Stanchion + Dropper Post Scratch Repair | GMBN Tech How To

Scratches on a fork stanchion or a dropper post that pass through the seals as they move up and down will damage the seals as they are used. So if you want your fork or dropper to continue to function as it should for as long as possible, doing these small repairs is essential.

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Repairing fork stanchions and dropper posts is delicate work, and you will require some specific tools and materials. Mostly however it requires attention to detail and the correct method which Doddy will walk you through in this guide.

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152 комментариев
Maciej Zych
I cant believe you didnt show the finished job :/
I (as Nicolai Lund-Jensen below) have a couple of issues with the process described. I'd take neither files nor sandpaper (nor polish for that matter) to the stanchions. Use a break-off knife (stanley, utility knife) blade and place the sharp bit parallel and against the surface at about 90° angle, and drag it over the burr. The stanchions have a hard coating so the blade won't "bite" into that, but it will bite into the (soft, aluminium) burr. You'll be able to get it absolutely flat and smooth like this. Then clean out the scratch (only here you can use some fine paper to rough up the surface INSIDE the scratch. Put your filler ONLY inside the scratch, don't get any around it. The stanchion coating is made to be porous so it can hold some oil and lubricate seals and bushings (not bushes). If you slather resin/varnish over it you're sealing the surface and degrading the lubrication in that area. Let it harden (in case of epoxy resin you can use your hair dryer to warm the spot up, this results in a harder fill. Then use the blade again in the same fashion to scratch off the excess resin/varnish. When applying the filler you need to make sure it is only inside the scratch, but makes a nice "bubble" above it, as it will shrink a bit while hardening. If you find there is a slight depression in your filler and you can't reach it with the blade, apply some more. When you're done, if you can, inspect the repair under high magnification. The filler surface should be dull, without any shiny spots. If it's shiny, you need to apply some more. Don't bother polishing, it is not rough enough to damage anything, and the little bit of roughness allows it to hold a bit of oil to aid lubrication.
This process is fit for a functional repair, as it will restore the surface in a best way I know, however it's not fit for cosmetic repair as it will leave the surface of the burr shiny and thus visible as an imperfection. If you want to also repair it cosmetically, use an abrasion tool (a file or sandpaper) to lower the surface where the burr was, so it can hold some resin.
Ryan Abbott
I think I'll start transporting my bike with the dropper slammed to protect the stanchion from now on
Orringe Juice
You're seriously the best at tech, you've saved me so much money through these videos
Nicolai Lund-Jensen
Top tip: Use a sharp blade from a utility knife to remove the filler material. If you hold it parallel to the fork stanchion, you'll get the right curvature straight away and will save a lot of time on polishing afterwards(If you even need to polish). Bonus tip: The blade is hardened steel whereas the stanchion usually is aluminium, so you can also use the blade to remove the burr to begin with, which will again leave you with the same curvature as the stanchions. Works a treat.
𝖘 𝖍 𝖎 𝖗 𝖔
I would recommend using regular steel needle files. Regular needle files will only take off the burr when light pressure is applied. Once the burr has been removed the file will skid across the surface IF you work with light pressure.

The diamond coated ones are basically like sandpaper. They scratch up everything they touch. These coated files will scratch the surrounding vicinity of the nick and go straight through the anodisation.
Salamander Workshop
I transport my bike with a cut pool noodle foam to protect it.
Dominic Hirst
Aluminium foil and water works really well to take out scratches. It is used on chrome so is really effective on forks etc. Flat square of foil, a bit of water and patience.
𝖘 𝖍 𝖎 𝖗 𝖔
Restoring the surface of a precision component with sandpaper without any form of rigid, straight backing will create small lumps in the surface and alter the geometry of the stanchion. You will probably not be able to see the lumps but they are there and they will put extra wear on the seals.
Please use a nice straight wood or metal backer to avoid sanding lumps into your stanchion.
Pretty sure you forgot to zip-tie it at some point :D
The ChaosEngine
When we transport bikes on the bike trailer at school we slam the dropper posts and put bits of foam pipe insulation over the stanchions and any other bits that look like they might rub. Cheap as chips and you can just tear it to size if you're in a hurry.
General Havok
One of the best vids ever! So valuable,thanks!
Bit of a sloppy job if you ask me, not surprisingly we are not shown the end result which is normally standard practice for these kinds of video.
For one I would stay far away from my stanchions with cheapie diamond files(very aggressive grit) and not slop nail varnish all over the place, nail varnish should be very carefully applied and only in the chip. Also you don't want to sand the good areas of the stanchion, so it would be wise to use masking/painters/tape to mask off everything but the filled scratch when you come to sand it and only sand the surrounding areas on the final smooth off sanding with ultra fine paper.
PS.. you can get black nail varnish and all kinds of colors, I'm sure it's possible to find one in near the exact shade of most stanchions.
Carl-Henrik Sjöstrand
Thanks for good video!

Any chance you could make a video on how to service a dropper post e.g take it apart clean change seals etc
Jackson Mississippi
Thank you ❤️😍🎊 you for your help
Carl Loin
What if you cannot feel the scratch? I got such I light scratch the other day. Can I just coat it with epoxy?
Manuel Wo
nice n' smooth af always :D great vid!
An_ d
#askgmbntech: Doddy, could you pls do a video on how to travel a fork (e.g. 160 to 170mm)? Preferably a Rockshox Lyrik or similar
Rick Clark
I have a set of forks and they have a gash in the stanchion that is clearly visible should i
repair it ot leave it?
Very helpful! 👍🏽 How long is this nail polish going to last on the stanchions?
heiril osman
Thanks for the video Doddy. Can't say I did not wince through the whole video. You are a brave man.
Brandon Austin
Kind of prefer videos early 🤙🏼
Ethan Branchi
What would you do if you had a Fox Kashima fork, shock or dropper?
Ari Brekkan
Great video. I've used a razor to remove burrs before with some success. Then the same procedure with emory paper and polish. Instead of nail varnish you can also use an epoxy which is a bit tougher.
Aron Hendrickson
Maplin what is this Maplin
Bob Baldridge
Great explanation! I have black nail polish on hand for exactly this reason. Hadn't heard of the metal polish but it makes a lot of sense to make it ultra smooth. Great tip!

I'm having a bit of a dilemma with a different part of the fork. Blown damper (2011 Fox F120 RL). Is it worth repairing/replacing just that part or do you think it's a better idea to just find a gently used replacement? #askgmbntech
The Island Engineer
I would use filler in just the scratch area not anymore like in this vid. All the polishing thins out the stanchion coating.
Nick Watkins
Great video Doddy hope I never scratch my stanchions but if I do I will now know what to do 👍.
Samuel Miserotti
Love this channel,
Thank you so much for this I just used this on my bike, and I was just about to get new forks Thank you so much 👍🏻👍🏻☺️
Zac Youngson
What happens when the filler breaks off inside and knackers the fork ?
TGS Video
U safe my money, thx a lot bro.
Flying Tiger
precisely why i avoid "uplift vans" like the plague ... i would rather peddle up and get half the runs in a day , and not have other bikes thrown on top of my ride ... some may think is fashionable to have scratches all over, and some may have disposable income to replace shocks forks and droppers that get gouged, neither one of which is me. i buy a dropper cost 300 dollars and need it to last as long as possible... fair play if i crash and suffer damage, but don't lean your shit all up against mine, i WILL hit the ceiling... ... a useful repair vid that i hope i do not need to practice... i've replace enough forks over the years due to scratched and damaged stanchions and try my best to avoid these types of things, especially when many times it can be avoided with some forethought in how you transport your bikes
Should you use anything on your stancion like lubricants after every ride ?
Pedro Teixeira
I've commented on a previous video, but I think you should look into ceramic coating, to see if it works.
Phill Gordon
Great video Doddy, as always! I can't figure out though why you use brake cleaner with the sandpaper. Why not just soapy water?Am I missing something? Keep up the great work love your videos
Patrick M
Could you use a sharpie to hide the scratches after filling them
mr maxxis
you can use pool noodles to protect your bike parts
Jack Beames
Can you do what you’ve done with kashima on fox forks. As I know kashima has something special about it??
kay poly
Is metal polish the same as paint polish? you know, the same paint polish we use when working on car paint job?
Rowan Connolly
#askgmbntech where do you get replacement sag/travel indicators?
Dj Rouge
Fantastic vid Doddy
Christian Hehir
Such a good video
Ride or die asti!!!XD
Cameron Lesley
Fantastic tip, thanks
Lubos Murin
Mental polish.
Luka Gorjup
Doddy, how does it look like now that is repaired? ;)
Shane Starita
I have a Suntour Epixon 27.5 TR that I'm bumping to 140mm... how can I get it more progressive as it doesn't take tokens like RS and Fox?
Viktor Ward
A bit too much nail varnish? You just need to fill the scratch and around 1mm outside the scratch. Then you don't have to sand it as much. Good vid as always!
Trevor Case
thanks for this video, about to do this myself as my bur ripped the lower seal and the metal spring came loose....going to repair it with this method and hopefully it lasts until I can get a fork replacement later.
Are there any bikers out there who use rubber fork boots on new air forks?
Сашуля Петров
Это pizdets
Jesse Richardson
I just found a scratch last week! I’ll have to try this.
Tomeka Pompey
Just do it yourself, go to woodprix page and learn how .
I have a scratch its very very small do i need to do that?
Elizabeth McDonald
could you use a colored nail polish to match then go over with clear?
Evan V
Excellent video
Jason Eastabrook
I didn’t even realise this was such a problem, luckily I have a brand new fork being installed to my bike right now so I will definitely be watching out for scratches now
Chris Longliveenduro
Awesome quality video!
Marciel Industries
A good tip I use for automotive paint chip repair is to hole punch the fine sand paper and glue it to the eraser end of a pencil, it will alow you you to concentrate the area you are sanding.
KangaPoo Pradjan
Cheap easy hack for owners to do with their bikes to protect the bikes and their backs
buy or obtain from somewhere some foam pipe lagging which can be sleeved around the parts that need protection during transit
then when ready to ride the bike place the lagging tube in your backpack in a big resealable bag (to keep it flat)so it forms a flat surface to cushion your back from the stuff in backpack bouncing around , job done
I have a minor scratch on both my stantion and shock. I have filled in the scratch with nail polish then sanded and finally polished them. They are minor, but I can still feel them. Will I eventually have to replace these parts because they will wear through the seals?
What if the scratch is above like the cashima print on a fox fork where u shouldnt be usin the last few mm of travel, is that just as important
The Flash
#AskGMBNTech Hey doddy, how do I fit an ISCG chain guide/bash guard to my new Canyon Spectral if it doesn't have the mounting points on the frame? Thanks and keep up the great work on the channel.
Madison & Jenn
I just bought a pair of 160mm 36's with the intent to lower them to 100mm for a dirt jump build, they were cheap because there's a little gouge in the stanchion, but it's about 30mm above the fork seals so once lowered it will never rub over the top seal. Are there any internal o-rings I should worry about it rubbing against and damaging?
Christian Hehir
Much needed
enduro trucker Ernie Desjardins
Try P O R 15 . Its a epoxy resin paint used for automotive restoration on anything rusty and old. This stuff is super duper tough paint. Stones off the tires wont even chip it. When i weld up a new trailer in my shop i use P O R 15 to paint it. Stuff last forever compared to paint. I used it on my 888rc and mt 66rc. Never know they were fixed. I have found the seal alway seems to need to be replaced once it runs over a nic and get cut by it. Change the seal and your brandnew secondhand.
steven t
There are some who agree n disagree with this method based on the comments. I dont think either way is wrong but which is better depends on the nature of the damage. I found epoxy good for deeper chips but not effective on shallow chips. Nail varnish + super glue mix is very effective for shallow chips but needs to be done properly to last (i dont agree with filing the chip). However filing the burrs is not the best way. Using a very sharp stanleys blade to shave off the burrs is more effective n isolates the chip. Just fill the inside of the chip, use painter's tape n make a hole almost the same size of the chip n just paste it on the stanchion. It makes isolating the chip effective to fill in the chip without slapping the varnish/glue mix all over but only inside the chip and a bit around it thn remove the painter's tape when done. and LEAVE IT FOR 24 hours to complelely harden (best in warm room). This is extremely important or it wont last. Next use a harder thn painter's tape material like any excess frame protecter film, make the same size hole as the chip n replace it with the painter's tape so as to isolate the chip n the varnish/super glue mix. This is for polishing the excess filling with very fine emery paper without buffing the uneffected area. Dont use the blade to shave off the varnish as most of the time you will just pull out the whole filling. Keep light firm pressure with the emery paper n polish the excess varnish+super glue mix on and around the chip until it is almost smooth over. This requires a lottttttt of patience so dont rush it. This method require more steps n patience but it is well worth it n the chip is barely noticed. Mine has been on for the last 6 months with no issues.. even if it eventually comes off i wld do it again as the effort is worth it if it last a few months n save a load in buying a new fork. I guess a good nail varnish and super glue is the ghetto resin epoxy.
Better yet, follow these steps and finish with black nail polish for rockshox forks. Go over the raised dried goop with a flat razor blade and get back on the trail like a real savage. Skip expensive brake cleaner and use 91% isopropyl alcohol if you're ballin on a budget. Can I get a hell yeah?
Tim McDroid
My 2 cents...Easy to make small nic into a big fix area...use painter tape and wrap around repair area..Its like fixin a rust spot on car..ayour 1 inch problem turns into a 5 inch fix..
Alex Paulsen
I started doing this on some 1997 Z1 Bomber stanchions. The gold anodizing they have on those things is hard as nails, some wet/dry sandpaper in a fine grade (800-1000) and a careless attitude made them smooth without affecting the coating.
Justin Rees
GMBN Tech, is there any disadvantage to using colored nail polish as opposed to clear varnish? My stanchion is black so I'd like to use black polish, but don't want to do so if it'll damage the stanchion
Steve B
the gamer and vloger
Doddy would putting pool noodle on my frame and stantions stop scratching
Henri Armstrong
RIP maplin.
I just preadure washed my bike and the dropper post was going wierd it rubbed on something. Im now home and i have a 13cm scratch
The Grind Don’t Stop
I’m Looking to buy a newer fork for my bike, should I buy a used fork with damage (like the one in the video) and repair it (like in the video) so it runs smooth and I can use it, thanks.
The Real Donald Trump
Scratched Stanchions? ....New bike!
Ethan Engelbrecht
If you don’t want scratches on your dropper/stanchion when your transporting it then just wrap a rag around it and then your good to go
Dũng Lê Văn
What does the metal polish do ? I mean, after you've filed the scratch down, put some nail vanish on it, smooth the surface out with emery paper; it pretty much smooth at that point right ? And would silicon spray affect the metal polish ?
ben murphy
Why don't they put covers on the stanchions like they used to?
Tomi Saaranen
5the comment
Mark Repaci
Hey can u talk about the new canyon torque it's an interesting bike and I'd like to hear your opinion
Jaster F.
Does this work with fox 36's kashima. Its doesnt feel rough. But I have a small amount of scratch. When I feel it, it doesnt feel like there are any scratches.
4:58 "So... I am going.." to be not liberal at all and tell you simple way: get a wooden toothpick and use it for filling the cavities. You might not even need sanding it. Duh! Never got stone chips on your car? (Pressed Thumb Up BTW)
Marvin Gourdol
Hi guys, I've noticed some "horizontal" play on my bontrager dropper post, do you know how to fix it ? Thx ! 😉
I used a different method but I don't want to say what I used just in case someone tries to do the same thing and make it worse or not get the same outcome.
Mtb Beta
Here is another video with some helpful info on fixing a damaged stantion.
Guys can you make some commentary over the new trunnion mount shocks about how you can brake on of the eyelets if you let on bolt loose and fucked up the thread?
PS bad english, sorry