HarleyTechTalk

Technical Forums => Milwaukee-Eight => Topic started by: MakoHD on November 25, 2019, 06:29:38 PM

Title: Chain conversion for 2020 low rider
Post by: MakoHD on November 25, 2019, 06:29:38 PM
Does anyone have the offset of sprockets figured out for the m8 2018-2020 low riders?
Title: Re: Chain conversion for 2020 low rider
Post by: jbroski on December 03, 2019, 07:40:41 AM
Scott at stfu has chain on a fat bob, I know different chassis but he might be able to help
Title: Re: Chain conversion for 2020 low rider
Post by: VernDiesel on December 04, 2019, 11:08:29 PM
I don't have any help for the sprocket spacing but I did consider a chain conversion for a bit. Curious if you are doing this because your are doing an engine build that will exceed the power that the belt will reliably withstand or wanting to gear for best 1/4 mile or another reason.

I re-geared my softy for dramatically better acceleration while retaining a reasonable top gear cruising rpm and top speed.  Maximum 1/4 mile gearing was out without overdrive gear in the transmission for me.

I chose a 30 tooth sprocket & 70 tooth pulley for a 3.15 final drive ratio. Stock cam peak torque is 3k my cam 3,500 with a max rpm of 6200. With this gearing 80 mph cruise rpm would be 3,300 still below my peak torque for ideal cruising and with a theoretical top speed at 6200 of 150 mph. At 6k shift into 6th would occur at about 120 mph. Well past even my theoretical max 1/4 mile speed.

Without an overdrive I think this is near ideal gearing for me. The stock softy final drive ratio is a super tall 2.79 that slows the rate of acceleration. At one time MoCo had final drive ratios around 3.30 pre EPA involvement days.