Knightyboy27 wrote: ↑
Mon Feb 08, 2021 5:20 pm
What is the min insert of your seatpost please?
From your photos, I would assume that given the constant thickness of the post, there is no specific insert range unlike other brands?!
Actually there is insert range for the seatpost. Its just the seatpost on the pictures above is 200mm long and so short that as you noticed it basically consists from the clamping zone and thereby has almost constant thickness. Also part of the reinforcements along the seatpost ends in the middle of the tube because the higher it gets - the lesser the lever of the load.
This is another cross section btw
But for longer posts we make 200mm clamping zones for 400/350mm long seatposts and 150mm zones for 300/250mm seatposts like on the picture below - on the right couple of finished seatposts with matte clamping zones. (actually the real lay-up for clamping zone goes 220mm up but matte zone goes only for 200mm just in case
Truth to be told - the post will be just fine in most cases even if clamped in the wrong place,
I cut the holes for the bolts by cnc-mill to make them precise and in order to do that - the post has to be clamped as high as possible:
Like on this video: https://www.instagram.com/p/CAgGGL_Fm6-/
(sorry, I'm too lazy to upload something on Vimeo for the minute of cnc mill cutting carbon fiber
so here is the instagram link)
Of course the tube is weaker in places without layers of carbon which go around the tube, but I tested it for the x3 loads of clamping which occurs when I set the post into the cnc mill and it was just fine. But of course the post which was clamped in the wrong place and broken won't be warrantied - we are small company and don't sell much but no one was smart enough and managed to break one yet) In worst case scenario with seatback, long post and the saddle pushed as far back as possible the post sustains 300kgf of load and then the saddle's rail breaks or bends if its made from steel. If rail is clamped for the middle - the post breaks around 400kgf of load.
And we make custom lay-up with longer or shorter clamping zones for free, so its not a problem anyway))
On the other side - I (and any other sane person) would recomend not to insert the post less than 70mm into the frame because it possibly will just break the seattube of the frame and that would be a real pain in the ass.