nose down and wheel spin to a minimum. Basically his best times out of a lot of runs were with the lowered gearing.

I personally loved my -1/+1 on the 1kRR but I went back to stock just for fuel economy. I know ... ya don't ride a sportbike for fuel economy But I mostly use mine to commute. It's the only way to go to work with a smile on yer face. I still gots my 520 sprockets and chain -- waiting for trackday or a weekend in the twisties.

Hey, I did a search and the article is in the June 2003 issue of Motorcyclist. If I find a copy I'll post it up here.

 

i did a -1 front only on my 02 f4i because i wanted more torque but i do alot of commuting which includes 30 miles on the interstate. i'd still love to have more torque but the -1 seems like a good compromise. i'm taching about 6800rpm at 80mph and am getting about 40 miles to the gallon.

 

good feedback. lately i've been considering a -1 also to get a little extra torque on takeoff, but i'm a commuter too.