schleprx7
Member
For those of you that are concerned about clamping ebikes or bikes in general by the dropper post. This video from Park Tools explains why this is not a problem:
Always clamp on the dropper, no problems at all. The jaws tend to mark the frame otherwise, and wreck the invisiframe wrap. If I had a carbon frame I would worry about damaging the frame as well. I think the stands are designed to work best clamping on the dropper, plus it's just convenient.For those of you that are concerned about clamping ebikes or bikes in general by the dropper post. This video from Park Tools explains why this is not a problem:
It's not so much about the clamp, it's more the idea that droppers aren't made to have 40 or 50 lbs of ebike hanging off them - it's one of those "it's probably going to be fine..." things (as long as the dropper is fully extended), and I can understand people being nervous about it.I think the stands are designed to work best clamping on the dropper
It is in fact 100% completely fine, as the video proves: The clamping force of the seat clamp is 70kg/cm (squared), whereas the clamping force of the jaws of the workstand exert a mere 4.3 kg/cm (squared). The rotational force on the post with a 14kg bike is a mere 27nm. Okay, most eebs are 7-10kg heavier, but for anyone good at these calculations (I'm not) it's still not a huge amount of force, compared to the forces transmitted by the weight of the rider, out on the trails. In the workstand, say you have a 24 kg bike. Even if the entire 24kg is hanging off in one direction, (which it isn't, the weight is distributed, say 60-40front/rear), this is nothing compared to 70-110kg of rider, exerting a rearwards force on the dropper. The only issues with clamping the dropper are 1) you want nice clean jaws 2) clamp with the dropper fully extended, otherwise on some posts the lifting force can create a vaccuum which will cause the air and oil to mix = saggy dropper post.It's not so much about the clamp, it's more the idea that droppers aren't made to have 40 or 50 lbs of ebike hanging off them - it's one of those "it's probably going to be fine..." things (as long as the dropper is fully extended), and I can understand people being nervous about it.
I've seen videos of people "tombstoning" off 100 ft cliffs and coming away completely unscathed - doesn't mean it's a good idea!It is in fact 100% completely fine, as the video proves:
Yes, and the video mentions this as being one of the essential caveats, as well as having a clean stanchion and clean jaws. I mentioned this in my post as well. The video proves, mathematically and by measurement, that any dropper post is perfectly able to withstand the forces exerted on it by hanging the bike from the post in the workstand. So really, your only argument against doing it is that you think it's a bad idea. Fair enough, you must do what you feel comfortable with , of course. But think about it. ParkTool have been around since nearly the dawn of time, and are considered to be a reliable authority on all things cycling. Through their YouTube channel, they have a huge amount of social responsibility. Do you really think they would come out and say it's 100% fine to clamp on the dropper if it wasn't?"the weight of the bike in the stand can extend the post and pull air past the internal seals inside the post"
Your new stand does sound like a great idea. Limitations working around the motor covers doesn't sound like too much of an issue, I've always had the bike upside down when removing the motor. I agree that it's best not to clamp even an alloy frame. As for the rotational force acting on the dropper held in the workstand, when you think about it , 70-110 kg or more of rider on the saddle is going to exert a far greater rotational force on the dropper than 24 kg of bike.The maths assessments are fine but the weight of the bike is not being taken vertically, it is at an angle and that may well be ok on a 9 to 13 kg road/mtb analogue bike but a 24kg Emtb??? I rate Park Tools expertise but until the latest E-EWS races there has not been a pro circuit for EMTBS and that is where a lot of their expertise is acquired...then passed down to consumer level. Even clamping the top tube on an ally bike centrally is hanging a lot of weight on a tube that is designed to withstand compression not lateral loads.........on a carbon frame it is a non starter.
I am getting the Park Tool PRS 22-2 which supports the bike from below the motor housing and uses a fork mount for stability. Looks a far better idea to me albeit with some limitations probably working a round the motor covers depending the bike. Ill let you know how it goes.
I think the point here is that we (the riders) are exerting force in the direction that the bike and its components are designed to take - that's not necessarily true in the context of hanging a bike from its dropper.when you think about it , 70-110 kg or more of rider on the saddle is going to exert a far greater rotational force on the dropper than 24 kg of bike.
You're worrying needlessly... well maybe not entirely needlessly.. if you're a fully grown adult who rides a mountainbike off road at any sort of speed that can't safely be held by either its' dropper seatpost or carbon top tube you have way more to worry about than what workstand to chooseThe maths assessments are fine but the weight of the bike is not being taken vertically, it is at an angle and that may well be ok on a 9 to 13 kg road/mtb analogue bike but a 24kg Emtb??? I rate Park Tools expertise but until the latest E-EWS races there has not been a pro circuit for EMTBS and that is where a lot of their expertise is acquired...then passed down to consumer level. Even clamping the top tube on an ally bike centrally is hanging a lot of weight on a tube that is designed to withstand compression not lateral loads.........on a carbon frame it is a non starter.
I am getting the Park Tool PRS 22-2 which supports the bike from below the motor housing and uses a fork mount for stability. Looks a far better idea to me albeit with some limitations probably working a round the motor covers depending the bike. Ill let you know how it goes.
No. On the trails, the post must withstand forces from all directions, with a much heavier weight than what a bike weighs. It is plenty strong enough to withstand the weight of an e-MTB in the workstand, even if your bike is at the heavier endI think the point here is that we (the riders) are exerting force in the direction that the bike and its components are designed to take - that's not necessarily true in the context of hanging a bike from its dropper.
Again, the forces exerted on the trails are far in excess of those in the workstand. For a long seated climb, the post is at full extension and you are perched on the front of the saddle. A whole lotta human = a whole lotta force.Let’s hope they are all strong enough where the topping out of the seat tube happens inside. That would be the weak spot I would think. Might not show up right away, but could weaken later and come apart. ?
I don't worry Gary.You're worrying needlessly... well maybe not entirely needlessly.. if you're a fully grown adult who rides a mountainbike off road at any sort of speed that can't safely be held by either its' dropper seatpost or carbon top tube you have way more to worry about than what workstand to choose
You are Swiss Toni, and I claim my five pounds!I have a super cheap £29 ebay special, looks identical to the Halfords one at £40
Skinny legs that spread easily.
Sure, she will squeal if you insist on bouncing your full weight up and down on top of her.
But work with her limitations, and get the position right and it feels really good
I am happy working on it, and leaving it unattended next to a proper cherished garage queen.
It isn't going anywhere.
If you have money to burn, fill your boots on a Park, but the cheapie gets the job done.
I think the Decoy will be a bit intimidated in that companyI bought a SpinDoctor Pro G3 12 years ago for my analog bikes. Now its just sitting in the garage waiting for the Decoy Shred! View attachment 42328
Got a link for this man ?I have a super cheap £29 ebay special, looks identical to the Halfords one at £40
Skinny legs that spread easily.
Sure, she will squeal if you insist on bouncing your full weight up and down on top of her.
But work with her limitations, and get the position right and it feels really good
I am happy working on it, and leaving it unattended next to a proper cherished garage queen.
It isn't going anywhere.
If you have money to burn, fill your boots on a Park, but the cheapie gets the job done.
Very impressive, but I can't justify spending NZD$800 for a bike stand, neither do I have the room in the garage to bolt it to the floor. Being a a pensioner, I purchased a Torpedo 7 bike stand for around NZD$80 a few years ago. It copes with my Giant Trance e +1 pro's 21 kg (minus battery) easily and has yet to fall over. Well done though.I built my own using a Park Tools clamp assy. Having a buggered shoulder, I struggled to lift bike into my old stand so built this with a 12v Boat Winch. All up cost @ $800.00 NZD
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I have the same design but by Park Tools. I use it for my Levo and my Whyte E180 and find it a lot more functional than a standard clamp stand. I can do most maintenance sat on a chair and just rotate the stand to get at both sides.Very happy whit this Feedbacksport,i use it to work on,wash etc
You can spin the bike around,folds up easy
It comes whit a bag whit front axel adapters also
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Assuming one doesn't want to spend a fortune on something bespoke, is there one?
Maybe with a ratchet to raise the bike to eye level or the like...
show me a picture and a rough price. Cheers IainEnded up designing and manufacturing my own, after getting frustrated with the poor quality and flimsiness of ones currently available. Maybe a bit 'over engineered'?
(I do happen to run my own engineering business, and have considered maybe selling them if there's any interest.... let me know)
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