Chain - How Much It Moves - Magiksc

Watch this video. Watch how much the chain bounces and moves. Watch how much it slaps the swingarm.



Thanks to Magiksc for the video.


So do you really think a 12t versus a 13t front sprocket will really make a huge difference in swingarm wear and damage?

Yamaha put the protector there for a reason. Keep an eye on it. Replace when needed.

But seriously, a 12t front isn't going to eat your swingarm like it's soft butter when compared to a 13t.

IMHO

That's a nice vid, thanks for posting it...

Pretty shocking how much the chain "flexes" and undulates under different conditions isn't it?

10 inches of travel in the suspension means the chain does a lot of dancing. A lot.

Maybe it's just me, but that chain appeared a bit on the loose side. While he's still on pavement it gets pretty slack when he decelerates, and then you see it go tight again as he applies some throttle.

I'm not arguing your point. I'm just saying that may, or may not, be an accurate depiction of what's happening on a properly adjusted chain.

slapping the guard isnt as bad as grinding up against it, which this chain looks like it does under decel.

Good video. Thanks Motokid.

My chain, yours, his, even that guy over there, does the exact same thing whether adjusted right or not. Be on it, if the guard starts to get shredded, replace it. Easy. That's why it's there.

My mountain bike, if I don't wrap the chain stays(swingarm) with a tube, after a day at the mountain, beats that shit out of it.

A chain is a hunk of metal whipping around bouncing slapping etc. Soft metal/plastic will lose every time.

Slack is always there, whether it's on the top or the bottom depends on whether you're on the throttle (bottom) or off the throttle (top)....not a point of concern, at least for me.

Thanks for the illustration.

DragonNester wrote:

Slack is always there, whether it's on the top or the bottom depends on whether you're on the throttle (bottom) or off the throttle (top)....not a point of concern, at least for me.

Thanks for the illustration.

Yep.

I think, generally speaking, a chain that's too tight is much more of an issue than a chain that's too loose.

Especially on a suspension system that has 10 inches of travel.

DragonNester wrote:

Slack is always there, whether it's on the top or the bottom depends on whether you're on the throttle (bottom) or off the throttle (top)....not a point of concern, at least for me.

Since the swing-arm pivot point is between the drive and rear sprockets, some slack is always present, but the chain is tighter when the front and rear sprocket centres line up with the pivot point of the swing-arm. Above and below that, as the rear suspension compresses and expands, the chain is looser. Basic geometric principles of a triangle. This effect is more exaggerated on bikes with longer rear suspension travel.

sturgeon wrote:

DragonNester wrote:

Slack is always there, whether it's on the top or the bottom depends on whether you're on the throttle (bottom) or off the throttle (top)....not a point of concern, at least for me.

Since the swing-arm pivot point is between the drive and rear sprockets, some slack is always present, but the chain is tighter when the front and rear sprocket centres line up with the pivot point of the swing-arm. Above and below that, as the rear suspension compresses and expands, the chain is looser. Basic geometric principles of a triangle. This effect is more exaggerated on bikes with longer rear suspension travel.

When you are on the throttle the counter sprocket is pulling the chain over the top and what slack is in the chain is at the bottom where no force is being applied. When you roll of the throttle the force applied to the chain is coming from the rear wheel and is pulling the resisting counter sprocket causing what slack there is in the chain to be on the top of the swing arm. Watch the video closely and even on smooth pavement you can see this effect in action.

I know where the slack is, I was just adding that it varies according to suspension compression. That's why MX bikes look like they have very loose chains when compared to road bikes. I've observed that those that come from road bikes sometimes have their chains too tight on bikes like the WRR. They ignore the recommended tension because it "looks too loose".

^ That is quite true.