31 toothfront belt sprocket and 66 rear
#11
Comparison of 28/68 to 31/66, in numbers, is right. The change results in a 13.6% change. But, this final drive ratio (31/66) is well within an acceptable performance range for the 883.
The "stock" final drive ratio (primary, 34/57 & drive pulleys, 28/68) is 4.07:1. The 31/66 final ratio is 3.68:1. For reference the final drive ratio for the 1200 (primary, 38/57 & drive pulleys, 29/68) is 3.52.
For anyone enjoying a 70 mph cruise rpm of about 3770, or 4850 rpm at 90 mph, the 28/68 final drive is great. But for those that prefer to cruise along at about 3300 the 31/66 pulley combination can get you there without changing the primary. And, if you want to drop another ~125 rpm, there is a 32 tooth front pulley available. Final drive ratio (34/57 primary & 32/66 drive pulleys) 3.46:1.
Increasing the cc doesn't lower the rpm, but it can sure get you to your cruise mph quicker!
The "stock" final drive ratio (primary, 34/57 & drive pulleys, 28/68) is 4.07:1. The 31/66 final ratio is 3.68:1. For reference the final drive ratio for the 1200 (primary, 38/57 & drive pulleys, 29/68) is 3.52.
For anyone enjoying a 70 mph cruise rpm of about 3770, or 4850 rpm at 90 mph, the 28/68 final drive is great. But for those that prefer to cruise along at about 3300 the 31/66 pulley combination can get you there without changing the primary. And, if you want to drop another ~125 rpm, there is a 32 tooth front pulley available. Final drive ratio (34/57 primary & 32/66 drive pulleys) 3.46:1.
Increasing the cc doesn't lower the rpm, but it can sure get you to your cruise mph quicker!
Last edited by Iron Horse 13; 04-17-2020 at 10:27 AM.
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Also, here is a link to the various conversion charts from his website 883sportster.com:
https://www.883sportster.com/_files/...8aea0fb11d.pdf
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96hugger (05-13-2024)
#16
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BlueridgeXL (05-15-2024)
#18
Yup...that is a Forum Member sirrom1 listing...
Also, here is a link to the various conversion charts from his website 883sportster.com:
https://www.883sportster.com/_files/...8aea0fb11d.pdf
Also, here is a link to the various conversion charts from his website 883sportster.com:
https://www.883sportster.com/_files/...8aea0fb11d.pdf