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.
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!
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.
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!!
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. 👍🏻
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.
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.
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.
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!
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!
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.
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:-)
Awesome video. It would be great to see those numbers for e-bikes which can be 60-80 lbs! I'm curious how the increased bike weight (and resulting increased rotational load) would impact the dropper post and its mechanical elements. Keep up the great work. You are helping so many of us by providing solid scientfic data!
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.
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?
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.
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.
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.
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.
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.
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.
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?
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.
I’m wondering if it applies to ebikes with a battery in a front-bottom tube, that makes it way more front-heavy. I’d probably remove the battery before clamping
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
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.
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?
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.
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.
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 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.
Re seat post collars - I've changed from standard collar on Scott scale labelled 4nm to a hope collar labelled 8nm, should I have stuck with same nm collar as stock or are all seat post forces equivalent (the hope is approx double width of stock)?
Seat post collars are a great example of where a torque specification is limiting and not always applicable. The there are now three manufacturers involved, so ideally all three should collaborate and agree on a torque. The frame maker, the post manufacturer and the collar manufacturer may have each different ideas. Here you want minimal torque to achieve the job, which is hold the post. If the post does not twist at 4Nm, then it will now slip down. If it takes 6Nm, then 6Nm is the right torque, etc.
My new tallboy will be here later this week. All i have for a bike rack is a trunk mount so i will have to use my top tube adapter to mount the bike. it. Is it ok to use the top tube adapter with the dropper post as long as i have it in the extended position?
What about forces when you are actually working on the bike ? If I work on BB I may apply more forces and weight...still not sure what’s best practice🤔
If it's a threaded BB you're working on and you're either torquing it down or cracking it loose, you can do it with the bike on the ground. At least that's how I do it.
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!
I tried the glove on the clamp thing but because I put a thin layer of float fluid on my dropper to keep it slick it just slides around, I clean rag instead worked a treat, thanks guys it’s been a question I always forget to ask after working on my bike
Anybody run into any finish issues clamping a Kashima coated Fox dropper post after a while? rookie MTB rider here, just wanna know? I've been clamping with a microfiber cloth but it does slide down
Hi guys, have a question. Can u rotate the bike up or down 45-90 degrees using seat post or need to use a frame for that. If yes how much clamping u can do for carbon frame?
I have been waiting for a legitimate argument for clamping dropper posts (from a good source). Thank you.
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.
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!
I don't have physics and applied math degree, but I do exactly like you do.
@@Jean-jk4zv well I’ll be the first to tell you, you don’t need one haha!
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.
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!!
just found this video, and it answered all my questions, wish I found it sooner.
It is about time authorities put this issue to rest. Clamp away! Thank you Park Tool.
yeah. Don't ride with the workstand attached to your seatpost.
I wouldnt get very far my workstand is bolted to the garage floor !
I can't believe they didn't test that scenario. 😁
@@nigeljohnson8022 Try! Someday you might be surprised ;-)
@@elcolessio5767 it would be one he'll of a workout
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. 👍🏻
Your welcome for clamping. Thanks for being a entertaining and informative duo!
these guys have amazing chemistry ! so nice to se happy people in their work life !! it makes me happy !
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.
Love this video.So refreshing to see someone showing the number and the actual engineering involved. Love it. 🖤
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.
thanks, just brought my bike stand and this was great in providing me answers to my concerns when working on my MTB.
Great tutorial video. I was concerned about clamping my carbon pivot by the dropper post while servicing my bike. No longer! Thanks guys!
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.
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.
You guys bring out my inner geek. I love this kind of info.
Thanks for clearing up the question of whether or not to clamp the post!
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!
Excellent "Post" !!....Seriously, very informative. Thank You.
Great video and backing it up with numbers. Thank you so much guys!
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!
What a great video guys this clears up a lot of debate in the shop! Changed my mind about this whole controversy. Thanks!
These guys are awesome! I love how they turned it into a discussion between the two of them lol
Great video guys! I appreciate the measurements, loads, and comparisons.
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.
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:-)
Miss you Scott!
Awesome video. It would be great to see those numbers for e-bikes which can be 60-80 lbs! I'm curious how the increased bike weight (and resulting increased rotational load) would impact the dropper post and its mechanical elements. Keep up the great work. You are helping so many of us by providing solid scientfic data!
Thanks for clearing out this myth 😊 I always tried to avoid clamping to dropper, but clamping to awkward points. Now it’s clear!
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.
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?
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.
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.
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.
Calvin is a national treasure
Thanks guys! This was very enlightening & helpful.
And nothing beats the science.
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.
Really like listening to you guys
i always use the main post and never the stanchion. I figure having the bike weight pulling down the from the stanchion would mess it up.
Wow! This is everything I was hoping for when I suggested this topic. Thank you so much for this extremely helpful video!!! ☺️👍🏻👍🏻👍🏻🙏🏻
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.
More points of contact with the ground the better.
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.
Two geniuses at work. Thanks!
Thanks guys you thoroughly answered the very questions I had!
I can NOT believe how much I have to learn !! Holy Cow !!
Ok, now I feel better about clamping my seatpost. Thanks for the nitrile glove idea.
You pair should be on national television and make a few people smile
Love these guys and Part Tool kit
You guys are hilariously intelligent. Rock on and thanks for such great info!
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.
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 😆
Thank goodness for fast forward.
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.
Thanks for making this video.
Love the gloves over the clamp trick.
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.
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?
What about using a top tube adapter, like for putting the bike on a trunk rack? Can the dropper post handle that?
Once clamped does the length of time it's on the clamp have any affect? I have the New Bluetooth post.
I love this video. It sure seems like they had a couple of pops before the director called "action."
Thank you. I was worried about this.
Man oh man, fun and informative.
Great video - you answered my question.
I sometimes clamp my bike on the chain
That's the only true way of doing it, my friend.
somewhere in the metric world.. :)
No clamp it by the degreaser
Ah that's a goo idea normally I clamp it by my spoke
I clamp it on the brake lever
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.
Brilliant video guys, thank you!!
I’m wondering if it applies to ebikes with a battery in a front-bottom tube, that makes it way more front-heavy. I’d probably remove the battery before clamping
Super helpful. Finally a clear engineering-minded professional answer, not just some Dad's opinion on mtbr.com ;D
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
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.
You can't beat science! Thanks!
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.
GREAT info, TY!
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?
Yes, id think the forces from the collar would change while it was in the stand... But it increases a lot more while riding.
Well that answers my concerns about my dropper. Won’t be wasting time clamping to the frame near the seat post anymore.
This was totally smart and funny. Thank you!😂
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.
Awesome, perfect and to the point with some engineering data. (And that you did imperial and metric)
Awesome. Well explained
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.
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.
If your threads are dry, that's a bigger problem than damage to your dropper.
@@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.
Re seat post collars - I've changed from standard collar on Scott scale labelled 4nm to a hope collar labelled 8nm, should I have stuck with same nm collar as stock or are all seat post forces equivalent (the hope is approx double width of stock)?
Seat post collars are a great example of where a torque specification is limiting and not always applicable. The there are now three manufacturers involved, so ideally all three should collaborate and agree on a torque. The frame maker, the post manufacturer and the collar manufacturer may have each different ideas. Here you want minimal torque to achieve the job, which is hold the post. If the post does not twist at 4Nm, then it will now slip down. If it takes 6Nm, then 6Nm is the right torque, etc.
My new tallboy will be here later this week. All i have for a bike rack is a trunk mount so i will have to use my top tube adapter to mount the bike. it. Is it ok to use the top tube adapter with the dropper post as long as i have it in the extended position?
Sure thing. Be sure that everything is very secure to prevent anything from falling off.
Thx guys! now i can work on my new bike 🤘😄👍
Great team work 👍
What about forces when you are actually working on the bike ? If I work on BB I may apply more forces and weight...still not sure what’s best practice🤔
If it's a threaded BB you're working on and you're either torquing it down or cracking it loose, you can do it with the bike on the ground.
At least that's how I do it.
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!
I love first-world problems. Great vid guys!
11:32 "Please clamp" lmao good reference
Really really interesting! Good to have this issue de-bunked scientifically
I tried the glove on the clamp thing but because I put a thin layer of float fluid on my dropper to keep it slick it just slides around, I clean rag instead worked a treat, thanks guys it’s been a question I always forget to ask after working on my bike
Anybody run into any finish issues clamping a Kashima coated Fox dropper post after a while? rookie MTB rider here, just wanna know? I've been clamping with a microfiber cloth but it does slide down
Nice video. Can a dropper seat post withstand a heavy ebike? Lets say 26kgs?
Hi guys, have a question. Can u rotate the bike up or down 45-90 degrees using seat post or need to use a frame for that. If yes how much clamping u can do for carbon frame?
what for clamping seatpost from madone SLR?
Clamp right to the exposed post above the mast. You may need to raise it.
good job boys great help
What about clamping the top tube?
Hello guys! I have a FAT HS Ebike that weighs close to 100 lbs with accessories. I need a repair stand to handle that, any recommendations?
For a bike that heavy we suggest one of our shop stands. PRS-3.3-2 or a PRS-33.2.
Thank you for settling this!
Nice demonstration 🔧👍