Chain adj.

cajunkym · 01-02-2007, 08:06 PM

I find it hard to keep my chain adjusted properly. It's either to tight or too loose. The marks on the swing arm are almost useless on my Diamo.
I've finally broke out a square, and with 30-40 mins. was able to get the chain somewhat right but still tight with sitting back showing 3/5 of an inch play as recommended on sticker. I work with marine fabricaters and am toying with calling in some favors and have an aluminium duplication made. It seems that the axle holes are not true and there is somewhat of a top cock to the right when my wheel is tight.
Any imput?

Ferrit · 01-02-2007, 09:11 PM

I've owned a bike from about every continent that makes them and have never had the marks on the swingarm line up. The chain will be the tightest when the swingarm is level with the engine cases. On my KLR I would use a couple of cargo straps to pull the swingarm up and adjust the chain to have about 1/2 inch of play at the bottom center. The Chinese chains are not known to be of the highest quality and and a replacement may be in order if the original has stretched.

dlunt · 01-04-2007, 08:29 PM

This was one of my biggest beefs when I first got my bike

Mine manual says 20 - 30mm. If I do this it stretchs every ride.
Then somebody suggested leaving more play, that it really helps.
I tried it and agree.
If you leave 1.5 to 2 inches of play it will stay that way for a long time without stretching or needing further adjustment.

Thumper · 01-15-2023, 10:41 AM

Most bike have the swingarm positioned so that it gets tighter when you compress the rear suspension. It can be significant. Check it before and the while someone hefty sits on it. It can really change.

Mudflap · 01-15-2023, 12:05 PM

Check chain free play by lining up the centers of the countershaft, the swing arm pivot bolt, and the rear axle. That will be the tightest point. You want 10mm to 20 mm deflection at the midpoint between the sprockets.

TominMO · 01-15-2023, 12:16 PM

The only measurement you need is from the middle of the swingarm pivot bolt and the middle of the rear axle, on both sides. They should be identical.

Since the swingarm pivots, when it is in the "down" position, e.g. on a centerstand or MX stand, the rear axle will be physically closer to the pivot bolt, if a straight line was drawn between them. When you take it off the stand, it pivots to the rear and therefore further away from the pivot. Then when you sit on it, it does this even more so. So yes, you need to leave more slack when you make the adjustment. The recommended slack is for when you are sitting on the bike, off the stand. Through trial and error you can figure out how much slack to have when the bike is on the stand.

Megadan · 01-15-2023, 02:35 PM

Quote:

Originally Posted by dlunt

This was one of my biggest beefs when I first got my bike

Mine manual says 20 - 30mm. If I do this it stretchs every ride.
Then somebody suggested leaving more play, that it really helps.
I tried it and agree.
If you leave 1.5 to 2 inches of play it will stay that way for a long time without stretching or needing further adjustment.

Your issue, and the result of the other persons advice are due to a simple fact.

All chain adjustment numbers are given for the tightest point of the chain in the travel of the suspension and on the chain itself (no chain is the same from link to link).

On these bikes in particular, the chain tightens as the rear wheel travels up through the arc of travel, which is not too unusual for many bikes.

For a bike like the Hawk 250 and CSC TT250, the recommended 3/5ths of an inch is when center of the countershaft, swing arm pivot, and axle all line up as Mudflap states.

Once done, and you let the suspension droop back down you will find that the chain slack in this position is more than an inch. I measured my Hawk at about 1 1/4 inches of slack (give or take 1/8th), and that is what I have always set my chain slack to. On the absolute tightest side of things I will set it to about 1 inch.

01-02-2007, 08:06 PM	#1
cajunkym Join Date: Dec 2006 Posts: 40	Chain adj. I find it hard to keep my chain adjusted properly. It's either to tight or too loose. The marks on the swing arm are almost useless on my Diamo. I've finally broke out a square, and with 30-40 mins. was able to get the chain somewhat right but still tight with sitting back showing 3/5 of an inch play as recommended on sticker. I work with marine fabricaters and am toying with calling in some favors and have an aluminium duplication made. It seems that the axle holes are not true and there is somewhat of a top cock to the right when my wheel is tight. Any imput?
	0

01-04-2007, 08:29 PM	#3
dlunt Join Date: May 2006 Location: Camby, Indiana Posts: 494	This was one of my biggest beefs when I first got my bike Mine manual says 20 - 30mm. If I do this it stretchs every ride. Then somebody suggested leaving more play, that it really helps. I tried it and agree. If you leave 1.5 to 2 inches of play it will stay that way for a long time without stretching or needing further adjustment. __________________ 2006 Flywing(Jianshe)100 2002 Suzuki DR650
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01-15-2023, 12:16 PM	#6
TominMO Join Date: Sep 2021 Location: De Soto, MO Posts: 1,939	The only measurement you need is from the middle of the swingarm pivot bolt and the middle of the rear axle, on both sides. They should be identical. Since the swingarm pivots, when it is in the "down" position, e.g. on a centerstand or MX stand, the rear axle will be physically closer to the pivot bolt, if a straight line was drawn between them. When you take it off the stand, it pivots to the rear and therefore further away from the pivot. Then when you sit on it, it does this even more so. So yes, you need to leave more slack when you make the adjustment. The recommended slack is for when you are sitting on the bike, off the stand. Through trial and error you can figure out how much slack to have when the bike is on the stand. __________________ 2021 Lifan Xpect--sold 2022 Lifan KPX 1972 Honda CT90--The Carrot 1969 Honda CT90--The Tomahto Cheesy is the WDK (workplace drama king). Now retired. Nope, back in the saddle. Climate: The Movie https://www.youtube.com/watch?v=A24fWmNA6lM How our government really works https://www.youtube.com/watch?v=QjadCd0VRBw Question all authority.....think for yourself
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01-02-2007, 09:11 PM	#2
Ferrit Join Date: Nov 2006 Location: Lawrenceburg, KY Posts: 178	I've owned a bike from about every continent that makes them and have never had the marks on the swingarm line up. The chain will be the tightest when the swingarm is level with the engine cases. On my KLR I would use a couple of cargo straps to pull the swingarm up and adjust the chain to have about 1/2 inch of play at the bottom center. The Chinese chains are not known to be of the highest quality and and a replacement may be in order if the original has stretched.
	0

01-15-2023, 10:41 AM	#4
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,613	Most bike have the swingarm positioned so that it gets tighter when you compress the rear suspension. It can be significant. Check it before and the while someone hefty sits on it. It can really change.
	0

01-15-2023, 12:05 PM	#5
Mudflap Join Date: Sep 2014 Posts: 1,913	Check chain free play by lining up the centers of the countershaft, the swing arm pivot bolt, and the rear axle. That will be the tightest point. You want 10mm to 20 mm deflection at the midpoint between the sprockets.
	0