Tightening the chain?
 

I tried to tighten the chain the other day while doing a variety of other things to my bike. I was sure to make sure that it is evenly matched on each side of the swing arm but I fear that I may have over tightened it.

I am going to loosen it up today but I was wondering if there is a sure fire way to know how much slack is good for the chain. I am probably over paranoid about slack in the chain and therefore tightened it when I didn't need to.

I noticed that it was making a loud zipping noise and seemed to make an odd vibration at about 10 mph when slowing down.

I was out of town all weekend so I haven't been on the bike or able to work on the bike but I was thinking about spending the day trying to get everything back to where it was.

Lesson: Don't fix what isn't broke.

Service manual. Do you have one? You need probably 3/4 to an inch of free play.

Check the play with a ruler- measure at the bottom of the link when you press down, and the bottom of the same link when you pull up. My manual calls for 30-40mm (1.2-1.6 in) of slack. I haven't felt a too tight chain, but too loose makes shifting feel sloppy- extra drive line slop.

I have a service manual, it says .8 to 1.2 inches of slack. I thought it was easily within that, but I don't know. It also notes that I need to have the bike on its side stand for accurate adjustment. I have it on the stands so maybe that has something to do with it although I can't figure out what.

The rear axle nut is supposed to be 75. ft lbs but I do not have a torque wrench. Maybe that is part of the problem.

The adjusters shouldn't let the axle move even if the nut is loose.:idk: Have you checked your chain guide? The plastic widget that saves your swingarm from getting beat up. It might be loose and constantly rubbing the chain.

Too loose = bad, too tight = worse. If you chain is loose, you will hear it slapping around. If its too tight, you may not hear anything or some type of popping. Over tightened chains can mess your shit up. They can wear out or break a counter shaft in little or no time at all.

First of all, buy a steel, millimeter ruler to check the alignment with. The tick marks on the swingarm are not precise enough to get the alignment right. Next, loosen everything up and re-adjust the chain so that you have the correct amount of slack, and a good alignment. Do each side, a little at a time, and alternate back and forth. If you go too far and the chain is too tight, loosen the adjustment nuts up, knock the wheel forward, and start again. Now, tighten the axle nut down and test ride it.

And don't forget the cotter pin!!

I think part of the problem was the fact that I was taking the axle nut completely off. When tightening it all back up this straitened the axle shaft out inside the adjustment block and tightened the chain further then I planned for.

I am outside working on it and may just wait till tomorrow so that I can get a good ruler and get this shit right. This sucks.

There should be two bolts (one on each side) that slide out and lock against the axle blocks to prevent it from sliding forward. Make tightening adjustments using those bolts, loosen the locknut, loosen the axle bolt, then use a wrench (should be 10mm on a zuk) to turn the bolt out against the axle block, this will slide the axle back very slowly, allowing VERY precise adjustment of the chain. Once the slack is right retighten the lock nuts and you're golden.

Also, the millimeter specific metal ruler is better than the notch marks on the axle, but the swingarm itself might be off slightly, not to mention whatever you are measuring it against, the best way to make sure the chain is right is to use a chain alignment tool, which can be had pretty cheaply ($10?) from any good dealership.

When you tighten the axle nut it will affect the chain. Something that none of your friends have mentioned is that you need to find the "tight spot" on your chain. Due to imperfections in manufacturing and installation,you are bound to have a spot in the rotation of the rim where the chain is the tightest. You need to find that spot and take your measurements from that point. You should have about 3/4" at the tightest point,with the bike on the kickstand and the axle torqued.

You should also check the straightness of the rear axle. A great way to do it is to measure from the swingarm pivit bolt to the rear axle... like this.
http://i99.photobucket.com/albums/l3...ld/Day6038.jpg

Thanks for the photo as usual Gas Man, wouldn't I need to measure both sides of the axle to insure that the length is equal on each side?

I have decided to take the cage to class tomorrow and when I am done, I am going to clean up the chain (again, but using kerosene) and then try to get it right with a proper method of measurement. I will also record the sound the bike is making when I rotate the rear tire.

Can this be done without getting the bike in a stand? My chain needs adjusting and I no longer have my Pit Bull.

I believe so, in fact my service manual recommends that final adjustments are made using only the kick stand.

I bought kerosene and a good metal ruler this morning, hopefully I can get all of this figured out tomorrow.

yes, chain adjustment can be done on the side stand.
and as stated, measurements should be taken while it is on the side stand.

Yes measure both sides... that is very important.

Loose is wayyyy better than too tight. I run my chain at the slack side of the measurement spec because I ride hard and do track days, both of which use more of the suspension's travel... when shit gets bottomed out your chain gets tighter...

The spec for my bike is 35 to 45 mm.... I run it at 45mm.
Ding ding! Winner.
No way... not for me at least. My service manual says to make this measurement with the rear wheel elevated. When the bike is on the sidestand the suspension is compressed a bit, causing you to set your chain more slack.
Wow, you made a helpful post AND I agree with you. WTF?

Guess I should close this thread up too.

I bought a ruler and was sure to remeasure everything properly. What seemed to be happening was that I was measuring the slack while the bike was on the stand and this wasn't working properly.

Once the bike was put on the ground the slack was way to tight. I can only imagine it go worse once I put my measly 160 lbs on it. Loosened it up and all is normal again!:rockwoot:

I agree - but my R6 it is 1-1/2" to 2"

as far as lining it up on both sides they have a chain tool you can use or a pair of calipers. the sure fire way is to move 1 flat at a time on the hex nut is how i do it. move 1 flat on left then 1 flat on the right. after each left and right turn check the tension each time then repeat until the tension is right.

That is my other lesson learned as well. Since I use a 10mm bolt on each side to push the axle out I will not just carelessly loosen both sides up as I did this time. Now that I have it measured properly I will be sure to turn each side proportionately. :dthumb:

Also when tightening the chain you should have the rider on it. The more weight on the bike the tighter the chain gets... that's all about geometry.

i hear what you are saying but i have identical measurements with me on the bike and with me off the bike..

I still disagree with this, as I said in my last post, at least for my bike. Maybe yours are all different.

The slack specification given in my manual is for the bike ON A REAR STAND. It doesn't matter what the measurement is or how tight it is with you sitting on it on the kickstand on a hill during a full moon. The spec is for the bike with the rear wheel off the ground. At least for my bike it is, and I think most bikes are this way.

If you do the measurement the way you're saying, the chain will be WAYYYYY loose compared to the spec when measured in the correct position.

yeah mine is the same way - on a rear stand..

i set mine to 40mm after the 520 chain conversion and after a track day it stretched to 50mm.. so i adjusted back to 40mm..

I had never heard of needing a rider to sit on the bike for the measurement but I suppose it could vary from bike to bike depending on the variance in sprocket distance under riding conditions. Although I would assume the idea of measuring the slack while the bike is at rest pre calculated with any fluctuations the bike might experience with a rider while moving.

http://img.photobucket.com/albums/v4...ance/Chain.jpg

I do know that I am not out of my mind though.

Maybe the Yamaha technique is the secret to Rossi's many victories? :idk:

Clearly you're doing it the way they suggest :dthumb: Like I said, my statements were just for my bike and how I thought most others were. Maybe less are like mine than I thought.

I find it interesting that they want you to do it on the sidestand... this doesn't make too much sense to me since many folks have different springs/springrates, different sag settings, etc... and especially with gixxers a lot of differing ride heights... seems a lot of variables could influence the reading. I'm just thinking outloud here though.

Like I said though, your bike may be different... and it is!

I'm sure if you follow your manual you'll be all set.

on a swingarm stand or standing up the bike would be the same thing.

My SV manual said on side stand.
Not sure on my buell... oh wait, nevermind :whistle:

Not to start an argument, but they would not be quite the same.

Please... do explain. The only difference I see would be some difference in weight. Otherwise the weight of the bike is still pressing down on the swingarm.

I'm thinking outloud here.

The weight is resting at different points depending if it is applied at the spools (by the stand) or at the axle (when resting on the ground), which would change sag since the lever arm acting on the shock has effectively changed. Also, the tire itself is a spring and damper so that effects things as well, it is like adding another spring in series, so it takes some deflection too. To add some angle to it via the kickstand can change things as well, i.e. some stiction is plausible. All of those things would tend to make the suspension not compress as much, which would give you a tighter chain slack reading than with the bike on a rear stand.

The differences would be slight.... but when you're trying to measure chain slack with a couple millimeter precision I think they would be significant enough to consider.

Not sure if I've explained myself well, but it makes sense to me. Also my shop manual very specifically says to have the tire off the ground to do it, which sort of encouraged my thinking about this.

And as I said earlier that they are suppose to be adjusted with the rider on the bike. So yes that I agree. But somebody didn't want to hear my point on that so I didn't think anybody would want to hear anything about weight distribution.

If you knew what the chain slack specification was supposed to be with the rider on the bike, I would agree with you that using the rider might allow the chain to be set to be at a better tension throughout the range of the suspension's travel.

But the specifications for chain slack are given, at least in my shop manual, for the case without the rider on there. So if you set the slack to that same specification with the rider on the bike it would be wayyyyy off.

Put the bike on it's center stand and check the free play. Oh wait, the manufacturers got rid of center stands because they weigh a few pounds. Or their lawyers made them get rid of center stands because some rider pulled a groin muscle lifting the bike up. The most useful things I ever had on a bike, the kick starter and center stand, are now ancient history.

Totally agreed NW!!!

ceo... then some bikes are different. Personally I would think you should set it with the rider. If not that is like setting the suspension without the rider.

Further, if you ever have your bike "dialed" in at a track day... they will always tell you that your OE chain specs are too tight. That if you fully unload the suspension the chain will get too tight and inhibit the suspensions travel. Happened to me...

Agreed for sure. My spec is between 35-45mm... I leave it at the slack side, I try to keep it at 45mm or a little bit more maybe. You use so much more of the travel when riding hard or at the track... don't want to fuck up that output shaft!

I would think you would over pull the chain and cause tight spots first... but who knows.

I have heard someone riding a bike with a too-tight chain. When their rear shock compressed passed a certain point (e.g. hit a large bump or something), you could hear the motor laboring due to all the radial loading on the output shaft. VERY VERY bad for the bike. Ouchie.