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Lower Dog bones

Old 11-28-2010, 02:00 PM
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Join Date: Jun 2010
Location: Leeds - England
Posts: 109
Lightbulb Lower Dog bones

I decided to finally write this up, should have done this whilst I was making them , but never mind, the distance to move the hole is the hardest thing to work out. And that is done for you,

This will lower the rear of the bike 15-20mm

I took one of my dog bones off and traced arround it. I worked out the ratio and length of the swinging arm and this gave me the figure I wanted I moved the shock mounting hole 8mm in an Arc. This was to maintain the fixed distance between the mounting holes. This stopped things catching in use or messing too much with the handling.

This gave me the pattern. Attached.

I cut a piece of 50mm x 4mm x 400mm 304 stainless into 2.
I cut the bar using a new blade, using a slow steady action.

I painted one of the pieces with engineers blue so that I could scribe the pattern on to it.

Firstly on this painted piece I marked the location of the hole centers and center popped them. Using these pops I took a pair of dividers and scribed arc's at each point. I then joined the arc's on the radius using a scribe. The result was an exact copy of my paper template.

I then drilled this painted piece with a 3mm drill, I used colbalt drills and a lot of home made lubricant ! (kerosene and water mixed) . You need to be slow and steady with stainless otherwise it work hardens.

Once I had drilled all 3 holes I then place the second piece behind it and clamped it in the vice, I used the holes in the first piece to act as a template to drill through.

So far so good, I then opened out 1 of the holes to 5mm and then placed a nut and bolt through it and tightened it to hold things together. I drilled through the next hole and again placed a nut and bolt through and tightened. The next hole I then opened up to 5mm then to 6mm and again placed a nut and bolt through. I repeated this in steps until all the holes were 10mm.
I used 3mm, 4mm, 5mm, 6mm, 8mm, 9mm and 10mm size drills. I had a friend squirt my home made lubricant whilst I drilled !

I left the pieces bolted together with the 10mm bolts. I removed the excess metal where posible with the hacksaw and set to filing the ends and shaping the dog bones.

I cleaned all the engineer blue off and polished the edges with a fine emery paper. I then split the two pieces and ensured the edges were smooth.

After fitting them, I dropped my front forks 10mm, Whilst not perfect, I did not want to drop the front any lower as then the fender may catch.

Total cost about 10 and a bit of sweat,
Attached Thumbnails Lower Dog bones-image345.jpg   Lower Dog bones-image344.jpg   Lower Dog bones-lower_cbr.jpg  

Last edited by wizard; 11-28-2010 at 02:28 PM.
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