Rear chain free play

[MatBin 5,115]

I know it has to be measured when on side stand and check for any tight spots etc, but how exactly do you measure for free play/amount of slack.

Is it how much the chain deflects upwards only, i.e. you measure from where the chain is to the highest position you can raise it to with modest upwards force, or the total movement up and down?

My chain will move down a little from its natural slack position if I push down on it with modest force, so, do I use that position as the starting point.

[Empty_Ten 455]

You've opened up Pandora's box now.  Standby for a different answer from everyone  

 

I measure total movement up and down with the bike unloaded (no one sitting on it or putting weight onto the bike).

 

For the NC, I do chain maintenance on the centre stand (yes, I realise the manual states side stand).  Having measured the slack on both centre and side stand, I have found them the same, just on different points of the tape measure.  For example, upper reading may be 2cm and lower 5.5cm whilst on the centre stand and then 1cm & 4.5cm on side stand

 

My method (not saying it's the correct way), just what seems to work for me. 

 

1.  Bike on centre stand, find the mid point between the sprockets (there's a little rubber guide on the bottom face of the swing arm which is my go to point) and place tape measure there perpendicular to the swing arm.   

 

2.  Push down on chain with modest force, not as hard as you can but equally, not a feather touch.  My MT07 manual suggested using a 2kg weight hung off the chain to measure the lower slack .  Take the reading off the tape measure using the chain rivet/pin as your measuring point.

 

3.  Push Chain up (again, with modest force) and again use the chain rivet/pin as your measuring point.  I aim to have 35mm from the upper to lower measurement before the axle nut is tightened (I find the slack tightens ever so slightly more once the axle nut is tightened up to 98nM).

 

4.  Tighten if necessary with equal turns on either side and making sure your adjuster marks are the same on either side.

 

5.  Spin rear wheel until 10-15 links of the chain have passed and repeat steps 2 & 3 until you have done the whole chain so that you can identify any tight spots.  Adjust slack to the tight spot. 

 

If the difference between the slack on the tight spot and recommended slack is too much, consider replacing C&S (eg, if the slack on the tight spot is adjusted to 35mm results in the rest of the chain slack being 40mm+).

 

 

Make sure you remember where you started off, or for good practice, use the split link as your first measuring point.

 

---------------------------------------------------------

 

Again, thats just my method.  I'm sure someone will disagree and say xxx method is better.

 

________________________________________________________

 

Compared to the other bikes I've had, the NC seems to require more frequent adjustment than the others.  The MT's have servicing intervals of 6000 miles and I found the chain slack remained within the acceptable limit from service to service so I never really touched the chain - apart from when the stock chain was near its end of life and needed more frequent tightening.

 

Contrast to the NC, I've had to tighten that far more regularly.  I'll write off the stock chain and say that was a lack of care by me.  With the new DID chain, after it's wear in/stretch period (1000 miles or so).  I set it to 35mm and after 3000 miles it was at the 38-40mm so needed tightening again.

 

 

 

 

[davebike 943]

Me as a pro I belive in KISS  look fo 40mm top to top or bottom to bottom 

Loser = longer life  so no less the 30mm 

 

Me 50+mm  + scottoiler running very rich  (oil is much cheaper than chains

I do not tighten until I can put the chain against the swingarm easly or it hits the main stand when on the sidestand !

Ok I odd but I like chains to last   Last I replaced was on the Fazer I had did 40K miles

 

[Andy m 23,744]

Up and down. Total movement wants to be less than the  length of your first finger, more than first joint in your thumb and shouldn't touch the swing arm except with a big push upwards . So long as there is slack and you can't see daylight between chain and sprocket it's fine. No need for weights, lasers, spanners with numbers on the handle, hourly checks, spreadsheets etc. 

 

Andy

[davebike 943]

The thing that suprises me is we see too thight chains most often  like 10mm play !

Oftem just had a tyre at Watlins :-(

[Steve Case 971]

I set mine to 35mm avge. but I'll let it run out to over 40mm avge. before I adjust.

 

I use a cheap set square to measure, chain against the square at lowest point then move up and measure against the scale on the ruler and look for less than 40+mm top to top.

 

Oh I also use a centerstand or paddock stand

[Steve Case 971]

Oh and at the mo its taking 4 to 5K before it gains the extra 5mm, and I think I'm average for chain abuse.

[Black15 66]

I was told by the Honda main dealer to adjust the chain to 45mm with the bike on the main stand. Most chains are over-tightened. I currently have 18,500 on my 2019 DCT and have never adjusted the chain other than at tyre changes. I clean the chain once a week with paraffin on a rag and have a Scotoiler fitted. My last NC managed 22,000 on the standard chain without a Scotoiler.

[Andy m 23,744]

11 hours ago, Black15 said:

 Most chains are over-tightened. 

 

That's dealers for you. I can't follow why though. Maybe it makes test rides seem smoother? Maybe the crazies who want chromed discs and exhausts without heat markings complain? Maybe they just like selling chains? 

 

I've had to slacken off chains after my last six dealer visits. One was bow string tight after the 600 service so I did it in the dealer car park. The Salesman was not impressed. Brought me a cuppa and pointed out where I could wash my hands though. 

 

Should be clear of this for a while now though. 

 

Andy

Edited September 11, 2021 by Andy m

[Tex 36,817]

 

46 minutes ago, Andy m said:

Should be clear of this for a while now though. 

 

Andy

Yay!! You have the ultimate solution to chain maintenance, dude. Enjoy. 

[larryblag 14,236]

Nearly every used bike I've had has had the chain adjusted bow-string tight. They must have a manual which says they must do this AND overfill the oil 🙄. 

Me, I have a stick - not a special stick, I think it's a 2 x 1 offcut. I check chain slack with this and adjust if required. For the oil level I use either the sight glass or the dipstick - not the other stick 👍😁

[Andy m 23,744]

1 hour ago, Tex said:

 

Yay!! You have the ultimate solution to chain maintenance, dude. Enjoy. 

 

 

Swings and roundabouts given the small block swing arm was designed for a 2-inch section tyre and the clutch arm is back there in the depths (which video "spanner" matey doesn't even wipe with a rag in his rush to cartoonify the bike 😣). 

 

Andy