Great video, thanks. Gave me the confidence to service myself. Tip @ 3:50 for cleaning Seal Head: slide it to top then wrap decorators tape (blue/ green adhesive paper tape) around post. Slide the seal back down over tape to remove grease, and repeat 2-3 times. Twisting in direction tape is wrapped helps too. Easier than the loose piece of paper! 👍🏻
This was a very helpful video and thread! I'd add 1 more thing... Mine kept sticking at the botton and so I took it all apart again, then it would drop, but not stick at the bottom/it would come back up when it wasn't supposed to... here is what I figured out: 1. Pull the cable from the hand lever through the bottom of the dropper to ensure its not kinked... 2. There is a sweet spot of tightness vs loosness for the dropper clamp that clamps it on to the frame... in my case, it was just a tiny bit too tight, but it was enough to affect the rise and drop to not work... I loosened the clamp like 1/8 of a turn, and Eureka! That was the sweet spot. Smooth as butter now. Hope that helps!
This video was super helpful for me, thanks! Used this video to take mine apart, paint it, and install a new service kit. The newer dust seal can be taken off, just grease the post well before gently pulling it off.
Great video, post was hanging up on release. Now it’s not staying all the way down and still not going up. Task failed successfully! Any suggestions looks like it’s coming apart again
Great video, very useful. Only suggestion would be to dedicate some time and advice to reinstalling (like where to lube, etc). You've got 6-min of in depth tear down, and one minute of sped-up install. They could use ~equal time. Regardless thanks for posting this it really helped!
I have the rebuild kit and my seat is moving back and forth - side to side - angle wise. I believe this is worn bushings - have you ever replaced these? Thx
the bottom of my bontrager b line off my 2020 trek doesnt have the allen bolt at the bottom of the post. I think it requires a special tool :/ please correct me if i'm wrong. cheers,
Thank you, helped me fix the creaking it made when twisting. What is your opinion on the quality of Bontrager droppers overall? Are there better options if looking to replace?
Thank you for the video, just the info that I needed. Unfortunately, I stripped one of the little screws to remove the end cap (2:19). I think they put too much loctite on it. Would you know the part number of that screw? I am thinking of drilling it out and hope for the best. Any other ideas? Thanks again
Strangely enough I serviced one yesterday that had the same issue. I removed the bolt using an "easy out" One pin is enough to hold the cap in place really but if you measure it up and google dog point grub screw you should be able to find some replacements
Hi, thanks for the video, the trouble is the seat post won't lock, and it has nothing to do with the cable, there must be an internal problem in the pressurised cylinder part. Difficult to sort out I imagine.
I have a tub of slickoleum. Can use that all over? Or what other easy-to-find grease? I mostly ride in North Vancouver BC. The Bontrager really slows down a lot when riding in cold and muddy conditions. Hopefully this helps.
ideally any waterproof grease. slicko is waterproof so why not, its probably just a tad more expensive to use than other greases but will make the head seal have less friction hopefully
I just acquired a used 2017 trek bike and followed these steps. Post goes up nicely but I need to bounce on it a few seconds to get it to go down. Is this more of a cable issue then?
Nice video. The Bonty dropper on my fairly new 2018 Stache just got pretty rachet sounding after getting caught in the rain one day. I pulled it off the bike following this video, but it looks different. Rather than a hex hole, i found it to have a circlip holding it together. I took the clip off but now i'm stuck, cant seem to pull it or twist it apart. Has anybody seen this?
Thank you for the video. Can you suggest what to do if that tiny actuator pin on the top end (2:14) of the air cartridge is only half the length as it should be. It looks like it is stuck in the rod and I can't get it out to it's full length.
@@highcarbrider thank you for the answer. I was regulary servicing my DP, but this happened after the winter when the bike was not used. I thik I will try to deseize this pin somehow.
@@highcarbrider OK I tried to unstuck it with mechanical tools, and nothing works. I am thinking to heat that end, but since it's pressurized container, I don't think that it's a good idea..
Wow this service tutorial looks so easy. I am having issue with my Bontrager line seatpost the saddle is wobbly left to right its not too bad but it is annoying and i t concerns me that bigger issue is about to come lol any advice? Thanks
I have had the same issue with my 2019 dropper, which looks slightly different from the one in the video. It’s very similar, though. If you disassemble the seatpost and look at the bottom of the inner tube, there are two plastic rods that act as guides and fit into corresponding grooves of the outer tube. These rods are prone to cracking, and when they crack, the seatpost develops rotational play. They are very easy to replace. This is the part you’re looking for: www.trekbikes.com/us/en_US/equipment/cycling-components/bike-stems-seatposts/bike-seatposts-accessories/bike-seatpost-parts-accessories/bontrager-line-dropper-key-way-kit/p/24705/
No action required. Common issue and they’re known to be trash like that. I have a problem with mine in that it’s taking it’s sweet ass time getting up when my brother with another brand (rock shox) literally makes a snapping noise coz it shoots the saddle back up so fast (mine used to do that but stopped after 12mths). As for ‘others’ experience the left-right saddle wiggle read the comments on the trek site here: www.trekbikes.com/au/en_AU/equipment/cycling-components/bike-stems-seatposts/bike-seatposts-accessories/bike-seatposts/bontrager-line-dropper-seatpost/p/24159/
Are the keys the part that makes it wobble. And ate they replaceable. Also from new I stuck an old narrow inner tube over my post like a boot. Works great and has done for 2 years
they do www.trekbikes.com/gb/en_GB/equipment/cycling-components/bike-stems-seatposts/bike-seatposts-accessories/bike-seatpost-parts-and-accessories/bontrager-line-dropper-key-way-kit/p/572184/
This thing has really no brass or plastic keys? I ordered a pair of "drop line keys" because i thought previous owner throw them away, but wont fit in.
Hello, good morning, I have the same dropp line. The problem I have is that when I put weight on it, it goes down on its own and when I remove the weight, it goes up on its own. I already cleaned it and checked the wiring. It is correct. I would like you to help me with it, friend. Thank you.
That’s is the valve actuation. Try this, remove it he post from the bike, disconnect the cable from the post then put the base of the post on something sturdy like a rubber mat so not damage the base of the post, then apply pressure to the seat (sit on it) if the post goes down you may have a faulty cartridge, if the post stays put then you have faulty cabling. If the latter, make sure the inner cable moves freely in the outer with little resistance. Contact the cable to the post and ensure there is play or movement in the lever before you feel pressure to actuate the post.
question: every time I drop the seat post, I have to remain seated for a few seconds in order for the post to stay down. If I stand up right away, it will slide up a few inches. Conversely, when I raise the seat post, I have to wait a few seconds before I sit. If I sit down right away, the post will slide down a few inches. It's almost like I have to wait a few seconds for the seat post to settle before getting up and sitting down. I've done the service. It's still happening. Any ideas?
Is the inner cable sliding smoothly inside the outer? It's possible the delay is down to the cable not releasing the actuator. How did the post operate off the bike?
it's the same off the bike. When I push the seat down with my hand, I have to hold the seat down a few seconds or else it would come up a few inches. When I pop the seat back up, I can't put any weight on it for a few seconds or else it will slide down a few inches.
Subseven714 if that’s the case I’d take it back to Trek and get a warranty on the post. I’ve only seen one with a similar issue and Trek warranted it no questions.
thats the newer one, there's no allen key spot on the newer one, once you have it off you already have access to the shaft. Just undo the bottom and then undo the seal head from the body shaft and you're good to go - the procedure is mostly the same
@@benpsykes Good evening. A follow up to the newer post question. Once you unscrew the lower piece with the 8mm hex, do you then need to remove the flat piece that is held on with a 2 sided nut of some sort? Is there a trick to that? Mine won’t budge, am I’m unsure of how much torque to apply to get it off.
@@michaelscotthanson6366 That doesn't sound the same at all, maybe a different design or yours is still the older design. On the one I had (now sold), you could just unscrew the plastic lower part from the tube, and then use a strap wrench or similar on the seal head to unscrew either end from the post body, which then let you access the inner post to clean and regrease. I don't recall any Allen key screws at all.
Ben Sykes sorry, I didn’t describe it well. There is a flat silver nut mounted on the end of the shaft. I realized there was a flat area on the shaft next to the silver nut to grab ahold of to prevent the shaft from spinning. Got it apart this morning. On another note, the new ones do not have the hard bushing or other pieces that the older ones have. The new ones have one plastic collet type bushing at the top, that’s all. Mine has developed so much play, that I now have to figure out if they make that part. The rebuild kit that is referenced in the online manual I found does not have the same part.
unfortunately its not a serviceable part, if the can has lost air or if the bleed switch has seized you will need to replace the can for a new one. They retail for about £55
My Bontranger dropper post clicks and shifts down a centimeter when I sit on it after I serviced the dropper as shown in the video. Any ideas wht could be causing this?
High Carb Rider. Thanks for the response, sorry this is probably a silly question but can I fix tht by the adjustable screw at the trigger or do I need to cut and shorten the cable?
Dropped the ball on that part. They are relatively cheap and are designed to be consumed. Maybe because it was so new he just overlooked that CRUCIAL point...
Island Aerial cheers yeah I managed to sort it in the end, literally just these two bits that pop out then you just pop 2 new ones in and assemble, nice and easy
Great video thanks, only thing was I don't think I agree with putting so much lube on it. I did this and it gummed up something horrific after 2 days riding. Took it apart, put a small amount of lube on and it works better than ever
Do you think I could do this service using Muc Off Bio Grease - or would that be too thick? (I don't feel like spending more on grease that I will infrequently use). Thanks!!
Solved this. There are two plastic pieces about an inch and a half long that fit in groves in the inner post and the outer post as the plastic wears the seat will get wobbly and evently the plastic tabs will not keep the seat in line at all. Take the plastic tabs out and make new ones with well defined edges, you'll notice the worn ones are rounded. Why did they use plastic instead of metal??? No idea. Just spent two hours shaping replacement plastic tabs just the right size to fit tightly in the notches.
