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Chain on Frame...


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ok, so i didnt listen to everyone, and kept adjusting my chain according to the dashes on the stock axel blocks on my 06. and sure enough, it did the damage that everyone said it would do.?:applause: so now what? i just ordered a new orn6 chain, and some tusk axel blocks, to avoid any further damage, but what should i do withthe damage already done? should i just forget about it, or cover it with a plate or something? IMG_1580.jpg

IMG_1578.jpg

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And after you did that, did you take a subsequent measurement by the method shown in the manual? What was that measurement?

I found that the manual was somewhat close. Instead of going off the bolt, I go right at the end of the rub plate...

If you run it on the tight end of the spec on what the manual states, you should be fine.

However, I think this value changes as you change sprocket sizes (Taller sprocket, higher value). It only took me about 30 minutes to figure out the tension limit, and about 10 minutes to make a gauge block.

Instead of removing the whole linkage, jsut remove the lower shock mount. There is plenty of clearance to such the tire all the way up.

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I found that the manual was somewhat close. Instead of going off the bolt, I go right at the end of the rub plate...

If you run it on the tight end of the spec on what the manual states, you should be fine.

And that's because the figure in the manual is the result of Yamaha doing exactly what you did; setting up the right chain tension with the swing arm aligned as in the article, then measuring the resulting slack with the bike on the stand. That measurement is then published, and if both the spec and the prescribed method is complied with, there won't be a problem.

The article is fundamentally accurate, and describes the true core method of arriving at a correct chain tension setting, and also the principals behind it, and it's useful to understand these things. But it falls well short of establishing that there is anything wrong with doing it "by the book", at least in the case of a YZ, and that was one of the authors contentions, expressly stated or not.

Your point concerning larger sprockets is well taken, however, and bears some consideration, and perhaps a double-check with the procedure described in the article. That's because the factory prescribed method of checking the chain tension doesn't measure the actual slack in the chain. It can't because the swing arm gets in the way of that. Instead, it measures how far above the swing arm the chain can be raised. If you went from a 49 to a 53, and one tooth larger at the front, the cumulative effect on the height of the chain above the swing arm at the mid point would be about 1/4" (.250). Not much, but it would mean setting the chain at the loose end of the spec.

The owners of '06 and later YZF's run into trouble because the chain on these is set looser than either the earlier models, or most other bikes, which is because the lower roller doesn't come into as heavy contact with the chain as in the early ones. This leads to the chain having an overloose appearance, and then being set by sight, rather than being measured, and ending up too tight in the bargain. Just be sure to measure, and don't crowd the tight side of the spec., you'll be fine.

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so let me clarify one last thing... what is actually offset that causes the misalignment of the axel? my blocks are identical in size and "dashes"...
What about the marks on the swingarm?

That's the right answer, usually. "Production Variances". The blocks are almost never at fault.

The absolute most accurate method is the one I went over involving the use of a straight edge on the sprockets.

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I just purchased 07 250F. Forgot how Yamaha seems to fail to allow adequate space for chain slop. Heading out to garage now.. Son only rode this 1 weekend so far,, Thanks for heads up reminder..

Was this damage from a Cheap worn out stock chain that got sloppy side to side? Or will proper tension and alignment allow use of stock chain? I read some where in a test that the stock chain should be replaced ASAP..

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my chain slack had been set perfectly, and have not had any wear on the sprockets yet, the only damage i have is on the frame, from misaligning the rear axel blocks. here is what i noticed with the stock DID chain...

at first the thing stretched like hell, and i was adjusting it every ride, but after about 6 months, it slowed its stretching dramaticaly, and now i only have to adjust it every 10-15 hours or so...

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  • 2 weeks later...
That's the right answer, usually. "Production Variances". The blocks are almost never at fault.

The absolute most accurate method is the one I went over involving the use of a straight edge on the sprockets.

Sorry to bring up a old thread...

But I went through my bike (along with the jetting kit, WOOP!) and measured my axle before removing the chain to clean it. I found it was off (by at least a 1/16".)

I removed the axle bolt and found that on the right hand side, the block fits snug on the axle. I then looked at the left side where the bolt is, and found that there is a 1/16" gap towards the rear of the axle. This is where the gap is!

I measured the skingarm marks and they were spot on. It seems that a hole that is enlarged on one side could throw off your alignment. I looked at my frame and it was very lightly rubbing it!

Luckily there's only one ride on the chain. The previous owner put on a new one since the DID was worn out pretty bad (probably because he did not measure it)

New blocks may cure it for me, but I find it easier and more accurate to just measure.

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