Topic: My chain goes tight, then loose, then tight, then loose......WTF?

[Boost_Junkiee]

Anyone had this issue? When I spin the wheel the chain goes tight then loose. The wheel is adjusted and centered on the hashes on the swing arm, the sprockets look good and the chain looks good but it feels like its binding or something? I was hoping not to have to drop more dough on a chain and sprocket so any help would be appreciated! 

[troppo]

could be a couple of frozen links binding when they go around the sprockets

[Boost_Junkiee]

Thats what I was thinking but I couldn't spot them. When riding the bike I can actually feel it.

[petercb750]

How does the chain feel on the sprocket - ie can you pull it away from the rear of the sprocket? Can you move the chain sideways by grabbing it mid way bewteen front and rear sprockets and pulling and pushing sideways (rather than up and down)?
If so, she's knackered.
Really sounds like your chain has a tight spot, or rather a stretched spot, and you've tightened it at it's loosest position, making it way too tight at the tightest position. Try to get a compromise between the two.
Our 400 was like this, but some of the resistance to spinning was due to a couple of the sprocket stud nuts working loose and rubbing on the bottom of the shocker mount. 

[Johnie]

I think you are on the right track.  Chain has some tight links.  Depending on the age you might be better off to just buy some new sprockets and chain.  That solved my problem and now I know where I am at chain wise.  Or you can take it off and clean it and dink around with it and try to free it up.  Guess it depends on the cash situation.  Good luck with it...

[jtb]

YOu really ought to replace the chain and sprockets.  If it's a 500 or 550, DON'T get an O-ring chain.

[754]

its pretty normal to get uneven wear, moreso if you or the previous owner did a lot of burnouts..

Adjusting at the tight spot is crucial, or it will be hard on the sprocket shaft bearing..

[jbswearingen]

YOu really ought to replace the chain and sprockets.  If it's a 500 or 550, DON'T get an O-ring chain.

Why not an O-ring chain?

[Klark Kent]

too wide.  itll wear into the engine case behind the front sprocket on most 550s.

[City Boy]

Your chain is kaput.Check sprockets very closely and change along with chain if any doubt about their condition.Bad teeth will wreck new chain prematurely.Buy the best chain you can afford,you won't regret it!

[DJ_AX]

I'd say to replace the chain and likely the sprockets too.
It is the "Main Drive Chain" ... one of those parts that are very important!
Like tires and front brakes... it better be working right!

I'd also recommend checking your swing arm play while your back there.
While it's on the center stand grab your rear wheel and try and move it side to side. It shouldn't move at all. If it does... you'll see how that can jive with the chain's tension. .. and then you'll need to replace the swingarm bushings.
Just resolved that issue myself. My bushings were so bad I felt like it was constantly yankin' my chain.

[754]

I fail to see how worn bushings can feel like an unevenly worn chain...

[upperlake04]

  An aftermarket rear sprocket I had was machined with a slight amount of slop around the  bolt holes which caused the sprocket to be able to be fastened non -concentric with the axle.  This caused the chain to tighten/slacken as the wheel turned. Easy to check with the bike on the centrestand and chain off,   by spinning the tire slowly while eyeballing the tips of the teeth for distance against something fixed and and set as close as possible to the sprocket.

[Boost_Junkiee]

Sweet, thanks for the info. Now I have a direction to go. I will check it out tonight.

[Boost_Junkiee]

What kind of chain should I get? I looked on ebay but they are all o-ring style? What kind do i need? I couldn't find the chain info on the site. I think its a 100 link correct?

[DJ_AX]

I fail to see how worn bushings can feel like an unevenly worn chain...

My bushings were worn to the point that the rear tire would move almost a 1/4" side to side. Push the wheel to the right and then chain gets tight.. to the left... it gets loose. The play in the chain tension varies a lot!
I would set the chain tension and it seemed fine... but then when riding... chain tension would vary depending on many things... turning, slope of the road, accelerating, decelerating.

[Boost_Junkiee]

I fail to see how worn bushings can feel like an unevenly worn chain...

My bushings were worn to the point that the rear tire would move almost a 1/4" side to side. Push the wheel to the right and then chain gets tight.. to the left... it gets loose. The play in the chain tension varies a lot!
I would set the chain tension and it seemed fine... but then when riding... chain tension would vary depending on many things... turning, slope of the road, accelerating, decelerating.

well its not worn bushings. When the bikes in the air and I am hand spinning the rear wheel I can feel it binding then getting loose. I think I am going to try to drop a link (the ones that are binding) and shorten the chain for now until I can afford a new one since I am already on the last hash on the sprocket. I did find out the chain is a 530 x 100 if anyone needs to know.

[greenjeans]

Any chance that the rear sprocket doesn't line up well with the front ?  Maybe a washer or something
making it wobble slightly ?  If you sight down the chain line is it perfectly straight. Could be that the sprocket
might have a slight wobble.

I just picked up a 100 link chain at my local dealer....$45   That's what came of mine - 72 CB750K2

[fixahonda]

I don't think taking a link out of a badly worn chain is such a good idea. It's not riding properly on the sprockets since the links are spaced further out than the sprocket teeth. This is kinda dangerous and will kill the sprockets in a short amount of time.
I picked up a new RK 530x100 from Bike Bandit for $25 or so shipped last week. Not too bad a price.

[754]

Chains can and often do wear at uneven rates.

It seems some have a hard time accepting that...

If the chain is worn, nothing will repair it, least of all taking out a link.

 And running it to tight or a bit tighter to get rid of some of that whipping.. is inviting other problems..

If you do not adjust it at its tightest point, a new chain may be the cheapest part of what is coming up next..

[gar]

754 - here's my 2c ... I had the exact problem.  I bought my bike 2 years ago with around 8k miles and I doubt it had been cleaned in, oh, 32 years.  I put the bike on the center stand and scrutinized the chain while I turned the wheel and could see there were a few links that were binding.  I first confirmed the wheel was adjusted straight.  I really didn't want to remove the swingarm to soak the chain in kerosene, so I took a scrub brush (the plastic kind you'd use on floors or kitchens with plastic bristles) and scrubbed the chain as I sprayed WD40 on it, and slowly turned the wheel.  I probably used 1/2 bottle of WD40, but if very effectively cleaned the chain and removed the debris that was impairing the smooth movement of the chain.  The tight...loose...tight cycle was eradicated. I bought a Castrol spray on lube from DennisKirk and have had no problems for two years now.
Hope this helps!

[754]

A sticky unlubed chain can do that..

 I sorta assumed that before anyone would post on here they would lube and adjust the chain first.. I realize that some new riders may have a bit of a time with this if they had never done so.

 Another thing to mention, if a chain is very dry, it can tighten up after you lube it, so always lube up and make sure the links are freed up before doing a final adjustment

[smccloud]

i'm dreading the day i have to replace the chain on my '72 750.  but i have a feeling it will be less than a year no matter what.  don't want to chance it when i'm giving my fiance and her daughter rides.

[DammitDan]

A broken chain will ruin your day. 

Severely over tightening a worn chain to save a little dough could very possibly break your chain.  And possibly punch a hole in your crank case.  And take a chunk out of your leg if you're running without a chain guard.

And it will leave you stranded.

A broken chain will ruin your day.   

[Boost_Junkiee]

A sticky unlubed chain can do that..

 I sorta assumed that before anyone would post on here they would lube and adjust the chain first.. I realize that some new riders may have a bit of a time with this if they had never done so.

 Another thing to mention, if a chain is very dry, it can tighten up after you lube it, so always lube up and make sure the links are freed up before doing a final adjustment

Just so you know, I did lube it up and I cleaned it before putting it on. I thought I stated that already....

[754]

You did say that, but then why do you still have a sticking link?

I was referring to the replies that maybe it needs oil and cleaning to get the kinks out.

[Klark Kent]

I remember hearing about a teflon chain lube that works really well but couldn't find the post here, while searching i found a great poll about cleaning and lubing chains-   

[Boost_Junkiee]

f&#* it. I just ordered a rk 530x100 m chain from cycle gear for $20. Best fix for my issues it seems Im tired of dicking around

[DammitDan]

I also recommend scraping together the extra bit of $$ to get new front and rear sprockets.  Leaving the old sprockets on there will wear a new chain out quick, and you'll be spending more time adjusting it and re-adjusting the chain than riding!

[Boost_Junkiee]

Obviously I am on a budget so I am looking for a place that has them cheap. Anyone gotten replacements cheap?

[mattcb350f]

+1 on replacing the sprockets.

It could be that your old chain was riding up on the sprockets causing the "tight/loose" condition. If so, the teeth on the sprockets could be bent over.

If you replace the chain and sprockets now you won't have to replace either for a long time  (DISCLAIMER: IF properly lubed and adjusted  )

 Matt.

[754]

check sprockets for wear, front wear out a lot faster than rears..

 an overly cheap chain my not save you money in the long run.

[Jakoba]

I have a 78K with 45,000k on her and I just replace the "Original" (according to my mechanic) 630 chain and the stock Sprockets 15/41.
I swapped them out with a 530 (D.I.D) 17/48 (JT Sprockets) conversion. Works real smooth.
I can't give you any rpm at high speeds yet.(only have my permit not allowed on a road with 80km or more posting) but I do know that at 60km (37mi) she is at 3000 prm and at 80 km(49.7 mi) she is at 4100 rpm.

I am very pleased with the upgrade.

Jako

[Industrial Cafe]

I know this is old, but my bike (with a newish chain and sprockets) has been fine up until today, when I was riding home and heard more chain noise than normal.
checked it out on the stand, and it's getting tight and loose.... seemingly out of nowhere.

the chain and sprockets have around 600 miles on them.
since we never really seemed to get a straight fix for the problem on this thread, I'll see if I can get to the bottom of this.

[gane]

ALL,  some things to check. 1st, if chain can be lifted away from rear spkt at rear center. replace. 2nd if at end of adjust. replace. 3rd, if chain tension changes at mid range by more than an inch, replace. 4th, if sprocket teeth show wishing or asymetric wear, replace.. in rare instances, sprockets can be "out of round", even more rare are bent c/s shafts. chains which sit for prolonged periods often develop "tight spots"where wrapped around c/s spkt. every pitch of chain has, a pin,roller,sideplate. when new, or worn equally load is distributed over 3-4 pitches at all times. a worn chain will wear out sprockets and vice versa. a broken chain not only makes one a pedestrian, but the possibility of physical damage or broken cases preside. As a much younger Gane I worked at a dealership which had a stack of broken 750 cases where drive chains had broken and destroyed 'em.  be safe. luck g

[Industrial Cafe]

ALL,  some things to check. 1st, if chain can be lifted away from rear spkt at rear center. replace. 2nd if at end of adjust. replace. 3rd, if chain tension changes at mid range by more than an inch, replace. 4th, if sprocket teeth show wishing or asymetric wear, replace.. in rare instances, sprockets can be "out of round", even more rare are bent c/s shafts. chains which sit for prolonged periods often develop "tight spots"where wrapped around c/s spkt. every pitch of chain has, a pin,roller,sideplate. when new, or worn equally load is distributed over 3-4 pitches at all times. a worn chain will wear out sprockets and vice versa. a broken chain not only makes one a pedestrian, but the possibility of physical damage or broken cases preside. As a much younger Gane I worked at a dealership which had a stack of broken 750 cases where drive chains had broken and destroyed 'em.  be safe. luck g

it's the strangest thing, I can put a magnetic pin on the swing arm and the sprocket looks out of round by 1-2mm.  sunstar and 48 are stamped on opposite ends of the rear sprocket.

the teeth touch when the "sunstar" comes around, and move away when the "48" comes around.

I don't have a camera anymore (thanks to my kids and a big cup of koolaid)
but I'll post the reason for the problem when i fiddle with it tomorrow.

[Industrial Cafe]

AAAH HA!!!

I loosened the axle one turn, turned the wheel till the chain was tight, grabbed the bottom section of chain with my fingers and squeezed with my thumbs on the swingarm and VIOLA!!! 
there was a squeaking sound,(like aluminum against rubber cushions) and the chain is no longer having the problem.
might have been from warming them up with the improper torque on the axle....
now to tighten to spec, and see if it's good.

[Industrial Cafe]

DOUBLE AAHA!!
SOLVED


it was the 4 bolts that hold the sprocket on.
they were loose enough to let it shift 1mm, enough to give me the problem.

[fang]

Congrats!  I was reading and reading, and thought that this sounded like the sprocket was not centered.  Believe it or not, this happens a lot -- probably more than the chain wearing unevenly.  That really does not happen all that often.

For future reference, if you have the tight, loose, tight, loose chain thing going on, the first thing to do is to make a mark on the rear sprocket and observe if the tight/loose thing corresponds with the sprocket's rotation.  If so, then you found the problem.

good work finding the problem.

peace and grease,
-fang