[ctandc]

Again...please EXPLAIN to me how the wheelbase Effects GEARING?

The 98+ Kat has a longer wheelbase than the pre 98-600. And looking JUST at OEM replacement chain / sprocket sets, the pre 98 750 APPEARS to have the same approximate wheelbase as the 98+.

(All the listings I have show a 112 link chain for 88-97 600 Kats, and 118 for 88-97 750 Kats and all 98+ Kats 600/750)

I do know that the 98+ 600 and 98+ 750 have the same swingarm. Which tells me the 98+ 600 wheelbase is the SAME as the 750.

Now...

The 98+ 750 came with a 15/45 setup which is a 3.00 ratio.

The 91 Kat 600 came with a 14/46 which is a 3.286 ratio.

So with the 98+ 750 engine and the 91 Kat 600 frame / chain setup, I am geared LOWER (higher numerical ratio) than the 98+ 750 was designed to from the factory.

Which means I'm turning higher RPM's at any given speed than designed by the factory.

AGAIN please let me know how the wheelbase (LENGTH of chain / swingarm) effects gearing? It effects the suspension and handling sure...but gearing?

The gearing is a direct result of the front and rear sprockets, and of course transmission ratio's and tire / wheel diameter.

15/45 = 3.00 ratio
14/46 = 3.286 ratio

Which means that (friction / hp limits etc aside) with my current sprockets, the engine is turning 8.7% higher RPM's that it would be with the 15/45 setup.

So I am GEARED LOWER. I don't know if the 'terminology' is the same in the motorcycle world (I can't imagine it would be different) as it is in the car world, but when you INCREASE the gear ratio (higher NUMBER) in the rear end of a car, it's considered lower gears.

This always means that the engine is spinning at a HIGHER RPM at any given speed than it was before the gear swap.

Think of it this way... LOW Gears = SHORT gears HIGH gears = TALL gears

Short = less mph at max RPM in a gear

Tall = more mph at max RPM in a gear

(AGAIN friction, aerodynamics, HP / Torque limits all play a role, but on paper that's how it works)

So if I'm turning @ 6250 RPM in 6th gear at 70 mph indicated (as I am now)....then by changing to 15/45 it would drop my RPM's by 8.7% which would be equal to @540 RPM. That would drop my RPM's at 70mph to @ 5710RPM's.

[arsenic]

CP can answer this question way better then I can, I don't do numbers well

[DumbLuck]

anything else you'd like to tell me I'm wrong about?

yes, your B/O spray. It dont work near as well as you think it does <g>

[arsenic]

wtf is that supposed to mean?

[DumbLuck]

it means i got a sense of humor and is jerkin your chain <g>

[arsenic]

ok next time use a joke I understand

[DumbLuck]

ok next time use a joke I understand

your straight lines are just too hard to pass up. even this is waaaayyyyyy too tempting and easy <G>

[ctandc]

Well I know for SURE now that the 14/46 gearing is effecting gas mileage.

On my normal commute I run @ 70-75mph...and tach indicates @ 6200RPM at 70...

This past weekend on my trip, I ran all backroads..and one long run on highway 60, which is 55mph, and even counting slowing down to 35 / 45 thru a couple of small towns, I was running around 60-65mph, tach a bit under 6K RPM...

I went to gas up on the last stop before I got home, and I was getting 51MPG vs the 39MPG I've been getting on my commute....

[thetable]

no, you're not. You don't base gearing on the engine, you base gearing on the swing arm and rear rim. You have a pre 600 swing arm and god only knows what rim you have, so face it dude, you're not geared lower, anything else you'd like to tell me I'm wrong about?

How could you base gearing on the swing arm? You could base chain length on the swing arm, but not gearing. Now Suzuki could have chosen gearing based on the length of the swing arm to keep the front end on the ground, but other than that, I can't see where it would matter. The gearing itself is based solely on the ratio of the number of turn the front sprocket turns in relationship to the number of times the rear turns. The swing arm cannot play a factor in this. Rear rim also does not play a factor, now the outside circumference of the tire does. One revolution of the wheel is still going to be one revolution of the wheel, the circumference of the tire is going to play a factor in how far the bike actually travels in one revolution.

As to picking a chain length, here is my suggestion, order two links longer than you think you need. If it turns out to be too long then push the pins out of the next available link. It will cost a bit more for the longer chain, and it will take more time to remove the excess, but you will have the piece of mind knowing that you will not have a chain that is too short. If the only change you are making is changing the sprockets from 14/46 to 15/45, I can see no reason the same length chain wouldn't work. I could do the math, but frankly I really don't feel like it, when there should be more than enough room in the chain adjusters to make it right.