How To Choose The Correct Dropper Post Size!

buying a dropper post can be a bit of a minefield you'll want to know how much drop you can have whether it'll even fit in your bike or not and whether or not to buy a lever separately so stay tuned and i'm going to go into depth about all the different things you'll need to consider when swapping or buying a new dropper post if you've already got a dropper in here and you just want to go for more travel so for example dropping this post in as far as it'll go and getting more travel for your money then you might just be able to measure how much you've got so i've got about 30 ml poking out here and i've got a 180 travel here so you could potentially go for a 210 if you were adding those together so if you want the maximum amount of travel or drop in your dropper post then you're going to need to work out your stack height so this is the stack height basically from clamp to clamp and you need to account for the fact that dropper posts have a collar at the bottom here and also it may not drop all the way in because there'll be a little bumper here or a clamp at the top so a stack height on here i've got 23 centimeters or 230 mil and my clamp and collar is about 30 mil so that basically means to get the maximum i can only have a 200 mil travel drop as it's the difference so if you're running a static post and your post from the bottom of your saddle to your clamp in your frame is for example 24 centimeters then if you minus 30 centimeters usually to account for the clamp and the collar then you'll know how much travel you can have as a maximum now if you're buying a new frame and you want to buy a dropper at the same time and you want the maximum then the way i work it out is to work out how high i want my saddle in relation to my pedals so my height is usually my inseam of my leg which is 79 centimeters or 790 millimeters so that is 790 so in order to get your maximum travel you need to do a little bit of maths here you need to subtract the crank arm length so 170 and you need to subtract the seat tube length from the bottom bracket which should be on your manufacturer's spec when you're buying it and then you need to subtract another 30 mil to account for the clamp and the collar and also minus the stack height on your saddle what you're left with is the maximum amount of travel you can have on your dropper bonus tip for you here keep an eye out for dropper posts that can be shimmed down so i've got a one-up dropper here which can be adjusted by 10 or 20 mils so i worked out that i could have 160 mil travel in this frame and they only did a 150 or a 180 but because i knew i could shim it down by 10 or 20 mils then that means i bought the 180 so that i could shim it down to the perfect 160. now it's all very well working out your maximum drop and trying to get that but you need to make sure that that actually fits inside your frame so as you can see i've got a little bit of a bend down here so we refer to this as the insertion depth so the insertion depth on a dropper is basically the measurement from the top where it goes up to the clamp all the way down to the bottom and you'll need to know that because obviously something like this which is quite long won't go all the way into my frame so i might not be able to run the maximum length possible anyway so in order to work out your insertion depth you can either get a tape measure and just measure down to where you think it's going to stop or you need to take your dropper post or your post out and drop something down until it stops sometimes it will stop on a bottle cage bus sometimes there'll be little collars that will stop it going all the way down or you can simply loosen up this bolt here and drop your post all the way down as far as it can go get a piece of tape just to mark at the top of the clamp and then pull it out and then you get to measure from the bottom of that tape all the way down and that's your insertion depth so if you want your post to go all the way in then you're going to need to work out what that is and check the drop post manufacturer specs on their insertion depth as well as knowing how much insertion depth your frame can take you'll need to know what size post it takes as well there's three or four on the market so you can pull your post out and have a look usually it's written on there so this one's a 34.9 and you just want to match that basically or you'll have to check the new specs on your new frame to see what post it takes and then match that when you're ordering your new dropper post another thing to consider with your frame and putting a dropper in there is whether there's any routing any cable routing for that dropper so this frame has an internal routing system here sometimes some frames will have some spare places to route an external cable on the outside of the frame like this but if you don't have any routing if it's an older frame perhaps then you may have to accept a lever-operated dropper so that's a dropper with a lever up here because otherwise the cable is not going to be able to come out anywhere so you won't be able to operate it other than that you could invest in a slightly pricier electronic version which means that it will talk to the lever on your handlebars without a cable you may notice that you can buy levers separately or sometimes you can buy droppers that don't even come with levers and that's because people just have different preferences on what levers they want to run and some levers will even be compatible with the clamps on your brakes one thing to bear in mind is which way the cable goes in if it's a cable operated dropper because if you're only upgrading the dropper and you want to keep your existing lever then you want to make sure which end the little feral on your inner cable goes so most modern ones will have the ferrule in the dropper end and then it will be clamped at the lever end some older dropper posts like this one has the ferrule in the lever and then it's tightened up at the dropper end so if i was swapping this for a newer one where the ferrule goes in this end then i'd need to buy a whole new lever as this wouldn't work with it now the benefit of buying the levers separately is that you can often get them to match make with your brakes so on my bike i've got some tram brakes so when i ordered my dropper i ordered a sram mmx or a matchmaker system so that the lever directly attached to the brakes and everything's nice and simple you can also do this with shimano so it's often referred to as shimano is or shimano ispec and there will be some aftermarket levers that will work with something like magura or other brands like hope for example so something to bear in mind if you want a different lever to what comes with your dropper then just make sure that the direction of the cable is the right way round otherwise they won't be compatible there are three types of droppers on the market you can get mechanical hydraulic or electronic so mechanical is basically a cable operated one these are usually the most affordable because it's a simple system and they can be quite easy to fix because it's just an inner cable through an outer cable basically and then the hydraulic version it can be a smoother action but reservising them requires bleeding much like hydraulic brakes so you want to account for whether you want to be doing that on a regular basis and then there's electronic so this will be a cable-free system it's very neat very clean looking no cables obviously but it does mean it will require batteries to be charged on a regular basis and for that reason it's probably a little bit more expensive than the other two options once you've got your new dropper it should be pretty easy to install at home but if you want a refresher then check out doddy's video on how to install a mechanical dropper or check out neil's video on how to install a hydraulic dropper and those links will be down in the description below i've also done a video showing you how to troubleshoot any problems with fast or slow droppers and how to fix a cable on the trail side so do check those out but for now enjoy shopping thanks for watching

Channel: GMBN Tech

Views: 45,415

Keywords: adjustable saddle, dropper seatpost, dropper seatpost sizes, dropper seatpost routing, dropper seatpost explained, internal dropper seatpost, external dropper seatpost, mtb tech, bike tech, mountain bike, Bicycle (Product Category), MTB, bicycle, gmbntech, GMBN, Global Mountain Bike Network, mountain biking, Downhill, XC, Cross Country, Enduro, MTB skills, bike skills, mountain bike skills, bike, bike riding, cycling, gmvn, Anna, Ҙ, 4772, ᐶ, ߚ‎, 1k, 1o, ኽ, 1v, ው, Ꮖ, ᢜ, plgbs, Ҟ, ፕ16, ҩ, Ҧ, Ҭ, Ҳ, Ҵ, Ҽ

Id: 5g9g6T5amIA

Length: 9min 37sec (577 seconds)

Published: Sat Jul 30 2022