I need to know how can I build this bicycle seatpost because I need a custom size of pipe, I need to build a mold or there are some others technics?
That seems excessively difficult to do. There are shims available to convert between common sizes on bicycles.
If you are set on making this yourself, simplify the shape and make a mold. I would split the design in 2 pieces; a clamping piece and a tube piece, post-bonded together.
You can’t make that effectively. Buy one.
No i can’t use a shim, this photo it’s only for example to se the head, i need to build a part like in this photo and I would like to know the technics to build
The second pic might be easier. You can design some sort of male mold and wrap it carefully. The adjustment posts seem to just be a solid CF rod, which is more or less easy to do. Might need pre-preg to aid simplicity.
Also, make sure you watch your layup, and get the fibers in the right direction.
That first pic, seems complicated…not sure how they do it, besides aquacore, or foam maybe?
The first one looks well made, and well designed. The second one is a joke, tossed together after raiding the spare bolts bin and playing with a drill press. Someone weighing more than 80 pounds might just end up with a carbon fiber pole up their arse.
I think it is more well built than that…
doesn’t have to LOOK pretty to perform it’s exact design!
tomorrow I will make a photoshop picture for show you what I want to do.
I would personally go with a full aluminum seatpost, the weight difference cannot be that much.
I have a lot of experience in bike parts, and granted you may not want to use 4130 Chromoly if you are looking to save weight, but 7075 or 6061 Aluminum should be fine. I agree that the top part looks top notch, and the bottom was rushed together. I have seen carbon fiber forks, handlebars, etc, however a lot of the time I still see them reinforced with aluminum, such as the portion where the axle bolts up on forks, or the knurled clamp where the neck clamps to the handlebars. I bikes have personally taken a beating, and I am sure there is a lot of R&D involved in the top part and when your safety is involved, unless there is a matched amount of R&D involved.
Thomson Elite or Masterpiece seatpost, man. I’ve seen too many broken seatposts made of cf over the years.
If you need to create one of this like the first pics, you need at least 2 pieces of mold, front and the back. When you created you must put at least 10 sheets of carbon (8 sheets of 205gr making 2,2mm thickness) . After that you must connect them together. The connection is a difficult part, you must fix the mold with extra modifications on it before you go to create the part. I will try to fix some drawing to understand.
and bars!! CF scares me. Designed wrong, used wrong, or clamped wrong…it won’t bend before breaking…it just will break!
Hi guys! thanks for all reply!
this the seatpost of my scott scale ISP, it’s a rithey alu single bolt. The new single bolt system clamp it’s very sick for me because not tightens the saddle well.
What I would like to do is to make a carbon seatpost with the design of old two bolts clamp system and a part of tube to fit my scott frame, I have made a photoshop picture to show you what I say
I can also buy a originale ritchey carbon seatpost in 31,6 mm size and cut the head with some tube and then make the extact tube size for my frame and attach to ritchey seatpost part.
what is the point in all this work just to make the CF head? There has to somethign out there that would suit your frame. Might as well machine everything out of aluminum than to figure out how exactly to layup the carbon and attach it to the Al seat post tube.
Well…I’ve gotta disagree just a bit on that one.
The way I see it, you sit on the seat, you only lean on the handlebars. No matter what you do on a bike, you’ll never be able to put as much stress on a handlebar as you will on a seatpost.
Further, if you’re using a 31.8mm handlebar, that’s often significantly larger than the seatpost.
I must give credit where credit is due, though. Easton’s first generation carbon composite Monkey Bar had something like 26 warranty claims in it’s first year, Canada-wide. When they changed over to the Zyvex/CNT construction, that number went down to 6 the next year, with most of them being over-clamping failures.
I do run one of their carbon bars, and it’s been flawless. But even then, I still can’t bring myself to using a cf seatpost.
+10000000 I agree
simple I want two bolts system.
I remember when CF was first gaining popularity for mass production, and I heard many bad things. I would have guessed things have gotten better designwise. Most things I heard were people clamping unevenly, along with a microcrack caused by fatigue, or human error. Good to know that the newer gens are better. I have one, but it’s also on my XC bike, which I do’t use for anything but flat paths anymore anyway.
I still wonder about a fully CF downhill bike with a sick amount of travel many years ago. I think the rear suspension was all solid CF, not pivoted.