[The CyberPoet]

Re: Gearing

DISCLAIMER: B4 anyone blows me out of the water on this topic I'm using wheelies as a way to measure bike acceleration (ie. a busa can pull a wheelie by opening up the throtle since it has a lot better acceleration).

Before you start using wheelie ability to measure acceleration, KNOW THIS:
The weight of the bike and the length of the bike from the center of the rear wheel forward act as a torque arm. This torque arm is what is being overcome to pull a wheelie. Thus, a bike with a short length, less weight in general, and/or it's weight further back (closer to the pivot of the torque arm) will raise the front wheel much faster than a bike with a longer length (longer torque arm) or the weight further forward (more forward bias on the torque arm), or just more weight. Thus, if you were to stick the identical engine (same HP) into a bike weighing exactly the same number of pounds (or kilograms), but the new bike had a shorter length, you'd get more wheelies without any difference in acceleration.

In simplest terms: If stick out your arm and you hang a 3lb weight off your wrist, it will take substancially more force to raise your arm than if you hang that same weight on your bicep instead.

Please CyberPoet, allow me:

check this out, may answer a lot of your questions.
http://www.motorcycleanchor.com/moto...ocketmath.html

Thanks -- appreciate it

ALSO KNOW THIS:
The kat wasn't designed to wheelie from the factory. A number of the components are designed with that fact in mind, including:
The front forks, which aren't designed to take a slam-down of the bike's weight. Stronger fork springs are recommended if you intend on stunting it.
The headlight & front upper fairing support subframe, which I've watched suddenly break away and drop the instrument panel, the headlight and the center of the front fairings on a harsh landing by a squid in my area (99 Kat 600 behind Lowe's one night). Safety wiring and some additional reinforcements may save you a very expensive repair bill.
The oil pick-up for the engine is in the front left; putting the engine into a serious wheelie will starve the engine for oil, as the pick-up will be clear of the oil pool in the oil pan. A slight issue for a slight wheelie, but a serious issue for anyone who might be planning on riding a wheelie for a longer distance. There isn't any simply way around this one except to buy a bike designed to handle wheelies (where the pick-up is located in the rear of the sump, usually in a center section that is lower than the rest of the pan).

Cheers
=-= The CyberPoet

[bonstrosity]

Cyber, I understand what your saying. The reason I used wheelies as an example is b/c most of us ride Kats, so all of our swingarms and everything will be about the same size and same weight (depending on the model of Kat we have). Otherwise I didn't know of a way to explain how much more acceleration you will get? Then everything would be weird do to different people's experience w/ high acceleration. Mine being very low since the Kat is the fastest bike I've ridden where as someone else who's ridden a busa might not think that those mods actually add a lot of acceleration. And to restate myself I have no interest in doing wheelies.

[The CyberPoet]

Otherwise I didn't know of a way to explain how much more acceleration you will get?

The standard ways most motorcycle (and car) magazines use is 0 to 60, 0 to 100, and top-gear roll-on times (like 40 to 70 in top gear). Plus the obvious quarter-mile times. All of which directly relate to the acceleration rate (and to a lesser degree, wind resistance). But what most riders around here know best is their butt dyno -- the feeling in the seat of your pants as the bike accelerates; if there is a noticable difference it's because of changes to that one bike and you're not comparing two similar bikes normally (because your Kat may have loose valve settings and more ring-to-piston wall slop than mine, and thus while identical, not perform as well).

The big butt-meter changes are:
JetKit properly tuned
Racier motorcycle oils (slipperier, lower pumping losses)
Ignition advancer
sprocket changes
Full end-to-end exhaust system
larger engine displacement (either bore-over & compression change, or engine swap)
NOX

Cheers
=-= The CyberPoet

[blkpitbull]

I did -1 in front and +3 on the back and there not way the front wheel of the Kat (600) will come up by just opening the throttle don't worry about it!

The 750 will, by just a -1. Crank it open to 5-6K, close it down, WHACK IT OPEN and hold on.

My stock geared 98 750 will do as you described above. It will clutch up in second, standing, and bouncing it as you clutch it!

[paperairplane]

my 90 750 will pop the front up under throttle in first

<austin powers>
Whoop dee do Basil
</austin powers>

I keep thinking about changing my gearing and never do it b/c I know I will hate it on the highway. Plus if I crash, it is not going to be b/c I was trying to do a stupid trick on my bike.

If you want to wheelie, get a RM250 - now THAT will pull the front end up!!! Better yet, get a big thumper!

Besides, it hurts less to crash in the grass....

[duff daddy]

HS, I understand how tough is it to change the sprokets and chain? fairly easy?

edit, i did this, it was a pain in my butt, the back sprocket is easy as sin but then the front was hard i had to get an impact socket then i had a prob with my clutch engagin, so its not that hard just annoying