confused about spocket teeth.

[syafi]

Which will be the correct one to lower engine rotation for same street speed
16 / 42 , 16 / 40 , 17 / 42

Currently I am at 6100 rpm for 60mph. I want to lower the engine rotation for 60mph to about 5600-5800rpm

stock is 16/42 & rear tyre size is 120/90x16

[fastpakr]

The two options you listed are pretty close. 17/42 would be 5740@60, 16/40 would be 5810@60. I'd go with the 17/42 to keep the rear sprocket reasonably large.

[lecroy]

If you can fit the 17 front, I would run it just for the wear factor.

[syafi]

Another thing to ask

Will it be too much If i want to reduce the engine speed furthermore?
my 118cc 2T bike go 55Mph at 6500rpm (with 17/43 spocket) so why this GS450L @ 3x the cc size can only reduce litte rpm for same road speed?

Which combination could be my best bet.

16/42 - 2.625 - 6100 (about 6100rpm @60mph)
16/40 - 2.500 - 5809 (could be based on calc)
16/38 - 2.375 - 5519
16/36 - 2.250 - 5228

17/42 - 2.470 - 5739
17/40 - 2.352 - 5465
17/38 - 2.235 - 5193
17/36 - 2.117 - 4919

Thank you

Syafi

[Big Jay]

Divide the front sprocket into the back one to get the ratio. The higher the ratio ( lower numerically) the taller your gear will be and lower your RPM.

Jay

[fastpakr]

Given that he figured out a chart of projected engine speeds with various sprocket choices, it would seem that he understands that.

[Clone]

I would first try the 16/38 combination. If that didn't give me the feel I was after then I would try 16/36. But you will find an almost 1000rpm reduction will give you a considerable feel change at highway speeds. You may find you will need to drop a gear for hills, maybe even for high winds. Try the 38 rear first for a month or so. If the feel isn't ok, get a 36, sprockets are cheap. 8)

[syafi]

Okay, will try that.

[IanFrancisco]

Re: confused about spocket teeth.

Which will be the correct one to lower engine rotation for same street speed
16 / 42 , 16 / 40 , 17 / 42

Currently I am at 6100 rpm for 60mph. I want to lower the engine rotation for 60mph to about 5600-5800rpm

stock is 16/42 & rear tyre size is 120/90x16

Your GS450L should be capable of around 105mph or 168kmh!

The GS450 motors aren't able to fit a 17T sprocket. Having said that, I find that my GS450S with 15/45 (3.00) stock gearing works well for me. I would not want to give up any acceleration as there's not that much of it! These motors will run all day at 8000 rpm or more so motor longevity/wear & tear is not an issue here. Keep clean oil in it, preferably synthetic, and the bike will run at 6100 rpm at 60mph for tens of thousands of miles. But if you want to lower the rpm by 500rpm at 60mph for comfort reasons, by all means go ahead. I think you will find that more shifting is needed on hills, but the GS450 6-spd transmission has fairly close ratios and running in 5th when needed is not too buzzy in my experience. Also your acceleration from stopped will be affected. Even with my 15/45 gearing if I rev up to 4 grand and dump the clutch I don't get a wheelie or arm-stretching acceleration, the motor just lugs down to 2k rpm or so and I pull away at a moderate rate of acceleration. Any fast car can keep up with me. The GS450S new would only do about 90mph in a 1/4 mile and 0-60mph in something like 6.5 seconds. The L's would be somewhat slower than that.

[syafi]

ahh then pls help me with this.

http://www.thegsresources.com/_forum/viewtopic.php?t=43092

[IanFrancisco]

I have a reply for you in that topic.

http://www.thegsresources.com/_forum/viewtopic.php?p=416323#416323