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Discussion Starter #1
Ok, posting this story just to show how useful having a lathe in your shop can be....

The backstory...
Turn out my new (to me) K1200LT had worn out shock and springs on it. So I study on the forum and make a choice on custom shocks and springs hoping to breath new life in my ride. I place my order for a set of new Hyperpro shocks and springs. Three weeks and $1500 later the little brown truck drops off my new shocks and springs.

Anyway, back to the story. I got the new shocks and was all ready to throw them in to the bike. I had it torn down and prepped to bolt them in place and put everything back together. So, the old shock comes out and looks like this:

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Here is a pic with the spacer pulled off of the upper mounting stem. It just slides off the top.

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Ok, in my hurry to get it back together so I could go riding the next day, I failed to notice there were no rubber washers on the mounting stem or stuck to the frame of the bike. I guess the old rubber washers either disintegrated or were not put back in place from the previous owner. That will play in to the fiasco that will happen later.

So, the old shock comes out and I get the new shock in place ( without the rubber washers on the mounting stem )
I get everything in place and get ready to torque it down. The bottom through bolt which is about 3/8 thick calls for 32 foot pounds of torque and I torque it in. In my hurry ( yes I was a idiot ) I assumed the torque value for the top bolt was going to be the same......馃槺 I started torquing the upper mounting stem and the next thing I knew I twisted off the stem right below the nut ! Remember the rubber washers not being installed? I was torquing directly against the metal spacer on the stem. There was no squishing of rubber going on like there should have been. I read the Clymer manual and found out the torque value for the top bolt was 26 foot pounds and not the 35 I had the wrench set to. I got so mad at myself for such a dumb rookie mistake. Needless to say, tools were thrown and stomping was done.

The brand new $650 shock I got delivered 30 minutes ago is now broke.... I am pissed....

I could send the shock back and have them put on a new mounting stem, but that would take about a few days to get back to the manufacturer plus probably another two week turn around time. I want to ride now !!
After calming down and thinking the problem out I came up with a solution and my mood changed so much for the better.

The stem twisted off right at the nut so I had plenty of stem left to do something with so I came up with this plan. The original thread was 10 mm x 1.00 but I did not have this die so I changed it up to 10mm x 1.25 and threaded the entire stem that was left.

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You can see from the picture the top end that was threaded with the 1.00 pitch was severely compromised when the new pitch of 1.25 was ran over the top of it. I knew this would happen and I planned for it so I trimmed off the compromised end.

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This left me with about 3/4 of an inch of good solid threading to work with. It should be noted as far as the strength of the mounting stem and hold the shock in place that the original nut hold the shock in place is about a 1/2 thick so I still have more threads left than the original design.
So now I start using the lathe to turn out a new stem.

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Below is the finished stem replacement. I measured the original shock stem length and planned out my replacement to be the same length. I knew it needed to be threaded on the old remaining stem so this was my solution. I measured the diameter of the spacer that normally slips over the stem and turned down my work piece to that dimension. I then measured the height of the spacer and trimmed it to the same length. The remainder of the new stem was turned down and tapped to 3/8 x 18 threads. Picture is below.

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Here is the new stem started on the old stem. Basically what I have is a stem that no longer has a removable spacer. I thought it through and could not see a reason that the spacer and the stem had to be two pieces.

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I put locktite on the threads and tightened it down.

Now on to resolving the rubber washer problem. The manual definitely shows an upper and lower rubber washer in the diagram. I studied the book and did my best to figure out how thick the washers should be. It turns out, the last time I changed my shocks on the Bronco that I saved the old rubber washers. I mounted them on a 1/2 bolt and put the bolt in my lathe. I spun it up and used my hack saw to cut new sections of the washer to the thickness I had figured ( guessed ) the factory rubber washers should be.

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After getting them cut to thickness I pulled them off and drilled the centers out to fit the new spacer. I then put it all together on the shock to see how much space I would have left for the motorcycle frame in the middle.

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The new stem worked out very well. I was able to get it installed and torqued down without any problems. The shocks should be rebuilt every two years so when I send them back to be rebuilt I will have them swap out the old sawed off stem and replace it with a new factory one. But, in the mean time I am riding on my homemade repair and all is well. I didn't get it all back together the next day, but it was much sooner than having to ship the shock back for the new stem.

I must say my lathe has turned out to be so handy. if you have room in your shop for one, it is a good investment.
 

Wrencher Extraordinaire
2005 K1200LT
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That was a great solution. I just can't believe the old shock was in there without the rubber washers, I have never run across that. I would love to have a lathe and I have room just not sure at this stage of life I should invest in one, but I am still looking for a good deal and will get one if the price is good. I used to run a little production shop with a full machine shop and electronics shop, I miss having access to that.
 
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Wow! Very cool. I think you will be fine until the first rebuild. When you think about it, that nut and stem don't have much stress on them since most of the stress is during compression not during rebound.

Just curious -- red or blue?
 

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Discussion Starter #4
Wow! Very cool. I think you will be fine until the first rebuild. When you think about it, that nut and stem don't have much stress on them since most of the stress is during compression not during rebound.

Just curious -- red or blue?
I agree on the compression issue. I factored that into my decision on how to fix this. The main stress on the upper stem is just to hold the shock in place which isn't that much force.

I am not sure what the red or blue question is asking....
 

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Kudos for the repair, but I think I would be concerned about the need for overhaul every two years. Unless you do Galactic mileages, a rebuild shouldn't be required for many years.
 

Wrencher Extraordinaire
2005 K1200LT
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14,120 Posts
Normal shock re-build interval is 30,000. Guess you could do that in two years.
 

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Discussion Starter #7
Kudos for the repair, but I think I would be concerned about the need for overhaul every two years. Unless you do Galactic mileages, a rebuild shouldn't be required for many years.
Hyperpro suggests rebuilds at 20k miles and they give you the first one for free.... so.....
 

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I agree on the compression issue. I factored that into my decision on how to fix this. The main stress on the upper stem is just to hold the shock in place which isn't that much force.

I am not sure what the red or blue question is asking....
Locktite. Where you screwed your extension to the stub.
 

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Wow, that was a real fine solution. It's amazing what can be done with a little ingenuity and the right tools. I'm looking at a shock replacement for my 2005 real soon so I would be interested on how you like the HyperPro's. I've looked at Ohlins but want to consider the alternatives out there too.
 
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