Adjustment of the chain is made with rider weight on the machine. A tight chain will load the rear shock, as a result the shock cannot rebound properly. This causes premature chain stretch, hooked sprockets and puts wheel/gearbox bearings under stress. Hope this helps.

 

First off let me say that I'm paranoid about:

1. Adjusting the chain too tight, thus causing stress/damage to the seal at the output shaft.
2. Leaving the the chain too loose, thus letting it make contact with the lower brace of the swingarm, causing damage to it.

Per the manual, the proper slack should be 30-40mm. That comes out to 1-3/16 to 1-9/16". Even at the latter, it doesn't seem loose enough. On my 2001 R1 (I know, different bike-different specs) I always adjusted the chain so that I could push it up to just touch the last inch or so of the underside of the chain guide.

When I adjust the chain on my 2008 to do the same, it seems that it comes awfully close to the lower brace of the swingarm if I push it down with some degree of pressure.

When I get the chain set to where I think it should be, it always seems to loosen up a tad while torquing down the axle nut. I tried stuffing a rag in between the chain and the sprocket, while turning the rear wheel to force the axle forward while tightening the nut (per the hint on the On The Throttle How To: http://www.onthethrottle.com/howto/project-gsx-r750-520-chain-kit/ )

What is the relationship between the chain and the rea suspension? How much does the chain tighten as the rear suspension compresses? While on the throttle, I'm assuming that the 'top' section of the chain is nice and tight since it's being 'pulled' towards the engine, but what about the 'bottom' section? Is it flapping in the breeze?

FWIW, I've got about 9,400 miles on her and haven't had any issues with the chain hitting the lower brace of the swingarm, but I just don't want to take a chance.

Any help you fellas can offer will be appreciated.

Thanks much,
MG

Pretty much covered by R1liam, and your 1st concern. Since the rear axle is traveling on an arc, with the pivot point being behind the front sprocket the chain typically gets tighter as you compress the rear end. I've seen them so tight that they limited the suspension travel of the shock.

I typically adjust the chain to a point where it is just about capable of hitting the chainguide on the swingarm, and then check with rider on to ensure proper clearance is available.

Usually when I tighten everything up, the chain tightens slightly, but in either case, you are best of checking after you've tightened, even at the expense of doing a few steps over.

As a general rule, I believe you are better off a little loose, than a little tight.

Hope this helps.

 

i just done my 07. i made it so on the bottom row of chain if you push up it just touches the chain guide above it. i did measure it. im not an expert, i did read the manual, there specs seem to be pulling the chain down and pushing up. i dunno. iv just been for a ride and seems fine.
its probley about the same as danq was saying. when doing mine i did a string wheel alignment. it was quite interesting. maybe something else you might want to look into.

 

String or straight edge is good. I don't ever trust manufacturers alignment marks cos they can be way out. I got aftermarket ones, checked alignment on these with my trusty straight edge and everything lined up correctly. Now "I know" I can trust the markings at any time.

 

I share the same frustration. Is there a measurement for checking chain slack while off the bike? I've read that allowing 1.4 inches of chain slack is at spec. Any thoughts? I believe my chain is too lose and "smacks" more than it should......

 

I've used this for years...........

http://www.muzzys.com/catalog/tools.html

Muzzy Precision wheel alignment tool

 

so how are you going to be able to adjust the chain...with the riders weight when your the only one in the garage?