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Nah I probably will do 6 speed further down the road though. Just didn't have the funds to do it when I was installing the stroker.
 

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Keep in mind one thing....The cases are only so wide....adding gears doesn't mean you can just toss a couple extra gears in and it's good. All the gears have to be made smaller to fit them all back in the same space.

If you build a nasty 194cc motor and go race it around the tracks or the twisties by you.....its going to get some serious punishment to the trans.....with the smaller gears it just makes it much easier to start grenading gears and causing some costly problems.

I have been building the crf50 and klx110 motors for years and it's pretty hard to know someone spent the kinda money they did on the trans and labor.....to watch it turn into a paperweight on the supermoto track.

Not trying to talk anyone out of the 5 speed or 6 speed. Just making sure this is something you think of before you decide to go that route.
 

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What changes are their to the 1-4 ratios, if any? Or is it all the same with an extra gear added like an overdrive?
 

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This is a chart I made showing the transmission ratios available; stock vs the three aftermarket transmissions that I'm aware of.
 

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Yes. And only if your bike has the power to pull a higher top speed with that gearing. Pretty certain the stock bike with 9hp can't. On the other hand, even if you can't do 60-mph, for sure you'd be able to cruise at 45-mph with less engine rpm. Also, there's no rule that you have to be in your top gear - if you stay in 4th gear without up-shifting, you're not worse off than if you only had four gears to begin with. Personally, moving in commuter traffic WFO at 8,000rpm quickly gets annoying. The lack of a fifth gear is the thing I most dislike about the Z125. Still, putting ANOTHER $410 into this little thing...
 

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I've had many bikes with six-speed transmissions. And one of them, the Honda CB1100, came initially with a five-speed and was updated as a model-year change.

Generally, I'm glad to have them; but I was thinking this, tonight...riding the Z through traffic. What would I need another gear FOR?

First is walking speed. Second pulls strongly; and the torque band overlaps with third.

Third is good for 45-mph rises in city/suburban traffic. Fourth, is of course, wide open...but I never get close to the redline on fourth.

And...maybe it's just my old-fartdom...but I'm GLAD to not have to ratchet the gearbox down more than three taps at lights. As opposed to five taps, and having the gear selection hang up, as those UJM gears do if you slap them down without loading them between gears.

Anyone wants to try and report...have at it. I'm interested - but I think Kaw was right in just putting in four gears and keeping costs down.
 

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I think that 4 is enough for this bike. Other may disagree. For a bigger bike I can see the need for more gears. 4 gears on the Z is fine with me.
 

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I'm at redline in 4th a good bit as I live and work on a major highway. I've been curious of the overall difference the 5th gear would make if anything significant at all as far as top speed.
 
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