Loose chain - really that bad?

[headshrink]

My chain is pretty loose and I'm going to adjust it this afternoon. But I was just wondering.... generally speaking, if a chain is left too loose, is that really such a bad thing (wear chain/sprockets, etc.)?

[bob706]

How far out of spec is it? Too loose is better than too tight but running it too loose for a while shouldn't hurt anything.

[headshrink]

I honestly haven't meassured..... it is pretty floppy though. If it won't hurt anything, I won't worry about it.

[kkim]

measure the slop and we can tell if if it's too much or to little. without numbers, you're guessing.

[headshrink]

oops, wrong thread, I'll reply here in a sec

[headshrink]

Sorry, about that last post, I typed in the wrong tab.

I tightend the chain a LITTLE last weekend, but knowingly not as much as I "should" because I find the suggested slack in the manual too tight (makes whiring noise). I started erring on the loose side after I noticed it always came back from the dealer a lot looser.... but it is still pretty loose. To answer your question Kelly, I just measured it at 2".

[kkim]

I'm another believer that loose is better than tight, too. I usually aim for the outside limit of the spec window (.8-1.2"), but often times end up too tight after everything is buttoned back up (I'm way too familiar with that "WTF whirring" noise you talk about ). I now aim for about 1.5 before things are tightened back up which usually puts me at about 1"-1.5" when I'm done.

Personally, I think 2" is a bit much, but if you keep a close eye on it (check it often), I'm sure you'll be fine. I really like it that these chains seem to stay pretty consistent after the initial "new chain" stretch and don't require much adjustment compared to the chains of years ago.

The main reason for being cautious of a too loose chain is the possibility of the chain coming off the sprockets. If you think you're okay, leave it where it is. Another reason is it can move around enough to touch other things which will wear grooves in things you don't want it to... sprocket covers, swingarm, chain guides, etc.

[headshrink]

Sounds good. Thanks for confirming what my gut was telling me, or leaning toward at least...

You notice I am becoming a little less OCD in my posts over time? It is funny when I see this in a lot of newbies, reminds me of me.

[backinthesaddleagain]

Remember too Bob to rotate the tire and measure in a couple spots, it might be 2 at one point and 1 3/4 at another. I just adjusted mine the other day and as Kelly says once buttoned up it is tighter. I am closer to .8 - 1.0 a little more snug than I'd like but since its within tolerance I will leave it.

[g21-30]

A loose chain is really bad, if it comes off a sprocket and you're doing 20-100 MPH! The faster you're traveling, the worse it could be.

[headshrink]

Originally Posted by backinthesaddleagain

Remember too Bob to rotate the tire and measure in a couple spots, it might be 2 at one point and 1 3/4 at another. I just adjusted mine the other day and as Kelly says once buttoned up it is tighter. I am closer to .8 - 1.0 a little more snug than I'd like but since its within tolerance I will leave it.

I knew about the buttoning-up issue, but didn't think (or didn't remember) about rotating the tire. I usually measure the chain with the rear on the ground to minimize button-up slack, but I guess I could push it around the garage a bit...

[komohana]

Originally Posted by headshrink

I usually measure the chain with the rear on the ground to minimize button-up slack, but I guess I could push it around the garage a bit...

so with the tire on the ground how much measured play do you allow?

[nate-bama]

yo pull down on your chain half way between your sprockets..don't pull hard just put pressure on it...look at your back sprocket's bottom..like 6'o clock if you can't see more than half a tooth your fine,,if you can see the sprocket tooth tighten your chain a bit

[Cedilla]

^ I will look at that before next ride. I have 6k miles on my bike and I have not adjusted my chain, I check the chain slack every time I lube it, which is every 500-1k miles, or every time I wash it. It still has not got any tight spots in it, but the chain feels a little loose, have not measured it, but I estimate around, 1.5 inch of play. I figured, its better a little loose than a little tight so ive left it alone.

[g21-30]

For the chain slack, just use an index card with a baseline and the two measurements .8" and 1.2". Hold the card lined up with the baseline behind the chain and flex the chain toward the other two marks. If the chain is between them, you're done.

------------- 1.2"

------------- .8"


------------- Baseline

Of course, the illustration above is not to scale, much less accurate!!

[backinthesaddleagain]

Originally Posted by headshrink

I knew about the buttoning-up issue, but didn't think (or didn't remember) about rotating the tire. I usually measure the chain with the rear on the ground to minimize button-up slack, but I guess I could push it around the garage a bit...

I push it around the garage myself. Too cheap for a rear stand at the moment. The reason to check a couple spots is that the chain might have tight sections. One spot might give you 1" slack, but anther spot might give you 3/4" slack. Just worth checking 2 or 3 spots.

[ScorpionNinja]

Originally Posted by backinthesaddleagain

I push it around the garage myself. Too cheap for a rear stand at the moment. The reason to check a couple spots is that the chain might have tight sections. One spot might give you 1" slack, but anther spot might give you 3/4" slack. Just worth checking 2 or 3 spots.

i use a Painted Marker and put a 'DOT' on the rear sprocket, at about the "12 o' clock" mark, once i find the tightest spot! now over time 6,000 + Miles atm ive ended up with 3-4 DOT spots that so far are always pretty close to the tightest part to use your tight-base!

When my nate had low miles, the first several times id do this, it would take forever to find the 'tightest spot', driving me ****ing CRAZY

So now i just line up and check the 3-4 12o'clock DOTs, using them at the starting point.. rather than spend 20mins rotating over n over finding that G-spot on the chain!

[backinthesaddleagain]

Originally Posted by g21-30

For the chain slack, just use an index card with a baseline and the two measurements .8" and 1.2". Hold the card lined up with the baseline behind the chain and flex the chain toward the other two marks. If the chain is between them, you're done.

------------- 1.2"

------------- .8"


------------- Baseline

Of course, the illustration above is not to scale, much less accurate!!

Oh man I didn't read the last sentence! I printed the page, cut out the chart, and set my tension. Just kidding - it does work good.

[backinthesaddleagain]

Originally Posted by ScorpionNinja

i use a Painted Marker and put a 'DOT' on the rear sprocket, at about the "12 o' clock" mark, once i find the tightest spot! now over time 6,000 + Miles atm ive ended up with 3-4 DOT spots that so far are always pretty close to the tightest part to use your tight-base!

When my nate had low miles, the first several times id do this, it would take forever to find the 'tightest spot', driving me ****ing CRAZY

So now i just line up and check the 3-4 12o'clock DOTs, using them at the starting point.. rather than spend 20mins rotating over n over finding that G-spot on the chain!

The G Spot of the chain... As much as I like my Ninja I just haven't gotten that intimate with it. Great reference.

[karlosdajackal]

I read in one of the bike magazines (either bike or visordown) that a loose chain can cost you up to 3 HP, although they don't mention what bike, so I'll assume a middleweight with around 100 HP, so what 3% power loss?

What is 3% of nothing (33 bhp ), about 1 HP. Can you afford to ride around with only 32 bhp instead of 33 bhp!

[backinthesaddleagain]

I would think that a dirty chain can cost you more power loss as well as faster wear, than a clean and loose chain.

[headshrink]

I tightened my chain and learned that is just easier once you have the "feel" for the proper slack. Just going by measurements alone for this particular job tends to leave me frustrated and re-loosening the chain. I think I am getting a feel for it though, and it is better now, albeit a lot more slack than kawi calls for (me thinks they lie).

Anyways, while I was in the process I made this DIY gauge for measuring chain slack quickly, without marking paper every time. I'll use the gauge for reference, but not necessarily as the standard for the "proper" tension.

[g21-30]

You say millimeters. I say inches. Whatever floats your boat!

.8" = 20.32 mm
1.2" = 30.48 mm
Baseline = 0 mm

[headshrink]

Originally Posted by g21-30

You say millimeters. I say inches. Whatever floats your boat!

.8" = 20.32 mm
1.2" = 30.48 mm
Baseline = 0 mm

Not my math, I pulled those numbers out of the manual.

[Momaru]

Hmmm, glad I checked here before buttoning back up. I've set the chain slack as 20-30mm total travel, pushed up to pushed down (measured at the bottom of the links) but haven't ridden since the last adjust. Instead it's 'neutral position' to max up OR max down, ya?

Edit: Nevermind, I seem to be doing it right, according to Banzai here:
http://www.ninjette.org/forums/showp...1&postcount=21

[Sailariel]

Quick Question: When you adjust the chain, do you adjust with the rear wheel up in a stand, or the wheel on the ground? When you sit on the bike allowing your weight to depress the rear suspension, the chain tightens considerably.

[2WheelGuy]

Originally Posted by Sailariel

When you sit on the bike allowing your weight to depress the rear suspension, the chain tightens considerably.

That is why the chain should be a little loose when you adjust it..

[RaceBikeRentals]

Here's a little trick:

As many have found, the chain will tighten when you tighten the axle nut. To keep this from happening, insert a shop rag (folded into 1/4 or 1/8) between the chain and the lower portion of the sprocket. Rotate the rear tire forward to pinch the rag between the chain and sprocket. While holding tension on the tire, tighten your axle nut. This will keep the chain from tightening. I use this trick every time I do a chain adjustment.

[kkim]

Originally Posted by RaceBikeRentals

Here's a little trick:

As many have found, the chain will tighten when you tighten the axle nut. To keep this from happening, insert a shop rag (folded into 1/4 or 1/8) between the chain and the lower portion of the sprocket. Rotate the rear tire forward to pinch the rag between the chain and sprocket. While holding tension on the tire, tighten your axle nut. This will keep the chain from tightening. I use this trick every time I do a chain adjustment.

okay... but why does this work?

[Momaru]

Originally Posted by Sailariel

Quick Question: When you adjust the chain, do you adjust with the rear wheel up in a stand, or the wheel on the ground? When you sit on the bike allowing your weight to depress the rear suspension, the chain tightens considerably.

I've been adjusting to FSM spec (20-30mm) from a rear spool stand. Any idea how much it tightens? I realize that'll likely depend somewhat on rider (I'm ~160lbs w/ gear) but seems a bit trickier to do with the tire on the ground.

[ninja250]

I tighten it on the stand and then set it on the ground and check at the tightest spot.

I figure if I try and set it for 24mm's of slack each time I'll account for a couple mm's of offset on each side.

[Sailariel]

Paul, I`m a pudgeball at 200 without gear. Will work on getting the chain right. Just replaced the front sprocket with a 15T. Will have to do some tweaking. We still have snow, so I can take my time and get it right. You know, if this forum gets any better, Kawa will have a lot of shop manuals they will not be able to sell. I really have it made. I have a heated garage with shop and a laptop--a very old one with a 400CPU sitting on the tool bench. I dail in the DIY for what I am doing and go to work--even a cave man can do it. These DIYs are superb.

[jonthechron]

Originally Posted by headshrink

I honestly haven't meassured..... it is pretty floppy though. If it won't hurt anything, I won't worry about it.

That's what she said.

[Momaru]

Originally Posted by Sailariel

We still have snow, so I can take my time and get it right. You know, if this forum gets any better, Kawa will have a lot of shop manuals they will not be able to sell. I really have it made. I have a heated garage with shop and a laptop--a very old one with a 400CPU sitting on the tool bench. I dail in the DIY for what I am doing and go to work--even a cave man can do it. These DIYs are superb.

Very much agreed on the forum, I've been opening the FSM just to check torques mostly. We've some 12" of snow down and another few coming so I've got time too. Definitely loving the warm workspace with a computer nearby as well: I've got the bike in my apartment (on a cardboard sheet and an old shower curtain to protect from drips) for the time being and just finished a CCT replacement as well as checking valve shims and a bunch of other minor things.

KC, thanks for the clearance spec. I've got it set at ~25mm total travel slack (firm push down to firm push up) on the rear stand, so guess it's easy enough to drop down and see what it does. Rear tire's only doing about 1 full rotation on a push with my foot (after pulling rear tire, greasing all the bearings and cleaning the bejesus out of the chain with a kerosene soak and relube) which is why I started wondering if I have it too tight.

[RaceBikeRentals]

Originally Posted by kkim

okay... but why does this work?

Dunno... just does

[kkim]

Originally Posted by RaceBikeRentals

Dunno... just does

ah... okay. FM, huh?

[RaceBikeRentals]

Hehe.... haven't heard that one in like, 20 years, dude.

[kkim]

[almost40]

I run a fuzz more than spec. When you compress the rear suspension it tightens up the chain a bit. A overly tight chain hinders the rear suspensions ability to work properly. Or so Ive read.

[2WheelGuy]

Originally Posted by almost40

I run a fuzz more than spec. When you compress the rear suspension it tightens up the chain a bit. A overly tight chain hinders the rear suspensions ability to work properly. Or so Ive read.

Very true, I always err on the loose side when I adjust my chain. As the rear wheel moves up through its arc it moves away from the transmission and needs a little slack in the chain for that movement. I do tech at track days and I can't tell you how many bikes come through with chains as tight as piano wire. Very unsafe. I've also seen an output shaft bearing on a transmission let go from a tight chain.