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Motorcycle.com has put together a dyno chart comparing the Z125 Pro’s curve to that of the Grom.

Before the Dyno came out, reviewer Troy Siahaan felt like the Z125 Pro had more power and torque at lower revs than the Honda Grom but will the dyno chart support his “butt dyno” findings?




Contrary to his butt, the dyno shows that the Grom makes more power and torque at lower revs with 8.3 hp at 7800 rpm, and 6.5 lb-ft at 6100 rpm while the Z125 Pro produces 8.3 hp at 7800 rpm, and 6.5 lb-ft at 6100 rpm.

On paper the Grom seems to be winning but on the road, butts are being won over by the Z125’s gearing. The Z125 Pro has a lower gear ratio of around 3.07 compared to the Grom's 2.27, paired with its revvier nature and the Z125 Pro will feel like it has much better acceleration.

Even though the top speed is lower in comparison, its rev happy nature makes this a trade-off that riders can live with. Looking at the chart, we can see that the Grom is leading until they hit the 7400 rpm range but once the aftermarket catches up and the Kawasaki can breathe easier we should be seeing an improvement.

Overall, the power differences between the two models are minute and the number gap can be bridged with a few aftermarket parts.
 

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Great share! We felt the same way when doing a fun quick race outside of the office. The Z seemed to get up and go a little more aggressively than the Grom but the Grom caught up after so many yards. Both bikes are a win-win and the aftermarket parts area will soon be filled with options for both bikes!
 

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Thanks for the summary and chart. Very interesting that the testers feel for acceleration (Z125 gernerally more peppy) doesn't match up with what we might expect from the dyno numbers. As Ari said in a recent video where he and a friend rode a Grom and Z125 Pro around San Francisco all night, we are all winners for getting another choice in the 125 street bike market. Let's see how our Kawasaki's respond to tuning!
 

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Can a Z125 owner verify the tooth count on the front and rear sprockets?

Some recent reviews say it's 14/30 and other places say it's 14/43.
 

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14/30 is true.
Thanks. That means Motorcycle.com's stating the final reduction ratio of 3.07 is wrong. It's actually 2.142, compared to 2.266 for the Grom.

So, the main difference is in the ratio of each gear, with the Z125s being lower in each of the 4 speeds.
 

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What a fantastic little article! Thanks for the share! Interesting to note that theres more power in the Honda!
 

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Yup, outstanding....I will probably try a 13t at the track coz I'm 220lbs. with a track length of 5/8 mile with 30 ft of elevation change. Gonna need that drive coming out of the corners.
 

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Thanks. That means Motorcycle.com's stating the final reduction ratio of 3.07 is wrong. It's actually 2.142, compared to 2.266 for the Grom.

So, the main difference is in the ratio of each gear, with the Z125s being lower in each of the 4 speeds.
Im curious the total calculated drive ratio including transmission ratios as well. Could make a difference. :nerd:
 

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.

The final Drive ratio on the Z is so out of wack. (way too high)

We had to install taller (and wider) tires, and a 15t front just to get it into realistic FD range.


 
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Curious to know as well ^ I'm pretty newb to this and that sounds really interesting. Also would like to see how it looks with the bigger tires !
 

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Think of it like when you ride your mountain bike.
And your in 1st gear........ you pedal really fast, but you don't really go anywhere.

Now, think about when you switch to 10th gear........ you pedal slower, and go faster.
You are basically "Bringing down the revs"

That's what we did on the Z125. By Gearing the bike down..... we brought the revs. down. So the bike has a little more top end speed but most of all isn't bouncing off rev limiter all the time.

Make the bike much more enjoyable to ride.


.
 

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Think of it like when you ride your mountain bike.
And your in 1st gear........ you pedal really fast, but you don't really go anywhere.

Now, think about when you switch to 10th gear........ you pedal slower, and go faster.
You are basically "Bringing down the revs"

That's what we did on the Z125. By Gearing the bike down..... we brought the revs. down. So the bike has a little more top end speed but most of all isn't bouncing off rev limiter all the time.

Make the bike much more enjoyable to ride.


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So you think sticking with the 15t is the way to go? I've got one on and did notice it corrected the speedometer. Hopefully when the FCs cone out they'll help make up for the slight loss in acceleration. Your thoughts.
 

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So you think sticking with the 15t is the way to go? I've got one on and did notice it corrected the speedometer. Hopefully when the FCs cone out they'll help make up for the slight loss in acceleration. Your thoughts.
.


That's exactly our plan.

.
 

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Was browsing the forum and thought I'd share my independent results regarding the grom vs z125 dyno numbers.

We did a "dyno shootout" at the dealership that I work at (Echo Cycle, Edmonton, Alberta, Canada). A friend happened to have his grom with him and we figured it would be fun to pit them head to head. I think he did more harm than good with the pipe (6.58 hp). My Z125 only has an intake on it and a -1 front sprocket (7.89 hp). Don't forget that we're at about 2400ft elevation here so everything makes a bit less power than close to sea level.

It won't let me post the links.......but the vid's are on youtube. Search: Kawasaki Daze and the dyno runs are titled by bike throughout the day.
 
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