My 1977 KZ750 Chain BROKE today while I was riding

650ed wrote:

SWest wrote: .................... cheap chains are dangerous......................

Truer words were never spoken! Don't replace that chain with another cheap piece of junk! Ed

Truer words were never spoken. Thats for sure!!!

Brakes, tires, and transmission. Three other things you don't skimp on. Buy the best you can!!!

Probably already mentioned from veteran riders but unless those sprockets have only very very small amount of mileage, replace them too. Very important.
Also, I've seen far too many riders on bikes with chains worn out and too tight!!
Loose is better then too tight.
If a loose chain is not grinding away on frame parts or swing arm pivots, and lubricated once in a while, they seem to go on for thousands and thousands of miles... too tight and lucky to get a few hundred to a thousand miles.

Its a twin, Here is a pic of it.

I have another question. After the chain got stuck in the rear, causing it to lock up, I removed the chain. The sprocket needs replacing, as its a little worn from the incident, and WHENEVER i change a chain I always replace BOTH sprockets too. I noticed after this whole thing happened, as I was waiting for a tow truck and had the bike on a center stand, when i spun the back wheel, it squealed and squeaked a little bit,

Im thinking I should change the rear bearing too? The wheel didnt squeak before the chain broke.

If you were happy with the gearing count the teeth on the front and rear and get the same Sprokets should always be changed with sprokets so glad your doing it. Since you'll have the wheel off quite a few like changing the bearings out.... check Ebay (all balls)......

I had a bike shop (Dad and him in business forever) rivet my master link X ring chain from Z1 to be sure it was done right. My old chain was in worse shape than I thought after removing it and might a lucked out too. Was a old RK good quality o ring.

I'm with Steve that it looks like a half link. I'm in a hurry and might have missed it but there is no more mention if indeed it was a half link???

The reason I'm bringing it up is......................................if it was a half link there is a reason it's in there. Purchase the same size sprockets you had before and you might end up with a odd number of drive chain links again?????????????

I have a couple of broken half links on my "wall of shame". Self inflicted of course. Live and learn......and lucky enough to still be riding.

Gordon in NC

im going with stock sprocket and chain. thats what was on the bike. It only has 9,500 miles on it and not much was changed on it since 1977

Thanks

The chain you show in your pics definitely is not the original chain. It is in fact aftermarket trash. The image below shows a half link. Notice that the side plates are not flat; Kawasaki never installed that junk. Your motorcycle would have left the factory with a size 530, 106 link EK530SH "endless chain" (see www.powersportswarehouse.com/p/Kawasaki#...50-B2-1977/070058E-7 ) That original chain would not have a master link; instead, all the links would be riveted, and it would have been an O-ring chain. When buying a new chain I highly recommend you buy an O-ring or X-ring chain. D.I.D. (not to be confused with cheap DID knockoff), Tsubaki, EK, etc. make excellent chains. Don't buy Chinese junk. Replacing the sprockets with the new chain is a very smart thing to do, otherwise even moderately worn sprockets will kill the new chain quickly. Be sure to buy quality sprockets. Ed

Thanks for this. Im changing the bearings also. I called bike bandit and they said there are THREE bearings on the rear, but ALLBALLS kit for my bike only shows two. Hmmmmm

Look at the link I provided in my previous reply. It shows the parts diagram for the rear hub. In it you will see there is one bearing marked #10 and two bearings marked #17. If you then look at the description list below the diagram you will see the part numbers for those bearings. Ed

I have a question. Im trying to determine if this is human error that caused the chain to fail. My mechanic put new tires on the bike last week. A day later this happened. How can i be clear on what caused chain failure....him or the chain?