Page 1 of 1
Gear ratios with Dropgear

Posted:
Mon Aug 25, 2025 9:36 pm
by karel021
Hey guys just to confirm regarding gearbox drop gear.
I guess the final drive should have the drop gear ratio included?
so if final drive in the gearbox is 3,27 and drop gear 1.13 = 3,6951 would be the number to put in correct?
Re: Gear ratios with Dropgear

Posted:
Tue Aug 26, 2025 9:36 am
by SOReilly
Assuming you are using a current GP firmware, Your drop gear should be in Gear Output Ratio.
Re: Gear ratios with Dropgear

Posted:
Wed Aug 27, 2025 2:40 am
by karel021
You are so right, just me being tired sorry for that.
i have input ratio set to 1.13, how ever i see there is a constant mesh gear as well and that is not 1.091 could that have any play in this?
gearbox is an albins st6 with clutch housing and drop gear at front.
Re: Gear ratios with Dropgear

Posted:
Wed Aug 27, 2025 9:32 am
by SOReilly
Yes we have support for fixed input drop gears, this would be the Gear Input Ratio parameter
Re: Gear ratios with Dropgear

Posted:
Thu Aug 28, 2025 7:01 am
by karel021
ok so drop gear at input and nothing with constant mesh ?
Re: Gear ratios with Dropgear

Posted:
Thu Aug 28, 2025 1:30 pm
by SOReilly
The 1.09 constant mesh gear changes the effective ratio of 1 though 5.
So the gear ratio you enter for 1 -5 would be the gear ratio * the constant mesh ratio with 6th being just the gear ratio as it doesn't use the constant mesh ratio.
We don't care as such about how the ratio is achieved within the gearbox, just that the effective ratio for 1st is for example 2.5724 (2.36 * 1.09)
Re: Gear ratios with Dropgear

Posted:
Fri Aug 29, 2025 7:01 pm
by karel021
Gotcha, not sure how i did Forsee this.
thanks for the quick reply