Chain Tension Adjustment

[STUBBORN]

put bike on center stand.
inspect chain, clean and lubricate if needed.
check play per manual. also on decal on side. you want 1-1/4" of play in middle of chain.
measure from center of swing-arm pivot to middle of axle on both sides, make sure they are even. this ensures chain alignment. take note.
Loosen rear axle nut just a bit to allow friction but allow it to move with adjuster nuts. but not overly loose.
IF axle is not even on both sides to swing-arm bolt, turn adjuster nuts on back on side that was further away to make them even. .
do in 1/4 turn increments.
recheck chain slack.
tighten adjuster nuts even amount after verifying axle is straight until chain slack is in spec.
tighten axle nut.
recheck adjuster nuts and make sure they are seated against adjuster plates. (usually will get a bit of a turn here).
recheck chain slack.
done.
remember.. too tight of a chain is worse than too loose of one,
as it can damage the output shaft, stress the chain causing tight spots, and wear out bearings.

​

Motion Pro Chain Alignment Tool | Parts & Accessories | Rocky Mountain ATV/MC

Shop for Tools, like Motion Pro Chain Alignment Tool at Rocky Mountain ATV/MC. We have the best prices on dirt bike, atv and motorcycle parts, apparel and accessories and offer excellent customer service.

www.rockymountainatvmc.com

 

[Kritou]

Is that 1-1/4" on it’s wheels with a rider’s weight on it?

 

[STUBBORN]

Is that 1-1/4" on it’s wheels with a rider’s weight on it?

In the YOUTUBE there is nothing on the bike on its center stand.

The tape measure is made from the floor up to the bottom of the chain.
Then measured again with the chain pushed up tight.
Subtract to get the slack.
The difference (slack) shall be no more than 1-1/4 inch.

 

[dmonkey]

The owner's manual has you check it on the center stand with no rider on it. If the tension is within spec then with the stock suspension bottomed out it will still not be too tight on the chain.

https://cdn.powersports.honda.com/documentum/MWOM/ml.remawmom.2021_31k2ea00_trail_125.pdf

 

[STUBBORN]

Measuring is the easy part.
If the chain is too loose, then happily, you get to tighten it.

Adjusting both sides equally to tighten the chain and
making sure the rear wheel is not crooked is the fun part.
(What happens if it's crooked?)

Prolly it's best to do this after installing a brand new chain.
Some recommend installing a new sprocket as well if it is worn.

 

[dmonkey]

(What happens if it's crooked?)

If the rear wheel is out of alignment the bike will not track straight, if you're riding through rain, snow, or mud you will see that the rear tire follows a different line than the front. It can also be noticeable when turning (one direction turns easier, the other harder) and when using the rear brake it will pull to one side. The rear wheel/axle being out of alignment will cause extra wear on the chain and sprocket, and if it's very far out of alignment it risks having the chain come off the rear sprocket while riding.

 

[Cpd419]

At 450 miles, my chain was extremely loose. My swingarm marks are dead nutz though

 

[STUBBORN]

Original chain?
(I have a brand new GOLD D.I.D. 428VX X-ring chain. @125 miles.)

The swing arm markings bother me with their inaccuracy.
I use two methods to check, these are:

- First, I use the Motion Pro tool which clamps to the sprocket so I can eyeball the angle.

https://smile.amazon.com/Motion-Pro...1661987715&sprefix=motion+pro,aps,113&sr=8-13

- Second, I measure how far I turn the nuts in on the adjusters. I had them all the way out at one point and I measured to make sure they were identical lengths.

Being a rookie, this method seems good enough to prevent premature chain, sprocket or tire wear.

 

[yoshi125]

I'm going to do this tomorrow morning. Just a note: the rear axle nut torque is 59Nm.

 

[yoshi125]

Mine turned out at 50mm with only 150 miles on the bike. After tightening it back to around 30mm, did a test ride, and surprisingly the shift from 1st to 2nd gear was a lot easier. I used to have to push the lever hard from 1st to 2nd, now it seemed easier.

 

[SneakyDingo]

Mine turned out at 50mm with only 150 miles on the bike. After tightening it back to around 30mm, did a test ride, and surprisingly the shift from 1st to 2nd gear was a lot easier. I used to have to push the lever hard from 1st to 2nd, now it seemed easier.

If you're having trouble shifting, especially with ~150 mi on the bike, check out the automatic clutch adjustment procedure as well.

The clutch goes out of adjustment somewhere between 100 and 600 mi as things wear in, and this adjustment procedure will help with difficult shifting. If you screw up the procedure, just start the procedure from the start again. It's very quick once you get the hang of it, only about 30s-60s.

 

[yoshi125]

Thanks that's next on my todo list. Just did the oil/filter today.