Shop Talk: Is It OK to Clamp My Dropper Post in a Repair Stand?

[@jaydavee]

yeah. Don't ride with the workstand attached to your seatpost.

[@nigeljohnson8022]

I wouldnt get very far my workstand is bolted to the garage floor !

[@MTBinKY]

I can't believe they didn't test that scenario. 😁

[@elcolessio5767]

@@nigeljohnson8022 Try! Someday you might be surprised ;-)

[@nigeljohnson8022]

@@elcolessio5767 it would be one he'll of a workout

[@xsmilezx]

This is awesome. I appreciate you going into the math and actually proving that the bike will be fine. Too many sources just estimate and don't PROVE that the bike will be fine. I have no room below the collar to clamp, so this makes me feel a lot better.

[@dmannino72]

I’ve always clamped my dropper post fully extended with a clean rag. Something I also do is loosen the pivot clamp on the stand so that the bike can slightly sway as you put the bike in, then lock it down. Especially if you pull a wheel out, loosen it, then the bike will automatically settle and then re tighten and keep working. This will reduce the lateral forces out on the post. I was a mechanic for 10 years, but also I have a physics and applied math degree, this logic plus my experience seems to be the best method to work on a bike with a dropper. Glad that you guys have done some testing to confirm my intuition about this. Thanks!

[@Jean-jk4zv]

I don't have physics and applied math degree, but I do exactly like you do.

[@dmannino72]

@@Jean-jk4zv well I’ll be the first to tell you, you don’t need one haha!

[@wreams2964]

I have been waiting for a legitimate argument for clamping dropper posts (from a good source). Thank you.

[@BartoszRogowski]

I'm trying to do as much as I can without going to a bike shop and your channel is the single best source of knowledge for me. Thank you for your time and thank you for this thorough explanation.

[@EpicRev1]

I've been clamping my Reverb dropper post (same one) for the last 3 years and no issues. I clean my post and the inside the clamps before mounting. Instead of using gloves I use a cut out piece of an old tire tube. When I clamp the post, I find the balancing point of the bike while clamped in the stand, so the force on the post is straight down (fully extended). For most bikes this means the back wheel will be higher (the bike is not level). Great video!!

[@evergoodstudios]

After working on my own bikes for years, i’ve never had a dropper post mainly for the myths this video has explored. Recently just got a bike with a dropper, and the question raised its head again. Needless to say, Park Tools have given reasoned and logical explanation, and put my mind at ease. Thank you so much. This video is invaluable. Another reason to choose park tool thanks guys. 👍🏻

[@DriverDude100]

It is about time authorities put this issue to rest. Clamp away! Thank you Park Tool.

[@steviebye1]

Thanks guys. I have the park tools stand and have been clamping my heavy (24kg) emtb on the frame, as I was lead to believe you should never clamp the dropper. I always wince when putting it on the top tube. No more, seat post from now on. Thanks from the UK. Great video.

[@chrisw3327]

Fantastic! Thanks! I am just about to get my first carbon-framed bike and only just considered that I should not clamp the frame. It's really good to know from the experts exactly how to clamp the dropper post without causing any issues.

[@AdF-RepublicOf6]

thanks, just brought my bike stand and this was great in providing me answers to my concerns when working on my MTB.

[@tommyestrada6464]

Thank You for clearing this up, although I was already clamping my dropper fully extended on the sanction, I hated having that seed of doubt.

[@jen3800]

these guys have amazing chemistry ! so nice to se happy people in their work life !! it makes me happy !

[@MatEmden]

Thanks guys. I really appreciate your expertise. Bike and bike components aren't cheap, so knowing how to and understanding why something is or isn't okay is money in the bank and more time riding!

[@michaelbauer6126]

Great tutorial video. I was concerned about clamping my carbon pivot by the dropper post while servicing my bike. No longer! Thanks guys!

[@snyper1401]

Thanks guys, I have one of my bikes clamped in my stand at the post right now and was thinking I hope I am not doing any damage to the post. Great videos always very helpful.

[@tubesockets120v]

Your welcome for clamping. Thanks for being a entertaining and informative duo!

[@El33G33kGoat]

Love this video.So refreshing to see someone showing the number and the actual engineering involved. Love it. 🖤

[@mrd6093]

THANKS GUYS YOU ARE THE BEST I HAVE 60 OR SO POUND FAT TIRE E BIKE WITH A DROPPER POST. I HAVE THAT STAND YOU WAS TALKING ABOUT AND I SURE ENOUGH WOULD NOT WANT TO HOOK IT UP WRONG.

[@PedalingDave]

Reading some of the comments below, how about putting the bike in the stand again and take a few measurements tightening a threaded BB to spec with a longer handled torque wrench...just to show those numbers too. Regardless, great video. Really enjoyed it.

[@MattRettmer]

Thanks for clearing up the question of whether or not to clamp the post!

[@JNOTECH]

I sometimes clamp my bike on the chain

[@th_js]

That's the only true way of doing it, my friend.

[@wawawewwa]

somewhere in the metric world.. :)

[@wolfendenracing2826]

No clamp it by the degreaser

[@peakltd7634]

Ah that's a goo idea normally I clamp it by my spoke

[@fonzo9405]

I clamp it on the brake lever

[@tolgaakyay]

Thanks for clearing out this myth 😊 I always tried to avoid clamping to dropper, but clamping to awkward points. Now it’s clear!

[@michaelmann3636]

Personally I rest the front wheel on the ground in most situations when the seat post is clamped in the stand. It’s just more stable and less torque on the work stand also.

[@mmaaddict78]

More points of contact with the ground the better.

[@scottjenson1344]

Lookin good in the Park Tool lounge guys! You guys would be proud of me, after the wheel bearing Tech Tuesday, I had the guts to disassemble and fix my in-laws' stuck sliding door and make it smooth as butter... now to fix their bikes:-)

[@parktool]

Miss you Scott!

[@SargeHitch95]

You guys bring out my inner geek. I love this kind of info.

[@CJinsoo]

just finding this video today-excellent topic. I stopped clamping by the seat-post when i got a dropper. as a result my work stand becomes less relevant as I have workarounds. I use wheel stands front and rear for most work. I use the Park frame work stand for drive train but rest the saddle on top of the massive Park stand clamp, which has a pretty wide surface. I think I only use the clamp on the Park stand when I remove my fork to service. Will hold it in the clamp by the steerer tube.

[@kenhuffmire9134]

What a great video guys this clears up a lot of debate in the shop! Changed my mind about this whole controversy. Thanks!

[@mamAmojj]

Hi guys. Thanks for the video. I appreciate that you mention metric. Still I think that correct way to represent this is talk metric and show imperial in screen. This is correct way forwards for everybody and makes world better place to live in.

[@seany2345]

Thanks for the videos guys! My bike is soooo happy I watch you videos and use the great knowledge I learn here to keep it clean, maintained, and ready to rip every ride!

[@arm4238]

Calvin is a national treasure

[@robbstack]

After watching this video, I went out to the garage, voided the warranty on my dropper post and clamped away! :D Thanks for the informative video.

[@MattiRemonen_Hki]

Thanks guys! This was very enlightening & helpful. And nothing beats the science.

[@wheeleyguy]

Excellent "Post" !!....Seriously, very informative. Thank You.

[@biketoshi5348]

Great video and backing it up with numbers. Thank you so much guys!

[@jdcunn11]

These guys are awesome! I love how they turned it into a discussion between the two of them lol

[@backpacker3421]

Thanks! Not the outcome I was expecting, and I think I'd still think twice about it. But I never really run into scenarios where post clamping is the only (or even best) way to put the bike in the stand. But I definitely learned a lot watching. You guys are great and I recommend you to all my friends interested in doing their own maintenance.

[@alantaylor6691]

I feel bad about clamping my seat post due to the weight of my wheels which are fat bike wheels. And the whole bike is 15 kg.

[@kevinadam327]

Great video guys! I appreciate the measurements, loads, and comparisons.

[@DGmtb51]

Thanks for the great info and explanation. Recently installed a dropper post, don't have enough room under the collar, so this helped a lot.

[@roncooke2188]

You pair should be on national television and make a few people smile

[@miiprai]

Wow! This is everything I was hoping for when I suggested this topic. Thank you so much for this extremely helpful video!!! ☺️👍🏻👍🏻👍🏻🙏🏻

[@navfilms]

Short answer: Yes, just make sure your jaws are clean and don't lock the stand in a stressful position.

[@petermorgan3702]

cheers, saved 10 mins of my time.

[@TorrentUK]

Thanks! I couldn't work out what the final recommendations were lol

[@LinkinPark4Ever1996]

And rise the seatpost to avoid vacuum creating air bubbler in the system

[@Combat556]

Thank goodness for fast forward.

[@SitavandaRita]

Two geniuses at work. Thanks!

[@jen3800]

I can NOT believe how much I have to learn !! Holy Cow !!

[@MrShinta786]

Really like listening to you guys

[@newttella1043]

Ok, now I feel better about clamping my seatpost. Thanks for the nitrile glove idea.

[@gpearce11]

I've heard the "switch it for a dummy post" idea suggested to someone with the wireless Reverb AXS, which I think is a great idea. Not only is it the only dropper with no cable routing to worry about, but its also the most expensive dropper on the market by a large margin. For everyone else with a more affordable internally routed post, the time and effort required is simply not worth it.

[@MotoErgoSum]

Well that answers my concerns about my dropper. Won’t be wasting time clamping to the frame near the seat post anymore.

[@skinnybricks]

11:32 "Please clamp" lmao good reference

[@Mike.Muc.3.1415]

Thanks for providing decent metric numbers. Outside the UK and US imperial units are more than exotic and there obviously are reasons why even NASA has switched to the metric system.

[@bengeist3227]

Thanks guys you thoroughly answered the very questions I had!

[@northkyt]

Awesome video guys! I've always gone by the conventional wisdom "Don't clamp dropper post stanchions"...not anymore. Clamp away! Only problem I can think of is, like you said at the end the rubber clamp pads better be very clean. If there is a piece of hard grit in there it could easily scratch the dropper post stanchion.

[@8584zender]

I love this video. It sure seems like they had a couple of pops before the director called "action."

[@machine7767]

Great analysis. Love the load cell and torque meter. In regards to torque 20 ft lbs is just that , twenty pounds hanging on the end of a lever that is one foot long. Convert that to inch pounds and it is 240 in lbs, which is 240 lbs hanging or pushing on a lever that is one inch long. So if the clamp was two inches tall, there would be one inch each direction of center to then there would be a 240 lb force pushing on the seat post to hold the bike in that position. If the clamp is 4 inches tall then the force would be half that. Good wrap up that the forces encounter ed riding a bike are higher than what the repair stand clamp will cause.

[@ianbarber6463]

Love these guys and Part Tool kit

[@Max-kw4px]

Super helpful. Finally a clear engineering-minded professional answer, not just some Dad's opinion on mtbr.com ;D

[@stewartlittle103]

Totally should have end saying “ Please clamp responsibly!”

[@promodsteve7882]

Great video, thanks for clearing this up. I think this whole clamping argument just comes down to using some common sense.

[@airsoferopromedio]

You can't beat science! Thanks!

[@johnhayes1641]

Love the gloves over the clamp trick.

[@eezing140]

Thank you. I was worried about this.

[@mikeb.3918]

Well thought out gents. Appreciate you crunching the numbers for us. Now if I could just get my Fox transfer to stop sticking 1" from the top. LOL 😆

[@baronvonrichthofen2021]

Nice effort, and good to know I can hang it on an extended post. However, I think I’m missing part of the evaluation, namely the part where torque forces on the post seal apply, and the forces in the length of the post. Based on the weight allowance of a rider, and the angles of the post, I would imagine the torque on the seal cap to be negligible in comparison. Likewise, I think the forces in the length of the post (rider weight) to be also not high in comparison. But the construction vertical is very different. It is not designed to have a tensile force acting on the post. So to know if you can hang the bike on the top part of the post, you really need to know what tensile forces the post can take. So personally I would probably not hang it on the top part without knowing. As demonstrated in the video, hanging from the bottom part of the post should be fine.

[@carlosadorno1544]

I clamp dropper fully extended (clean surfaces) by its stanchion, trying to avoid locking on stressful positions that can produce high bending moment at the post.

[@KiwiveloWorkshop]

Great video. Would it be safe to think the seat post collars force increases when the bike is in the stand and clamped or worked on while in the stand?

[@parktool]

Yes, id think the forces from the collar would change while it was in the stand... But it increases a lot more while riding.

[@MaquinasDePalomitas]

Man oh man, fun and informative.

[@werdna130]

You guys are hilariously intelligent. Rock on and thanks for such great info!

[@cwsmith17]

I love first-world problems. Great vid guys!

[@rsayagues]

Thanks for the video. I have an S Works Turbo Levo with electronic dropper. Any recommendations as to how and where to clamp my Park Tool stand? Thanks

[@yonglingng5640]

Is it the Reverb AXS? If it is, you can use any scrap seatpost instead since that dropper post is easy to reinstall, like a regular seatpost.

[@datjeepcray4188]

Thanks for making this video.

[@WBOS72]

Great video - you answered my question.

[@bluestraycat]

Really really interesting! Good to have this issue de-bunked scientifically

[@mathman0101]

Great thoughtful video Park Tool set the reasoning out for why we do things the way we should. That should be knowledge banked before you work on the bike. Can we have more videos on the mechanical side as well. You need to do a complete video work on Bearings - I would bring Hambini into that discussion. Also get manufacturers feedback as you did here. There are lots of claims being made but we need objectivity and measurable data to prove the claims.

[@williamtaylor5899]

This was totally smart and funny. Thank you!😂

[@bigarnd]

When I’m happy and I know it i clamp my hands 🗜 🖐🏼

[@amigaman9433]

6:53 a decimal point can make quite a difference, *1.419mm²* would be *0.0021inch²* your conversion should read *36.0515mm²*

[@parktool]

That's actually a comma, although for the sake of our international friends (in countries that use the comma to denote the decimal place), it would've probably been best to just leave it out 🤓

[@v1ncen715]

@@parktool Indeed. 2,2 inches square is 0,001419 meter square, so that's 1419,35 mm square.

[@TheHolymoses]

Awesome, perfect and to the point with some engineering data. (And that you did imperial and metric)

[@Dr.Schlitz]

Kudos for how you handle the issue of metric vs imperial units. So many creators are positively passive-aggressive is their use of metric units, even when the majority of viewers are more familiar with imperial units. We’re here to learn about bikes (or whatever the subject of a video may be), not receive a scolding about the continued use of imperial units.

[@youyangsmtbiker5780]

Nice video. Can a dropper seat post withstand a heavy ebike? Lets say 26kgs?

[@michael_emtb]

Brilliant video guys, thank you!!

[@TylerFernandes94]

I am wondering if this kind of thinking is the same with my concerns for putting up a 80+ lb fat tire ebike. I am worried the bike would be too much front heavy twisting pressure to clamp the bike by the seat post. Going by this video, it should be fine - correct?

[@kawikajones9436]

I don't worry about it because I have the Park Tool PRS 22.2 bike stand.

[@MusicBent]

I love the test at 9:20, but what happened when you rotate 90 to read the serial number? Or lean on the FRW-1 to loosen a stuck BB, or freewheel? And which manufactures recommend clamping where?

[@wydra9-1]

The only stress that didn't get mentioned that I feel would be worth it, is side to side rotational.

[@LarryRichelli]

This review reminds me of the movie "Fargo"!

[@trailbuilder5789]

Thx guys! now i can work on my new bike 🤘😄👍

[@nebno6]

I literally buy park tools whenever I can because of the mustached man

[@enpluson1539]

I actually came up with about half the squeezing force from the bolt. I went with the formula for dry metric threads according to my German mechanics handbook in metric.

[@EmyrDerfel]

If your threads are dry, that's a bigger problem than damage to your dropper.

[@enpluson1539]

​@@EmyrDerfel most threads come dry or with loctite from the factory and most torque specs as well. if you torque up lubed bolts to the dry specs, then you have a real problem. Unless it is actually specified that way, like with the santa cruz pivot bolts, which have to have the shaft lubed and the threads coated with loctite, torque specs are for dry threads.

[@BigVanLittleAdventures]

The verdict is out! I had 2009 dropper I clamped on the stanchion for 7 years... A collet ended up breaking at the bottom eventually rendering it useless. Not sure if that was the cause but 7 years on a dropper seems like a long time.

[@backpacker3421]

If 7 years on a dropper is a long lifespan, that sounds like a good reason not to use one.

[@parktool]

That would have been one of the earliest droppers on the market. If that lasted 7 years without fail, thats awesome! Did you ever send it in for service?

[@BigVanLittleAdventures]

@@parktool I opened it and cleaned and regreased it a couple times but that was it. It was the specialized command post which I think was their first gen.

[@ronalcasid3844]

Thank you for settling this!

[@leroyholmes9131]

Awesome. Well explained

[@dwaka08]

Great team work 👍

[@John-uo1qf]

Would be interesting to see the actual dynamic loads the post takes during a ride - this was alluded to but hard to test - but if it was easy anyone could do it!

[@danielpobrien]

Forces in Metric are not measured in kg's they are Newtons (N). Whoever ran the conversions failed to realize the difference between a lb-mass and lb-force. And when you divide the force by the area you should not refer to that as "force", what you have calculated is the stress. While I don't disagree with your conclusion on clamping dropper posts, I fell that the static analysis that you've tried to present was lacking.

[@LasseGreiner]

Daniel: Nice trolling, but I agree.

[@LasseGreiner]

Daniel O: Also the conversion for the area cannot be right. But alas, who am I to judge (actually professor in engineering ;-)).

[@kingcardbeard1471]

Nice to have some official tech to point customers too if they say anything :D

[@carlosadorno1544]

Sometimes remove either front or rear wheel to help balance-out weight (minimize bending moment to the post) if a stressful position is needed.

[@tonyfernandez6178]

Once clamped does the length of time it's on the clamp have any affect? I have the New Bluetooth post.

[@jobicek]

Correct me if I'm wrong, but isn't the clamp clamping the seat tube and not the seat post? Post gets clamped in turn by the tube. That's still not the stanchion. And isn't the seat tube offering quite a bit of resistance to this? Hence the significant clamping force. Moreover, it's typically the maximum torque AFAIK. Meaning, you shouldn't exceed it and in a light frame, there probably isn't much margin (hopefully, they at least accounted for the inaccuracies of torque tools and it's not a hard, never exceed limit as that wouldn't be very user friendly). In clamping applications, if you can get away with less (perhaps you used a gripping compound), it's typically not a bad idea (another consideration is the screw coming loose from vibration). Also, are you sure you should lube that thread? I know grease will help with corrosion, but if torque is specified for a dry thread, you can over-clamp and damage parts. As you surely know. When you clean the jaws, don't forget to clean the stanchion itself. Bikes should be kept clean, but we all know how that works. ;-) Personally, I'm not really worried about the weight of a bike breaking a post. Although it doesn't give me a nice feeling seeing a bike nose up held by a seat post. Where it really starts getting uncomfortable for me is when people start working on the bike and applying forces to it. Imagine token swap in a fork, pressing down the wrench to prevent it slipping, on a good half a meter moment arm. And you can see the flex in the whole thing, it's not like it's rock solid. Not a nice fuzzy feeling at all. :-) That's why I quite like stands that support a bike from the bottom, like your PRS 22.

[@Jason-tr2pt]

What about using a top tube adapter, like for putting the bike on a trunk rack? Can the dropper post handle that?