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Aging & Worn
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Discussion Starter #1
I guess it was a couple of months ago, I had the chain replaced (no, I didn't personally do the work; could have, but wanted a "Professional" to do it).

I had a few things done when I dropped the bike off, but the Chain and Sprockets were part of that work.

It figures that a "new chain" would stretch, and I checked it every now and then, but.........

Today, (this morning before it gets "hot") I put the bike up on the lift and was checking things out.......I noticed that "on the lift," with no pressure on the tires, the Chain had a throw to it that was well beyond the recommended "1 inch" that should be maintained.

What has YOUR experience been with:

-New Chain Stretch
-The difference in "throw" when the bike is on the ground
-vs- being up on a lift where the tires are not in contact
with a firm surface

-Soupy
 

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Aging & Worn
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Discussion Starter #3
The chain should be measured with the wheels on the ground.
Ah, the things we learn. I had set out today to simply clean and re-lube the chain, and my neighbor (a former motorcycle rider himself) stopped by, while the bike was up on the Lift. He manipulated the chain and it had about 2 1/2 inches of play. Immediately he commented that "that new chain of yours has STRETCHED dude! You need to tighten that up."

Given the fact that he is very "mechanical" (I have known him for many years and trust his mechanical instincts, generally) and has owned bikes (more than one) in the past, I was glad to have his input, because I didn't want to make that kind of adjustment without the experienced eyes of someone, looking over my shoulder.

I'm surprised, based on the reply that chain tension should be checked when the bike tires are in contact with the ground, that my experienced neighbor didn't say that at the time.

He DID note the tightened condition after we set it down however. Certainly we got rid of the 2 1/2 movement, THAT'S for sure. With the wheels down on the ground, the throw to the chain is just under the recommended "inch."

We were careful with the camber(equal distances for each side, in the adjusters) as we did the work, and I believe there is still some potential stretch to a "new" chain, right?

I cleaned it, re-lubed it.

-Soupy
 

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American Legion Rider
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18,518 Posts
I also had better luck simply because I didn'y understand chains that well, having my wife sit on the bike when I adjusted. It simply kept me from over adjusting. Someone that does it all the time would know how but I didn't. My first chain was gone in nothing flat because I'm sure I over adjusted even though I thought I was doing it correctly.
 

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Premium Member
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5,271 Posts
How it is adjusted is very bike specific; the geometry of the bike determines whether it should be lifted, or on its wheels. My old CB450 is adjusted while on the center stand. Another thing to consider is, are there saddle bags, and are they full or empty? They can make a big difference in the wheels-down measurement.

The most accurate way is to lift the bike, disconnect the shocks, then lower it until the chain reaches the tightest point. There should be minimal slack at that point, but some, so the chain isn't over tight. Once you have that spot determined, you can then measure it with everything connected, either lifted or on its wheels, and use that number.
 

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Discussion Starter #6
...................so the chain isn't over tight.......................
Knowing that the recommended slack is 1 inch (on my particular bike, and quite possibly on many bikes for all I know) and ..........knowing that I'm about 3/4 of an inch right now.........

What is the danger?

-Soupy
 

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Assuming you are measuring it using the correct method (weight on or off wheels), then you are on the tight side. Most manuals give a range, and, if you are in that range, it should be OK. But, if you have less slack than the minimum recommended, when you go over a good-sized bump, or ride 2 up, you can move the swing arm to the point that the slack effectively goes to zero, or even over-tight, at which point you will add excess wear to parts of the chain. For example, my CB450 is adjusted on the center stand, and the range is 0.4-0.8 inches; I set it to ~0.6" and, since I have shorter than stock shocks, tested it by raising the wheel until the sprockets and swing arm axle were in a line. At that point, the chain had approximately 1/8" movement at the center. If I had set it to about 3/8" slack, it would have pulled tight enough to strain the chain parts.
 

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Aging & Worn
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Discussion Starter #8
So worst case, the chain could snap? On the less dramatic side of things, it could put unnecessarily quicker wear on the sprocket teeth and chain itself? Is that about it?

I'm not doing off road mountain biking. I'm just commuting 14 miles a day (including the Lunch run to home and back) on paved secondary roads (or does that matter in this scenario?) and some highway at times.

I'm not carrying a rider, the shocks are good. So I'm figuring it is a "wear" issue, and not as much a catastrophic issue if it was slightly over-tight, right?

I believe there must be a tolerance involved, but you guys/gals that are more experienced with these types of things, would know better than "I."

Hey........I'm just hoping I tightened the main wheel bolt tight enough!! (lol).

-Soupy
 

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Worst case scenario would be your rear wheel locking up if the chain or sprocket snaps. And that could be tricky. Atleast thats what i have been told. Im not afraid to admit I would crap my pants if that happened. Better to be safe than sorry
 

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Mostly, it will shorten the chain and sprocket lift, but also stresses the bearing on the output shaft of the transmission and the wheel bearings. How much depends on how much strain is involved. Oh, and riding city streets still flexes the rear wheel, more than you may think, as you go over spots where the pavement rises and falls. And, depending on the design of your bike, your weight alone may put the chain at or near maximum stretch. If you want your chain to last, get the adjustment within the proper range, keep it clean and lubed; my chains have lasted, easily, 10-20k miles, or more. I don't really know how many miles, but it takes years to need a new set.
 
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