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Old 03-20-2016, 07:09 AM
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cannonball2 cannonball2 is offline
Motorized Bicycle Elite Member
Join Date: Oct 2010
Location: Colonial Coast USA.
Posts: 3,286
Default Re: rear suspension #2

About the IGHs I run both the Nexus and the SA S3X.

The Nexus has direct drive in 2nd with a .733 reduction in first and a 1.36 OD of 2nds direct ratio.

The S3X has 3rd as direct are the other ratios are lower. It is nice to have engine braking this hub gives. Plus it will drive in any direction.

For a Nexus build if you ran a primary of 11t/25t a secondary of 10t/44t top speed at 4k rpm would be 40mph, 52mph @ 5k rpm. This gives a low ratio of nearly 14:1 for take off.
To lower the ratio add teeth to the primary jackshaft sprocket. Remember a stock CG sprocket bolts directly to an 18t sprocket on the Nexus.

The S3X is not so easy dealing with the sprockets as the center is larger and the sprockets have a different spline set up. It is tough, handles pedal starting a CG with no issues. Its an excellent hub! Worth the extra $$ and time need to make a sprocket for it. The Nexus is more fragile but I feel will last with care. Plus they are cheap as dirt if you shop around.
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