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Discussion Starter #1 (Edited)
Put a 17 tooth counter sprocket on a couple weeks ago.
After 400 miles, here's my observations:
All benefits, no real drawbacks.
I think it's the best mod done to the bike, short of the luggage. Makes the bike much smoother to ride, as it takes the engine out of the buzzy range.
I typically ride 70-90mph, 30 miles to and from work, curvy roads, several stop signs.
Gas mileage is up to 45ish from 42ish.
At 80mph with the stock gearing, I was turning around 6000rpm. Now it's about 5200, which is a much smoother rpm for the engine.
Basically it's like adding another gear to the bike. The only downside is that I have to remind myself to downshift one more gear (rather than lug away in 2nd).
1st gear is now good for around 50mph at redline. This may seem high, but it's still relatively low to me. My Hayabusa did 85+ in first and my ZX-14 does 80+ in first.
Dunno what the stock gearing did in first.
I think with the stock gearing 70mph (indicated) was 5100rpm........now it's around 4600rpm. 55mph used to be 4000rpm, now it's 3600rpm.

Removing the stock sprocket was impossible with a large 1/2" breaker bar. Didn't work with the (cheapo) 1/2" impact at first either. Cranked the output psi on the air compressor to 120psi, and it spun off no problem.

Also lowered the rear suspension 2", and raised (lowered) the front around 1". I'm 5'10", but I was blessed with short legs. 2" makes the bike a whole lot easier to get on and off of. Had to crank the pre-load up a bit, but no major problems with just my fat ass (280lbs) on the bike. I do occasionally hit the peg feeler on the right now, and the cut-down kickstand will touch down on the left. This is at very aggressive riding (85mph thru 40mph corners). No problems at mortal speeds.
If my Daughter (110lbs?) is on with me, we'll rub the rear tire if I hit a big dip at speed.

Hope this helps the fellow lurkers.
 

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Had to crank the pre-load up a bit, but no major problems with just my fat ass (280lbs) on the bike. I do occasionally hit the peg feeler on the right now, and the cut-down kickstand will touch down on the left. This is at very aggressive riding (85mph thru 40mph corners).
I've been reading Trevitt's "Sportbike Suspension Tuning", so I now know just enough to be dangerous ... ergo, take this with an ounce of synthetic oil. One side effect of a larger front sprocket is more squat, due to the change in chain angle. It follows that if you're riding aggressively with a larger sprocket, you'd have more weight transfer to the rear. Since you also lowered it, it's hard to say how much of your new touchdown problem is due to which change.
 

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I think with the stock gearing 70mph (indicated) was 5100rpm........now it's around 4600rpm. 55mph used to be 4000rpm, now it's 3600rpm.
Standard gearing (true speed) is 20kmh per 1000rpm in 6th; ie 62mph at 5000rpm. The indicated speeds are a joke on those half-baked instruments.
 

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Discussion Starter #5
It follows that if you're riding aggressively with a larger sprocket, you'd have more weight transfer to the rear. Since you also lowered it, it's hard to say how much of your new touchdown problem is due to which change.
I'd say most of the problem is the weight transfer of my fat ass........
:mrgreen:
 

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Standard gearing (true speed) is 20kmh per 1000rpm in 6th; ie 62mph at 5000rpm. The indicated speeds are a joke on those half-baked instruments.
At least they seem consistent. I also see 6K at 80mph. I have read a lot on here that the speedo is a joke though.

To the OP:
I'm curious, do you notice any additional lag at low rpm?

Or do you notice you have to do a little more clutch work to get going from a stop?
 

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Discussion Starter #7
I'm curious, do you notice any additional lag at low rpm?

Or do you notice you have to do a little more clutch work to get going from a stop?
Sorry for the delay.
I wouldn't call it lag, but first gear is definitely taller.
Does take more clutch.....or more "resolve" to get away cleanly in first gear. Can't be lazy with the clutch and throttle from a stand-still like you can with the stock gearing.
With the stock gearing, I could take off in second. You won't want to try that with the +2 front sprocket.

Still think it's one of the best things I've done to the bike.
I'd say + 1 countershaft would be a no-brainer to anyone who rides normal pavement.
 

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I put a 17t front sprocket on about 10k Klms ago. I was going to do all the scientific things like fuel consumption comparisons, speed and rev analysis, but I got lazy and/or couldn't be bothered, I just liked the way the bike went, just loping along. I didnt think of doing any squats. Maybe if I put a lot of weight on I should bumb up the preload and do some squat analysis work.

The sprocket did (naturally) lower the cruising revs thus I got slightly better fuel consumption, but not much. It is a bit harder to pull away from stand still, but after a few times you don't notice it. I go dirt roads/ tracks occasionally and have to slip the clutch some times in the real tight spots, but then when the track opens up you can hold 1st a bit longer to the next corner.
I think next sprocket will be 16t, but will decide depending on wear rates, maybe:confused:
 

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I have a 16/45, which almost the same as just a 17/47 . I love it, wouldn't go back. The gears don't need to be shifted so often in town now too.
 

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I did fairly complete mileage measuring before and after w/ the 17t front and saw nothing diff when speeds were <60 mph on a varying set of roads. Continuous high speed (70+mph) resuted in a few mpg increase w/ the 17t at most. If would be safe to say there is little measurable diff between stock and 17t.

There is more clutch slipping needed to get started compared to stock. No real matter on pavement but it makes a sig diff if you spend any time off road and esp if you need to get started on a steep grade w/ bad surface conditions.
 

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.. oh ya, the stock speedo is inacurate as all know. But it is repeatable which mean you can calibrate your head to it to know how fast you are going. Mine indicates about 1mph low for every 10mph I'm traveling (ind 40 is really 36, ind 70 is really 63).
 
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