-1 +1 Driven Power Up Kit

[RACreative]

Any advise will be much appreciated... I searched the threads but did not find anyone who has done this gearing. I just ordered the Driven Power Up Kit. It will be here Monday. I decided to go with 15-47 for a -1 Front and +1 Rear. They say it will be faster off the line... just curious if anyone else has done this gear ratio and what there opinions are. Thank you in advance for any opinions. (I was going to keep it stock but Chaparral in San Bernardino could only find one rear stock sprocket and it was in Georgia with no idea as to how long it would take to get it)... rather than waiting I found Surfside Moto in San Clemente who was able to get me the Driven Kit in 2 days... needless to say I went with the kit. Hope it is a good choice...

 

[Chevyfazer]

The +1 rear won't be that noticeable but the -1 will more than make up for it. I take it you don't do much highway riding? But expect for your bike to turn about 1000 more rpms in every gear, say if you used to cruise at 75mph in 6th at about 6k it will now be about 7k, plus a speedo healer would be wise investment. That gearing change would also shave about .5 sec off your 1/4 mile times maybe more depending on how good of a rider you are

 

[UselessPickles]

expect for your bike to turn about 1000 more rpms in every gear

More precisely, your RPMs will be about 9% higher at any given ACTUAL speed, and your indicated speed will be about 9% higher than stock gearing. With stock gearing, the speedo is already about 6% optimistic. With -1/+1, the speedo will be about 16% optimistic. With Chevyfazer's 75mph at 6000rpm example, you'd be at 6500rpm with an indicated 87mph using -1/+1 sprockets (but still actually traveling at 75mph).

That gearing change would also shave about .5 sec off your 1/4 mile times maybe more depending on how good of a rider you are

It actually won't really affect 1/4 mile times if you know how to launch well. It will give slightly better time if you launch softly, but nowhere near .5s. Lots of info here: http://www.600cc.org/forum/f89/effects-changing-sprockets-23986/#post314731


While it does accelerate off the line a bit quicker than stock, I think you'll mostly get the illusion that it accelerates much quicker because you'll run up through the RPMs much quicker and have to shift into 2nd gear at a lower speed (redline in 1st gear at 45mph rather than 52mph).

 

[Chevyfazer]

More precisely, your RPMs will be about 9% higher at any given ACTUAL speed, and your indicated speed will be about 9% higher than stock gearing. With stock gearing, the speedo is already about 6% optimistic. With -1/+1, the speedo will be about 16% optimistic. With Chevyfazer's 75mph at 6000rpm example, you'd be at 6500rpm with an indicated 87mph using -1/+1 sprockets (but still actually traveling at 75mph).



It actually won't really affect 1/4 mile times if you know how to launch well. It will give slightly better time if you launch softly, but nowhere near .5s. Lots of info here: http://www.600cc.org/forum/f89/effects-changing-sprockets-23986/#post314731


While it does accelerate off the line a bit quicker than stock, I think you'll mostly get the illusion that it accelerates much quicker because you'll run up through the RPMs much quicker and have to shift into 2nd gear at a lower speed (redline in 1st gear at 45mph rather than 52mph).

9% is exactly 1080rpms so forgive me for being 80rpms off lol. I agree that it mainly has to do with the riders ability but there's a thread going on the fz6 site and everyone who went to a 15t front from a 16t has shaved about 1/2 sec off their 1/4mile times, so it's not really a illusion it really does make the bikes quicker by letting the motor run through the power band quicker in 1st - 3rd where most of your acceleration is done at.

 

[UselessPickles]

9% is 9%. It's not a specific number of RPMs. At 4000rpm it's only a difference of 360rpm.

As for 1/4 mile improvements, there's just too many other possible factors that could shave .5s off the time, such as practice and learning to launch better, different wind, temperature, humidity on different days, shifting at different RPMs, etc.

The results that I posted take out all the human and environmental factors and show exactly the difference in the performance of the bike itself. Follow my link to see the results of different gearing combinations. Scroll up to the first post to read about all the theory of what changing gearing actually does.

 

[Chevyfazer]

9% is 9%. It's not a specific number of RPMs. At 4000rpm it's only a difference of 360rpm.

As for 1/4 mile improvements, there's just too many other possible factors that could shave .5s off the time, such as practice and learning to launch better, different wind, temperature, humidity on different days, shifting at different RPMs, etc.

The results that I posted take out all the human and environmental factors and show exactly the difference in the performance of the bike itself. Follow my link to see the results of different gearing combinations. Scroll up to the first post to read about all the theory of what changing gearing actually does.

I 110% agree with you about a bunch of factors that can change the time but the one person I'm referring to ran his bike before and after, same track, same rider, almost same weather, you still can't take the human element out as you did on your post which I did read and is very informative, but on something like that you can make computer models until your blue in the face and still miss certain certain things, like the fact that a lowered geared bike overcomes the wind drag better at any speed than a stock geared bike does, by giving it more tq from the gearing change. Don't get me wrong your model is awesome, but that would only be the times say if the bike was on a treadmill operated by a computer. Computers can give you a good idea of what to expect but timeslips don't lie

 

[JonKerr]

I didn't do the +1 rear but the -1 front is a huge change. You will want to get a speedo healer. It's so far off to start with then you throw in a gear change and you're really guessing how fast you're going. I'm actually having to relearn how to ride some of my favorite roads because I'm so much higher in the RPM range. Roads that I used to just ride in 3rd the whole way, I'm having to kick into 4th at times, then a quick down shift into 3rd into some corners and get rolled back onto the throttle a little earlier. It really does help with coming out of a corner, you just run out of steam a lot sooner. Not really a huge issue for street riding, but for the track it's going to make a big difference. Instead of running Chuckwalla in 3rd the whole way and just not pushing extremely hard at the end of the longer straights, I'm guessing I'm going to be changing gears 13-14 times in a lap on that track now.

 

[RACreative]

Thank you!

Thank you everyone for all the info. Most of my riding is my daily commute down i10... however it is not to often that the traffic is loose enough to hit any high speeds. I do need the quicker acceleration for certain situations. I really appreciate all the info. So, I guess it was not a bad choice to change from stock.

 

[UselessPickles]

I did read and is very informative
...
a lowered geared bike overcomes the wind drag better at any speed than a stock geared bike does, by giving it more tq from the gearing change.
...
your model is awesome, but that would only be the times say if the bike was on a treadmill operated by a computer.

You should re-read my thread more carefully. Lower gearing definitely does NOT give more wheel torque at any given speed. Lower gearing increases torque at any given RPM, but reduces speed at any given RPM. You'll get more wheel torque at some speeds, and less torque at other speeds.

Also, my model does take into account effects of drag (air resistance), and can even adjust for temperature, humidity and air density (for both drag and engine power output). It simulates optimal clutch slipping during the launch, simulates the time it takes to shift gears (bike decelerates due to drag during that time) and even simulates shifting at the best possible RPM in each gear. Of course it can never be 100% accurate to real life, but it is definitely good enough to compare how changes to the bike would change performance with the assumption that the rider launches and shifts the bike flawlessly.

If you gain .5s in the 1/4 mile by changing to a -1 sprocket up front, it's definitely not the sprocket that made the difference. Heck... I have more than .5s variations in my runs on the same bike on the same day because my name isn't Ricky Gadson

Timeslips don't lie... about the performance of the rider on the bike... if you correct the times for atmospheric conditions. They can definitely tell lies about the bike itself.

 

[Chevyfazer]

You should re-read my thread more carefully. Lower gearing definitely does NOT give more wheel torque at any given speed. Lower gearing increases torque at any given RPM, but reduces speed at any given RPM. You'll get more wheel torque at some speeds, and less torque at other speeds.

Also, my model does take into account effects of drag (air resistance), and can even adjust for temperature, humidity and air density (for both drag and engine power output). It simulates optimal clutch slipping during the launch, simulates the time it takes to shift gears (bike decelerates due to drag during that time) and even simulates shifting at the best possible RPM in each gear. Of course it can never be 100% accurate to real life, but it is definitely good enough to compare how changes to the bike would change performance with the assumption that the rider launches and shifts the bike flawlessly.

If you gain .5s in the 1/4 mile by changing to a -1 sprocket up front, it's definitely not the sprocket that made the difference. Heck... I have more than .5s variations in my runs on the same bike on the same day because my name isn't Ricky Gadson

Timeslips don't lie... about the performance of the rider on the bike... if you correct the times for atmospheric conditions. They can definitely tell lies about the bike itself.

I guess we'll just have to agree to disagree lol.. I pretty much grew up at the dragstrip and wether it be cars or bikes, from what ive seen and done changing final drive ratio a decent amount has always gained me and others a minimum of .3 on the 1/4 and at least a .1 on the 1/8

 

[UselessPickles]

Just an example of how other factors could significantly skew results of comparing time slips from different days (or even from different times on the same day):

All else being equal, a stock FZ6R with a 170lb rider and a full tank of gas running into a 10mph headwind would be 0.26s slower in the 1/4 mile than the same bike and same rider with 2 fewer gallons of gas and no headwind.