little brother's Rhyno's crank gets caught turning on downhill.
I've grown apart from the BMX/freestyle era. Now I'm into mountain biking and such, but my little brother who's got a Rhyno freestyle bike asked me this afternoon why his chain was messed up. At first glance, it looked 110% fine. I took it for a ride and I figured out what the problem was.
When you are going downhill pretty fast and stop pedaling, every so often you feel something "grab" as if it's trying to turn the pedals. It's not hard like it'll grab and turn the pedals no matter what, but it's enough you can feel it's not right.
I took the wheel off and spun the gear and it spun just fine. It didn't hesitate or anything, just kept spinning. But once back on the bike, it was doing the same stuff. My other brother has the exact same bike (they're matching Rhyno's) and his doesn't do this, yet their chain tension seems to be the same.
What can I do to fix this?