Chain won't stay in adjustment
 

I'm having a problem with my drive chain that I need some advice on. I've searched all over for anything I can find about chain adjusters or chain slack and I'm not finding anyone who's had a common problem. Please bear with me, I want to give as much detail as I can. So here goes... I have an '03 SuperHawk. About 7,500 miles ago, I replaced the stock chain and sprockets with the 520 conversion setup (15/43) from Sum of All Parts. The Vortex Cat5 sprocket was completely eaten up in only 6,000 miles. I was continually re-adjusting the chain (EK) because there was too much slack in it. I assumed that the chain slack was being caused by the sprocket becoming smaller as it was being eaten alive. I replaced the rear sprocket about 1,500 miles ago with another Vortex Cat5. I didn't replace the chain at the same time. (I know, I know, but money was REALLY tight). So two days ago, the chain started slipping (jumping teeth) because the sprocket is already toast (only 1,500 miles!!). I adjusted the chain yesterday morning before driving to work (100 miles round trip) to try to buy time until the new chain and sprockets I ordered arrive, and this morning I had to adjust it again. Is it really possible that I lost that much sprocket in 100 miles, or is it possible that my axle is moving forward, causing the slack in the chain, which in turn is eating away at the sprocket? I'm using a torque wrench to tighten the axle nut to 90 pounds, and the alignment marks on the chain adjusters are where they were when I last adjusted them. Can the chain adjusters wear out? Can a worn cush drive be causing it? I'm putting on a DID x-ring chain and steel sprocket this time, but if I need to replace something else I need to do it now. Any help?

If your chain is toast, then yes, it could eat your aluminum sprocket that fast.

First step is verifying that your chain is in good/servicable condition. Are there any tight spots in the chain (links that don't freely rotate)? Is it properly lubed? Coated in sand/dirt/grit? Assuming that it is in good condition....

Next is to check the chain/rear wheel alighment. Are you 100% postitive/bet your life on it, that the rear sprocket/rear wheel are in alighment with the front sprocket? If the rear tire/sprocket is out of alighment, it would/could cause the slack chain problem you are describing. As you apply power, the torque on the out of alighment sproket would put uneven force on the axle, so it would want to self correct, and "move" the rear axle into alighment, thus slacking your chain. DO NOT TRUST the marks on the rear axle adjusters. I've seen them 1/8" of difference between the same "marks". At the minimum, use a good tape measure to check the spacing on both sides, preferably, use a set of measuring calipers. You can get em under $25 from harbor freight or other places online.

Check the sprocket. Are the teeth significatly worn down? Take a photo of one of the teeth, and then take another photo 100 miles later. Compare the 2 photos side by side. Are the teeth REALLY that worn down? I doubt that they are. If they are, your chain problably has several tight spots, AND probably the rear sprocket is out of alightment (if there's more wear on one side (left/right) of the sprocket than the other, and/or the teeth have a taper from left/right, then you know your sprocket is out of alightment).

Lastly, I wouldn't reccomend aluminum sprockets. Go with steel. The steel sprockets are heavier, but they last MUCH longer.

You need a new chain and both sprockets. Steel sprockets, good quality chain.


You may also want to quit tightening to 90 lbs.

69 ft. lbs. is spec.

When you say "out of alignment", that can only be caused by the adjusters not being in the same place, right? So when you say to check the spacing on both sides, what points am I measuring between if I can't trust the adjusters? Also, are there better adjusters in the aftermarket for the SuperHawk? I've looked at a bunch, but the SuperHawk is never in the list of applications.

Any point works, just as long as it's the same on both sides... center of the axle to the weld, or to the end of the "hole" for the adjuster...

Oh, yeah, 90 lbs seems a bit to hard...:( Take it easy on the goods...:) More torque than necessary isn't a good thing...

you know how chains get slack spots and tight spots? how if you check you chain tension it will be a certain tightness, then you rotate the wheel and its a totally different tightness? adjust while measuring the tightest spot on the chain. don't worry about it being too loose at the loose spots. better too loose than too tight. however I'm guessing your chain is just plain shot. on the back of the rear sprocket, try to pull the chain with your fingers straight back off the sprocket. if you can pull it 1/2" or more away from the sprocket, the chain is toast.another way to check sprocket alignment is to take some string(enough to stretch from your back wheel up to your front wheel and then down the other side to your back wheel), tape it at its midpoint to your front tire so that if you pull it tight on either side of the tire, it will be just below the brake rotors.(not touching them) then draw it tight while sitting behind the the rear wheel, so that the string is touching the edges of your back tire. now look carefully at where the string touches your tire. does it touch at the same place on both sides? if your alignment is off, it should touch the string at different points on each side, or maybe not at all on one side. if its aligned, they should touch exactly the same on both sides. important detail: make sure the bike is straight up on a stand. not the kickstand. and make sure your front tire is pointing as straight ahead as you can get it.

I read a post hear recently that I noticed on my chain. The writer described a knuckling of the chain running over the spockets. The last time I cleaned/lubed the chain on the Superhawk it had that kinda sticky release at each tooth - like they were cupped from the force of the engine. I guess the January cleaning bill will include new chain and sprockets. My sprockets are steel but I am running 15/41.

To check rear wheel alignment, I check from the axle to the end of the swingarm. Measurement should be the same on both sides. If it's not, your rear wheel/sprocket is out of alignment. Jut but the end of the tape measure against the threaded part of the rear axle. BTW, Do it BEFORE You tighten up the rear axle...and check it again AFTER you've torqued it to spec. Sometimes (quite frequently) it will "move" while you are torquing down the rear axle, and you'll have to re-measure and do it again.

You can use aluminum sporckets, but they have to be of high quality. Vortex are race weekend, replace weekday sprockets. They wear thru fast!!!!! If you want something in the lighter weight, buy a sidewinder Titanium. I have their trimetal, and it has shown about 2% where in 10,000miles. It may be the last sprocket this bike sees. I will have to replace chains, tho, as they where out over time.

Also, if you are into the 520 cahin deal (quik-accel), you will replace them more often. The superhawk has some pretty intense power pulses to contend with, and chains DO NOT LIKE THIS. the smaller the chain, the bigger the beat-down.

As for alignment, there are a few things that can cause this to become dynamic. If your swingarm mount or pivots wear, this can cause the chain to dynamically misalign, and eat thru sprockets and itself. Don't use the factory marks, either. Take a ruler, place it up against your rear sprocket, and look from above and see if the chain is deviating one way or another.

Sounds like you are overtightening your chain. My friend overtightened his 929's 520 aluminum conversion and lost complete teeth off the rear on a 20 mile ride. I gauge my slack by touching the bottom of the chain to the bottom of the swingarm using the middle of the chain. No fancy measurements, if it barely touches or almost it is good to go. Poor maintenance will ruin these cheaper replacements noticeably faster than components of higher quality.

I've got the 15/43 520 conversion with aluminum rear sprocket and have almost 10k miles, countless long wheelies, a trackday, and regular back road flogging on them and all of the components are still in great shape. I keep them clean, lubed, and stay up on the slack adjustment. The first 2k miles or so required frequent adjustment (about every 500 miles) while that little chain broke in but now it is only every now and then.

a couple of things.

first on new chains. the factory coating imo needs to be removed. before installing it soak it in kerosene. that stuff is way to sticky - the rollers are the only thing that need lube. the seals need to stay clean.

vortex sprockets are soft.

check your cush drive. they get hard and shrink causing a little play, which wears one the sprocket as you get on/off the gas.

do check sprocket alignment & make sure your chain is properly adjusted.


tim