Sign in to follow this  
Followers 0
monkeyseemonkeydo

Home Made Dropper Post

21 posts in this topic

Cross post from trials-chat in case it's of any interest to those in here. Basically frame is 27.2mm and the options for dropper posts are few and far between while being silly expensive so I put one together with a cheap 25.4 seatpost, plastic USE shim as a bush and automotive gas strut giving a full 150mm of travel. Currently adjusted by manually operating the QR but considering looking into a remote system if I can be arsed.

Right, here we go. First up pics in the lowered and raised positions:

p1000467medium.jpg

p1000466medium.jpg

The components: The gas strut had to be turned down by a fraction to clear the ID of the seatpost and I just used a couple of bits of delrin to act as a spacer to the top of the seatpost and a stop which sits on top of the main pivot tube inside the seat tube. It's set up so that at max extension the post sits at the perfect height so it always goes to the right place and I can then lower the post to anywhere up to 150mm when I feel like it. A little bit fiddly to operate the QR on the move to start with but now pretty slick at it and since a lot of dropper posts operate via a lever under the nose of the saddle I didn't think it was too bad.

p1000473medium.jpg

Close up of the ball ended screw that goes through the seat clamp and seat tube:

p1000474medium.jpg

The travel:

p1000475medium.jpg

The only mod needed to the frame:

p1000476medium.jpg

Hopefully a video...

4 people like this

Share this post


Link to post
Share on other sites

That's ace! I had been wondering about making a dropper post and thought about those office chairs that have the lever but figured they would all be too large! Had never thought about using a car strut :) Nice one!

Share this post


Link to post
Share on other sites

It obviously works quite well with this frame because the main pivot gives a nice surface for the delrin disc to sit on but I'm sure there'd be ways to make it work all the way to the BB shell if needed. The little ball ended bolt also means the seat clamp can't rotate when it's loose so it's always where you expect it to be (Y).

Share this post


Link to post
Share on other sites

Yeah I need to figure that out on mine, as it would hit my BB. I'm sure I can make some sort of wedge to go in the seatube that goes in through the BB area. I have a CF 27.2 seat post with a use plastic shim, so my seatpost slips up and down a treat which is ideal for this setup! Looking forward to trying this out

Share this post


Link to post
Share on other sites

What would you want this for? Is it just for lazy seat adjustment?

Share this post


Link to post
Share on other sites

What would you want this for? Is it just for lazy seat adjustment?

A poor mans way of having a seat dropper I guess.

Share this post


Link to post
Share on other sites

I get that...but what is a dropper post actually used for? I had a quick google, but couldn't really understand what it did!

Share this post


Link to post
Share on other sites

Its a quick way to adjust seat height without stopping basically

Share this post


Link to post
Share on other sites

That's a brilliant bit of work they, cheap too I expect!

What would you want this for? Is it just for lazy seat adjustment?

I've got a reverb post on my Five, so much better being able to ride non-stop without getting off and adjusting the seat height. Until you try it you might not 'understand' how great it is!

Edited by AndrewEH1

Share this post


Link to post
Share on other sites

Aaaah! Lazy then :P

P.S - Paul...you're a fanny. You know why ;)

Share this post


Link to post
Share on other sites

Ha ha, taken your time to notice mate ;)

And yeah dropper posts are lazy, and expensive. I think the expensive part is what makes them so essential...

Share this post


Link to post
Share on other sites

Part of it stems from not knowing if I wanted a dropper or not but fancying having a go. I could quite happily afford a Reverb or whatever but the Scotsman in me thinks it'd be silly having the single most expensive part on the bike being a seatpost (whole bike was only £750 I think). The strut was about a tenner, the seatpost is a cheap £10 jobbie (not the lightest but obviously has slightly thicker walls for machining purchases. Total cost of the whole setup was about £30 I guess.

Not so much lazy as allowing the height to be adjusted on the fly. If you know you're coming up to a steep section, you don't need to either stop and adjust or make do with trying it with the saddle up your arse you can just adjust it on the go. To be perfectly honest since doing the bodge I haven't used it that much but it's good to know that I can when I want!

Share this post


Link to post
Share on other sites

I love this Dave, I've been thinking about getting one, but I'm not sure if I need one, much like yourself. I don't like the idea of the lever being under the saddle it looks iffy, but for some reason using the seat qr looks better. If I knew how to I would love to try it on my frame, but I don't fancy drilling a hole into a carbon frame.

Anyway, top job. Your not just all muscle :P

Share this post


Link to post
Share on other sites

Nor does your attitude towards this forum.

The topic is 6 years old. You'll get over it.

Share this post


Link to post
Share on other sites

Just because you asked so nicely (and because someone else asked for them via a message a couple of weeks back)...

p1000466medium.jpg

p1000467medium.jpg

p1000469medium.jpg

P1000475 (Medium).JPG

p1000476medium.jpg

p1000474medium.jpg

3 people like this

Share this post


Link to post
Share on other sites

I'd rather not ride at all than not have a dropper post.

1 person likes this

Share this post


Link to post
Share on other sites

I don't use mine much (note I have now got a Brand-X Ascend on the whyte rather than a bodged gas strut) but when I do want/need it (especially at trail centres etc.) it's brilliant. I'd still never spend £200+ on one though as a seatpost is such a minor component of the bike I just can't warrant it. £109 on the perfectly usable Brand-X though is spot on.

Having just checked I see the Ascend XL is currently £109.99 on CR... may have to splash out on that for my bike and give the 125mm version to the missus!!

Edit: Slight change of plan. Bought the Ascend XL (with a £10 off voucher they sent me :)) but sold the old one to my brother in law for £70 instead! £1.20 per extra mm... Worth it :P 

1 person likes this

Share this post


Link to post
Share on other sites

Have you thought of how to make a remote of this? I was thinking of something that squeezes the seat post clamp and a lever would loosen that action letting it rise. Any one else have similar ideas?

Share this post


Link to post
Share on other sites

Thanks for making the photos available again. Helps to show how you avoided the post rotating while its being adjusted.

I'd be tempted to try drilling the hole on the opposite, already slotted, side of the seat tube. Not sure if it'd work out, but it'd be less noticeable if I ever resold my frame.

I found this page because I was thinking of using a shim to provide a slot inside the tube and adding pins or a ridge to the post in order to avoid rotation. That way I'm not taking material off the post. Would be reliant on something like silicone to avoid the shim rotating though.

Was thinking of this kind of diy job on my jump bike. I ride to the start of trails and getting the seat straight (and up to the right height) each time is a pain. I've got a downhill hub and drivetrain on it, but only really so I can ride to the start of lines/trails.

I've got a couple of droppers including a Brand-X, great value and no-nonsense. Maybe I should just pay the £100 for an externally routed Brand-x, only 125mm adjustment though and another cable for the remote (it being a jump bike and all).

 

Share this post


Link to post
Share on other sites

I've had a go at my own (see my previous post). I'm trying it first without a gas struct. Even without one, for my purposes, being able to lower and raise, one-handed, without repositioning, is an improvement. :)

I realised my bike has two slots for the seat clamp, so I could run two bolts and slots instead of one. In order to get the first slot straight I laid the seat post down on a flat and even surface, pushed a piece of box section along it and scribed a line down it. I then used a sharpened steal bolt, to deepen the first slot and create a second slot, by threading it into the modified seat clamp.

At first I tried using a relatively thick seat clamp, but the aluminium was to soft to hold a thread. Having to start again was unfortunate as I'd already made two grooves on the seat post. As there are two bolts and slots the spacing needs to match up. <_<

So I ended up using the bolt and nut ends of the now ruined aluminium clamp with three layers of 28mm waste pipe solvent welded together for thickness. To create a thread I recessed a couple of nuts on the inside of the pipe (hence the pipe thickness). I used a couple of sharpened M4 brass bolts, with the hope that brass might be softer than the aluminium seat post. I've shortened the bolts to a length that includes a pair of washers each, that way if the bolts wear I can remove a washer to compensate. I left a bit of thinner pipe sticking up above to stop the actual seat clamp from rotating.

IMG_20190602_160333.jpg

IMG_20190602_160349.jpg

IMG_20190602_170106.jpg

IMG_20190602_170126.jpg

2 people like this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Recently Browsing   0 members

    No registered users viewing this page.