Ironman sprockets - damaged my engine??

[d2w]

I've had good success with this (relatively) low-cost chain alignment tool from MotionPro; it clamps onto the rear sprocket and you sight-down the rod while adjusting the alignment nuts until you're pointing true to the counter-shaft sprocket. I don't hold much faith in the alignment marks on the swingarm.

Dale

[GMP]

Tony,

I will try the red loctite, as I have a new sprocket set to install before I start riding again. What brand and part# do you use, as there are more than a few. I also have a green stud and bearing mount compound designed to fix excessive clearance fits.

Good advice on the chain adjustment. I too use a caliper for the initial adjustment, and then only turn the adjuster nuts in equal increments. marking a flat with a black sharpie makes this eaiser.

The comment from Dirt Tricks about leaky GasGas countershaft seals is not exactly accurate. The seal/collar does not leak, but the leak can be from between the collar and shaft. The main cause of this is if the o-ring that seals the shaft is bad or if the sprocket is not a tight enough fit against the collar to compress the o-ring when the clip is installed. Thats why I shim the sprocket so that it requires some compression force to get the clip on. This exact condition was way more common on my KTMs.

[cal_tony]

Glenn,

The TT site is where I obtained most of my info on the LocTite fix. The DRZ section

http://www.thumpertalk.com/forum/sho...d.php?t=625998

actually has a comprehensive analysis of the problem and the fix. Along with that are numerous individual threads re. that fix and other LocTite fixes.

Having said that, I'm always amazed by the number of long time riders that unlike you or I don't spend the time or effort to line their sprockets up correctly. Also, many don't understand that the tightest part of the chain on the sprockets occurs when the swingarm is parallel to the ground and that to get a feel for setting the distance between the sprockets you need to see how tight the chain is when everything is in a strait line. Most owners manuals give directions for setting up the distance while the bike is sitting on it's wheels and they specify a certain looseness. But they don't indicate that this looseness is needed so that at parallel the chain isn't binding. If they don't understand this, chances are at some time or another they've gone too tight and began the process of wear that can lead to problems with all or any of the components between the secondary shaft and the rear wheel.

Tony

[rpduc]

O.K. I'm trying the Red Loctite and shim for snug fit on the clip.

I will pass on measuring to the stop blocks with a caliper though.

I personally don't believe the swingarm is mfg'd to a tolerance that you could trust measuring to some point on it. A straightedge on the rear sprocket and eyeball to the front is my preferred method.

The shop manual for my Husky 610 outlines a good method for checking/setting chain tension. The longest point the rear suspension reaches with respect to chain length is when the countershaft sprocket, swing pivot and rear axle are in in a straight line. It's simple geometry.

I compress my suspension with a ratchet strap until the three are aligned. Then I set the chain at a comfortable tension, release the ratchet straps and note someplace where I can take a measurement. Now I have a reference to check chain tension without going through the ratchet strap thing every time.

IMHO part of the issue with chain tension by measurements is the arbitrary amount of pressure one can apply when taking the measurement. I assume the factory has tried to hit some "average" with it's recommendations but IME the factory suggestions are most always too tight. That's especially true on my Duc.

[MattR]

Originally Posted by cal_tony

Glenn,

The TT site is where I obtained most of my info on the LocTite fix. The DRZ section

http://www.thumpertalk.com/forum/sho...d.php?t=625998

actually has a comprehensive analysis of the problem and the fix. Along with that are numerous individual threads re. that fix and other LocTite fixes.

Thanks for the link.
I will try the 271 red loctite since it is readily available. According to the link, the stronger 638 green loctite fills gaps up to 0.015". It is available from McMaster-Carr and it's pricey, but a source if you need it.
http://www.mcmaster.com/#91458a43/=1g374l

[GMP]

The 638 is the stuff I have, used it on Cannondale transmission cassette bolts.

[rpduc]

I went to a local Loctite "distributor" and they didn't even have 638, but it looks like that might be a good choice. I was able to procure some Loctite 660 which has a slightly lower tensile strength than 638, but is supposedly able to fill gaps to .020. I will submit a report after I've had some time on the sprocket. Both 638 and 660 are labeled as "retention" compounds. Looks like 660 might be the most appropriate for the task to me. All of the rest of the products mention "close fitting" parts.









After cleaning up the countershaft thoroughly for Loctite application I could definitely see a wear pattern on the shaft itself. Not good, but I figure I'll be ready for a bottom end by the time I need to replace that countershaft anyway...

[MattR]

Originally Posted by rpduc

I went to a local Loctite "distributor" and they didn't even have 638, but it looks like that might be a good choice. I was able to procure some Loctite 660 which has a slightly lower tensile strength than 638, but is supposedly able to fill gaps to .020. I will submit a report after I've had some time on the sprocket. Both 638 and 660 are labeled as "retention" compounds. Looks like 660 might be the most appropriate for the task to me. All of the rest of the products mention "close fitting" parts.

The 660 is referred to as "quick metal" by filling gaps. It will be interesting to hear how it performs. Keep us posted!

Here is a link for other folks to buy online if needed.
http://www.mcmaster.com/#7570a27/=1ing58

[Skidad]

With that 660 stuff my question is how is it going to be getting the C/S sprocket off. It has about a 2500 lb shear strength. While I like the idea that concerns me (allot). Loctite say heat local area to 250 degrees. http://www.loctite.sg/sea/content_da...g_Compound.pdf

The 638 is even stronger @ over 3500lbs shear strength http://65.213.72.112/tds5/docs/638-EN.pdf

Any thoughts???

[cal_tony]

In spite of all the LocTite products out there that will do the job and each with increasing strength, my advice is to try the RED first. It is the minimum and the most readily available of the high strength variants. I've been using it for quite awhile on my sprockets and it seems to have worked in my case. If you try it and it doesn't seem to hold try the next stronger variant on the product list. However, I wouldn't advise using one of the more permanent versions if you don't need it.

Tony