Calsun

A dropper post adds more than a full pound of weight to a bike and most people want a control lever on the handlebar and so a place needs to be found for it which can be a problem even with straight bars on a mountain bike. I added a dropper to my hardtail bike but I tried a Specialized gravel bike with a dropper seatpost from the factory and the seat would move around in the seat tube which I did not like at all. I am sure there are posts about the problem online if one looks.

big john

In the example I gave it adds less than 1/2 pound, or 200 grams. I'm sure as these things are developed for road bikes they will become lighter.
The remote lever is small and can be mounted anywhere on the bar. Nearly all MTBs are 1x so it goes where the left shifter would have been. Even with a front derailleur the dropper can fit on the left, near the grip.
The dropper on my mtb is solid feeling no matter what position it is in and does not move around, and it's an inexpensive one.

FrankTuna

I wonder if the bigger seat tube allows them to build a more robust dropper?

I tried a PNW 27.2 dropper on my Salsa Cutthroat. They advised it was perfectly suitable to use on the trainer, but it developed a slight rock that became noisy enough to drive me nuts. There was probably 1 or 2 degrees of rotational wiggle too but that was in spec.

I love the idea of a Sram AXS dropper that you could easily swap in/out but yikes those are expensive (if you can find them)

big john

I have a KS Integra and I think the diameter is 31.6. It has a collar that can be snugged up if play develops. I can see how a clunk/click could be very annoying.

msu2001la

This thread is amazing. The immediate response with photos of the 18lb bike hanging from a scale... wow.

A couple of notable things about Matej Mohoric's bike from MSR - his dropper post had 60mm of travel. It was a non-sponsor correct Fox Transfer SL Performance Elite post. He said he experimented with a 120mm dropper as well but found it too inefficient to pedal when dropped. The dropper was controlled by a "grip shift" mounted on the right drop. He says he raised and lowered it several times on the Poggio descent.

Mohoric's bike also had a 180mm XTR rotor on the front..

https://www.cyclingnews.com/news/moh...-dropper-post/
https://www.cyclingnews.com/news/a-d...ilan-san-remo/

bamboobike4

My first impression: maybe my gravel bike needs this....it would maybe get me from next to last to third to last.

RNAV

Question, coming from someone who has never been mountain biking and has never used a dropper: if the lower saddle height is so much better, why not ride at that height all the time?

WhyFi

Pedaling.

RNAV

Oh. So you only "drop" the saddle height when you're not going to pedal?

himespau 

Right, lower center of gravity for more stability (and maybe aerodynamics) while descending. It'd hurt your knees to pedal all the time with the saddle that low.

tempocyclist

Pedalling and putting power down is difficult with the saddle lowered.

Basically on the trials you ride uphill and most of the flat stuff with the saddle at full height, then drop it to tackle the descents. It's super useful on the technical and steep downhills. I'd never go back to not running a dropper on my trail bike.

Riding on the road, I've never thought to myself that a dropper would be in any way useful.

PeteHski

Great bit of lateral thinking by the team. Descending on a road bike with the saddle at full height is always a compromise, especially if you are tall with long legs. It will be interesting to see if anyone uses a dropper in the Grand Tours after this. But I don't think there is such a compelling case as there was for mtb use.

msu2001la

It will be interesting. I think it's probably like putting a target on a rider's back now. If they show up at the start line running a dropper, it's pretty clear that they've scouted a descent and have a plan to attack on it. In a Grand Tour stage, it seems like other teams would mark that rider and prevent them from getting into the breakaway.

I'm also wondering about specific measurable aero benefits. I'm sure teams have done testing on this. Does the benefit from a 60mm drop in saddle height for a few minutes during the final descent really offset the aero drag from running a round seat post for the other 6 hours of racing? Mohoric used 60mm so he could still pedal while dropped - but doesn't that affect his power/efficiency as well? Does the extra few hundred grams of weight make any difference on HC climbs?

I'm wondering how much of Mohoric's advantage on the Poggio was simply psychological. He thinks the dropper makes him faster therefore he's faster.

PeteHski

Well he was obviously primed to attack on that last descent and the dropper was clearly a key part of that plan. So yeah, I'm sure it was a psychological boost knowing that the others were all sat up on pogo-sticks when he charged past!

But for sure a 60 mm drop makes a very significant difference to the handling on a technical descent. He was right on the limit and taking time out of some very talented bike handlers. They obviously tested it and found it to be enough of an advantage to race with it. It worked perfectly as planned since he literally won the race on that final descent. Aero is not that critical unless you are riding a TT. Sitting in a group I doubt you would notice the difference between a round and aero seat post. As for weight, his bike might still have been at or very close to the UCI minimum.

Ultimately races are won and lost on specific key segments and in this particular case the last descent was critical. He nailed his strategy perfectly and the dropper most definitely gave him the edge on that critical descent, evidently without holding him back significantly for the other 6 hours. I don't think this is the last time we will see a dropper raced on the road. They will be all testing them after this result! I predict droppers will become a regular feature when there are critical descents involved unless the UCI decide to ban them.

mstateglfr 

I think dropper posts would largely suck on road bikes- they wiggle, fail, and are heavy. The really good ones wiggle less and are lighter, but they are also really expensive.
I look forward to seeing aero droppers to fit all the aero seat tubes on frames these days. That has to be an expensive endeavor since each brand has different shaped aero seat tubes.

They cant go back to round since they have spent so much energy showing how terrible a round tube is.

79pmooney

Mohoric went down that descent 12 seconds faster than two great descenders. Nibali the year he won and Sean Kelly years ago. 12 seconds isn't chump change. (770 feet or 2 1/2 football fields at 35 mph. 1/4 km at 56 kph.)

Edit: addressing mstateglfr If MSR opens the door for road droppers, the quality will improve (play will come down), they will get lighter and eventually the price will level out and over time, the rest of the bike costs will catch up. And lesser posts will also get better. (Think disc brakes. These are another game changer. The cost of a dropper relative to a normal seatpost isn't that far off from disc brakes vs rim brakes. And like disc brakes, most of the time in a race these things are just extra weight and a little less aero.) Also, my prediction - someone will come up with a dropper mechanism that easily adopts to any aero shape. When that happens, the question racers will be asking is "why does't this bike have a dropper?".

Chandne

Now you have me looking at wireless droppers. I use droppers on all my mountain bikes, and being we have steep mountains here, they would be awesome on a road bike.

cyclezen

For racing on courses where downhills are lengthy and technical, or anyone who takes their road downhilling to a level of limit; droppers will become std.
They will go thru an evolution of tech, quickly... We'll go from alu to CF in a heartbeat, w/ segmented drop points, release and adjustment w/o cable actuation, for all types of seatpost configs.
And plenty of us, the great unwashed, will also not live without it...The tech for rebound/compression will be the interesting thing to watch develop...
inevitable and actually essential in the next incremental improvement of road downhill (as it has proven in mtb).
Ride On
Yuri

Chandne

Hahah true enough about those horrible round tubes (that never slip). I'll pay for a light round-tube wireless dropper. Been using them on the MTB for at least ten years and could not live without them now. I do live in a mountainous region so that is the ONLY reason I'd like a dropper- for those long and steep descents.