Dropper Post Advice

Hi Forum,

I’m new to MTB from Road Cycling after a few years of hiring to ride trails. I’ve now bought a decent bike but would like a dropper but need some advice.

My optimal pedalling seat post height is with 140mm of seat post out of the seat tube.
The seat tube is 31.6.

What of the following options should I go for:

1) Giant Contact Switch 150mm Travel 30.4 with shim (travel will allow a full slam but will be slightly too high fully up). £125 inc. shim.

2) KS Lev 100mm Travel 31.6 (only available in 100mm in my budget). £136.

3) Giant Contact Switch 125mm Travel 30.4 with shim. £125 inc. shim.

Thanks for any advice,
Liam

My optimal pedalling seat post height is with 140mm of seat post out of the seat tube

Well you aren’t going to squeeze 150mm drop into 140mm of space and even 125mm may not work because of the collar etc on the seatpost. You will have to check the specs very carefully to make sure you get a dropper that will fit

Also, is your frame the correct size? I’m guessing it’s a frame with a bit of a seat mast to it?

With only 140 mmm total ,I’d say you can fit a 100mm dropper.

Looking at this (maybe slightly out of date):

(current version)

If your ‘G’ dimension is 140mm, it appears only a 75mm post would fit.

The main thing is to get the right saddle height at full extension, then fit in as much drop as you can/want/need – I don’t know of any where it is possible to limit the travel in the upwards direction.

Thanks for the replies, especially the diagram.
My C+D is 140 so the 100mm KS eTeni + a 30mm when slammed would only be 10m below optimal pedalling height.

I can’t find any Giant spec sheets so at least I have confidence in the KS.

Thanks,
Liam