chain shortening techniques...

kmx125r

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#1
Hi All,

My KDX250SR that I bought about 2 months ago is my first bike with a 520 chain. I just bought a new Regina O-ring chain but it has 120 links and I only need 112 (geared 14/48)...

I do not possess a chain breaker and it appears one is not available in Manila, how else can I shorten the chain?

On my KMX125 (428 ordinary chain) I just grind down the pin and punch it out... no problem... can I / should I do that with my new Regina??? Please advise...

Salamat (thank you),
 
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#2
Our chain breaker broke and my dad used a grinder,a nail, and a hammer to break my renthal chain and it took like 45 minutes of constant hammering to break it! You can do it if you have the time. By the way, make sure its the correct length because after 45 minutes of constant pounding we found out it was too short :eek:
 

KDX1

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#3
Breaking chain

I just went throught this with my new chain. My local bike shop sold me a piece of junk chain breaker and it ended up being broken, not the chain. So I got out my air grinder and put a grindingstone on it and ground down the rivit tilll it was flat, then took a punch and hammer to it. After about 5-7 minutes of pounding, the rivit was out and the chain was the correct size.Remember that once the chain is shortened, it can't be lengthened. The proper way to measure is with the chain on the bike and the adjuster alll the way in.
I hope this helps.



00 KDX 200
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GNCC
:cool:
 
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#4
To ease things cut through the link just to the side of the pin you are grinding -this way you only have to push the pin thru one plate if you see what I mean. The pin will remain attached to the back piece of link but the cut allows you slide it out intact.

Measure twice cut once. Remember the old chain might have been really stretched if you are using that as a guide.
 

kmx125r

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#5
chain is shortened...

Thanks for the input...

I ground down the pin I wanted to "push out" and it only took 30 seconds to knock the pin through... no damage... YEAH!

I counted the links and it is the "standard" 112 for a KDX250 (geared 14/48)but it still seems long. It seems like it should be 111 links but of course that can't be. When I put the uncut chain on the bike for proper measuring... I could not get it on the sprockets in the 110 links length - even with the adjusters at minimum. With 112 links the cam adjuster is already at "5" and the chain still looks loose... how do I set the proper slack in the chain? Any thoughts?

David, thanks for the "cut through the plate tip" I like that one... next time.

Thanks...
 
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#6
Yeah cutting through the link saves a lot of hassle but you do have to be a little clever holding the chain when you punch it.

Sometimes a gearing vs chain length combo puts you in a posi where the chain adjusters are in the half worn position. It is irrelevant. By the time your chain stretches that far it is probably toast anyway. You can always remove a link later but please nobody reading this think I’m endorsing removing a link of a very stretched chain, that is stupid. Do the usual pull the chain off the sprockets & if you see ½ the teeth then it is too stretched to carry on with.

Make sure any tensioners you may have on the bike are pulled out of the way when fitting up the chain for length. After you adjust it sit on the bike & check the chain doesn’t get too tight, loosen as required.
 

dirt bike dave

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#7
kmx125sr - many of the new, high quality chains will not stretch very much at all, and running it too loose is always better than too tight! With 14/48 gearing and a 112 link mine was always around #5 on the adjusters.

If you don't ride on the street and want to gear for the trail, the 110 links will fit with a 13 tooth countershaft (adjusters all the way in) but not with a 14.