Tech Tuesday - Specialized Command Post Blacklite Maintenance
What's needed: • Adjustable strap wrench • Hex keys • Shock pump • Isopropyl alcohol • Grease • Clean, lint free rag | Some helpful pointers: • Don't even think about taking the post apart before releasing all of the air pressure - you will lose an eye if you don't... or not. But let the pressure out of the post before removing the upper tube in order to prevent flying parts and possible injury. • A strap wrench, which only cost about $10 USD at the hardware store, is required to loosen the upper seal head. Don't even think about using vice grips or anything else to do the job. • Make sure to measure your seat height (or make a mark on the post where it enters the frame) so you know exactly where to clamp your post when you're finished the job. • There is nothing but sticky grease holding the twin brass keys in place - make sure that they don't fall off when you pull the upper assembly out of the lower tube. • Even though the cable tension shouldn't be affected during this job, be sure to check it once you're done the rebuild. Does the post lock in place firmly? Can you easily find the middle height position? |
Step 1 - The Blacklite post employs a slotted cable stop on its head that allows you to remove the actuation cable without having to loosen the clamp bolt. Pull straight down on the housing just below where it enters the stop, then pull the cable out through the slot. Undo the seat post clamp bolt, or QR lever, and slide the post out of the bike.
Step 2 - You absolutely MUST remove the air pressure from within the post before taking it apart, but take a pressure reading with a shock pump before doing so. This will allow you to refill it to the same pressure that it was using before you disassembled it (never go above 40 PSI). With it at full extension, depress the schrader air valve located at the bottom of the post with a small hex key - you should hear the ''pppphhhh'' sound of the air escaping.
Step 3 - You are now going to use the bike itself as a clamp to hold the post's out tube while you loosen the seal head. Slide the post back into the bike and clamp it in place, but do not reattach the actuation cable. Wrap your strap wrench around the seal head and turn it counterclockwise a few turns to loosen it. You should now be able to completely unthread it by hand. Slide it up the post's stanchion tube.
Step 4 - With the seal head undone you can now remove the post's upper assembly, but you'll have to activate the locking collet mechanism to do so. Pull down on the activation arm with your thumb to free the upper tube, allowing you to slide it straight up and out of the lower tube.
Step 5 - Our Blacklite test post has been in solid use for over a full year now, not seeing any maintenance whatsoever until this Tech Tuesday, which explains the contamination inside. It requires a good cleaning and new grease in order to move smoothly once again. The large O-ring just under the seal head is the top out bumper. Check it for splitting.
Step 6 - Slide off the split bushing and both brass keys, giving both of them, and their locations, a good cleaning. Place both brass keys back into their slots. Check the upper seal head's condition by sliding it up and down on the stanchion - it should move relatively freely but still feel tight. Now is also the time to clean the Blacklite's lower tube that is still clamped into the bike.
Step 7 - Preload the split bushing by squeezing it together gently before placing it back into its groove. This will help keep it from popping off when you slide the upper assembly back into the lower tube.
It's time to apply a thin coating of grease to the post's locking collet, lower bushing and brass keys, as well as spread it over the stanchion tube. Something with similar consistency to Slick Honey, a durable but light and slippery grease, will work well. Thicker grease acts on the post's return speed, slowing the rebound down, and a thinner grease will have the opposite effect.
It's time to apply a thin coating of grease to the post's locking collet, lower bushing and brass keys, as well as spread it over the stanchion tube. Something with similar consistency to Slick Honey, a durable but light and slippery grease, will work well. Thicker grease acts on the post's return speed, slowing the rebound down, and a thinner grease will have the opposite effect.
Step 8 - Slide the seal head and upper bushing up the stanchion tube and then reinstall the freshly greased upper assembly back into the lower tube. Do this by depressing the activation arm on the post's head with your thumb, relaxing the locking collet to let you slide it into the lower tube. Be sure that the brass keyways are lined up correctly, with the saddle inline with the bike's top tube and the 'Command Post' badge on the lower tube facing straight forward.
Pay special attention to the split lower bushing that mush push past the opening of the upper tube - its edge can easily catch, pulling it out of place. Slide the upper bushing down until it's fully seated in the top of the tube.
Pay special attention to the split lower bushing that mush push past the opening of the upper tube - its edge can easily catch, pulling it out of place. Slide the upper bushing down until it's fully seated in the top of the tube.
Step 9 - Pull the seal head down the stanchion and turn it clockwise with your hand to tighten. Give it a good cleaning with isopropyl alcohol before using your strap wrench to snug up firmly.
Step 10 - With the seal high tight, loosen the seat post clamp bolt and remove the entire post from the bike in order to add air via the schrader valve. More air will result in faster return speeds, while less air will slow the rebound down, but never exceed 40 PSI.
Step 11 - Put the post back into the bike and reattach the actuation cable by first putting the anodized red cable clamp barrel in its cradle, then pulling down to get enough slack to slide the housing end in place in the cable stop. Double check the post's action before hitting the trails, making sure that the cable tension in correct.
Step 11 - Put the post back into the bike and reattach the actuation cable by first putting the anodized red cable clamp barrel in its cradle, then pulling down to get enough slack to slide the housing end in place in the cable stop. Double check the post's action before hitting the trails, making sure that the cable tension in correct.
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In the end you might be better off just sending it in if you don't like to tinker.
-Seth
And for a video, check this out: www.youtube.com/watch?v=K0X3sLMo-TA&feature=BFa&list=PLF743802EEFDFCA3F
Slick Honey is what is normally used for lube, but for cold weather (below freezing) an oil can be used- just be careful to invert the post when inflating the post so oil doesn't get in your shock hose.
If so, then soon I can do the maintanace on mine based on this TT.
Thanks for covering this topic Pinkbike!
Any way we can get a solid fox 40 service with fit cartridge service too. I have searched for a good solid how to vid (being I'm a bit more of a visual learner) and came up fruitless. As a down hill rider I'm kinda suprised to see that there has not been anything on here coving the 40.
http://www.bluetoad.com/article/For+411%3A+Rebuilding+The+Specialized+Command+Post/320421/0/article.html
Turns out my rebuild was not necessary, the inside after a year of riding was beautiful. The issue I was having was post releasing in climbs. Turns out it is due to cable flex from how I routed it through the rear shock.
Thanks again, this article saved me from making a problem.
Anyone have any tips on removing this? It's from a 2013 and should not be that old. It was never services before so I didn't over tighten it.
Why don´t you do something more useful like maintenance pivots or ghetto mods ?? Would be much more appriciated