Topic: Measure chain stretch

[crashmaster]

Looking in a repair manual, how to measure chain stretch. It says to measure the entire chain between the pinholes. If the stretch of the chain is computed to be greater than 10 mm for 1 meter of length the chain should be replaced.

Sorry, but I don’t get it. Don’t I need to know the overall length of a new chain in the first place? Which I can’t find. And do I include the master link in the measure? If anyone has any tips, I sure appreciate it.

[HondaMan]

Normally, this is done with the chain off the bike and laying on the floor. I still do it that way (those who've bought my CB500/CB550 Book can see it pictured), though usually laying on a 2x4 board to help keep it clean of more dirt. A finishing nail driven in at one end of the board makes a nice post to hold the first link. Then individually push all the links together toward that first link, measure the length, then pull hard on the chain and measure it again.

If the bike is a CB750, these generally use a 100-link chain, so the stretch calculation is simple: is it stretches more than 2% it will show 2 links' difference in length between compressed and stretched. That's the normal wear limit. If it is allowed to stretch beyond 3% in length the sprockets will take a beating and wear quickly.

[crashmaster]

Thanks HondaMan. That seems like a way more intuitive way to do it.

[scottly]

A quick check on the bike is to pull the chain straight back from the rear sprocket at the 3:00 position: if there is daylight between the chain and the sprocket, it's pretty much worn out.

[BenelliSEI]

I use the front edge of an 8’ wooden bench with a nail driven into one end. It absolutely amazes me how a little bit of pin wear converts into inches when X 100!

[BenelliSEI]

A quick check on the bike is to pull the chain straight back from the rear sprocket at the 3:00 position: if there is daylight between the chain and the sprocket, it's pretty much worn out.

Clever!

[Don R]

 My brother taught me and then drag racer Tom Klemme saw me do it and remarked that's how he checks chains, both pull the chain back away from the sprocket at 3:00 like Scott said.

[PeWe]

A quick check on the bike is to pull the chain straight back from the rear sprocket at the 3:00 position: if there is daylight between the chain and the sprocket, it's pretty much worn out.

That's the way doing it.
I checked my K6 last week. I can lift chain. My other bike, chain can not be lifted.

It feels rattly sideways too.
Modern X ring chains do not stretch as chains in the 80's.
DID 50HDS o-ring had to be adjusted rather often by releasing wheel axle nut and adjust.

I'll replace the chain and sprockets at next tire change, ca 4000km left.
Chain is a stronger version, D.I.D 530ZVMX X-Ring Chain.
33690km done, so ca 37650km in total despite +100whp.

My almost stock K2 has the weaker D.I.D ZVM-X, still a strong chain for CB750.
Both chains have riveted master link.
Hollow type, so simple tools works.

I recommend to order one or 2  extra master links with the chain. It's easy to make mistake when rivet.

Below after I had pulled chain with fingers. The chain look a little bit dirty. Grease and dust. To be cleaned..

[rotortiller]

My brother taught me and then drag racer Tom Klemme saw me do it and remarked that's how he checks chains, both pull the chain back away from the sprocket at 3:00 like Scott said.

+1 that's how we learned to do it as children and it still holds well today.

[Rayzerman]

Best combine that method with a later Honda recommendation.... see pic.  No need to have a chain all stretched out on the floor, just get a metal scale and measure across 20 links.  Each chain link is 5/8" or 0.625.  A good general rule, although I have seen chains worn way worse than that, which I would consider unsafe.

[Little_Phil]

That's not much over 0.5%. Seems like a better limit.

[HondaMan]

I never run my chains past 1% wear since 1980. This lets the rear sprocket last past 80k miles in fine shape. I have only used 2 rear sprockets up on my 750 in over 160,000 miles because of this practice. I've used 4 counterspockets (on #4 in its 'flipped' condition now, it gets flipped every 3000-5000 miles) in that time - and more rear ties than sprockets added together!

Normally, if the chain can be lifted off the middle of the rear sprocket far enough to see the root of the sprocket tooth, you are past 2% wear. If the chain can be pulled as far away as to see the mid-tooth grind line of the rear sprocket (i.e., 2/3 of the tooth height), the stretch is passing 4%. Once past 2% the wear rate multiplies: before that it is largely additive. This is a tried-and-true industrial maintenance schedule on much of the chain-driven conveyance machinery I built when I was (30+ years) a Controls Engineer: in factories where precision was needed the 1% or 2% rule dominated.

[PeWe]

I had to fill my stock of parts thanks to this thread

I looked for "after X-mas" sales.
Got sprockets for a special price if order within 30 minutes.
JT sprockets
17t for less than $20US/each. Only 1 allowed.
(I have one new, plus 18t)
48t for $40US/each.  Ordered 2.
(I have one new)
(My new sprockets in stock will soon go on my K6.)

- Now looking for a special price on a  chain for a stock CB750. Still a strong chain with riveted masterlink.

Both new chains I have are for more power. I have another CB750 to assembly too.

I like to have spares on hand. Not waste riding waiting for service parts.

I prefer to change sprockets with chain. Sprockets are relatively cheap compared to the chain.
Sprockets might not be worn evenly which can apply more force on chains individual links due to less number of teeth that share the force at the same moment.

I have snapped the chain twice on my K6 in the 80's. I was lucky to not crack the case.

The lift height of my chain can also be affected by a worn rear sprocket and chain stretch

The adjustment marks on the swingarm have not changed much during the years. Not as the old weak chains the bike had in the 80's.

Even an o-ring chain back then stretched very quickly with frequent wheel adjustments.

Teeth look worn.

EDIT:
Found a good enough chain
RK 530 MAX X RX-Ring 100 links
It match the D.I.D VX  x-ring chain my K2 has.
Shop gave me a 30 minute offer again! Now the RK chain for ca: $66US. Almost half than a similar D.I.D VX.
Strenght between old VX and VX-3.

[HondaMan]

Hey, PeWe: can you get the Diamond XDL chains there? They are not O-ring type, just plain ones.

[PeWe]

Hi Mark,
There are many 530 chain alternatives here, but not Diamond XDL.

There are plenty of DID, RK, EK and DC  chains with good tensile strengths.
X, O- rings.
And without rubber seals as often  recommended for off road bikes.

I think DC is also called AFAM lately.

I have a  DC 530MZO-G
Now also sold as:
AFAM 530XSR2-G/DC 530MZO-G

[bryanj]

Got to say it, chains dont stretch---- they wear

[BenelliSEI]

Got to say it, chains dont stretch---- they wear

So true! And one of the few things that gets measurably longer as it wears!

[PeWe]

The chains my K6 got in early 80's needed wheel adjustments very often.
If it was at first mark on swingarm when new it ended up a few marks later.
Even the DID 50HDS o-ring chain that was much better than the cheaper ones. Riding in rain and not lube it quick enough killed it.

The stronger x-ring chains the bike has got since 2013 has not needed as much wheel adjustments.
Sideways wiggle when done.

I have also found a really good chain lube spray, Motorex Road strong.
Long lasting lube.

[MauiK3]

It's difficult to imagine the conditions inside chain links as they move along getting wet and dirty, no wonder they wear. Years ago someone sold some sort of nylon rear sprockets for these bikes. They did not last very long.

[PeWe]

I tried a nylon rear sprocket in early 80's. It should be better for the chain.
I think it did not last long. I did not buy another one.

[Don R]

 I've owned 750's with the nylon sprockets and the 360* plastic chain covers that included the oil dripper bottle. They mostly ended up back to original. The K4 with the nylon sprocket had spent 20 or so years at an airport, it was the only one that didn't need the carbs cleaned. It lived on aviation fuel. It also had a pamco ign. and would start even with nearly no battery voltage.

[newday777]

I tried a nylon rear sprocket in early 80's. It should be better for the chain.
I think it did not last long. I did not buy another one.

I had the same results in the 77/78 years Per. It was a 1 time purchase I think in my last season of being a parts manager. Very poor life it had. They touted less weight and stronger....ah, yah right..... Bit once.

[willbird]

Hmm I was thinking to remove the chain from the bike and hang it vertically with some kind of a weight at the bottom end.

Having it's length recorded or marked when it was new was how I was going to gauge wear over time.

My CB500X is getting the most of my miles now, the OEM chain died at 8k miles due to stiff links which was caused by it being dry inside and rust on the pins. The replacement chain (DID O ring) at an additional 8k (new sprockets were used) has no stiff links. Thinking to use an X ring chain next time and record it's length new as I described above and go from there. So far I have never re used sprockets except when I was 16 years old and working for $1 an hour, just seems irreverent to put a new chain on used sprockets. They do it where I work, Diamond industrial chain in an industrial environment. One machine had hundreds of #40 chains about 10" total length, in that case the chains were much much cheaper than the sprockets.

Bill

[crashmaster]

great info - thanks!

[Tracksnblades1]

Got to say it, chains dont stretch---- they wear

So true! And one of the few things that gets measurably longer as it wears!

😂😂😂

Reminds me of a long term client of mine talking about Redheads😜, Money, and Manhood..
I told him that I thought all three (Redheads, Money, and Manhood) were very similar. Regardless of the amount blessed with, I believe, we all think we could do better with a little bit more.

He only replied, I’m going to use that too..😏😁

[bryanj]

With all this talking about length it is far easier to remove it and see how much it bends sidways, that is both sets of sideplates on the floor and see how much "curve" you can get in it

[MauiK3]

Would be interesting to see side movement of an old and new chain side by side, the difference would be easy to spot.

[PeWe]

Or the easier way as mentioned earlier, lift change a bit off rear sprocket if possible.
Sideways wiggle can be checked when verifying correct slack.

A riveted chain will be opened when replacing it, not before