Short 125mm dropper

Rowan404

Hi, I am looking for an 125mm internal dropper that has a very short insert length. Right now I have a 2017 reverb 150mm and it is maybe a few centimetres too long. Suggestions are appreciated. I don't have a huge budget so something cheaper would be nice. Thanks

The Rookie

If you are 30.9 the Giant dropper is pretty compact as it uses a cartridge insert (also handy as a stealth to external swap is a 5 minute DIY job).

JBA

Brand-X Ascend is only 410mm overall length. Only 120mm drop though: will you miss those extra 5mm?

(The 150mm travel Ascend XL is 455mm overall.)

Rowan404

JBA wrote:

Brand-X Ascend is only 410mm overall length. Only 120mm drop though: will you miss those extra 5mm?

(The 150mm travel Ascend XL is 455mm overall.)

Thanks but that would be too long. If it was a 120mm, I would need it to be in the mid 300's in overall length. I am need of shorter insert length, not overall length. My 150mm reverb right now is 440 total length and it's a 3 or 4 centimetres too long in insert length.

Rowan404

The Rookie wrote:

If you are 30.9 the Giant dropper is pretty compact as it uses a cartridge insert (also handy as a stealth to external swap is a 5 minute DIY job).

My bike is 31.6, do they not make ones for that?

The Rookie

Eh?

You say the Reverb 3cm too long and the BX is 3cm shorter....sounds spot in then? Why does a 120mm need to be a mid 300mm? That makes no sense at all.

No Giants are all 30.9 so that is what their seatpost is.

Rowan404

The Rookie wrote:

Eh?

You say the Reverb 3cm too long and the BX is 3cm shorter....sounds spot in then? Why does a 120mm need to be a mid 300mm? That makes no sense at all.

No Giants are all 30.9 so that is what their seatpost is.

The BX is a 120mm post whereas the reverb is a 150mm. The shorter length of the BX is just because of the travel being shorter meaning it still won't fit in my frame.

steve_sordy

Anything here?

https://www.alltricks.fr/surl/choisirsa ... copique_v2

Rowan404

I found a 410mm 150mm one up dropper and a race face aeffect 385mm 125mm on jenson usa so I'll probably go with one of those two. Thanks for the suggestions tho. One other quick question while I'm here though. My reverb lever clamp connects to my guide brake lever meaning I can't mount the brake lever without the dropper lever. What would I do when I get a non sram dropper post lever? Are there adapters for such a situation?

The Rookie

Rowan404 wrote:

The Rookie wrote:

Eh?

You say the Reverb 3cm too long and the BX is 3cm shorter....sounds spot in then? Why does a 120mm need to be a mid 300mm? That makes no sense at all.

No Giants are all 30.9 so that is what their seatpost is.

The BX is a 120mm post whereas the reverb is a 150mm. The shorter length of the BX is just because of the travel being shorter meaning it still won't fit in my frame.

Your nuts!

The total length is from the bottom to the saddle rail fully extended, you say the Reverb is 3cm too long, so you need one 3cm or more shorter regardless of the drop or if it’s a fixed length post. The BX is 3cm shorter and will suite.

Rowan404

The Rookie wrote:

Rowan404 wrote:

The Rookie wrote:

Eh?

You say the Reverb 3cm too long and the BX is 3cm shorter....sounds spot in then? Why does a 120mm need to be a mid 300mm? That makes no sense at all.

No Giants are all 30.9 so that is what their seatpost is.

The BX is a 120mm post whereas the reverb is a 150mm. The shorter length of the BX is just because of the travel being shorter meaning it still won't fit in my frame.

Your nuts!

The total length is from the bottom to the saddle rail fully extended, you say the Reverb is 3cm too long, so you need one 3cm or more shorter regardless of the drop or if it’s a fixed length post. The BX is 3cm shorter and will suite.

This is the last response I'm going to make to you since you clearly don't understand the situation. The total length is when the post is fully extended, therefore an 150mm post when fully extended will have a longer overall length than an 120mm just because of the travel. If an 150mm post has a 440mm length and an 120mm post has 410mm length they will fit into the frame the same.

The Rookie

You are nuts, no they won’t, the shorter post (with a shorter drop) will be 3cm less into the frame for the same saddle height or the same insertion for a 3cm lower saddle height, the amount of drop affects it’s short length not it’s full length. But as you don’t want sensible help I’m out, Darwin may be a threat to you.

Rowan404

The Rookie wrote:

You are nuts, no they won’t, the shorter post (with a shorter drop) will be 3cm less into the frame for the same saddle height or the same insertion for a 3cm lower saddle height, the amount of drop affects it’s short length not it’s full length. But as you don’t want sensible help I’m out, Darwin may be a threat to you.

You are not helping me out. I know for a fact that if I bought brand x it would not fit in my frame and would be a complete waste of money. There is a reason they have overall length and insert length. So people don't make the same mistake you are trying to get me go make. I've already explained this to you twice but you are too stubborn to actually listen.

Rowan404

And am saying this from experience, unlike yourself. I bought an 125mm reverb at 420mm length and it was longer than an 150mm at 440mm length.

Rowan404

And I've already found a dropper that will actually fit into my frame, no thanks to your terrible suggestions.

The Rookie

Rowan404 wrote:

The Rookie wrote:

You are nuts, no they won’t, the shorter post (with a shorter drop) will be 3cm less into the frame for the same saddle height or the same insertion for a 3cm lower saddle height, the amount of drop affects it’s short length not it’s full length. But as you don’t want sensible help I’m out, Darwin may be a threat to you.

You are not helping me out. I know for a fact that if I bought brand x it would not fit in my frame and would be a complete waste of money. There is a reason they have overall length and insert length. So people don't make the same mistake you are trying to get me go make. I've already explained this to you twice but you are too stubborn to actually listen.

I’m trying to help you, you’ve not at all explained in meaningful way why you think it won’t fit, and keep going on about it’s drop which is completely irrelevant still, if you don’t want help I won’t.....

JBA

The Rookie is correct.
Shorter drop usually means shorter overall length so for a given saddle height a shorter post will have less insertion.

Let’s assume for the sake of simplicity you want your seat clamp 200mm above the top of the seat tube: a 440mm post will have 240mm inserted in the seat tube. A 410mm post will have 210mm inside the seat tube.

JBA

Rowan404 wrote:

And am saying this from experience, unlike yourself. I bought an 125mm reverb at 420mm length and it was longer than an 150mm at 440mm length.

That’s not possible. Mathematically speaking 420mm is 20mm shorter than 440mm.

Rowan404

JBA wrote:

Rowan404 wrote:

And am saying this from experience, unlike yourself. I bought an 125mm reverb at 420mm length and it was longer than an 150mm at 440mm length.

That’s not possible. Mathematically speaking 420mm is 20mm shorter than 440mm.

Rowan404

JBA wrote:

Rowan404 wrote:

And am saying this from experience, unlike yourself. I bought an 125mm reverb at 420mm length and it was longer than an 150mm at 440mm length.

That’s not possible. Mathematically speaking 420mm is 20mm shorter than 440mm.

Bad wording sorry, I meant the 420 has a longer insert length than the 440. This is because the 420 has 25mm less travel but Is only 20mm shorter in overall length.

Rowan404

The Rookie wrote:

Rowan404 wrote:

The Rookie wrote:

You are nuts, no they won’t, the shorter post (with a shorter drop) will be 3cm less into the frame for the same saddle height or the same insertion for a 3cm lower saddle height, the amount of drop affects it’s short length not it’s full length. But as you don’t want sensible help I’m out, Darwin may be a threat to you.

You are not helping me out. I know for a fact that if I bought brand x it would not fit in my frame and would be a complete waste of money. There is a reason they have overall length and insert length. So people don't make the same mistake you are trying to get me go make. I've already explained this to you twice but you are too stubborn to actually listen.

I’m trying to help you, you’ve not at all explained in meaningful way why you think it won’t fit, and keep going on about it’s drop which is completely irrelevant still, if you don’t want help I won’t.....

Tell me how drop is irrelevant yet the posts are measured when fully extended? That makes no sense at all.

The Rookie

Your fitment issue is with the post fully extended, hence drop is irrelevant - it doesn’t go any further into the seat tube when dropped, so the important dimension for you is fully extended (in the same way as you’d measure a fixed seatpost), your current post you say is 3cm too long fully extended, so you need one 3cm shorter fully extended, which the Brand X is, hence sorted.

steve_sordy

If you refer to the link I added in the eighth post from the beginning, showing the geometries of a range of different posts by manufacturer and drop length, you will see that a bigger drop does not always correlate with a longer overall post (and other geometric oddities).

JBA

That is correct, steve_sordy. However, for a given saddle height a dropper post with a shorter overall length must have a shorter insertion depth than a longer post. Rowan404 doesn't seem to be able to grasp that.
The only thing that could put a spanner in the works is if the quoted overall length does not include the cable/hose attachment mechanism at the bottom of the post.

steve_sordy

I was hoping that I could demonstrate that you could both be right, (without actually spending any time investigating EXACTLY what you had both said of course, because I'm an idle b4stard!)

Rowan404

JBA wrote:

That is correct, steve_sordy. However, for a given saddle height a dropper post with a shorter overall length must have a shorter insertion depth than a longer post. Rowan404 doesn't seem to be able to grasp that.
The only thing that could put a spanner in the works is if the quoted overall length does not include the cable/hose attachment mechanism at the bottom of the post.

That isn't my problem though. For my purpose I need a post that can be slammed and not hit my shock. In this case just getting a post with a shorter overall length and less travel may not fit without knowing that the insertion length is short enough as well. I think we are talking about two different things here.

Rowan404

The Rookie wrote:

Your fitment issue is with the post fully extended, hence drop is irrelevant - it doesn’t go any further into the seat tube when dropped, so the important dimension for you is fully extended (in the same way as you’d measure a fixed seatpost), your current post you say is 3cm too long fully extended, so you need one 3cm shorter fully extended, which the Brand X is, hence sorted.

My fitment issue is purely that the insert length is too long on my current dropper. Hence, I need a shorter insert length. Just getting a post that is shorter in overall length will not tell the whole story as there are multiple variable factors that go into overall length. Drop being one of them.

Rowan404

Thought I stated this pretty clearly in my original post.

The Rookie

Rowan404 wrote:

The Rookie wrote:

Your fitment issue is with the post fully extended, hence drop is irrelevant - it doesn’t go any further into the seat tube when dropped, so the important dimension for you is fully extended (in the same way as you’d measure a fixed seatpost), your current post you say is 3cm too long fully extended, so you need one 3cm shorter fully extended, which the Brand X is, hence sorted.

My fitment issue is purely that the insert length is too long on my current dropper. Hence, I need a shorter insert length. Just getting a post that is shorter in overall length will not tell the whole story as there are multiple variable factors that go into overall length. Drop being one of them.

A shorter post automatically has a shorter insert length for the same saddle height, the extended length is fixed, so if you move the top you move the bottom.

Rowan404

The Rookie wrote:

Rowan404 wrote:

The Rookie wrote:

Your fitment issue is with the post fully extended, hence drop is irrelevant - it doesn’t go any further into the seat tube when dropped, so the important dimension for you is fully extended (in the same way as you’d measure a fixed seatpost), your current post you say is 3cm too long fully extended, so you need one 3cm shorter fully extended, which the Brand X is, hence sorted.

My fitment issue is purely that the insert length is too long on my current dropper. Hence, I need a shorter insert length. Just getting a post that is shorter in overall length will not tell the whole story as there are multiple variable factors that go into overall length. Drop being one of them.

A shorter post automatically has a shorter insert length for the same saddle height, the extended length is fixed, so if you move the top you move the bottom.

I don't really see how any of this applies to me. Like I said I need the post to be slammed on my frame and my current one doesn't let me do that without hitting my shock. A shorter overall post like the one you told me to buy will not always be shorter in insert length. You could have a 400mm post with a 350mm insert length.

JBA

This is getting stupid!

What exactly do you want?

Your original post stated that the 150mm drop Reverb had too long an insertion depth so you wanted a 125mm dropper that was approximately 3cm shorter overall.
Now you are saying you want a post that is slammed on your frame. Why does it have to be slammed? As long as it is inserted beyond the safe limit everything will be fine.

A 400mm post with 350mm insertion would mean a drop of only about 30mm when you take the collar in to account.

Try and do a few drawings and hopefully the penny will drop.