Rock Shox Quadra rebuild CHEAP - done

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I have a 94 trek 930 with rock shox quadra 10 forks, theyre dead so its been sitting for some time. My buddys teen son was looking for a trail rider to keep at their cabin. Guess what pops up, '94 trek 930. Exact match to my bike with a bit smaller frame. It was meant to be. The rock shox on the second bike have a little life but not much.
 
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After watching videos on how to rebuild rock shox, the elastomers are what goes bad, other than corrosion and grit.

If youre not familiar, elastomers are 3/4" urethane bar stock. After pulling one out, Its a purple floppy solid rod 6" long. Thats for quadra rock shox, judy rock shox have stacks of shorter elastomers so you can tune the ride ( different design with tubular elastomers that slide over a rod and remove as a pack). Replacement elastomers are $55. WHOA.

I considered rigging some springs. But there no dampening, maybe a spring and rubber combo......

I started learning about PUR polyurethane specifications.

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Found this handy little chart. Shore A spec (middle) is the one we'll look at. Shore A is the closest thing to durometer I can find for this material.
 
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Found this on amazon. $11 for 48" of 3/4 diameter shipped to my door.
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Amazon didnt know Shore A spec on the bar.
I looked up the manufacturer, small parts inc, and by checking their manufactuer number againt some Shote A data they had. The Shore A is in the manufacturer number.
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Gonna rebuild one of the rock shox with Shore A 60, PUR polyurethane bar in place of the elastomers. From the chart above, 70 is car tire rubber, 40 is pencil eraser.
We'll see how it rides. If i dont like it I can move up or down durometer (shore A #) or cut the bar in half and go harder or softer to tune the suspension.
 
Sorry about going absent. Bought a couple trucks at an asset auction, took a while to get them picked up.

Original elastomer is purple, New is yellow. New is a little larger diameter but fits in the tube and end caps fine. Seems to be the same durometer from finger nail test and finger bend test - not real scientific.
Original was 6 1/16, cut the new material to 6 1/4, just cause it seemed like a good idea.
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I need to make a long 5mm hex extension before i can tear these down.
Interested to see if adding length and new elastomer makes these ride well, i can always cut a 6 1/2 or 6 3/4 piece. Have plenty of material.

I can practice on friends kids bike fork rebuild since hes about 130 lbs, see how stiff they are and adjust for my fork rebuild to carry more....um...mass.
 
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Got a chance to finish this up today and ride.
New PUR rod at 6 1/4 feels great. Took that inch or so of deadness out of the top of travel that rock shox get.
Ill likely go 6 1/2 on mine for a little more stiffness.

The bike itself is great, looks like all original parts, everything cleaned up and tuned up well.
Its a bit small for me, but brought back some memories.

Need to pull my trek 930 off the shelf and go thru it. Shox are figured out, the rest is wear.
 
Circling back here, got an IM asking questions.

After going thru this rebuild, I think many specs of the PUR rod could be used. I chose the spec that i thought would give the best results, based on info I could find for comparison. If that specific spec is not available, find the right diameter and give it a try. Its somewhat tubeable with length of the rod.
This is not a specialty material specific to rock shox or the bike world, these PUR bars are used all thru manufacturing industry in various diameters. Dont get gouged on price.
 

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