chain adj.

[bigbore2]

If i have bike on center stand [84 1100], should bottom chain [the chain that returns to rear sprocket] be able to touch the lower chain slider if i push up on it if properly adjusted?

[Arnie]

I wouldn't think so.  The spec is for 15-20 mm movement on the chain.  Up to 25mm (1") SHOULD be fine.  More than that, you should tighten the chain - move the rear wheel back with the adjusters.

Arnie

[SlowOldGuy]

I've never been a big fan of using a "slack" measurement to adjust my chain.  Way too many variables if you've done any suspension work and especially if you've modified the ride height.

Much better to pull one of the shock or linkage bolts so you can move the swingarm through it's full range of travel and measure/adjust slack at the tightest point (which will be at the point where the rear axle is horizontally in-line with the countershaft axis).

That shock/linkage bolt probably needs some grease on it anyway.

DavidR.

[tmkaos]

I've been told that slack should be checked with rider on bike, wheels on ground - kinda makes sense to me as this is the condition where slack is important, as everything (swing-arm position) is set as close to road condition as possible. This was by a supposedly reputable bike mechanic - he said 15mm - 20mm of play when in the ride position..

This is what I've been doing for the last 3 yrs, no issues with excessive wear after 15,000km since the last chain and sprockets went on.

Sound about right?

I can't work out the physics in my head if slack increases or decreases as you go from centre stand to on the ground... All i know for sure is too much slack is bad but too little ain't great either..

[weymouth399]

I've been told that slack should be checked with rider on bike, wheels on ground - kinda makes sense to me as this is the condition where slack is important, as everything (swing-arm position) is set as close to road condition as possible. This was by a supposedly reputable bike mechanic - he said 15mm - 20mm of play when in the ride position..

This is what I've been doing for the last 3 yrs, no issues with excessive wear after 15,000km since the last chain and sprockets went on.

Sound about right?

I can't work out the physics in my head if slack increases or decreases as you go from centre stand to on the ground... All i know for sure is too much slack is bad but too little ain't great either..

This is how I also check my chain adj. But I do check for the tight spot in the chain while on the center stand first, adj that spot of the chain. All chains will have a tight spot.
If riding double a little looser that the 20 mm closer to 25mm plus for slack.

Bob W

[SlowOldGuy]

It would depend on the angle of the swingarm when under the "road condition."

If your rear axle axis is ABOVE the countershaft axis then you're fine, any further suspension deflection will cause the chain to be looser.  But that's an indication of a badly adjusted or worn out rear suspension.

If you adjust the slack on the centerstand or when the rear axle is below the countershaft, then you need to make sure there is sufficient slack for those big bumps where the rear axle will approach being horizontal with the CS axis.  Otherwise you're going to cause unnecessary stress on the chain and CS case bearings.

How often does one need to adjust their chain?  I check it at every tire change, but I haven't loosened a chain adjuster in years.  My check involves undoing the shock linkage and checking the slack through the total SA arc.

Slack definitely decreases from centerstand to ground.  A too loose chain is far better than a too tight chain. 

I'm terrible about chain maintenance.  WD-40 occasionally, maybe actually spray on some chain lube twice a year before a trip.  My '93 is still on it's original chain at 32Kmiles.  I changed the chain on my '85 back in '00.  The ZVM wasn't availalbe so I got a VM rated chain.  Got at least 20 Kmiles on that chain and don't ever recall having to adjust it.  FZ1 at 25 Kmiles is still on stock chain.

DavidR.

[yamaha fj rider]

Talking about lubing chains modern o ring type  chains need almost no lube and adjustments. I like the dry lubes which does not attract dirt, did try the chain wax once think it ruined the chain will never use it again.

Kurt 

[andyb]

It's hard to explain, but slowoldguy is right on tension.  If you align the countershaft, axle, and swingarm pivot, the chain will be at the tightest at that point.  If there's something that limits them from getting into that alignment, then as near to it as things will go; then you know the chain will never become tighter than that.

All chains do not have tight spots.  At least, mine damnsure don't.  I've certainly had that in the past though!  Buying better chains and taking better care of them seems to make the difference.

Some people will simply clean their sealed chains with simple green or the like, and have good luck with that.  I like WD40 or Howes on mine, partially because it's slightly lubricating, they're good at cleaning, but mostly because they prevent rust.

A too loose chain will be noisy and less smooth.  It'll also flop about, have a bigger chance for derailment, and will wear a bit faster.

A too tight chain will just snap.  Hopefully it's in a good mood when it breaks, because it'll do a truckload of damage to your engine cases if it's cranky.

[bigbore2]

Thanx for all the replies.  Think I will do the slowoldguy method as I need to grease the bolt.  That is how I adjust for my dirt bike too.