15/48 sprocket performance

[YamaSpeed]

I have been reading about this but I have not read many reviews of this mod. I am curious how people who performed the mod feel about the results.

1. Does it drastically improve accelleration?
2. what RPM is 100 Kph / 60 Mph in 6th?
3. Do you find you are shifting more in the twistys?
3. What happens to your top Speed?
4. Could you hit the red in 6th?

I would like to hear about the experience. Not the theories/hypothesis.

Thanks

Yamaspeed

 

[opds9091]

I have been reading about this but I have not read many reviews of this mod. I am curious how people who performed the mod feel about the results.

1. Does it drastically improve acceleration?
2. what RPM is 100 Kph / 60 Mph in 6th?
3. Do you find you are shifting more in the twists?
3. What happens to your top Speed?
4. Could you hit the red in 6th?

I would like to hear about the experience. Not the theories/hypothesis.

Thanks

Yamaspeed

1- As far as off the line you still have to hit the power-band, but instead of it being at 6k it hits around 4k and when you keep the throttle open hold on cause ounce your in The band and it's time to shift, the front wheel is off the ground.
2 - I'm not to sure but i think in 6th gear doing 60 you are at 6k.
3 - Before i did the mod the bike went to 140-150, now with the sprocket's changed you lose top end, but no a big matter because there is no reason to do over 100 anyway.
4 - The bike has never, well i never made it to red line, some say there is a rev limiter but when i hit the throttle and ride the rpm's to 13-14k the bike hit's a flat spot. Like i said earlier, you will bang threw the gears and before you know it you are up in the 100mph.

If you do the mod make sure you get a speed-o-healer, my bike was off -14.8%.
This is one of the must do mod's IMOP.

 

[YamaSpeed]

Good to hear. This is exactly the info I was looking for. Thank you opds9091 for taking the time to review this mod.
I am going to make a parts order for this soon. The local shop is suggesting Sunstar sprockets. we will see... I have to do some more research on that stuff.

Thanks again

Yamaspeed

 

[DefyInertia]

Can I throw out some theory now that you got an answer you like?

You'll never redline the bike with stock gearing in 6th gear. So in order to lose top end speed you'd need to change the gearing enough to allow a 6th gear redline.

For practical purposes, your top end over the 1/4 mile or at the race track will increase since you wont' have enough room to redline 6th at most road courses even with this gearing. The perfect gearing depends on the track....

Bottom line, you're gonna have a bike that puts power to the ground a hell of a lot harder and the downside is relatively small unless you do a lot of touring or are only a highway commuter or something.

I run 15/46

 

[Fz6Sa]

3 - Before i did the mod the bike went to 140-150, now with the sprocket's changed you lose top end, but no a big matter because there is no reason to do over 100 anyway.
4 - The bike has never, well i never made it to red line, some say there is a rev limiter but when i hit the throttle and ride the rpm's to 13-14k the bike hit's a flat spot. Like i said earlier, you will bang threw the gears and before you know it you are up in the 100mph.

I take it you newer been to the German Autobahn? ("NO SPEED LIMIT" ZONES!!!!:rockon

 

[flamewulfe]

Does fuel economy really suffer at highway speeds? I want to do the conversion, but I hope to do a few long trips sometime in the life of the bike . . . and any idea as to what the new quarter mile times are after the conversion? I think stock is something like 11.3ish . . .

What's the new top speed after the conversion?

 

[oso2k]

Does fuel economy really suffer at highway speeds? I want to do the conversion, but I hope to do a few long trips sometime in the life of the bike . . . and any idea as to what the new quarter mile times are after the conversion? I think stock is something like 11.3ish . . .

What's the new top speed after the conversion?

I went -1/+2 and I would say fuel economy is affected. Before my conversion, I got ~50MPG. After, I got about ~35MPG. Never did a quarter mile run but I would say 0-45 is significantly faster (still not quite like my R6S), less lag 45-65, and it begins to flatten out at 75-80. First prior to conversion, 1st was good for 65MPH, now it's good for 55MPH. 2nd got you 90MPH, but now it's about 75-80MPH. Overall, I'd say new top speed is about 125-135MPH vs. 145-150MPH (depending on rider weight). All speeds indicated.

 

[someone08]

oso2k are you now getting on it a little more b/c of the lower gearing or are you still doing about the same speeds/ acceleration, because i would like to do this when i have a little more coin in my pocket too.(college sucks)

 

[davidsa1]

Here's my 2 cents! I have had both the -1/+2 and the -1 as well as stock. I currentley have the -1 for me that is the best I do alot of country riding as well as city riding and is good for both.With the -1/+2 the torque was great and I loved it for around town riding but hated it on long rides. As far as the gas millage goes I cant help there not one to pay much attention to it.

 

[oso2k]

oso2k are you now getting on it a little more b/c of the lower gearing or are you still doing about the same speeds/ acceleration, because i would like to do this when i have a little more coin in my pocket too.(college sucks)

You can ask wavex too (since we swapped bikes for a few minutes for a ride around LBC), but the FZ6 feels like a slug with the OEM gearing compared to my -1/+2 and PC3 setup. Pull is harder in all gears. No need to get on it. In fact, I would use the same gear (3rd) running Angeles Crest Highway to the 9 mile point where T's into Angeles Forest Highway. But I had totally modified my bike for track work so I how I define "getting on it" might be different. No I'm not running a track pace, but there is much less need to downshift to pass a car that is pacing (or running 5-15MPH faster) with this gearing. I became more inclined to wind out the gear and then shift up (and that's because the gear shows up a lot quicker now). A shift light should be recommended if you go -1/+2. -1/0 (which requires no chain) probably has longer gearing down low, but also less pull down low.

 

[Smittyboy]

How much would it cost (a cheapy like me) to just drop a tooth up front and a speedo healer? Sprocket would be 30ish? speedohealer would be 150 ish? Guessing...

 

[hardway]

I've got the sprockets ordered for the -1/+2, but this talk of the combo sucking on long rides is bothering me. What are the big drawbacks on a longer ride, just more shifting?
I know Defy does some long ones and you used just the -1 up front, did you ever try the -1/+2 combo?

 

[Hollywood416]

Personally I am more than pleased with just the -1 front adjustment. I feel no need to do the +2 rear. IMHO if your looking for that much more you just need a bigger bike. I can't imagine the highway RPM's with -1/+2 it's bad enough with just the -1.

 

[davidsa1]

Personally I am more than pleased with just the -1 front adjustment. I feel no need to do the +2 rear. IMHO if your looking for that much more you just need a bigger bike. I can't imagine the highway RPM's with -1/+2 it's bad enough with just the -1.

That is what I did not like about the 1/2 sprockets the RPM's where to high for anything more than just around town.

 

[YamaSpeed]

How much would it cost (a cheapy like me) to just drop a tooth up front and a speedo healer? Sprocket would be 30ish? speedohealer would be 150 ish? Guessing...

You are right on the money.

 

[YamaSpeed]

Thank-you everybody, this is all very useful information regarding this mod.

Yamaspeed

 

[OneTrack]

I finally got around to installing a 15t front sprocket and Speedohealer this morning. The weather has been beautiful here in Vancouver yesterday and today, so I put a Temporary Operating Permit on my FZ6 and went riding.
I used Speedohealer's online calculator, which recommended a setting of -11.1%. This proved to be absolutely right on the money, as the speedo read exactly the same speed as my GPS.
The -1 front sprocket makes a world of difference to the performance, however I did find things to be a bit "buzzy" in 6th for a while, and was looking for a 7th gear even more than before. I'll see how this works out when I start riding more later on in the Spring.
I would suggest that just going -1 on the front is quite sufficient.

Oh, edited to add some "cruising speed" numbers for a reference with the -1 front sprocket in 6th gear:-

100 kph = 6000 rpm
110 kph = 6500 rpm (this produced a high frequency "buzz" through the gas tank)
120 kph = 7000 rpm (cracking a WOT at this speed was very, very impressive )

 

[Nightshader]

You guys should use: Gearing Commander: Motorcycle Gear Ratio Calculator for Sprockets RPM Speed Chain ( not my site ) but it's really good.

It will even calculate the number of rev's the chain has to do in order to hit the same tooth on front and back sprocket. Also the max speed deincrease/increase, sprocket to sprocket distance with stock link count, and many more details.

 

[darkstofknightz]

A little late here on the discussion, but I too did a sprocket conversion. I didn't exactly go 15/48 I went a little more extreme, but for my purposes it really really worked out. The acceleration the bike has now compared to before to me is night and day, and I would do it again in a heartbeat. As for the highway, I don't do commuting on my bike but I do a lot of highway runs with my friends and for me, it doesn't really hassle me. That being said I can see for long daily commutes it might become a issue.

 

[psnbye]

I know the mod works great for most people that try it, but when I tried this mod, I did'nt like it and in fact I removed the sprocket the next day and gave it to another member on the forum for free!
It was really "buzzy". It seemed to rev out quicker and I didn't like the way it felt at higher speeds.
Just goes to show that not every mod is for every rider.
I kept the Speed-o-healer though since stock spedometers are slightly off anyway.