Mountain Bike Reviews Forum banner

Clamping dropper posts in workstands?

53K views 67 replies 32 participants last post by  274898  
#1 · (Edited)
From what I have read from people's opinions is that you shouldn't clamp a dropper post in the workstand. If you do, it should be on the lower part of the post and not the stanchion. However, I brought my bike into the bike shop and they clamped it on the stanchion. I asked them "are you supposed to clamp it like that?" They said your body is heavier than your bike which make sense. However on second thoughts, I don't think there is as much lateral forces on the post when pushing it down with your body as opposed to the bike swaying back and forth clamped on a workstand. So, I am not totally convinced it is safe to clamp it on the stanchion and not sure if the bike mechanics are correct on this one.

Anybody have information on what manufacturers have said or input if it is safe to clamp your dropper into a workstand?
 
#2 ·
I clamp by the stanchion also. I do use a piece of neoprene as padding between the post and the clamp.
I also rest the front wheel on the ground if it's going to be in the stand for an extended amount of time.
Not sure if any of that is necessary; but I know it doesn't hurt.

Sent from my SM-G920V using Tapatalk
 
#4 ·
My seatpost clamp and seal head of the post are very close in size. I clamp right at the seal head and seatpost clamp. I've used a clean rag on the sanctions before but it's not something I want to risk. Weight is not the issue, scratches are.
 
#5 ·
Yeah, I think the risk is more from scratching the stanchion than anything else, though I suppose the lever force of the weight of the bike when the stanchion is clamped can add wear to the bushings internally. Still, I think the primary risk is from scratching the stanchion.

I tend to clamp on however much of the lower part of the post is exposed on my bike. Which amounts to roughly half of the area of the clamp itself. Some of it touches the stanchion, but I'm not squeezing grit onto that stanchion.

I cringe a little bit when a shop clamps the stanchion of my dropper into the stand with a dirty rag, though.
 
#6 ·
Really depends on the seat post, some posts use the stanchion as a sealing element, some don't. As a Mechanic I don't waste time trying to figure it out, if I can't clamp it neatly by the lower collar I put a clean rag in the clamp jaws and clamp it by the stanchion. The one thing I will NEVER do is clamp it or hang it by the seat while the post is in ANYWAY compressed
 
#10 ·
That would be a giant PIA if I had to do that as a shop mechanic for every bike with a dropper and is unnecessary overkill.
I don't even have a dropper yet but I've ordered one and I've specifically chosen an external-routed one. It literally takes seconds to unclip the cable and pull the post out. Another few seconds to drop in an old seat-post. Many internal-routing posts also have quick-release cable fasteners at the base of the post. $25?

It seems to me that the desire to clamp on the dropper is not driven by a strive for best practice. I think you just want to justify doing it because it's the quickest and easiest thing to do. It's about saving time and money, not saving the dropper post. But what do the people who make the posts say?

Specialised Command Post:
"CAUTION: When placing the bicycle in a workstand, do not clamp the bicycle by the seal head or upper tube section as they are both part of the air seal system inside the seatpost"

RockShox Reverb:
"To clamp a Reverb equipped bicycle into a bike stand, loosen the seatpost binder bolt/quick release at the frame. Raise the seatpost to the Minimum Insertion line then tighten the seatpost binder bolt/quick release to the frame manufacturer's recommendation. You may need to detach the hose from some of the cable guides in order to raise your seatpost to the Minimum Insertion line. Do not exceed 6.7 N∙m (60in-lb). IMPORTANT:clamp the seatpost into the bike stand just below the top cap. do not clamp the seatpost by the top cap or allow the hose to be clamped as this may damage the seatpost"

Thomson Elite:
"It is not a good idea to use the seatpost to hang the bike in any way. In a work stand, it is possible to crush the outer tube when clamping pressure is applied. If you are supporting the bike by the gold stanchion, you can damage the internal components."

Fox Transfer:
"The anodized surface of the upper seatpost, like a rear shock body, serves as a sealing surface. Always take every precaution to avoid causing abrasion damage to the anodized surface of the upper seatpost. The upper portion of the Transfer seatpost may be carefully clamped in a workstand. Do not clamp the cable pulley mechanism of collar cable routed Transfer seatposts."

So the manufacturers say that either you must not clamp on the upper tube at all, it's not a good idea or you can do it but you need to be careful not to scratch the coating. Would you clamp on the stanchions of your suspension fork? No? Well it looks like your bike mechanic would.
 
#11 ·
It's a bad idea, but what to do since most have droppers. The "substitute a standard post" is a good idea,but not really practical.If it's a external cable, just pull the post up enough to clamp on the lower post.

I've been LIGHTLY clamping on my frame ALWAYS supporting the front wheel on a box/whatever. My $0.02
 
#12 ·
It's a bad idea, but what to do since most have droppers. The "substitute a standard post" is a good idea, but not really practical.
I sympathise with bike mechanics. I don't think manufacturers give a stuff about how their new innovations effect the guys who have to work on the bikes, look at internal routing, but it's not an excuse for sloppy practices. For many years I did all the work on my car myself because I was fed up with mechanics who did not do it properly. It wasn't a one-off, it was every time. Every trade is the same, it's not about doing a perfect job, it's about doing a passable job as quickly as possible. Minimise time on the job to maximise profit or maybe just to try and stay competitive. Bike mechanics are hit particularly hard as no one wants to spend a lot on bike maintenance. People regularly ask why I don't service bikes for a living and I tell them it's because it would be too hard to earn decent money. I understand the situation.

However, I don't think it's an excuse for advocating something that's not a brilliant idea. Clearly, if you can avoid clamping on the upper section of a dropper post, you should.
 
#13 ·
I have turned the clamp on my Stand horizontal and just hang all my bikes by the top tube. Don't even clamp them. I have a soft clean micro fiber rag to protect the paint. Never been a problem. My cross bike doesn't have a dropper but its a pia to remove the seat bag to access the post. And i would not clamp my dropper due to the lateral force already mentioned
 
#14 ·
I hang my bike by the seat rails where they meet the seat post (not using the stand clamp) with the dropper (LEV external) fully extended. If the seat post can't handle this then there is no way it's going to support my fat ass on a ride. I use the work stand clamp only when absolutely necessary
 
#18 ·
I hang my bike by the seat rails where they meet the seat post (not using the stand clamp) with the dropper (LEV external) fully extended. If the seat post can't handle this then there is no way it's going to support my fat ass on a ride.
It's not about the weight. Depending on the design of the post, it might not be a good idea to do that because you're pulling up on the top post. It's designed to take weight pressing down and pulling up could damage seals or other internal parts. It could be fine, you just need to check the advice for your particular post.

... don't forget to non-permanently mark the post to ensure your precious seat height doesn't change by .25mm, then spotlessly clean that mark after taking just a couple of seconds to reinstall it....
You're only confirming what I said. You don't clamp on the dropper because it is best practice, you do it because it is quicker and easier for you. I understand that, I just don't want to copy you.

Some of your objections are silly to be honest. I stick a piece of masking tape on a seat-post before I pull it out so that it goes back at the same hight. Doesn't leave a mark and yes, I have old seat-posts in a basket. Does not take up a huge amount of space and does take seconds to lift one.

I do get that some posts are more of a pain to deal with and I would charge extra. I would say to the customer that either they risk clamping on their post or they pay more because they've bought a stupid internal hydraulic post. Choice is theirs. The bike industry has been dumping extra work on mechanics for years and I don't see anything wrong with letting the end user know that his choices in bling have consequences for his wallet.
 
#15 ·
"I don't even have a dropper yet but I've ordered one and I've specifically chosen an external-routed one. It literally takes seconds to unclip the cable and pull the post out. Another few seconds to drop in an old seat-post. Many internal-routing posts also have quick-release cable fasteners at the base of the post. $25?"

"I don't even have a dropper yet but I've ordered one and I've specifically chosen an external-routed one"
- Which should NEVER be clamped externally in any way

"It literally takes seconds to unclip the cable"
- If it has a cable, which end unclips, do you compress the post first? of the 20 plus posts out there they all do it different. If its hydraulic then I'm face with a possible remote bleed afterwards and takes significantly longer than "seconds"

"and pull the post out."
- don't forget to non-permanently mark the post to ensure your precious seat height doesn't change by .25mm, then spotlessly clean that mark after taking just a couple of seconds to reinstall it.

"Another few seconds to drop in an old seat-post."
- yes if I had and "old" seatpost just lying around in one of the 6 "standard" sizes in arms reach, I don't, I'm gonna have to find a used one, space is limited in a bike shop and costs $$, yes an old seatpost doesn't take up a lot of individual room, but neither do the 500 other odds and ends we "might need some day"

"Many internal-routing posts also have quick-release cable fasteners at the base of the post"
- Yes "many" do, by this point we've applied "tools" to the bike, applying tools carries an inherent risk, "wasn't that way before you touched it", "inherent risk" to resolve all issues carries a cost.

"$25?"
- We bill at $60 an hour, could that take 25 minutes, absolutely. But you are obviously an experienced home mechanic and you should do it your way when you finally get a dropper of your own
 
#16 ·
In general, it is not a good idea to clamp any stanchion/sliding surface. If you have to do so, do it lightly. Most modern bike stands will allow for clamping in various places, such as lightly clamping the frame itself if necessary. Clamping down on carbon frames can be worse, or better, depending on the shape of the frame and how much force is or is not applied. There's not a perfect answer.
 
#20 ·
Personally, I don't like the idea of using a clamp on the stanchions of the seat post. There are several problems I could see happening. One is the stanchions could get scratched. Regardless how of clean your stanchions are and how clean you think the clamp is, there are inevitably going to be some dirt that will get caught between the two when you use a clamp on it. This will cause scratching and eventually wear over time. Secondly, dropper seatposts are designed to take weight from sitting, not in the opposite direction. This along with lateral pressure could cause the dropper post fittings to become loose or seals to fail.

If I were a bike shop I would invest in one of these and one of these so as to not piss my customers off.

 
#23 ·
I will hang the bike lightly by the seat on my reverb. However that is to take some weight and the front tire is still on the ground. If I need to do more work I lower seat post. Remove it leaving all the cables installed and put in the stock fixed seat post. I don't want to camp on the moveable part of the seat post. Why risk it? I am not getting paid to this work so time is cheap compared to a new seat post.

For shops where time is money... yeah it is more complex.
 
#25 ·
Not Mine. :skep:

Your right though, it's never a good idea to clamp the sanction. I hang by the saddle, use the feedback scorpion bike stand or clamp around the collar as a last resort. When I built the bike and if I need to do major work I swap out the post. :thumbsup:
 
#29 ·
Your dropper has multiple stanchions?

Maybe the guy who is working on your bike knows more about it than you (as evidenced above) and therefore should be able to make that decision for himself? If you want to nitpick practices that the manufacturer's themselves say are safe, then you should do your own work.
 
#30 ·
Only when not fully extended. There is a mechanical connection when the post is fully extended, making it perfectly safe. I was told that by a SRAM tech, as well as shown on a dry Reverb he took apart to show us... Not to mention, it 'clicks' when it hits full extension which would seem to confirm that even for the layman.

You are totally correct when it comes to a lowered post though... I try my hardest never, ever to put any upward force on the post when lowered even slightly. That won't break anything, but it will require a rebuild to get fluids back where fluids go and air back where air goes.
 
#28 ·
Do you expect a new frame too if they clamp by the frame? I have seen more frames damaged by a bike stand then a dropper post, in fact I have never seen one damage a dropper.
Not sure if you're trolling... A bike shop clamps your $3000 carbon frame.... and you're cool with that?

Either way, dropper or frame, if it has the potential to have a negative affect on the part it's not cool. If you're working on your own bike to each their own, but for a bike shop to say, I don't have time to take care of my customer's bike the best way I can is asinine.

And like I said, if I took my bike to a shop and they clamped it by the frame or by the stanchion, I'd be pissed.
 
#32 ·
The manufacturer disagrees with you, as do the techs charged with training shops how to work with and service them... There's no need to act like it's a mysticla

As I've said three times in this thread now, the sag develops when the bike is lifted or hung from the post when it is dropped below full extension as it pulls oil past the IFP into the air.
 
#39 ·
Sorry to revive an old thread but I’m getting my first bike with a dropper post. It seems some think it’s ok to hang a bike with dropper by post or saddle and some don’t. My SC Hightower has a RockShox reverb which seems fragile?
Can I hang my bike from the solid/adjustable portion of my seat post (where the dropper goes into) or is that just as bad as holding by the stanchion? I hate to hold up by the frame but if that results in less potentional damage then maybe that’s the way to go...
 
#40 ·
Sorry to revive an old thread but I'm getting my first bike with a dropper post. It seems some think it's ok to hang a bike with dropper by post or saddle and some don't. My SC Hightower has a RockShox reverb which seems fragile?
Can I hang my bike from the solid/adjustable portion of my seat post (where the dropper goes into) or is that just as bad as holding by the stanchion? I hate to hold up by the frame but if that results in less potentional damage then maybe that's the way to go...
Clamping on the lower portion is totally fine. The work stand clamp shouldn't put any more pressure than the seat collar of the frame, so no problem.

The risk of clamping the stanchion is from scratching it, primarily. LOTS of shops will clamp the stanchion, and should at least put a rag in there to minimize scratching risk.

I avoid clamping the stanchion if I can, and use a rag when avoiding it would be too much of a pita, like on my wife's bike.

Sent from my VS995 using Tapatalk
 
#41 ·
Sometimes I will clamp the top tube depending on what I am working on. Other times, I will loosen the dropper, raise it up, and clamp it from its base. Seth from Seth's Bike Hacks came to the conclusion to just clamp it by the stanchion. He covered this in an older video.