Shredded, AGIAN!. Aftermarket hub suggestions?

In what I'll call the old-days, the "three-finger rule" was using three fingers, stacked, to measure the gap between swing-arm and chain.

If your three fingers measure 1.6 to 1.8 inches in width, you might be able to get away with it.

However, such methods corrupt the system. So use a ruler or caliper

DaveJ

I made a chain tension go / no go gauge from a block of plastic. Make it 1.8 inch square. Then cut a 0.2 inch notch out of one corner. With the bike on the stand slide this block under the chain at the last bolt in the chain slider, with the chain in the cutout. The chain should easily fit on the 1.6 inch portion but you should not be able to lift the chain onto the 1.8 inch surface. Do it at several points on the chain.

I have checked a lot of peoples chains, about half are too tight. I bet this is why so many people blow up their hubs.

The parts didn't come today as I was expecting, but I was able to take a few pics of the mess. Here they are...

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OUCH! Hurts my wallet more than anything though!

Later,

tt

[ July 30, 2002: Message edited by: teamtoxic ]

Teamtoxic,

This is a very familiar site.

Note how the sprocket is bowed. This is caused from it being pulled out from the hub towards the front sprocket.

In other words, if the hub gave away, your sprocket would be flat.

Great photos.

DaveJ

This failure is from too tight a chain. Look at how just two bolts on the hub failed as the sprocket folded over. If the hub had failed because of too much torque you would have probably seen all six failing in rotation. If there was too much impact radially (like bottoming hard) I would expect radial cracks in the hub at the spokes or axle.

Don't take this the wrong way, but realize that most of us have not had this failure and you have had it twice. I bet after you run the chain looser you wont see this again.

[ July 31, 2002: Message edited by: mikeolichney ]

A guy that I ride with has a CR250, he had a shop do the chain and sprockets. He rode it half a lap and then got tossed over the bars when his rear sprocket folded over sideways. He was lucky, it was on a woop prior to a long table. If that would have happend on the face of the table, and it would have for sure, he would have definitley gone to the hospital.

Originally posted by DaveJ:

In what I'll call the old-days, the "three-finger rule" was using three fingers, stacked, to measure the gap between swing-arm and chain.

If your three fingers measure 1.6 to 1.8 inches in width, you might be able to get away with it.

However, such methods corrupt the system. So use a ruler or caliper

DaveJ

I'm old, so I use this method. I'm also somewhat anal and measured my finger width first. Put the bike on a stand and measure from the screw hole closest to the rear axle on the the plastic thing-a-ma-jig that protects the swingarm.

It's always best to error on the loose side.

Bill

Maybe I am missing something here....I have been using the old " three finger rule" on each 400-426 I have owned, that would be 5 of them. I have never had issues with too tight a chain, chain sliders getting eaten up, or hubs/sprockets breaking. Maybe this method does work.......I also torque the sprocket bolts/nuts at the required torque value...no problems with any of the above failures. :)

On the lose side is fine.

But the recommendation of using one's anatomy may put a kid with skinny fingers in the hospital.

Let's move on and use something a little more formal.

Thanks

DaveJ

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