-1/+2 and 520 conversion
#1
-1/+2 and 520 conversion
I have decided to go with a -1/+2 gearing and a 520 conversion, I just wanted to know from you guys who have already done this, how much top end do you loose, about what rpm is 80mph at in 6th and can you feel a significant difference in low end power. Also what companies do you recomend for parts. All input is appreciated.
#2
#3
RE: -1/+2 and 520 conversion
Check out this link, input f4i and your custom configuration. Looks like you give up 11.3% of top end, rev limiter kicks in at 128mph, your speedo error will approach 20%. I have this mod on my track4i. Your chain/sprocket wear and mileage will worsen. It does give you more drive. That speed is gonna cost ya!
http://www.gearingcommander.com/
http://www.gearingcommander.com/
#4
RE: -1/+2 and 520 conversion
I did a 520 with -1 in the front. The low end is tremendous in power and speed.
Pros: Low end power excellent. Can bring front end up with the twist of the wrist.
Cons: Bike runs at higher rpms, fuel mileage is lowered, top end suffers. Speedometer inaccurate. I installed a Speedohealer to correct my speedometer. But I have never topped out the high end since my conversion. So I don't know what the top speed is, I have never needed to go that fast.
The rpms with a -1 at 80 mph is approximately 7000-8000 rpms. Never really looked. Posted speed limit is 75 mph on the interstate.
Conclusion: The low end power is worth the trade, cuz I don't need to go over 100 mph. I like to zip around town.
Pros: Low end power excellent. Can bring front end up with the twist of the wrist.
Cons: Bike runs at higher rpms, fuel mileage is lowered, top end suffers. Speedometer inaccurate. I installed a Speedohealer to correct my speedometer. But I have never topped out the high end since my conversion. So I don't know what the top speed is, I have never needed to go that fast.
The rpms with a -1 at 80 mph is approximately 7000-8000 rpms. Never really looked. Posted speed limit is 75 mph on the interstate.
Conclusion: The low end power is worth the trade, cuz I don't need to go over 100 mph. I like to zip around town.
#5
#7
RE: -1/+2 and 520 conversion
The conversion provides 2 benefits. Lowering the gear ratio improves acceleration. This feels very similar to riding around in 5th instead of sixth gear and you can see how that feels yourself. The bike will vibrate more at a given speed because it is running 11% higher RPM.
The second benefit comes from the reduced weight of the sprockets and chain. The chain is thinner, hence lighter, the sprockets are aluminum, also lighter. The weight difference isnt great, but it is rotating mass. Performance might improve as much as loosing a few pounds of rider weight or a few ounces of wheel weight. I've heard dyno guys say you might get around 1-2HP.
I dont think it makes much sense for a streetbike, costs almost as much as a track day, and increases your maintenance and operating costs. It was practically the last mod I did, and rated well below better gear, rider training, suspension and brake work in terms of return on investment.
The second benefit comes from the reduced weight of the sprockets and chain. The chain is thinner, hence lighter, the sprockets are aluminum, also lighter. The weight difference isnt great, but it is rotating mass. Performance might improve as much as loosing a few pounds of rider weight or a few ounces of wheel weight. I've heard dyno guys say you might get around 1-2HP.
I dont think it makes much sense for a streetbike, costs almost as much as a track day, and increases your maintenance and operating costs. It was practically the last mod I did, and rated well below better gear, rider training, suspension and brake work in terms of return on investment.
#8
RE: -1/+2 and 520 conversion
I have an 00 F4 and I went -1/+3...whereas before the bike was very sluggish at low rpms...now it is just as quick low end as it was high end before...not quite sure top speed yet...i got an EK SRX 520 conversion kit and Renthal Sprockets...
Oh yeah...and I got a speedohealer ($100) to recalibrate the speedometer...it was off by 20%!!! (so if I was going 100mph it would say 120mph)
I got 39mpg last time I was out (country ride avg speed 50, but at times 80+)
Oh yeah...and I got a speedohealer ($100) to recalibrate the speedometer...it was off by 20%!!! (so if I was going 100mph it would say 120mph)
I got 39mpg last time I was out (country ride avg speed 50, but at times 80+)
#10