[dirtyBob]

I've owned a lot of bikes in more than 30 years of riding, and I've never had this issue. Every time I go off the lip of a jump about a half second later in mid-air I hear a clunk and feel it. It's a pattern on jump trails. Jump clunk jump clunk. It feels like the derailleur and or the chain or the culprits. It has thrown the chain a couple of times but doesn't do it often. It's a 2018 gorilla Gravity and I'm riding a GX SRAM derailleur. If I take two more links out of the chain it will be too short in the lowest gear. Anybody had this happen to them and know the fix or even where it's coming from? Why it happens? Thanks in advance for any help or recommendations.

 

[dirtyBob]

It's not the suspension. It's the drivetrain. I feel it in my pedals when it clunks. And I work on everything on my bike outside of building Wheels. And I wrote in my original post that I can't take out two links because it will be too short to reach the highest gear and then I'll have to throw out the chain and buy another one. Thank you though.

 

[dirtyBob]

Thanks for the reply. It's not rattling. It's one, solid, predictable "thunk" that I feel through my feet about a half second after leaving the lip of a jump, as if all the slack in the chain grew taut immediately, and then it's gone. back to normal chain slapping.

 

[dirtyBob]

Thanks much for the replies. I'll give the chainless no derailer jump run a try, and tightening the derailleur too. Most appreciated.

 

[dirtyBob]

It's not chain slap. But thanks.

 

[dirtyBob]

Turns out it was a low engagement hub on a bike that must be prone to severe pedal kickback? The reason I'm guessing this is that I finally got the set of wheels I was waiting on and they have onyx hubs (that have immediately engaging sprag clutches). Put them on the bike and took it for a spin yesterday. No clunk on any jumps.
Thanks a bunch for the suggestions.