Topic: Chain problems

[Darrell]

I've been riding my bike great for the past month or so, but the last two times I've ridden it I can hear a really loud clanking sound coming from the chain. I tightened it a little (though it wasn't too bad) and checked it wasn't hitting the chain guard or anything. When I run it with the chain guard off on the center stand, though, it will jump violently every few seconds (the sound I hear is probably it doing that against the chain guard). Any idea what could cause that? It only has a tad over 11k miles on it and the oil's always been changed at 2k mile intervals, so I hate to think it's the transmission failing. Could the chain be too loose and need replacing?

Also, don't know if this has anything to do with it, but even when I align the rear axel to the same marks on each side of the bike, the rear tire is still off the left pretty bad. Its been like this since I got the bike from my uncle (the original owner) and he's never laid it down, so I guess its been like this from the factory. The tire isn't wearing wrong, I never feel any problems when riding (even upto 100mph), and I've never had a problem with the chain, before this problem of course. Is this normal? Could the whole frame be off if the axel is on the same notches on each side?

Thanks for any help guys.

[eldar]

You need to line the chain up not the frame marks. Metal fatigue and old maufacturing techniques cause alignment to go haywire.

That hop is from the chain not meshing with the sprockets correctly. So check sprockets to make sure no teeth have been pulled out of alignment and align the sprockets and see where your wheel is. Generally if there is a wobble, then things are out of proper align. You may also want to check your bushings in the swingarm and the wheel to make sure they are not worn cause that can also cause your problem.

[TwoTired]

Unless your bike has been in continous service since the sixteen hundreds A.D., you can eliminate metal fatique as an issue with an SOHC4.

You did, however, fail to mention anything about your chain lube practices.  Wear may be a significant factor.

Did your "new" chain go over used worn sprockets?  Worn sprokets will wear a chain faster than when married to new sprockets.

Put your bike on the center stand.  Slowly rotate the rear wheel while continually checking for chain tension.  If the tension changes with chain position, you need to replace your chain, as you have worn link pivots.  Also check that each link lays straight after coming off the sprocket.  Each pivot must rotate freely to do this.  Any kinking of the links will also change the overall length of the chain, and therefore the tension.  The change in tension whips the chain into nearby motorcycle bits... like the chain guard.

Why do you think the rear wheel is misaligned?  It needs to travel in the same plane as the front tire and not necessarily center in the swing arm.  Fine tune of rear wheel alignment can be checked while riding.  At the crown of the road and hands off bars, you should be able to ride straight forward without needing to lean your body either left or right.  If not, and assuming your frame is straight, tires are properly crowned, head bearings good, and swing arm pivot are all as the factory provided them, then change the rear whell alignment a bit until it will track straight with hands off.
The axle marks on the rear swing arm are good guides but not precision ones.
Cheers,

[MRieck]

Don't run the bike(in gear) on the centerstand. Are you running a 630 chain?

[Darrell]

Don't run the bike(in gear) on the centerstand. Are you running a 630 chain?

Why not? I don't know what size (?) chain I'm running.

[MikeDeB]

About two months ago I had clunking coming from the rear of one of my 750's.  It usually happened when I took off from a stop.  What it turned out to be was a very worn chain and sprockets.  I had checked and adjusted the chain tension when I put the bike on the road and had it set properly (I rode this bike only a few times after I bought it two years ago).  Also, the alignment of the axle was forward in the swingarm indicating there should have been some chain life left.  The noise developed over a short period of time.  What I found was a badly worn chain and sprockets.  Replacing them eliminated the noise.

First check and see how far you can pull the chain away from the rear sprocket.  It should only come away from the sprocket a quarter inch (or thereabouts).  If it comes away enough to clear the teeth then the sprocket is badly worn.  Also look at the condition of the sprocket teeth.  The valleys should look uniform in shape; not elongated or egg shaped.  You should also check the condition of the front sprocket and if either sprocket is suspect replace both along with a new chain.

[MRieck]

Don't run the bike(in gear) on the centerstand. Are you running a 630 chain?

Why not? I don't know what size (?) chain I'm running.

The no load condition causes the chain to whip and slap around. The larger(heavier) the chain the worse it becomes.

[Darrell]

Don't run the bike(in gear) on the centerstand. Are you running a 630 chain?

Why not? I don't know what size (?) chain I'm running.

The no load condition causes the chain to whip and slap around. The larger(heavier) the chain the worse it becomes.

Ohhh, so that's why it was whipping like that. I haven't tried riding since I tightened the chain a bit, perhaps that did that trick.

Otherwise I'll be trying all your suggestions. Thanks!

[eldar]

Tired, I WOULD worry about fatigue. What do we know about the the bike BEFORE he got it. Maybe some yahoo took to jumping the bike a bit sometimes.  WHat about the climate where he lives. In Minnesota, a lot of salt is used on the roads and if the bike is ridden before the salt gets washed off, It can cause rust and weakening on any sohc just like a car. All I am saying is that the frame should be checked thoroughly to ensure there is nothing that is weakening.

That is another thing. sprockets can wear out and there would still be life on the chain.

[TwoTired]

Tired, I WOULD worry about fatigue.

I have no problem with you worrying about fatigue.  I just don't think it is reasonable to cause others to worry about it unwarranted.  Clearly, that's just my opinion, though.

What do we know about the the bike BEFORE he got it. Maybe some yahoo took to jumping the bike a bit sometimes. 

The message said he said he got it from his uncle.  With some luck he is a big, burley, beligerant type who takes exception to being called a yahoo.  Then you can add that worry to your stash, too. 

WHat about the climate where he lives. In Minnesota, a lot of salt is used on the roads and if the bike is ridden before the salt gets washed off, It can cause rust and weakening on any sohc just like a car.

Silly me, I assumed Mozigod had eyes that could distinguish redish brown rust from black paint on the frame, as well as rash from failed jump attempts.  Besides, rust is metal conversion, not fatigue.  You also forgot to warn him about the gravitational effects from the alignment of the planets, as well as microscopic aliens living in the chain lube and mining the nearby metals in his chain and sprockets to make starships.

All I am saying is that the frame should be checked thoroughly to ensure there is nothing that is weakening.

Well nothing wrong with that!  Perhaps you can give us examples of just how to do that and how you've come to be assured that your own frame is truely up to the task.  We need details and pictures, too!  Be sure to post examples of all the SOHC4 frames that you have found "fatigued" and explain how they came to be that way.  This way, we can avoid worry about such things in the future.  We might even make this into a FAQ, so all may benefit for years to come!  Thanks in advance.

Er, just how do you know your bike hasn't had a yahoo owner?  Oh, never mind.  We can all probably take a pretty good guess about that.

Cheers,

[mick750F]

Ouch...

[eldar]

Oh my bike WAS owned by a yahoo. A yahoo who got drunk and dumped it.

Rust is a conversion yes but if it eats away at something, that area will be weaker and thus more prone to fatigue. They dont make these frames as strong as they do just for kicks. So there is nothing unwaranted about checking for damage that could cause fatigue. That is called being concerned for your health and family if you have one.

So just cause you have never seen a picture does not mean it has never happened and as how I live a couple hundred miles away from ANY motorcycle salvage yard, I will not waste the gas to assuage your doubts.

Sorry but if fatigue can happen anywhere else, regardless what caused it, it can happen on a bike. Even an sohc.
I guess you dont worry about safety though. So you dont even bother looking for possible cracks whick my flex under stress. Maybe some of us do though. That is our right and it is not "unwarranted". Safety is paramount.

[Raul CB750K1]

Running the bike on gear while on the centerstand cause what Terry says. As the wheel is hanging and the shocks are not compressed the chain tension is not the same as when loaded.

Also, many people think it's convenient to do it that way to lube the chain. That is a BAD idea, it's just so easy to get your fingers or hand caught between the chain and the sprocket. I always lube the lower part that is uncovered, move the bike along and repeat.

Regarding the uneven chain tension, it's not only due to rusted or tight links -that it can certainly be-, but also due to the "out-of-circle" of sprockets. Say that both front and bottom sprockets are a 1 or 2 mm off-center -sorry I can't think in odd inch-fractions, but somewhere between 1/16 and 1/32-. When the front sprocket have the excess radius facing front and the rear sprocket have the excess radius facing back, the chain is tightened the most. When both excess radius are facing to each other sprocket, the chain is the less tightened. If it's just 1 mm on each sprocket, there is a difference of 4 mm lenght between both extremes. I hope you can get the picture. You have to put the bike on the centerstand, touch the chain and rotate the wheel until you feel the most tension. Once you are on spot, put the bike down and set the free play as indicated.


Raul

[dpen]

If you're going to do anything to your chain with the bike on the stand, motor running & in gear, will you give me a call?
I'd love to be there as I'll be the first to buy your bike when you find you can't ride it because you have no fingers.
As far as rear wheel alignment goes, it took me a while but my K7 shows a difference of 2 notches on the swingarm when the rear wheel is perfectly aligned to the front wheel.
Everyone has their own way of alignment.
I can't run a straight edge along my wheels because of the type of 4 into 1 I have.
I've drawn marks on two identical blocks of wood & sit a block on each side of the front wheel touching the tyre (same place on both sides).
By lying down behind the bike, I can sight along the rear wheel & make small adjustments.
Position yourself so the front & rear of the rear tyre are in line then adjust the wheel so that the same markings on the wood are visible at the front wheel.

[Darrell]

If you're going to do anything to your chain with the bike on the stand, motor running & in gear, will you give me a call?
I'd love to be there as I'll be the first to buy your bike when you find you can't ride it because you have no fingers.

Heh, all I did was run the bike to listen for the noise, as it's only when I'm driving and it's sort of hard to look and get your ear by the area when you're also trying to miss parked cars. Trust me, I'm not that stupid!

With the chain at proper tension when I'm sitting at it, that rear indicator mark is at the "replace" portion, so maybe the chain just needs replaced? How long do they usually last? I only have about 11k miles on the bike.

[dusterdude]

damn,you guys are hard.

[mick750F]

If you're going to do anything to your chain with the bike on the stand, motor running & in gear, will you give me a call?
I'd love to be there as I'll be the first to buy your bike when you find you can't ride it because you have no fingers.

With the chain at proper tension when I'm sitting at it, that rear indicator mark is at the "replace" portion, so maybe the chain just needs replaced? How long do they usually last? I only have about 11k miles on the bike.

   Time for a new chain and sprockets.

Mike

[Lumbee]

    ...that twowired is a trip!!!   Yep Moz...time for new chain/sprokets...go on and get with that 530 chain w/15 tooth front sproket and 48 tooth rear...

https://www.partsnmore.com/motorcycle-sprockets.php?make=Honda

[Darrell]

Wow, those prices are a lot cheaper than when I first priced out a new chain real quick the other night. The few places I looked wanted ~ $130US!

I'm now reading the average OEM chain life span is 10k-13k miles. I don't know, I guess I just assumed they wouldn't stretch that fast and would last a good 30k miles or so. Thanks for the info guys. I'll replace it and let you all know how I make out.

Nice site, thanks for the link RaDigga.

[mick750F]

   ...that twowired is a trip!!!   Yep Moz...time for new chain/sprokets...go on and get with that 530 chain w/15 tooth front sproket and 48 tooth rear...

https://www.partsnmore.com/motorcycle-sprockets.php?make=Honda

mozingod...Are we talking about the bike in your avatar? If so, they came with 14/43 sprockets. There's no problem in changing to 15/48 but if you do you'll lose some of your zip. If you do a lot of highway cruising you may find the bike is a little less buzzy due to lower rpms with the 15/48 set-up. I went to 15/44 with my last chain/sprocket change on my '78 750F. It's a little less buzzy at highway speed but still has some zip.

Mike   

[Jersey550F]

What's with all the sarcastic-spiteful replies?? I remember getting a similar reply for a post and thought, who are these guys?  How about we keep these responses friendly and not so "how stupid a question"

[eldar]

I understand where you are coming from jersey. Some people just like to think they know it all.

I just like to offer help if I can and support people if they want tp try new things.

There is no dumb question especially if it may compromise a persons safety.

[dpen]

We have a tradition in Oztralia called "taking the piss."
This translates to having a laugh or a joke at the other persons' expense.
This is always meant in a friendly way & is followed by the right advice (or a beer, depending where you are.)

A simple way to check the chain tension is to take a piece of wood (or metal) and attach it to a base plate so it stands upright.
Stand it beside the rear wheel (on the chain side).
Grt someone to sit on the bike and adjust your chain to the right tension.
Move the chain up & down & mark the limits.
Now put the bike on the centrestand & do the same thing.
From now on you can adjust your chain properly with thye bike on the centrestand by using the second set of marks.

[Jim Shea]

IS there a simple way to check chain tension? Is there supposed to be a certain amount of movement up and down? If so how much approx?
Cheerts,
Jim.

[Lumbee]

slack should be 0.04-0.08 inches, or 10-20mm...

...now that I'm looking at this, can this be right?  This is out of the clymers manual, the mm seem right, but 0.04-8 seems way to small, shouldn't it be 0.4-0.8?