Weird bottom bracket
I want to add a motor to my bike but it seems that the weird bottom bracket is going to force the motor to rotate too far down. The rear suspension has what appears to be a flex limiting bar that enters the bottom bracket so rotation of the inner ring isn't possible. The clearance between the crank center and the point where the front shift anchor attaches is about 57mm. As configured, the bike has a crazy low climbing ratio so maybe I should start with another bike and keep this one as-is. I like the bike but I'm getting a little old to ride trails aggressively. Any thoughts?
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I'm sure nobody other than me cares, but it turns out this is GT's "I-Drive" suspension system. It seems like imaginary marketing hype to me.
Google's Gemini AI provided this additional detail.
How I-Drive Works:
Independent Drivetrain: The I-Drive system isolates the drivetrain (crankset, chainrings, and bottom bracket) from the main frame and swingarm pivot.
Eccentric Bottom Bracket: The eccentric bottom bracket is the key component. It allows the entire crankset to rotate slightly as the rear suspension compresses and extends.
Benefits:
Active Suspension: The independent drivetrain prevents pedal bob (suspension movement caused by pedaling forces), allowing the suspension to remain active even under hard pedaling, improving traction and control.
Efficient Climbing: The rotating crankset helps maintain chain tension and reduces pedal feedback during climbs, making the bike feel more efficient.