[reo scorpio]

So I measured the up and down deflection on the chain and came up with 40mm. Spec is 47-55. Would you go through the hassle of adjusting or would u just leave it as is?

Was going to adjust it this morning, but that axle nut was way over torqued. So I took it to my shop and they were able to loosen it for me, but felt that the chain did not need adjusting. I know they just eyeball it, and I would probably do a better job myself, I just don't want to mess up a good thing and walk away with a misaligned tire or something.

As of now, I have not noticed any whine from the chain or anything, though might be hard to tell with the Scorpion exhaust.

Just looking for feedback...




Scorp

Also, anyone know where to dl a 09 service manual? I have the '07, but the swingarm and some other things are different, so I'd like the most up to date version.

 

[04Fizzer]

It's too tight. Needs to be loosened.

 

[RJN2112]

Too tight. The slack needs to be there, so the swing arm can move through it's full range of motion without stretching the chain.

The chain does not go through the same arc as the swingarm.... that means the working distance between the top of the front sprocket, and the top of the rear sprocket is not constant. As the swingarm extends, the distance increases. The length of the swing arm is the lever that stretches the chain.... that can be a whole lot of stretching force.

I have kept the chains on my last 2 bikes at the loosest end of the spec, for that reason. As long as the chain does not skip off of a tooth, it's tight enough.....:boink

 

[FZSilver]

Too tight. The slack needs to be there, so the swing arm can move through it's full range of motion without stretching the chain.

The chain does not go through the same arc as the swingarm.... that means the working distance between the top of the front sprocket, and the top of the rear sprocket is not constant. As the swingarm extends, the distance increases. The length of the swing arm is the lever that stretches the chain.... that can be a whole lot of stretching force.

I have kept the chains on my last 2 bikes at the loosest end of the spec, for that reason. As long as the chain does not skip off of a tooth, it's tight enough.....:boink

As the swingarm extends the chain actually gets looser. When both sprockets are in line that is the tightest the chain will get.

 

[bumblebee]

a little too tight is and creates more problems than a little too loose

 

[RJN2112]

As the swingarm extends the chain actually gets looser. When both sprockets are in line that is the tightest the chain will get.

What point of the sprocket(s) are you referring to? TDC?

Just to ensure our references are the same, when the swingarm is nearest the frame, that's the suspension compressed. The arc described by the swingarm and sprockets puts them closest together at that point, doesn't it?

With the suspension fully extended... uncompressed. At that point, the TDC of the rear sprocket is below the TDC of the front, isn't it?

By my thinking, the top run of chain is the working run.... the front sprocket pulls the chain forward, which turns the back wheel..... that's the part that is under load. The bottom run is just the return to repeat the use.

That distance, between TDC and TDC is what I define as the working chain.

The bottom run, where we measure slack, does get looser as the swing arm extends.... because the top is getting tighter. It's got to be loose enough to prevent stretch, at that point..... to ensure there is slack at all points in the arc. That's why extra slack with the suspension unloaded is okay; so long as there is not enough to allow the chain to slip off the teeth.

 

[reo scorpio]

Re: Chain Slack question

Okay, so I went ahead and adjusted the chain per the manual. Got it set at 53mm and just decided that was good enough. As you all have said, loose is better than tight, so I figured I would go on the loose end of the specs.

As for alignment, my hash marks never seemed to line up before, so instead I measured from the edge of the axle bolt enclosure to the edge of the swingarm on both sides (see pics) and they both came out to about 69mm.

Do you guys think that is an okay measurement to use? The hash marks seem to be about a mm off from each other, but the wheel and the chain seem to be running smooth.

Thanks,

Scorpio

 

[FZSilver]

A more accurate measurement is from your swing arm pivot to your axle nut, but the one you did should be close too.

RJN2112, we might be saying the same thing just wording it differently. Measure your chain tension with your bike on the center stand. Then have someone compress the suspension untill the swingarm is level with the ground and in line with the front sprocket. That is when the chain will be the tightest.

 

[RJN2112]

A more accurate measurement is from your swing arm pivot to your axle nut, but the one you did should be close too.

RJN2112, we might be saying the same thing just wording it differently. Measure your chain tension with your bike on the center stand. Then have someone compress the suspension untill the swingarm is level with the ground and in line with the front sprocket. That is when the chain will be the tightest.

I'm pretty sure we both know what we mean, and it amounts to the same thing, LOL.:lao

My '05.... every time a shop has touched it, they have totally F'd up the rear wheel alignment. Last time I had the shop pull the wheels to replace the tires, I got the bike back with one of the end caps cocked, and the tensioners AFU. The newer swingarm marks are much better than the earlier design, in that regard.

 

[reo scorpio]

A more accurate measurement is from your swing arm pivot to your axle nut, but the one you did should be close too.

RJN2112, we might be saying the same thing just wording it differently. Measure your chain tension with your bike on the center stand. Then have someone compress the suspension untill the swingarm is level with the ground and in line with the front sprocket. That is when the chain will be the tightest.

Seems tough to get an accurate measurement that way for me. Everytime I do, its a different number! You just mean from the pivot bolt to the center of the axle nut?

I won't be able to ride it until tomorrow, but I am hoping its okay.

Thanks guys,

Scorpio

 

[FZSilver]

Seems tough to get an accurate measurement that way for me. Everytime I do, its a different number! You just mean from the pivot bolt to the center of the axle nut?

I won't be able to ride it until tomorrow, but I am hoping its okay.

Thanks guys,

Scorpio

Yeah that will work or make some kind of a setup like this.

 

[bumblebee]

I align my rear tire using the laser level pointing down the center of the top of the chain from the rear to front sprocket