I've got regular Profile cranks, a new Gack hefty sprocket 3/16, new ACS fat claws freewheel 3/16, new KMC 3/16 chain. The chainwheel is smooth on both sides(does not have a recessed area where it meets the crank arm). It did not come with a washer either. I used my old washer on the inside to hold the sprocket snug on the spindle. When I test rode it I noticed a considerable tight spot. I took it back apart and centered everything again and it still has a sizeable tight spot. Everything on the drivetrain is new and the wheel is centered, so if anyone has any tips I would be most appreciative.
Whiskey

[ November 19, 2003, 04:21 PM: Message edited by: Whiskey ]

my guess would be that the freewheel has an issue with runout (concentricity). take your chain off and spin the rear wheel and hold the freewheel so it does not spin. if you can visibly see the freewheel rise and fall, this is likely your problem. you may also observe lateral movement which will add to the tight spot problem. chances are that the chainring is machined well enough that it does not contribute to your problem. i am also assuming your old washer is not damaged, that it is machined well and has good concentricity. i have seen this problem many times before, it is usually the freewheel. this is also one reason why a freehub setup is superior to a freewheel.

Thanks, I'll check the freewheel tonight.
Whiskey

I have three ACS claws and only one spins true, the other two gave me the same problem you described. They were all brand new when I installed and tested them.

After rechecking everything, the chainwheel washer was the problem (had some play in it). A trip to LBS and $1.09 later the problem was solved.
Whiskey

That's the problem I'm having on my cruiser. Tight-loose-tight-loose. Annoying. I got a new chainwheel (39t odyssey utility), new freewheel (17t acs) and new 1/8 in chain (a crappy one from my non-bmx lbs),and it's still doing it. There are two spacer washers on the drive side, and they're kind of sticky and hard to get on and off of the spindle. Can I run the chainwheel without them? Any other ideas?

[ November 24, 2003, 04:10 PM: Message edited by: big_ugly_bike ]

no, I just find out that hub's body side on threadline got little bend that is why freewheel make a little whoop, like when you snap out of gate so harder and it gotta be that hub's body threadline side went a tiny bend bit! so that make tight-loose-tight-loose. okay, ookay, let take off a chain and let spin wheel really middle slow and look at on frewheel and see it little whooper like side to side, not up and down, see it? so don't think that a freewheel is fault, no! it is on hub's body side of threadline that cause of it is make un-level a little-tiny bit! thats why it make tight-loose-tight-loose chain going.

so the crank and chainwheel and freewheel are nothing wrong and the hub's body from threadline side is fault that make little tiny whoop.

Robert

[ November 24, 2003, 10:32 PM: Message edited by: VRMNC ]

oh and everyone have the same problem and I have too. so do not worry about it beacuse all the hub (any brand name) are not prefect round, eh? except the cassttle hub are little prefect (w/o freewheel and it come with a cog). so it is not bad when you see it come tight-loose-tight-loose and just ingore it. hub is still little strong anyway. so all the factory who make the hub that not prefect threadline round, I guess. see?

Robert