Bonneville America Forums Forums Technical Forums General Tech Driveline slack, or play when shifting... Clunks..

Ok guys,
I'm the newbie here I know, but I need your help. I just took the first couple spins on my new-to-me 2012 Bonnie America. I noticed right away that if I don't concentrate on doing whatever I need to do to get a smooth shift, I get a nice audible "clunk" right before re-aplying the throttle after an upshift. Especially going from 1st to 2nd. All my other bikes shifted effortlessly and smoothly with out even a thought. With this bike it's really a conscious effort to get a smooth shift transaction with no clunk or jerking of the bike between on and off throttle applications. I worry that there might be some sort of issue with the bike's transmission or drive line somewhere. I understand the cush drive bumpers wear out quite rapidly on these bikes? My bike only has 3300 miles on it, but I wonder if maybe the previous owner(s) put the bike through hell in those 3300 short miles and that's why it ended up at a used powersports dealership where I found it. Any ideas or help would be greatly appreciated.

My Speedy shifts nice and smooth so something seems to be going on. Check the cush drive. Just grab the sprocket and give it a wiggle froward and back in line with the chain. If more than a mm or 2 movement i would pack it. I used 3mm alluminium plate in mine, turned it into a different bike. Also check chain tension, I go for around 30-40mm free play, also might pay to check the counter shaft sprocket nut to see if its loose.

I agree with Cloudy, check the chain tension and cush drive. But I also changed to Lucas 10w50 and she never shifted so smooth.

The shift itself can normally be noisy clunky, thicker oil reduces the noise, but there shouldn't be a clunk AFTER the shift.

With certain oil I've had clunky shifts. Pretty smooth with the Amsoil I now use. It could be something as minor as clutch cable adjustment. Maybe it's just not fully disengaging.

the chain would be my first look and then maybe the clutch play (on lever) otherwise try this, when you are thinkin of shiftin but before hand place some upward pressure on the gear lever then clutch and i think you are going to find it move upwards better, if not the other suggestions are all good.

Mine starts this shift harder when it's time for an oil change. Like she's trying to tell me it's time for new oil.

Thanks man, Ill look into those things.

Take care,

Mike

Thanks for the oil tip!

Mike

That's the drive line lash I'm refering to. After the shift if I don't concentrate on applying the throttle smoothly after the clutch is out, I'll hear and feel a clunk as the bike takes up the slack and starts to accelerate.

Mike

Thanks, I'll look into the clutch cable adjustment.

Mike

Thanks, I'll give that a shot.

Mike

And if that oil suggestion doesn't appeal to you, we've got lots more. Just ask!