Possibly obvious question alert but…
if a dropper is advertised as 420mm length and has say a 100mm drop, if you allow 20mm or so for the collar does this mean you have 300mm in the seat tube if is it’s as low as it can go?
or put more simply is the stated length the total length of the post fully extended??
I'm assuming yes but it’s not always obvious when reading shop listings.
trying to find something for my sons 24” clash which has a short seat tube, but he’s only just on it and the post is slammed right down so struggling for options.
Hoping not hoping for a growth spurt.
Oh and I do appreciate the real answer is if post is all the way down anyway why does he need a dropper 😂
backstory: it has a funny seat post combo by gusset (odd choice for a kids bike) where the post is screwed directly into the saddle. Saddle is horrible and knackered so will need a new post to replace it anyway and he will need a dropper eventually so this is just me trying not buy two posts.
All the droppers I have ever bought have had a diagram showing where each measurement is.
What you suspect lines up with what the diagrams I have seen generally display. The total length is extended including the mechanism, then you subtract the width of the collar and the drop. And a bit more for the gap between where the drop ends and where the rails start. The width of the collar can vary too, just to make it not easy, although I don't think I have had any that are more than 30mm
It varies. Some take account of the mechanism. Some not so much.
https://www.oneupcomponents.com/pages/dropper-post-length-selector
