Author Topic: Chain Tension  (Read 1618 times)

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Offline Dammerung

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Chain Tension
« on: June 19, 2012, 10:58:03 AM »
Hey guys and girls!
                                 So my 73 CB750 is sitting due to a small issue. I noticed on the centre stand upon spinning the rear wheel, the chain was acting funny. A bit bouncy. Upon closer inspection i noticed that the tension goes from tight to lose and tight to lose while spinning the rear tire. I know the standard is 3/4" of play. But in my case when it is lose its about an inch plus and when its tight its really tight. I dont want to ride it like that. Im sure it cant be good.

So basically when i spin the rear tire and keep a feel for the chain it varies from tight to lose.

Please help!!

Offline strynboen

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Re: Chain Tension
« Reply #1 on: June 19, 2012, 11:00:20 AM »
thek the rear hup for vear
i kan not speak english/but trying!!
http://forums.sohc4.net/index.php?topic=60973.0
http://forums.sohc4.net/index.php?topic=144758.0
i hate all this v-w.... vords

Offline Dammerung

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Re: Chain Tension
« Reply #2 on: June 19, 2012, 11:05:23 AM »
thek the rear hup for vear

Sorry I kant make out what you meant. Sorry noob here

Offline MCRider

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Re: Chain Tension
« Reply #3 on: June 19, 2012, 11:23:16 AM »
Check the rear hub for wear.

But i don't think that's it.

The chain has worn unevenly. Very common situation. One segment of the chain has little wear, making it tight. The next segment of chain has more wear, and its loose.

This happens from uneven lubing of the chain.  The wear occurs where the pin goes through the roller. The inside of the roller wears in an oblong, giving the impression it has "stretched" in the vernacular.

Lube well, Adjust to the tightest point, with weight on the bike. ride until you can buy a new one.

Another test is to push up on the bottom row of the chain. At about 3 OClock on the rear sprocket, pull the chain away from the sprocket. If you can see daylight, its on its way out.

Replacing the chain without replacing the sprockets will cause the chain to wear faster. I think you can get 2 chains to every set of sprockets. Others will differ.
« Last Edit: June 19, 2012, 11:26:32 AM by MCRider »
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline Dammerung

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Re: Chain Tension
« Reply #4 on: June 19, 2012, 12:08:14 PM »
Check the rear hub for wear.

But i don't think that's it.

The chain has worn unevenly. Very common situation. One segment of the chain has little wear, making it tight. The next segment of chain has more wear, and its loose.

This happens from uneven lubing of the chain.  The wear occurs where the pin goes through the roller. The inside of the roller wears in an oblong, giving the impression it has "stretched" in the vernacular.

Lube well, Adjust to the tightest point, with weight on the bike. ride until you can buy a new one.

Another test is to push up on the bottom row of the chain. At about 3 OClock on the rear sprocket, pull the chain away from the sprocket. If you can see daylight, its on its way out.

Replacing the chain without replacing the sprockets will cause the chain to wear faster. I think you can get 2 chains to every set of sprockets. Others will differ.


A friend of mine from this forum has asked me to check the "Flange" that the rear sprocket is connected to. I will definitely look into the chain. It is old and quite dirty at the moment. Old Bike barn has 18/48 sprockets and 530/100 chain for 90 dollars or so in total. It sounds cheap but if its good quality i may as well order it. What are your thoughts?

I apologize but i havent understood the test. Push up at the bottom on the chain and at 3 o clock on the sprocket pull the chain away to see if it gaps?

Offline Dammerung

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Re: Chain Tension
« Reply #5 on: June 19, 2012, 12:16:04 PM »
Also, when you say adjust at the tightest point you are talking about moving the rear tire right? Im sorry once again im still learning. I am a bit shocked at the size of the nut in the rear. What size is that? also if you cud give me a quick guide to adjusting the rear tire id really appreciate it

Offline MCRider

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Re: Chain Tension
« Reply #6 on: June 19, 2012, 12:21:32 PM »
One of the first dilemna/frustrations I encountered in motorcycling was this subject, the tighty loosey chain. I went to shops, no help, suspected out of round sprocket, etc. All bogus. It was the chain plain and simple, as I've described. Once you learn it you'll be able to tell others and seem like a genius.

That chain/sprocket deal sounds good. You can shop it till you're blue in the face. Just by something that's decent, get some experience and make a better choice (if so) next time.

I changed subjects on you a little. Your first problem has no test. The fact that it is tighty loosey indicates to me the chain is worn unevenly. The only way that can be fixed is to replace it.

The second issue now becomes how critical is it that you replace it right away. That's where the second test comes in. You described it correctly. If it passes you can run the old chain a while longer. It will be noisy and wear the sprockets faster. And you should adjust it at the tightest point, meaning the loosey part will be...loose.

If it fails the test, you should replace it right away.
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline MCRider

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Re: Chain Tension
« Reply #7 on: June 19, 2012, 12:36:41 PM »
Also, when you say adjust at the tightest point you are talking about moving the rear tire right? Im sorry once again im still learning. I am a bit shocked at the size of the nut in the rear. What size is that? also if you cud give me a quick guide to adjusting the rear tire id really appreciate it
Yes, a quick primer on adjusting the chain by moving the rear wheel. We'll start on the centerstand, but revisit that issue.

Remove cotter pin, loosen the "big" nutloose, then spin it back tight by hand.  Don't know the size, use the tool kit tool or an adjustable wrench.

Loosen the lock nuts on the adjuster bolts, one on each side.

Turn the wheel till the tightest run is on the bottom. turn each adjuster 1 flat at a time. If necessary to get your adjustment. You'll see some index marks on the swingarm and the adjuster bracket. These should align. Exampole if the left is back 2, the right should be back 2. Back to adjusting, till the chain has its prescribed 3/4 inch up and down.

Tighten down the axle nut. At least 50ft lbs which would be standing on an 8 inch wrench. The axle nut holds the wheel in place not the adjuster bolts. Tighten the adjuster bolt lock nuts to keep them in place. Adjust your brake pedal before riding.

Now about the centerstand. The wheel travels thru an arc as it goes up and down. It is furthest from the engine when it is straight back. It is there that the adjustment should be made. But this is hard to do alone. So the default is to put it on the stand. But you'll see the wheel drops down and is closer to the engine. If you adjust at this point, when you drop it off the stand it will tighten up too much. So you have to experiment, with help, and figure out where it should be with weight on it v on the CS. Once you know you're own bike you can do it on the stand without help.

Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline Dammerung

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Re: Chain Tension
« Reply #8 on: June 19, 2012, 12:37:53 PM »
One of the first dilemna/frustrations I encountered in motorcycling was this subject, the tighty loosey chain.
If it fails the test, you should replace it right away.
\

Thank you MCRider :) I will be ordering in the stuff and fingers crossed the chain holds up for a while longer. Im very certain ive been riding it like this for a while now actually. Its only recently i realized this kant be right.

Offline MCRider

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Re: Chain Tension
« Reply #9 on: June 19, 2012, 12:41:18 PM »
YW. 

It will be quieter and smoother with new parts. Besides being the right thing to do.
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."