rear chain adjustment


merry xmas lads and happy new year. can any one tell me there way of adjusting rear chain and what slack they leave. i find the adjusters and marks on stander-ed adjuster blocks pretty unless. the sun was shinning on Monday morn. a little cold but got the mt 09 out for a run. was brilliant just to go for a blast. sore loads of bikers doing same thing. cant wait for the summer.
 

Kinjane

New member
Ignore the marks, 'simply' align the wheels then go for chain adjustment :confused:

Measurement opinions will vary but I keep mine to a minimum total slack of 38mm (dry) with the suspension fully extended. This is measured on the lower run directly below the end of the plastic chain guide at the chains tightest point. Once the chain is lubed it will tighten up a little and that figure will alter.

Before tightening the axle I put a thick rag between the sprocket and the chain and turn the wheel backwards to pull the wheel up hard against the stops. Once the axles been correctly torqued I put the rear brake on and turn the wheel forwards to lock the caliper bracket hard against its own stop.

I've needed to move the wheel back 1mm (ie one completed turn of the chain adjusting bolts) in just over 6,400 miles (and 1&1/2 tyres) to keep the chain adjusted. There will be other methods, but this one's mine :)
 

LewFZ1

New member
Axle nut torque 150nm, adjust screw torque 16nm, according to the service manual the specs for the chain slack are 5.0mm to 15.0mm. They go on to say if the slack is greater than 25.0mm the chain will damage the swing arm.
There has been a bit of a discussion on the 5mm/15mm figure given in the owners manual and also the service book. General concensus is this is a typo in the books. I certain do not have my chain adjusted to 5mm or 15mm. I have mine setup to 20mm and even then I think it is tight but we will see. For wheel alignment I use a Vernier to ensure equal distance is achieved on both sides. In the service manual it says to place the bike on an stand so the rear wheel is elevated, the owners manual says to do it with the bike on the side stand.
First check the chain adjustment over several places, walking the bike back and forth. Reason for this is so you can see if you have a tight spot on the chin, stiff links etc!!.Slacken off axle nut, back off the lock nut on the adjusting screw adjust chain side 1/2 a turn, adjust brake side 1/2 a turn until desired amount of slack is achieved. Nip up Axle nut, recheck chain slack, tighten up adjusting screw lock nut and re-torque axle nut to 150nm. If you do not have a torque wrench pre mark the axle nut and an aligning point on the next to the nut and tighten to the marks. This is the method I use but I am sure some one may have a different view.
 

stevecbr

Member
I run mine at 25mm, measured on side stand.
I use vernier calipers to measure distances are equal both sides, photos attached
mt CHAIN ADJ (2).jpg
mt CHAIN ADJ (1).jpg
 

LewFZ1

New member
So basically the Yamaha Service manual that the service technicians in Yamaha dealerships from all over the world will be working from on our bikes might as well be binned then?
 

fizzy

Member
So basically the Yamaha Service manual that the service technicians in Yamaha dealerships from all over the world will be working from on our bikes might as well be binned then?
As far as chain tension and rear spindle torque settings yes , I really don't know how they justify having the chain that tight
 

Kinjane

New member
As far as chain tension and rear spindle torque settings yes , I really don't know how they justify having the chain that tight
From an engineering point of view those figures would be correct for when all three axis are in alignment. A chain must have a certain amount of running slack, but too much and its own weight will accelerate wear due to the whipping action which occurs between sprockets along top and bottom run. So 5mm is the running slack and the additional 10mm the amount of wear considered adequate before adjusting back to running slack.

But those figures would never normally be supplied because it either involves removing or compressing the shocks to obtain the minimum figure every time the chain needs adjusting.
It's standard practice to quote the minimum figure either for when the suspension is fully extended whenever there is a centre stand supplied or for when lightly compressed under the bikes weight when there is only a side stand supplied.

Where things really go wrong is when a longer shock is fitted and no account is taken of the need for the much larger amount of chain slack for when the new shock is measure fully extended.
Crankcase damage from where the chain has been run too tight is not a pretty sight.
 

bobh

New member
I've just spent a happy hour or so faffing around with rear wheel alignment and chain adjustment on my new -09 before it goes in for its 600-mile service. Generally I prefer to get it right to my own satisfaction before it goes in, and tell them to leave it alone - I've had too many bad experiences of dealers' workshops over-tightening chains, and as I use Wurth Dry Lube in the summer months, I'd rather they didn't slather loads of white grease all over.

When I collected it the chain was way too tight (no slack at all, even with the bike on the sidestand), so I sent it back into the workshop before riding away. It was still tighter than I'd like when I got it home, so I backed it off a bit more, keeping to the max play of 15mm. Even then, it doesn't really pass my "stick a big bloke on the pillion seat and check if there's still a bit of slack" test. So today I decided to have a go at doing the job properly.

My normal procedure is to start with the chain a bit too slack, then nip up the rear wheel spindle so it's just binding and adjust the chain exactly before torquing up the wheel nut. But for some reason that didn't seem to work on this bike - as soon as I torqued the nut up, the adjuster block on the drive side moved back away from the adjuster screw, making the chain too tight. I think it's because the adjuster block is quite a slack fit in the slot in the swing arm, so as you tighten the spindle it turns the block, which "walks" it back along the slot. It only happened on the drive side, the brake side stayed hard up against the adjuster. So after a lot of trial and error I've got it somewhere near,. though being a bit fussy about these things I'll probably have another go tomorrow. It does explain why the workshop may have over-tightened it, if they didn't do a final check after torquing up - not that that really excuses it.

I did wonder if switching the spindle round, so the nut is on the drive side, might stop the adjuster block "walking", at least on the drive side where it's more critical. Anybody tried that, in fact is it possible?

I also discovered that the wheel alignment, as delivered, was some way out, which might explain why it's seemed happier going round left-handers than right. Somewhat to my surprise, after lining it all up with the aid of some 50x50 RHS, the alignment marks seem to be pretty close - though they're not exactly the ultimate in precision engineering.
 


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