Possibly a stupid dropper post question (for Trek Remedy)

Ordered a Brand X 480mm length dropper for a pressie for my son’s Remedy…. (yes, Christmas presents for bikes 😀)
Without fitting it (in case I need to send it back, like) how can I accurately measure that it’ll fit the frame? Will I need to remove the old one completely? Or is there a clever way to measure the drop in the frame my old brain can’t get a handle on?

cheers!

Contact trek to ask for the max insertion depth for your lad’s frame?

Unless the existing post is branded, and you know its dimensions, it will be hard to know for sure if you have the clearance without getting it out and sticking a ruler down it. It’s normally a good time to tip half a pint of muddy water out of the bottom bracket as well…

Yeah I’m 5 mins in @hols2 – does he actually mention how to measure the internal drop for a Remedy (or any other frame for that matter)?

Unless the existing post is branded

The existing post is a Bontrager, but he wants a longer one in there. I’ve tried taking it out, but there’s like, cables and it’s not obvious where the limit is in the frame.

Cables in the way after you’ve taken it out/disconnected it? Do you know the collar to base depth on the Bonty post (ie what the frame can definitely take?)

What travel has the existing post got?

it’s not obvious where the limit is in the frame.

You need to insert a post that is too long. When it reaches the maximum insertion that the frame will allow, mark the post and remove it. Then you can measure how far you can insert into the frame. You’ve ordered a 480 mm post, so subtract the frame insertion from 480 and you will know how much post will be sticking out of the frame. You can then compare this to how much of the current post is sticking out. If it’s a stealth dropper, you also need to allow room for the cable at the bottom.

https://www.trekbikes.com/gb/en_GB/equipment/cycling-components/bike-stems-seatposts/bike-seatposts-accessories/bike-seatposts/bontrager-line-dropper-seatpost/p/24159/

That will give you the length of the current post as a guide to what ‘might’ be possible. The fact that longer posts are specced for bigger frames suggests to me that you need to check carefully.

Cables in the way after you’ve taken it out/disconnected it?

“Will I need to remove the old one completely?”

So, no. I guess the answer to my question is no then. There isn’t a clever way. Cheers anyway.

If you insert a regular seat post there will be no problem with cables in the way as it will be open ended at the bottom and hollow , then just do what hols2 says .

If its any help the dropper post you get with Remedys in the last couple of years have been 395mm long with 125mm drop.

Cheers, that ^^ would’ve worried me, having purchased a 480mm! But, good ol’ CRC, it turned up last night and I was brave enough to remove the Bonty (only ever had Reverbs before- cable ones are blimmin easy aren’t they!) and 1) compare shaft lengths (missus) and 2) shove an old seatpost in the hole and measure that against the new one. All looks fine. Long as the kid’s legs are still growing.
Thanks for the replies.