Mountain Biking - How loud can chain slap get?

For a while I've noticed a very large crack sound when I do a drop larger then a curb (more so on dirt) on my bike, a K2 Attack with a 150mm fork (my main concern at this point), that would be taller then twice the height of a curb or so. It's bothered me a lot since the sound is deafening but nothing has broken, bent, or has shown signs of damage. The best way I can describe it is that if you did one drop and heard it, you would be frantic trying to find what broke, your first thought being the frame.

I've read that on hollow aluminum frames, the chain slap can get extremely loud if the stay is not covered. However, the chainstay on this frame is quite small and not really connected to another part of the frame where the sound could resonate.

Anyone else had some sort of really loud sound crack? I'll try and get some sort of recording of it tomorrow if it'll help.

Edit: I'm prompted to ask now because on a ride yesterday, we rode up singletrack and down this "unimproved forest rode" that is nothing but rock a bit bigger then gravel. Not a rock garden by any means, but the type of thing you can ride over easily but by the time you get to the bottom your hands are either in agony or you cant feel them at all. Point being, the whole time this noise wouldn't stop. So it's not just drops, but rapid bumps as well.

You could zip-tie an old innertube to your chainstay. That would probably help with the chain-slapping-on-metal noises. Also, if you have that much slack in your chain, your chain tension may be a bit on the low side. When you're descending, try keeping the chain on the middle ring and in one of the larger cogs in the back.

Agree, put something on the chain stay and see if the noise quiets.

Do you hear the sound when you are pedalling out of the saddle? Your description of the forest road sounds similar to what happened to me. Every small bump - and pedal stroke - made a loud (embarrassing) creaking noise and it turned out to be my seatpost. Not sure about you though... unless you were seated when you landed the drops which I doubt.

I don't think it's chainslap unless you have a loooong chain.

For a while I've noticed a very large crack sound when I do a drop larger then a curb (more so on dirt) on my bike, a K2 Attack with a 150mm fork (my main concern at this point), that would be taller then twice the height of a curb or so. It's bothered me a lot since the sound is deafening.....

Deafening? Are you sure its that loud? Are you talking like a 300 weatherby mag? I find that hard to believe.

I think it depends on who you are slapping with the chain.

Lizard Skin

Lizard Skin

+1

Lizard Skin

Only if you like to actually pay for something that you could do for practically nothing. Good ol' innertube and a zip tie or elec. tape and yer good to go.

Only if you like to actually pay for something that you could do for practically nothing. Good ol' innertube and a zip tie or elec. tape and yer good to go.

I always likr to zip tie it on and then wrap over it with the electric tape. Just looks a little cleaner to me...

I think the tube looks cleaner than the Lizard Skin. My FS came with a Lizard Skin, and my rear tire clips it very slightly. Just enough for it to fray (and the tires are only 2.1's, so it's not like I'm running something really wide where it shouldn't fit). I left it on because, hey, free Lizard Skin, but I'd never actually pay money for one when I basically get a free chainstay guard every couple of weeks...and one that won't fray at that.

I have a Lizard Skin but it's getting kinda Cheeto'd from being slapped around. I'll go the tube route next time.

hollow aluminum frames

I'd like to see a solid aluminum frame.

Laterally stiff, vertically compliant.

I'd like to see a solid aluminum frame.

Laterally stiff, vertically compliant.

I'd like to see a nerf frame so it doesn't kill my gentlemanly area when I fall off the pedals and seat.