Expanding seat post!!!!!

[peteb1962]

Hello all, I have an steel bike made by Clive Bonavia without a seat clamp. I am told that at one time expandable seat posts were available. I can't seem to find one on line for a 27.2 reynolds 753 frame. Anybody have any ideas where I can get one. The current seatpost is gummed in!

Cheers Pete

 

[hamster]

Search for Quill Seatpost as well.
https://www.retrobike.co.uk/threads/27-2-quill-seatpost.412691/https://www.ebay.co.uk/itm/391303867809

 

[novocaine]

it's call a pivotal post, they are popular with the BMX folks. they require a special saddle as you need a hole to get to the top bolt. with this in mind I rather doubt that a vintage road bike would be using this style of post and suspect something else is going on. Campag and moser did one with the bolt at an angle in the post, rare as a rare thing now though and you will pay through the nose for it.
you could make your own if you find a suitable layback seat post and drill the top.

 

[marshalllucky]

Quill seat posts were used by Peugeot for a short time in the mid 80`s on some of the 531 and vitus 980 frames so they ARE definatley a thing that exists, I once had a PSV10 model Peugeot with a quill seat post . They do come up on ebay from time to time and are correctly referred to as quill seat posts and not the same as the BMX variety in that you can use any saddle . You could always look for a complete bike with one and sell on the rest ! , there`s one on ebay at the moment here for example .

https://www.ebay.co.uk/itm/234183259682?hash=item368668f622:g:pV0AAOSw3yZhMRAi

 

[foz]

As said quill posts are difficult to find and expensive, you can use the BMX type with any saddle, just fit saddle to post, then fit post into frame without clamping (use tape and/or zipties to stop it sliding all the way down), find the height you need it to be set at. Remove post with saddle from frame, remove saddle from post, fit post to frame and tighten, then fit saddle to post... it's a bit of a hassle, but not difficult. Certainly easier than mesauring, cutting, and fitting a modern integrated seatmast (and without the potential to leave it FUBAR!)

You would need to make sure you can get enough saddle setback though, as I think the BMX posts are only available in zero setback

 

[Jesper]

I have a "quill" post for my late 80s Moser Leader "SC". It's not the OE Moser post and only cost me about 10 quid at the time (about 3 years ago. you do not need a special wrench; it has an allen head bolt exposed on the side. I cannot remember the name, but I will check it and post it here. It is 27.2mm and is not a BMX post as it has some offset to it.

 

[peteb1962]

I have a "quill" post for my late 80s Moser Leader "SC". It's not the OE Moser post and only cost me about 10 quid at the time (about 3 years ago. you do not need a special wrench; it has an allen head bolt exposed on the side. I cannot remember the name, but I will check it and post it here. It is 27.2mm and is not a BMX post as it has some offset to it.

Hi Jesper, That sounds good. If only I could find one. I am having the frame resprayed at present, but looks like I will have to go down the gumming route.

 

[Jesper]

Hi Jesper, That sounds good. If only I could find one. I am having the frame resprayed at present, but looks like I will have to go down the gumming route.

I know I got it used at my local shop; a good place to look since not many folks are using that type of post. I got lucky with the size being correct though. I keep thinking it was an Avocet branded post; that bike is in my storage unit so I'll verify this weekend. I know a lot of Moser owners who ended up cutting a slot in the seat tube and using a collar style clamp; but that "uglies up" a really nice looking fillet brazed conjunction.

 

[Jesper]

Hello all, I have an steel bike made by Clive Bonavia without a seat clamp. I am told that at one time expandable seat posts were available. I can't seem to find one on line for a 27.2 reynolds 753 frame. Anybody have any ideas where I can get one. The current seatpost is gummed in!

Cheers Pete

Hi Pete,

I checked out my Moser, and it has a Sun Tour 27.2mm quill post . As I said it has the tightening bolt accessible on the side of the post so no special tool required to reach it; no removal of saddle required either. I do not know it you can find one or what the price would be. It has worked fine for me but I am fairly light at 140 pounds so I cannot vouch for how it would be for someone another 25 to 50 pounds heavier than myself.

Good luck,
Jesper

 

[novocaine]

Hi Pete,

I checked out my Moser, and it has a Sun Tour 27.2mm quill post . As I said it has the tightening bolt accessible on the side of the post so no special tool required to reach it; no removal of saddle required either. I do not know it you can find one or what the price would be. It has worked fine for me but I am fairly light at 140 pounds so I cannot vouch for how it would be for someone another 25 to 50 pounds heavier than myself.

Good luck,
Jesper

Thats a really interesting seatpost Jesper. I've never seen one with the bolt to the side like that, it means there is some clever bit of magic going on inside to convert transverse axial motion to linear motion in the other plane. I'd love to see what's inside but I won't ask you to show me.