Dropper Posts: Things are hotting up

[Captain Fastbastard Mayhem]

In order to fit the 150, you'll probably need about 3 to 4cm of exposed seat post in order to make it work, if you're going in the same make and model.

 

If you're going to a different brand, it's not as easy as that.

 

Measurement A: top of seat tube (at clamp) to seat rails at maximum extension (at highest saddle position, current setup)

 

Measurement B: bottom of collar (seat clamp side) to seat rails (new dropper)

 

Measurement C: maximum insertion depth (may need an old normal seat post for this) from post clamp to bottom of post.

 

Measurement D: distance between bottom of collar and bottom of new dropper.

 

If measurement B is larger than measurement A, then it won't fit as your saddle will be too high. If it's the same or less than A, then move on to measurements C & D. If measurement D Is smaller than C, it'll fit. If it's bigger than C, you WILL have to run the dropper with some post exposed, and then you MUST have some leftover room between measurements. A - B must be equal to or more than the difference between C - D.

 

The reason it's more difficult than just measuring the post, is that there are different stack heights on the seat clamp, different overall lengths and different collar sizes. There are also different frame designs which may limit just how far you can get the seat post in.

[Captain Fastbastard Mayhem]

Easiest way to do it is just to do a test fit before you buy. If you're buying online, then best make sure your measurements are spot on.

[splat]

Anyone with Specialized dropper seat post experience?

Mine wouldn't stay at full extension on today's ride. It kept dropping an inch or so, every few minutes. Very frustrating.

 

I am hoping that its just a cable tension adjustment, but didn't want to fiddle while riding in case I made it worse.

[AlanD]

In order to fit the 150, you'll probably need about 3 to 4cm of exposed seat post in order to make it work, if you're going in the same make and model.

 

If you're going to a different brand, it's not as easy as that.

 

Measurement A: top of seat tube (at clamp) to seat rails at maximum extension (at highest saddle position, current setup)

 

Measurement B: bottom of collar (seat clamp side) to seat rails (new dropper)

 

Measurement C: maximum insertion depth (may need an old normal seat post for this) from post clamp to bottom of post.

 

Measurement D: distance between bottom of collar and bottom of new dropper.

 

If measurement B is larger than measurement A, then it won't fit as your saddle will be too high. If it's the same or less than A, then move on to measurements C & D. If measurement D Is smaller than C, it'll fit. If it's bigger than C, you WILL have to run the dropper with some post exposed, and then you MUST have some leftover room between measurements. A - B must be equal to or more than the difference between C - D.

 

The reason it's more difficult than just measuring the post, is that there are different stack heights on the seat clamp, different overall lengths and different collar sizes. There are also different frame designs which may limit just how far you can get the seat post in.

Sjo, that's a whole lot of measurements but I understand what you saying.

 

Going for different brand, have a reverb currently and will be buying online.

 

So what's the real advantage of that extra 25mm drop over the 125mm other than getting the seat a bit more down. I feel mine gets down enough to be out the way.

[BaGearA]

I think 125mm or even 150mm must be nice but I got my dropper 3 weeks ago and only 100mm drop but its changed my riding so much #confidencefordays

[Captain Fastbastard Mayhem]

Sjo, that's a whole lot of measurements but I understand what you saying.

 

Going for different brand, have a reverb currently and will be buying online.

 

So what's the real advantage of that extra 25mm drop over the 125mm other than getting the seat a bit more down. I feel mine gets down enough to be out the way.

That's all it is. I would dearly like the new 170mm reverb, but tbh the ticket price is far more than I'm comfortable with and I cannot honestly say that I need that extra 20mm drop over what I have. Would be nice for DH days, but meh. Far rather spend elsewhere if at all.

[Matchstix]

Depending on your length and size bike, but for a med frame 100-125 should be more than enough

[Captain Fastbastard Mayhem]

But no. 125 is sufficient for pretty much everywhere. And you know it fits!

[Skylark]

That's all it is. I would dearly like the new 170mm reverb, but tbh the ticket price is far more than I'm comfortable with and I cannot honestly say that I need that extra 20mm drop over what I have. Would be nice for DH days, but meh. Far rather spend elsewhere if at all.

But the Pro DH guys seem to run their seat posts relatively high(and majority with no dropper), suppose that's for some saddle rest when pedalling through flat sections, vs the slopsstyle/dirt jump guys who slam it right down?

[Matchstix]

I rode a demo bike with a dropper last weekend. And for me personally, unless I gets reaaaaly steep. Wouldn't need to drop a post more than 50mm, and that is for the majority of the CT trails

[Captain Fastbastard Mayhem]

But the Pro DH guys seem to run their seat posts relatively high(and majority with no dropper), suppose that's for some saddle rest when pedalling through flat sections, vs the slopsstyle/dirt jump guys who slam it right down?

Yes, but remember that those frames have VERY low seat tubes and as such their high is like a normal bike with the saddle dropped a good 100mm or so. But they also run them that "high" so they can use the saddle to manipulate the bike in the air with their legs.

 

Also slopestyle and dj guys whip and spin their bikes. A high saddle is anathema to that

Edited April 24, 2016 by Myles Mayhew

[AlanD]

Decided to go with the 125mm drop as feel thus sufficient and I know it all fits.

 

Now all I need to do is shim it as I have a 31.6 seatpost and the Giant dropper is 30.9

 

Anyone got a shim for this as I cannot source one locally? I know you can make one with a beer can which seems what I need to do.

[Martin PJ]

Decided to go with the 125mm drop as feel thus sufficient and I know it all fits.

 

Now all I need to do is shim it as I have a 31.6 seatpost and the Giant dropper is 30.9

 

Anyone got a shim for this as I cannot source one locally? I know you can make one with a beer can which seems what I need to do.

 

I have tried the beer can shims, not so lekker, except as a temporary measure, looks bad and doesn't hold the seatpost as tight as it should. Bought a shim off eBay, it was about R100. I works very well and is neat.

[AlanD]

I have tried the beer can shims, not so lekker, except as a temporary measure, looks bad and doesn't hold the seatpost as tight as it should. Bought a shim off eBay, it was about R100. I works very well and is neat.

Ok cool. Will go search for one then and see the cost

[Martin PJ]

http://www.ebay.com/itm/272090591519?_trksid=p2057872.m2749.l2649&var=570900622040&ssPageName=STRK%3AMEBIDX%3AIT

 

This was it, see if you can get the Fourier brand cheaper from some other seller. It was decent.

[MTBeer]

Just a note to those guys who may have just bought a Giant dropper (or are planning to). If it has external routing get it changed to internal ASAP. The external routing causes endless problems where the cable housing enters the dropper under the seat. There is continuous movement there when the seat goes up and down, causing cable jamming and hence seat not staying up or down.

 

Internal routing will sort this out.