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Disclaimer / background: I have a Speed Triple 1200 (156whp), I had a Grom 125 (8whp), I am just trying to visualize what the zx4rr is going to be like realistically, as a casual road rider. As I will probably sell the cbr650 if the zx4rr works out (flash and all that jazz.)

We know the non-ram peak power is 76 hp crank, we know 26.5 ft·[email protected], we can compute peak power happens above 15k.

Literally just took a zx25r chart and relabeled 5,10,15,20... to 8,16,24,32... because it actually seems like a decent napkin estimate, basically +60% 250 -> 400 engine size ratio.

I had a blast on my first bike Ninja 250R which was about 25whp per the internet. Looks to me that shifting the zx4r at 8K will be about 32 whp. This is 4x Grom peak whp, and about +30% over a Ninja 250's peak. 32 whp is shifting my cbr650 around 4.5k rpms which is pretty lazy in the revs honestly.

Even shifting at 5K would still be 2x the Grom's peak whp, 16whp should be enough power to move with typical traffic (Grom's 8whp was not imho.) My conclusion being I should be able to shift at least as low as 4-5K and still move happily with traffic.

Considering the level of these humble numbers, in retrospect I'm glad we got the 4R and not the 25R.

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