520 Kit & -1 front +2 rear sprocket

[spy]

Probably a noob question, but I'm still a noob so...

What can I expect besides the obvious boost in acceleration?

What else will it change on the bike? Would I need to dial in the suspension again after the conversion?

I'm just looking for a lil more "go" for those times when it's hard to get "that person" on the straights. HAHA Ok, that's not really a big deal but the truth is, I wouldn't mind the extra acceleration. I know I'll need a speedo healer, not worried about that.

Guess I'm trying to figure out if I'm going to like it or not at this point in my riding. btw - This is a track only bike. Is it a pretty smooth transition between stock gearing and going -1 +2 on the back or does it take some time to get used to the change?

[Spy007]

the change in your sprocket has no impact on your suspension.... kinda boggled by that question.

Its going to lower your top speed and increase your acceleration. Its going to make the bike a bit easier to power wheelie, so you will have to learn a lil bit more. I dont remember that the 05 gixxer 600's came with stock for chains but if it was bigger than a 520.. you will also gain a lil horsepower from the reduced weight (lighter rotating mass and all).

Speedo healers are good for all bikes... since we are all off by a certain % stock. Even more-so when you change the gearing.

Enjoy!

[Spy007]

Oh, and more to add.... the better your corner exit speed, the less you have to worry about "catching up to the guy on the straight" because you would have carried more speed through and out the corner and have to make up even less than they would. Work on your lines and everything else... and it will do more for you than any performance mods.

[badgixxer]

i'm -1 +2 on my 636 and it was interesting to get used to... rear tire will spin up easier so you can't grab a whole hand full throttle as early when exiting corners... definetly more prone to wheelieing coming out of corners... you mnay be in differnet gears in some corners than what you were previously used to....

and if you want more "go" to catch peeps on straights get a 1000

[spy]

I agree 007, I'm not looking into the mod to drop lap times or anything.

There are those times when I do carry more speed then the person in front. However, some corners you just can't pass, and instead have to brake check and line up behind. Even getting on the gas on the way out first isn't enough. But like I said, It's not to lower lap times or to "get faster".

badgixxer- that's also one thing that was in mind. The different gear thing.... the tracks I mostly ride have quite a few turns were if I take the turn in one gear my rpm's too low coming out and if I take it in a lower gear the rpms too high. I'm thinking this might help there as well.

007, badgixxer......Thanks for the replys.

[malik ross]

for a track bike going -1 in the front would be a good start. -1/+2 gives you better acceleration but also requires more shifting. you have a lower top speed in each gear and less flexibility.

[spy]

Originally Posted by Spy007

the change in your sprocket has no impact on your suspension.... kinda boggled by that question.

"There's much more to your bike's driveline than just delivering power to the rear wheel via a chain and a couple of sprockets; gearing selection can affect acceleration, top speed and even handling.

Now for the fun stuff. Notice on the chart how 15/44 is virtually identical to 16/47 gearing...or is it? One obvious difference is that with larger sprockets, 16/47 gearing will give a shorter wheelbase than with 15/44, giving your bike a slightly more rearward weight bias. Or, maybe it's enough of a change that you could add a link to the chain and lengthen the wheelbase. Given sprocket sizes and chain length, comparative wheelbase numbers can be calculated and added to the chart, eliminating any guesswork.

A front sprocket with fewer teeth works the chain harder and robs power, as the chain has to curl more to match the smaller diameter. In general, a 14 tooth front sprocket is the smallest advisable, with 13 being used in extreme cases.

One thing to watch is clearance between the swingarm and chain. Smaller sprockets can result in the chain laying on the swingarm, and actually working the suspension when power is applied. One notable example is the early Kawasaki ZX-7R, on which many racers had to have the swingarm relieved for chain clearance. With high-horsepower machines, chain pull and its effect can be altered using sprocket selection. Anti-squat torque-which extends the rear suspension under power-is determined by swingarm angle and the distance between the swingarm pivot and top chain run. Even if the chain doesn't touch the swingarm, running it close to the pivot will enhance the anti-squat torque, much in the same way raising the swingarm pivot does.
"

[gsxr_fan2003]

dooo it...i have it...with a speedo healer of course... and well when 4th gear redlines your at about 113-115 mph... so big change

more noticable and usable power down low

[midnightrider10]

i love it, only thing is every time i give full throttle front end comes up, but a gentle tap on rear brake keeps her down

[hobart_barista]

Im very interest on doing a -1 +2 on my bike aswell, however, the thread after this is interesting, I might just start off with a -1, I'm assuming I want need a new change. Ive got a zx-6r 2000, and i'm wondering, will this lower quarter mile times?

[Grashopr]

Originally Posted by spy

"There's much more to your bike's driveline than just delivering power to the rear wheel via a chain and a couple of sprockets; gearing selection can affect acceleration, top speed and even handling.

...
One obvious difference is that with larger sprockets, 16/47 gearing will give a shorter wheelbase than with 15/44, giving your bike a slightly more rearward weight bias. ....

...Or, maybe it's enough of a change that you could add a link to the chain and lengthen the wheelbase. Given sprocket sizes and chain length, comparative wheelbase numbers can be calculated and added to the chart, eliminating any guesswork.

A front sprocket with fewer teeth works the chain harder and robs power, as the chain has to curl more to match the smaller diameter. In general, a 14 tooth front sprocket is the smallest advisable, with 13 being used in extreme cases.

One thing to watch is clearance between the swingarm and chain. Smaller sprockets can result in the chain laying on the swingarm, and actually working the suspension when power is applied. One notable example is the early Kawasaki ZX-7R, on which many racers had to have the swingarm relieved for chain clearance. With high-horsepower machines, chain pull and its effect can be altered using sprocket selection. Anti-squat torque-which extends the rear suspension under power-is determined by swingarm angle and the distance between the swingarm pivot and top chain run. Even if the chain doesn't touch the swingarm, running it close to the pivot will enhance the anti-squat torque, much in the same way raising the swingarm pivot does.
"

From what I've seen at the track, GSXR's running -1 +2 doesn't have a problem with a -1 front sprocket as far as swingarm clearance goes. I know that the older ZX7's had a problem with this, but most bikes dont have this problem til you go to -2 in the front or farther. Shortening the wheelbase? That's a chain length issue, if you've got the skills to be able to tell the difference that a shorter wheelbase by one chain-link gives you, you probably wouldn't need to ask about it. Most of the time you can adjust your preload/fork height to make up for the weight bias that shortening the wheelbase causes, but that's only applicable when you're on the ragged edge, and in all reality, body positioning can help make up the differnece just as well.

The BIGGEST differnences for us 'mortals' is going to be that your speedo will be WAAAAYY off (speedo healer) and the gear/revs that your'e running into/out of a corner. I run -1 +2 on very small tracks, but on the street, it's too much for me; on the highway I'm running VERY high revs at cruising speed, normally -1 +1 is still nearly too much, -1 +0 is a good place to start. However a 520 kit is ALWAYS nice. Less rotating mass plus the -1 front makes the bike feel like it's on steroids on the street. Good luck!

[Spy007]

Originally Posted by Grashopr

From what I've seen at the track, GSXR's running -1 +2 doesn't have a problem with a -1 front sprocket as far as swingarm clearance goes. I know that the older ZX7's had a problem with this, but most bikes dont have this problem til you go to -2 in the front or farther. Shortening the wheelbase? That's a chain length issue, if you've got the skills to be able to tell the difference that a shorter wheelbase by one chain-link gives you, you probably wouldn't need to ask about it. Most of the time you can adjust your preload/fork height to make up for the weight bias that shortening the wheelbase causes, but that's only applicable when you're on the ragged edge, and in all reality, body positioning can help make up the differnece just as well.

The BIGGEST differnences for us 'mortals' is going to be that your speedo will be WAAAAYY off (speedo healer) and the gear/revs that your'e running into/out of a corner. I run -1 +2 on very small tracks, but on the street, it's too much for me; on the highway I'm running VERY high revs at cruising speed, normally -1 +1 is still nearly too much, -1 +0 is a good place to start. However a 520 kit is ALWAYS nice. Less rotating mass plus the -1 front makes the bike feel like it's on steroids on the street. Good luck!

+1

Honestly exactly what I was going to say.

Spy, your quote about the suspension changes really would only impact a high performance race team where *every* little bit helps. These are the people who rigorously test and change every aspect of the bike to get that tenth of a second faster in lap times. Regular bikes will not notice a difference. In fact, no 2 bikes will ever get the exact same suspension setup for optimum performance when getting to that level of setup. Getting a good setup by a suspension shop will usually work for you through most performance upgrades and mods without having to re-tweak it. Granted getting it set up a couple times a year isnt a bad idea since oil breaks down and suspension changes with wear and tear.
Having a suspension shop set you up will definately help as well if you havent done so already. It will give you MUCH more control in the corners and a much more solid feel to your daily riding.
Also... brakes are a good upgrade. If you can keep up somewhat with the guy you cant get around in the corners... braking later give you the edge as long as its controlled. Most of the passing is either at the start of a corner or the end, rarely you will see it mid corner because of the specific lines.

[LDS]

It's a good idea to have a selection of sprockets (as well as appropriate length chains) for a track or race bike.

Ideally, you want to be at or about red line in high gear at the fastest part of the track, and be ready to shift to the next highest gear at the exits of the turns. That's under ideal conditions, and will probably never happen. Plus, as you get faster, you can tweak your gearing to try and keep your shift points consistent.

[Road Rash]

So, I am interested in something like this mod. Will a 520 chain w/ a -1 front sprocket, make a noticible difference? I do not want a wheelie monster on my hands. I just would like a little extra ummph down low. I ride in town to & from work, occasionally on the interstate, & go on rides w/ some descent twisties. After reading Grashopr's post, it makes me wonder if I want a -1/+2 on my F4i. And lastly, how much top end do you actually lose w/ a -1/+2 or any sprocket mod? Thanx.



RR

[Foo_909]

I found this on motomummy:

"Now to gearing. You often here of -1 or +2 or -1/+2. Well if you hear - numbers it normally means going down a tooth in the front sprocket. This gives you more acceleration out of your bike (feels like more torque and it's noticeable), but on the downside you will lose roughly 10mph of top speed in 6th. So if you went 185 mph you'll probably only go 175 now. before getting into redline or wherever you were before in the rpms. When people talk about + numbers its normally talking about the rear sprocket as this also increases acceleration. The most common setup (especially for 1000cc bikes) is +2 in the rear. This gives you a noticeable gain in acceleration with a loss of about 7mph on the top end. You can also combine the two and run -1 in front and +2 in the rear (a -1/+2 setup) this will give you crazy acceleration, but you'll lose 15-20mph on the top end. it's great for stunters or drag racers. Going down 1 tooth in the front is equal to going up about 3 teeth in the rear. So if you do +2 in the rear it's a little bit less drastic of a change then -1 in the front."

Good read guys, I'm a noob also and learning.. looks like I may do a +2 on the rear with a 520 kit in the future.