This is possibly a stealth ‘wanted’ Ad!

But, am looking for a dropper for my gravel bike.

Needs to be around 100mm drop (125 is too much), externally routed, and 30.9.

Brand X seem to do a 100/105mm. They do an 85mm too, but as far as I can see, that is just 27.2.

RSP Plummet only seem to come on 125mm drop as far as I can see.

Anything else out there?

Any workarounds if I were to get a longer travel dropper? I suppose the advantage of a dropper is being able to set the seat height anywhere in the range.. but in reality, how easy is it to set it at the right pedalling height on the move?

A 27.2 dropper plus shim to suit your needs
Edit: forgot the link!!
Shim

Any workarounds if I were to get a longer travel dropper? I suppose the advantage of a dropper is being able to set the seat height anywhere in the range.. but in reality, how easy is it to set it at the right pedalling height on the move?

You mean fitting one that’s too long and never fully extending it? Don’t try, it’s a nightmare. You will never find the right spot.

One up do adjustable posts by 20mm, so you can buy the 120 version and adjust it to 100mm travel.

Just use a 27.5mm Brand X with a shim.

Have you looked at PNW? Various external options, some 30.9, some 27.2 + shim.

If its a steel frame, I’d consider drilling it for internal routing which would open up options enormously.

Using longer posts – Reverbs always come with an Enduro collar which limits the travel. If your choice has a matching dia upper shaft, then one of those would work (and probably available for the cost of a wanted ad), or look at the various “seatpack dropper adaptors” that 76Projects or Wolftooth do.

If its a steel frame, I’d consider drilling it for internal routing which would open up options enormously.

It’s Titanium, so I’d sooner not!

Using longer posts – Reverbs always come with an Enduro collar which limits the travel

Think the issue is not to limit how much it will drop by, but to stop it raising to full height if I were to go for a longer (than ~100mm) dropper.

Shorter cranks allow for a longer dropper, as do thicker pedals.

Trim a little off the seat tube if you feel brave enough? Low stack saddle too.

How to you feel about non-remote droppers?

If you’re open to one of them, the KS Dropzone is nice; light and reliable

I had a 30.9mm, 125mm one on my Alice, I’m fairly certain they do a 100mm version

For me at least, it was very handy to be able to switch out for a rigid post without having to faff with cable removal

It’s Titanium, so I’d sooner not!

First thing I did to my ti frame was to drill it to take an internally routed dropper, no more/less sketchy than drilling a steel or alloy frame if done right.

Also having tried non remote droppers in the early days of dropper posts and then again briefly in the early days of gravel bikes I’d avoid like the plague.

As above, don’t get one that’s too long for your preferred seat height, mine was only 5mm too high and even that was a pain.

Too long in terms of drops further than you need, doesn’t matter. I rarely use all of my dropper travel, generally drop to about mid height