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Chain sag spec - standard vs low

1K views 4 replies 3 participants last post by  rx35285 
#1 ·
For those of you with standard suspension - what does the chain sag spec label on your bikes indicate?

Here's the chain sag spec on my bike, a low model.

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The reasons for asking are 1) the manual seems to indicate more sag than indicated on the swing arm, 2) I'm curious as to why the specs given in the manual are different for standard vs low, and most important 3) I'm "working" on the bike to avoid helping my wife wash windows.

Thanks in advance -
Dave
 
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#2 ·
The maximum distance the chain travels is when there is a straight line between the centers of the front sprocket, the swingarm pivot and the rear sprocket. The low suspension bike is closer to this point at rest.
 
#3 ·
The decal on my 2009 F650GS swing arm says 30-40 mm for the chain slack. I usually keep my slack at 30 mm as there seems to be less slop in the drive line with the tighter slack. However, 20 mm seems kind of tight to me. As far as I know there is no difference between the standard height 650 and 700 swing arm lengths and suspension strokes, so you wouldn't think there would be any difference in the required chain slack. :confused:
 
#4 ·
As far as I know there is no difference between the standard height 650 and 700 swing arm lengths and suspension strokes, so you wouldn't think there would be any difference in the required chain slack. :confused:
The swing arms are the same. The strokes must be different by definition - i.e. the lower shock has a shorter stroke. See my post #2 for why the spec is different.
 
#5 ·
Thanks for checking Richard. Yeah, as bmwroadster pointed out, the 20-30 mm spec would logically be for the lowered bikes since there is less swing arm travel. The formatting of the table in my OM was the first reason for posting the question. I just wanted to make sure my bike isn't mislabeled.

Thanks to both of you!
 
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