Topic: Crank hp vs rear wheel hp

[Tracksnblades1]

76f 18T/45T  130/90/17 metzler

18/45 is gearing for the salt flats, not roll-on drag racing.

You're Funny.😁

Actually before children and gray hair, I rode a bit with friends that had Ks and Fs.
Between all of us friends, I'm not sure if we missed any sprocket combinations or tuneup
variations. Since the bikes were somewhat close in performance, we would compare our progress
against the unchanged bikes.

As for sprockets, as a group, I think we tried from 16/48  - 18-43. My personal experimentation
never really increased the top speed more than 1mph or so, even with your so called salt flat gearing.🤓
Some gearing actually cost top end unless you were willing to go to float rpms. Actually on my bike it only changed how fast you got to top speed and how high the rpm while there. I think it was at its horsepower wind resistance limit.  When comparing with one of my buddies bike with near identical performance, Mine seemed to fade a little if you let the gearing allow the rpms to get out of the red...Since I rode interstate during the week to work and the 18/45 kept the needle from getting to much out of the red on weekend top speed blasts, I've never went back. One buddy on a 75k loved the 16/48 combo. We eventually installed a 75f engine on that bike after a picture window appeared after a missed shift at 25,000miles.

Two of the F's were traded for a 79cbx and a v65
one K went 836 and is still local but never ridden.
the other 75k was sold, picture windowed again, and scraped.

[PeWe]

I changed front sprocket from 18 to 17 on my K6 to give it more power at higher speeds back in the 80's. No problem when cruising on Autobahn all day long in over 160kmh. Screaming 4-1
 Stock 48 rear.
17:48 feels better on all gears. Only 250 rpm more at 100kmh (60mph).

Even with much more torque, 1000cc 17:48. Recently changed to 18:48 when replacing the drive chain when the planned 120/80-18 wheel has less diameter than previous 120/90-18.

My brown K2 had 57-58 whp on dyno 2020. Almost stock except for Yamiya no numbers 4-4 with baffles in but no "wool".
Cruzinimage 61.50mm K7 pistons that gives a little bit higher compression. From around 150PSI to 170-180PSI.

It got Dyna-S end of last season that woke it up a little bit more One point start to struggle so I visited a shop 1.5 km away. Installed Dyna-S in 30 minutes.
Set plate into middle position, fired it up and adjusted it a little with timing lamp. Idle OK and full advanvce at 2600-2700 rpm.

It works fine with cut adv springs to ensure no advancer play advancing the ignition way too early.
Coils are new stock.

KN filter for stock airbox is ordered to replace the aftermarket paper filter.
Who knows, time for another dyno to count all ponys running in there!

To measure the AFR, baffles need to be removed.

[Tracksnblades1]

I changed front sprocket from 18 to 17 on my K6 to give it more power at higher speeds back in the 80's. No problem when cruising on Autobahn all day long in over 160kmh. Screaming 4-1
 Stock 48 rear.
17:48 feels better on all gears. Only 250 rpm more at 100kmh (60mph).

Even with much more torque, 1000cc 17:48. Recently changed to 18:48 when replacing the drive chain when the planned 120/80-18 wheel has less diameter than previous 120/90-18.

My brown K2 had 57-58 whp on dyno 2020. Almost stock except for Yamiya no numbers 4-4 with baffles in but no "wool".
Cruzinimage 61.50mm K7 pistons that gives a little bit higher compression. From around 150PSI to 170-180PSI.

It got Dyna-S end of last season that woke it up a little bit more One point start to struggle so I visited a shop 1.5 km away. Installed Dyna-S in 30 minutes.
Set plate into middle position, fired it up and adjusted it a little with timing lamp. Idle OK and full advanvce at 2600-2700 rpm.

It works fine with cut adv springs to ensure no advancer play advancing the ignition way too early.
Coils are new stock.

KN filter for stock airbox is ordered to replace the aftermarket paper filter.
Who knows, time for another dyno to count all ponys running in there!

To measure the AFR, baffles need to be removed.

Did the 17T increase your top speed? 
Slower or faster ?

[PeWe]

I changed front sprocket from 18 to 17 on my K6 to give it more power at higher speeds back in the 80's. No problem when cruising on Autobahn all day long in over 160kmh. Screaming 4-1
 Stock 48 rear.
17:48 feels better on all gears. Only 250 rpm more at 100kmh (60mph).

Even with much more torque, 1000cc 17:48. Recently changed to 18:48 when replacing the drive chain when the planned 120/80-18 wheel has less diameter than previous 120/90-18.

My brown K2 had 57-58 whp on dyno 2020. Almost stock except for Yamiya no numbers 4-4 with baffles in but no "wool".
Cruzinimage 61.50mm K7 pistons that gives a little bit higher compression. From around 150PSI to 170-180PSI.

It got Dyna-S end of last season that woke it up a little bit more One point start to struggle so I visited a shop 1.5 km away. Installed Dyna-S in 30 minutes.
Set plate into middle position, fired it up and adjusted it a little with timing lamp. Idle OK and full advanvce at 2600-2700 rpm.

It works fine with cut adv springs to ensure no advancer play advancing the ignition way too early.
Coils are new stock.

KN filter for stock airbox is ordered to replace the aftermarket paper filter.
Who knows, time for another dyno to count all ponys running in there!

To measure the AFR, baffles need to be removed.

Did the 17T increase your top speed? 
Slower or faster ?

Going faster was my intention. I got the advice from a biker friend that knew other CB750's that were a little bit too weak in higher speeds and could not fully rev at max. So 1 cog less at front could improve.

I do not really remember, but not slower
Felt like same acc up to speedo 180 kmh,  a little bit slower to 200kmh. Then squeeze it up to 210kmh after a km or so.
I hoped to reach 220kmh

It was perfect for touring  with 2 persons and luggage.
When leaving a gas station beside Autobahn  I could manage to enter Autobahn at 160 kmh where I shifted to 4th.
836cc , ported head 34/28mm valves,  valve train friendly Action Fours SS-1 cam, loud 4-1. Alternator was lightened too. A perfect CB750 touring bike! 18:48 should not be that good in need of acceleration on 3rd and 4th, keeping the pace on 5th despite hills.

Acceleration now with higher compression 970cc kit, 125-75 cam is more brutal. But still not eager to run that fast.
Now probably an almost constant acc to 210kmh, probably possible to soon enter 220kmh.

I prefer the quick and safe to 190kmh only which happen very quick!

There are more wild hogs and deers (rather big ones) out there nowadays.
Elks or moose not that common today as for 40 years ago.
Bad driving women the most dangerous  hazards today.

[Old Scrambler]

Scottly..............check your PMs