Hi guys I'm doing a custom in frame shift kit using the Honda GXH50. The motor arrived yesterday and now that I know the dimension I am ready to start purchasing parts for the primary reduction and drivetrain. I did a bunch of searching but couldn't find a comparison between gearboxes and what the ideal primary ratio for use with a shift kit and GXH50 is. I wish to stay in the power-band for most common riding without having to whine the engine out to 7000 rpm all the time.
I see Staton uses his 16:1 gearbox and then uses a 12-16T pinion to drive a 48T chainring giving a very high final reduction. Then I see other kits using the Grubee 4G etc. which are only 4:1 or 5:1 primary reduction. It seems there is big gap between these 2 systems. Since I am building a custom belt drive setup I can build whichever ratio is ideal. Does that lie somewhere in between?
For my purposes I need good bottom end as I am a tall guy and I live in the hills and will have to climb 18deg grades, as well I plan to ride this mountain bike on the trails. Given that criteria what would you guys suggest for the primary ratio from the engine crank to pedal cranks.
Thanks for the help.
I see Staton uses his 16:1 gearbox and then uses a 12-16T pinion to drive a 48T chainring giving a very high final reduction. Then I see other kits using the Grubee 4G etc. which are only 4:1 or 5:1 primary reduction. It seems there is big gap between these 2 systems. Since I am building a custom belt drive setup I can build whichever ratio is ideal. Does that lie somewhere in between?
For my purposes I need good bottom end as I am a tall guy and I live in the hills and will have to climb 18deg grades, as well I plan to ride this mountain bike on the trails. Given that criteria what would you guys suggest for the primary ratio from the engine crank to pedal cranks.
Thanks for the help.
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