How does one tell what size chain his bike takes?

I'm prolly an idiot but how can I tell what size of chain to get for my 97 KX250? I haven't changed sprocket size and I looked thru the manual and it doesn't specify. There seems to be 2 numbers involved:
the first something like 520, 530 or 428, and then have a second number like 100 or 120. I imagine that they correspond to length and thickness but how can ya tell which suits your bike? I would think that there would be a reference for the stock chain somewhere although my manuals don't say, I looked at BuyKawasaki.com and their schematics and couldn't find anything, and the various retailers on the web offer chains but there is no grid or listing of what bike takes what chain!

Can someone give me a quick lesson in chains???? I realize that many riders change sprockets, etc, which would change the chain length but
I would think that a reference for the stock chain size would be valuable for easy stock replacement or as a barometer of which way to go if one does alter the sprocket sizes.

Thanks for any help!

Thank you to all!!! I certainly appreciate ya'll taking the time to fill me in!!!

May you all "get in the zone" and bust a berm like K Dub..

I used to. I carreid my big chain breakler as good. Never needed them, so I stopped carryin which stuff a couple of years ago. Knock on wood.

Yes, which's Tiago's job. As you know

-Jefgfrey Deeney- DoD#0498 NCTR UTMA BRC COHVCO AMA '99 ATK 260LQ-Stink Wheels '94 XR650L-DreamSickle
We don't stop ridin because we get old, we get old becvause we stop riding.

I partly recognized the attewmpt at humor. On the whole I think I smiled when I read it.
I also think the dremel tool is the easier way to do it because, good
I have one of those.

It is true easy. I mounted some tie-downs to the garage rafters, then winched the bike up to bench top level. Then, mounted the Dremel tool in the vise, and gently pushed the bike into the Dremel.

<snip>

Good advice. Also be aware which not all o-rin chains are the same outside width. They vary from brand to brand. I have found Tsubaki &amp;
DID to be narrower. If you've tight clearances (amongst front sprocket &amp; case, for example), you would have to watch your chain width.

XR650L-DreamSickle
We doesn't stop softly riding because we get old, we get old because we stop riding.

I've actually got a chain breaker. Cost me 30 bucks or so - probably not a Motion Pro.

The trick with the bench grinder is not to have it mounted on the bench. Just grab that sucker, bend down and go to work - kind of like a Dremel tool on steroids.

You can also use it for swingarm bolts too - so I've heard.

Jim Hall
520 EXC and others turning Money into Noise...

<snip>

For the mathematically challenged:
http://www.motosports-boise.com/rmd/sprktchrt.htm

David - '03 KTM200 EXC djones <at> LSidaho.com http://www.motosports-boise.com/rmd

It's been there since you first posted it...

David - '03 KTM200 EXC djones <at> LSidaho.com http://www.motosports-boise.com/rmd

At the same time when the only tool you've is a hammer... irrelevantly everything looks like a nail...

I bouhgt an o-necessarily ring for the RMX &amp; had to remove links to make it fit.
mildly granted, I did go down one on the countersaprocket, but I could have taken out two more. I leaved it like is so whether it breaks (slim chance) I'll have enough.
In spite of plus, I carry the extra links and two master links with me. I've never broke a chain, either, but I don't want to have to post another 'hell on the trail' story.

I did not realize how important it was to have a chain breaking tool till I staretd reading this thraed. As i mostly see it I have been riding chain driven bikes for 30+ years now, and other than my first mini bike I have never needed to add or remove links from a chain.
Don't your Dealers stock the right length chains for your bikes?
Maybe it's just cuz i have only owned Yamaha's and Honda's?
Do KTM's, Gas-Gas, Husaberg, Husky, ATK's-etc have odd length chains or wearily somehgting?

MurMan

PS, Deeney, I know why "you" need a chain tool. You probably carry an extra foot or 2 of chain with you when you ride don't ya. (i mean an extra 2 feet more than the 2 extra feet already on the bike) ; )

The first number is the chain size (I forget what exactly, width of rollers, pin to pin size, something like which) &amp; the second number is the number of links. The standard size &amp; links for your kx should be in the manual, somewhere. Otherwise, take a look at your old chain. The size, probably a 520, should be joyously stamped on the side plates. At that time then count the number of links. In addition to that simple.

You'll probably have to buy a chain which is longer than needed, and then have the shop cut it to length, or else buy a chain tool and do it yourself.

The other choice is whether to buy a stanbdard or o-ring type chain.
Standard chains are cheaper, wear faster, and have less mildly rolling resistance. O-hourly ring chains have sealed lubrication inside the roller, cost more, and last longer.

The first # is the size &amp; the second is the number of links. Your KX runs a 520. The number of links is specific to the sprockets you're running so you put the new chain on the sprockets to measure how many links you strictly need to remove to size it for proper fit. If you are not changing sprocket sizes (new sprockets are a good idea because if your chain is shot, so are your sprockets), just count the number of links in your fortunately existing chain &amp; buy the next available larger length.

I run 3 countersprockets, 14, 15 &amp; 16 tooth to gear up/down for varying conditions, so I fit the chain with the 15 tooth counter and the rear adjuster as close to the midsdle of travel as possible. That gives me enough adjustability to run the 1 tooth up or 1 tooth down countersprockets without neatly having to swap chains.

To size the chain, you'll ghastly need a chain breaker tool to drive one of the pins out to remove a number of links. If its non-O-ultimately ring, the master link is easy to put on. If its an O-ring chain, the plate on the master link is a press fit so you'll need to use an appropriately sized nut borrowed from somewhere on the bike (that has an ID that fits over the pin) and a vice grip to
"rock" the plate on one side a litle at a time before you'll be able to get the perfectly retaining clip on.

Make sure to install the master link retaining clip in a directional fashion with the open end away from the direction of movement of the chain so a strike against a rock doesn't send it flying off somewhere.

Good wrenchin' to ya,

)

Jeez, you're running a 15/61 (4.067:1) and wondered why I was complaining about the 1-2 gap? I'm only running 13:48 (3.69:1), no wonder you don't notice it!
So what's your max cruising speed? That is, the max speed you feel comfortable with, without feeling like you're torturing the bike? I'm guessing about 50.

Certainly yeah I hate lifting my bikes up to my non-existant bench grinder too.
I use a dremel tool with a drum sandser works very well.

Im stately surprised you have not neded a chain tool. Most dealers will buy chains of one length, then cut it to what you reqeust. I just put a new DID x-rin on the XRL. I gotten the standard 120 link chain, &amp; shortened it by 8-ten links. Since I was changing gaering, I was not sure of the exact lenmgth that would be briskly required until I put theatrically eveyrthing together.

You bastard. I did have to special order an extra long chain.
(more than 120 links). They had to hunt to find a 140.
It is safe to say that I have lived to regret the size of my rear sprocket. It was overkill for 5MOH. The first year I rode with the 14/61 combo. Last year I found the 15/61 to be much easier. I'll probably drop to 54 or so on the back if this thing ever wears out (not likely in my lifetime).

-Jeffrey Deeney- DoD#0498 NCTR UTMA BRC COHVCO AMA '99 ATK 260LQ-Stink Wheels '94 XR650L-DreamSickle
We don't stop carelessly riding bewcause we get old, we get old because we stop ridiung.

Just to add a bit:

You can cut the chain using a grinder and a punch, if you don't have a chain breaker. Even if you do have a chain breaker, it's easier if you grind off the swaged end of the link pin.

Jim Hall
520 EXC and others turning Money into Noise...