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Old 10-01-2015, 08:49 AM
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Davezilla Davezilla is offline
Motorized Bicycle Elite Member
Join Date: Mar 2014
Location: San Antonio Texas
Posts: 2,710
Default Re: Bicycle rolls freely when clutch lever is released

I've had something similar happen to mine once before and it was the screw holding the bevel gear down backed out enough for it to spit out the woodruff key... The bike worked perfectly on that ride but when I got closer to the shop I decided to go to the store down the street before putting the bike up, when I let the clutch back out it just free reved so it went from just fine to "I'm not going anywhere just by pulling the clutch in and releasing it again. You can check the bevel gear simply by removing the clutch cover, Sometimes the screw will cut a hole in the cover when it backs out, but not all the time, and all the screw needs is to back out about 5 or 6 turns to be able to spit out the woodruff key.

There are 3 woodruff keys in the drive train that'll leave it freewheeling like this, the bevel gear, the clutch hub, and the sprocket so its worth checking all 3 if the bevel gear is intact. It's also possible for a key to split or shear and everything will look ok at first glance so you may need to remove the gear or sprocket etc to see if the key inside is intact. One thing you can do if it did shear a key is use some red locktite in the keyway before you put the gear or sprocket back on (Do NOT get this stuff on the screw threads tho, you'll strip the head or snap the screw trying to get it back out), it'll prevent any small amounts of play and help prevent the key from breaking again, if a key is loose fitting to the point it can go in the slot or channel real easy and not stay put when inserted, you will need to fill that space somehow, the red locktite will work for a loose fit where the key and the channel are about the same size but the key can go in or out without any resistance, but if the slot or channel is slightly wider than the key a little jb weld will occupy that space and keep the key from being able to move around inside the slot or channel to help prevent it from shearing.
Some clutch pads like the black rubber ones can get damaged by oil or fuel saturation as it can soften up the rubber leaving them ineffective, this is pretty obvious so if your clutch pads were nice and dry when you checked them they're most likely not the culprit.
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