Taller gearing?

[Cortez]

Hello everyone!

Excuse the wrong subforum if I posted in the wrong section, but I wasn't sure
where to go with this.

I was wondering.. in this day and age where everyone is going for shorter
gearing to get better acceleration.. has anyone went the other way?

I've done +1 on the front sprocket on my Kawasaki ER6F/650R and the
change was perhaps a bit more then I wanted, but it made the speedo
GPS accurate at virtually all speeds, however, the result was that I still
had indicated (for example) 60mph at 4500 revs and I was actually going
faster all the time then before, but the speedo was more accurate.. so I was
thinking, maybe I'll do the rear sprocket on this bike, and at least SEE the
difference I made.


The question is.. what to do.
I'm aware of the gearing commander web site, and I'm looking at -1 or -2
at the rear sprocket, both giving a rather small difference.

I'm just looking for lower cruising revs.
The bike will likely be ridden at 75mph when touring, and this would probably
return somewhat better MPG figures.

...and if I'm reading the gearing commander web site correctly, the -1 at
the back, while not a big difference (in 6th gear especially) should prolong
the life of the chain.

Any thoughts?

Or should I just go +1 at the front and forget everything else?

Stock is 16/46, if the gearing commander web site is correct and the
FZ6n has the same gearing as the FZ6S.

Thanks!

 

[outasight20]

I have the +1 front sprocket and stock rear on my bike. I get between 40-45 city and 50-55 highway MPG's. the acceleration really isn't affected that much. I still run a sub 12 second quarter mile. The lower rpms on the highway are nice too

 

[Cortez]

I have the +1 front sprocket and stock rear on my bike. I get between 40-45 city and 50-55 highway MPG's. the acceleration really isn't affected that much. I still run a sub 12 second quarter mile. The lower rpms on the highway are nice too

Thanks.

+1 front seems optimal, but rear sprocket is probably cheaper to replace.
I was also wondering if going -1 or -2 at the back will make the speedo
more or less accurate, if anyone knows? The speedo now seems less accurate
then my Kymco scooter.

Did you have worse MPG figures before the swap or is it too hard to
follow?

With stock gearing, I tend to shift 1st to 2nd, then 2nd to 4th and 4th to 6th around
town.. the bike doesn't seem to mind 40mph in 6th so why not use it.

 

[yamihoe]

my front sprocket was $22....cheap enough for me lol

 

[Cortez]

my front sprocket was $22....cheap enough for me lol

They're about $35-40 here, rear is $20ish.. not much money either way.

 

[yamihoe]

thats interesting...i found the opposite they wanted that price for the rear.....either way neither sprocket is difficult to change.

 

[outasight20]

With the +1 front, my speedo is within 1% of GPS at all speeds. I also find it strange that the rear sprocket is cheaper where you live. I paid about $20 for the front sprocket here and a rear one costs about $35.

I think doing +1/-1 or +1/-2 would sort of defeat the purpose of what you want. Your speedo would be slightly farther off and you would get less gas mileage. Yes, I did notice a slight improvement in MPG's when I fitted the larger front sprocket. The only time I wish I had the stock or -1 front is when starting from a stop on an uphill with a passenger. It now requires much more clutch slip.

 

[mave2911]

As I do a bit of long distance touring, I have also gone +1 at the front. As shown, this makes the speedo correct to 1%.

Hopefully when I get my bike back, I'll be going to the Mad Max Museum and will be ale to advise on fuel economy difference with the change in ratio.

Cheers,
Rick

 

[Cortez]

With the +1 front, my speedo is within 1% of GPS at all speeds. I also find it strange that the rear sprocket is cheaper where you live. I paid about $20 for the front sprocket here and a rear one costs about $35.

I think doing +1/-1 or +1/-2 would sort of defeat the purpose of what you want. Your speedo would be slightly farther off and you would get less gas mileage. Yes, I did notice a slight improvement in MPG's when I fitted the larger front sprocket. The only time I wish I had the stock or -1 front is when starting from a stop on an uphill with a passenger. It now requires much more clutch slip.

I won't do both front and back, but + at the front and - at the back do the
same thing, together they'd do more of the same thing so I don't see how
that would make the fuel consumption worse.

 

[Cortez]

As I do a bit of long distance touring, I have also gone +1 at the front. As shown, this makes the speedo incorrect within 1%.

Hopefully when I get my bike back, I'll be going to the Mad Max Museum and will be ale to advise on fuel economy difference with the change in ratio.

Cheers,
Rick

Do you maybe know how much it was off before?
I didn't check GPS yet, but a local radar on the side of the road seems to
show a 6mph difference at 40mph, and that's A LOT.

Still wondering if the -1 or -2 at the back would make the speedo more accurate or make it worse?

 

[mave2911]

Do you maybe know how much it was off before?
I didn't check GPS yet, but a local radar on the side of the road seems to
show a 6mph difference at 40mph, and that's A LOT.

It's about 7% off with stock sprockets.

Cheers,
Rick

 

[dpaul007]

I've also done +1 in the front. My next change of chain and sprockets I'll probably go back to stock. Just for curiosity as I've only ridden my FZ with the +1.

 

[Cortez]

I've also done +1 in the front. My next change of chain and sprockets I'll probably go back to stock. Just for curiosity as I've only ridden my FZ with the +1.

I just find it funny that I can use 6th gear as low as 35mph, and there's no
issues, the bike just pulls cleanly. It's my first 4 cyl bike so.. and I'm aware that
the FZ6 is one of the least torquey bikes out there.

I remember when I had my first ride on one in 2007, coming off my Ninja 650R
(ER6F, 650cc twin), the FZ6 felt like it was 400cc, compared to the 650R.

The 650R would pull A LOT better from low revs, but the FZ6 got faster above
8k or so. But even then I felt that the FZ6 was a better bike in every other
way other then torque. There and then I said I'd get a Bandit 1250..

 

[YZF73]

Still wondering if the -1 or -2 at the back would make the speedo more accurate or make it worse?

-1 or -2 in the rear without any change in the front will make the speedometer more accurate, but not completely.

With the stock gearing at 16/46, a change of +1 tooth at the front is approximately equal to -2.875 teeth at the rear.

If I remember correctly, a speedometer error of 7% has been stated by other forum members with the standard gearing. So with a stated error of 1% with +1 up front, we have 6% error correction effectively over 2.875 teeth, equal to 1% per 2.09 teeth, and 6.27% for 3 teeth.

However, as the relative ratio of the front and rear sprockets is changing, this value is not completely accurate. In order to get the best estimate of the error correction, we must take the relative ratio of both possible new setups into consideration.

As stated above, with the stock 16/46 setup, 1 tooth at the front is equal to 2.875 at the rear. For a 17/46 setup, 1 tooth at the front is equal to 2.706 teeth at the rear, and for a 16/43 setup, 1 tooth at the front is equal to 2.688 teeth at the rear. If we work out the speedometer error correction for these ratios, we get 6.65% and 6.70% respectively.

Again this is not definitive, but the speedometer error correction seen from either +1 at the front, or -3 at the rear should fall somewhere between 6.27-6.70% depending upon which setup you choose to go with. Either way, the speedometer error difference between +1 at the front, and -3 at the rear I would consider to be negligible, we're talking 0.43% in the absolute worst case.

Setting the maths aside, mechanically speaking If choosing between +1 at the front and -3 at the rear I would recommend going +1 in the front; this minimises the amount you will have to move the rear wheel forward, hence minimising any change in suspension geometry. Also, the larger the front sprocket, the less demand you're putting on the chain, as it doesn't have to travel about such a tight radius... slightly higher efficiency, and less wear and tear. :thumbup:

Obviously if you wish to go with -1 or -2 at the rear you don't have an option, but if its between +1 front and -3 rear, definitely got for the +1 front.


If you wanted some info regarding fuel economy, and why lower engine speed doesn't necessarily equal lower fuel consumption, I'm more than happy to discuss it... just give me a shout! (Warning!!! If you get me started there's no telling when I'll stop)


Hope this helps,

Yamahaboyz

 

[fb40dash5]

I've got a 16T front with a 45T rear. IIRC my speedo is pretty close to dead on now, or at least good enough for me. I didn't notice any power loss, but I don't think it was lacking stock like some do, either.

 

[YZF73]

Original post (#14) edited, please re-read if you wish, contains a correction to one of the calculations and some more explanation... sorry guys. :ban:


Yamahaboyz

 

[Cortez]

-1 or -2 in the rear without any change in the front will make the speedometer more accurate, but not completely.

With the stock gearing at 16/46, a change of +1 tooth at the front is approximately equal to -2.875 teeth at the rear.

If I remember correctly, a speedometer error of 7% has been stated by other forum members with the standard gearing. So with a stated error of 1% with +1 up front, we have 6% error correction effectively over 2.875 teeth, equal to 1% per 2.09 teeth, and 6.27% for 3 teeth.

However, as the relative ratio of the front and rear sprockets is changing, this value is not completely accurate. In order to get the best estimate of the error correction, we must take the relative ratio of both possible new setups into consideration.

As stated above, with the stock 16/46 setup, 1 tooth at the front is equal to 2.875 at the rear. For a 17/46 setup, 1 tooth at the front is equal to 2.706 teeth at the rear, and for a 16/43 setup, 1 tooth at the front is equal to 2.688 teeth at the rear. If we work out the speedometer error correction for these ratios, we get 6.65% and 6.70% respectively.

Again this is not definitive, but the speedometer error correction seen from either +1 at the front, or -3 at the rear should fall somewhere between 6.27-6.70% depending upon which setup you choose to go with. Either way, the speedometer error difference between +1 at the front, and -3 at the rear I would consider to be negligible, we're talking 0.43% in the absolute worst case.

Setting the maths aside, mechanically speaking If choosing between +1 at the front and -3 at the rear I would recommend going +1 in the front; this minimises the amount you will have to move the rear wheel forward, hence minimising any change in suspension geometry. Also, the larger the front sprocket, the less demand you're putting on the chain, as it doesn't have to travel about such a tight radius... slightly higher efficiency, and less wear and tear. :thumbup:

Obviously if you wish to go with -1 or -2 at the rear you don't have an option, but if its between +1 front and -3 rear, definitely got for the +1 front.


If you wanted some info regarding fuel economy, and why lower engine speed doesn't necessarily equal lower fuel consumption, I'm more than happy to discuss it... just give me a shout! (Warning!!! If you get me started there's no telling when I'll stop)


Hope this helps,

Yamahaboyz

Jesus.
That's a lot of numbers right there.
Need to get some sleep before I take all that in.
I won't be shoutin' at ya any time soon!

Looks like I should look no further then +1 at the front.
I just wish I could make the 6th gear taller, and leave everything else as it is.

Drop it by.. like.. 1000 revs or more.
Watched some vids on YT, the GSR600 has a 1000 rev drop between 5th and 6th,
that's probably great for cruising.

Thank you!

p.s. The only downside too al this is I'd still be going 100km/h / 62mph at the same indicated revs, but moving faster,
read: I'd be riding faster all the time. That's what happened on my Kawasaki. I forgot that the speedo was more accurate
after a while and just kept riding at the same indicated speeds as before.