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PostPosted: Fri Jun 07, 2013 1:00 pm 
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Joined: Thu Jun 06, 2013 3:51 pm
Posts: 1
I've been on the lookout for an expanding seatpost for my Vitus Dural 979. The previous seatpost sheared clean through & I stupidly binned it, thinking it would be easy to replace. This seatpost has an allan key bolt running from the top where the seat is secured, right down the middle of the seatpost. When tightened it draws a wedge up inside the seatpost, expanding the seatpost out against the bike frame tube. They are impossible to find. Anybody know where I could buy one?


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PostPosted: Fri Jun 07, 2013 2:15 pm 
Devout Dirtbag
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Joined: Sun Oct 02, 2011 3:40 pm
Posts: 121
Location: Sevenoaks
I know just the sort of thing you mean, my old Vitus had the same set-up. The only advice I can offer is to try cycle jumbles. When I went to the Herne Hill Good Friday meet there was all many of strange old stuff available from various traders.


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PostPosted: Fri Jun 07, 2013 7:41 pm 
Old School Grand Master
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Joined: Fri Oct 14, 2011 8:41 pm
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Location: Cumbria
Peugeot and Moser used a similar system, not sure about trhe size though. Might be worth including those names in any searches?

Shaun


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PostPosted: Sat Jun 08, 2013 12:04 am 
Retro Guru
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Joined: Mon Sep 24, 2012 9:10 pm
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I think there was a Sun-tour post with that feature.


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PostPosted: Sat Jun 08, 2013 7:45 pm 
rBoTM Winner
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Joined: Sat Aug 28, 2010 3:44 pm
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Location: at my computer
You can actually make your own if you so wish.


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PostPosted: Sat Jun 08, 2013 8:41 pm 
King of the Skip Monkeys
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Location: Moomin Valley
Citoyen du monde wrote:
You can actually make your own if you so wish.


what he said


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PostPosted: Sat Jun 08, 2013 8:58 pm 
Old School Grand Master
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Location: Cumbria
You mean use a stem bolt and drill through the top of a normal seat post?

shaun


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PostPosted: Sat Jun 08, 2013 9:18 pm 
King of the Skip Monkeys
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a 25.4mm wedge would need machining down but I cant see a problem. match the angle of the wedge to the post and off you go. its no different to fitting a quill stem at the front.


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PostPosted: Sun Jun 09, 2013 9:14 am 
rBoTM Winner
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Joined: Fri Jan 27, 2012 10:01 pm
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Location: Nottingham
ChiefCrowLeg wrote:
I've been on the lookout for an expanding seatpost for my Vitus Dural 979. The previous seatpost sheared clean through & I stupidly binned it, thinking it would be easy to replace. This seatpost has an allan key bolt running from the top where the seat is secured, right down the middle of the seatpost. When tightened it draws a wedge up inside the seatpost, expanding the seatpost out against the bike frame tube. They are impossible to find. Anybody know where I could buy one?


Is that the only type of seat post you can use?

On my Vitus there is a grub screw on the frame casting that tightens into the seat post to hold it in place. As mine is a Cyclo cross frame I have also supplemented this with a clamp type fitted around the post itself which stops it dropping down.


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PostPosted: Mon Jun 10, 2013 2:18 am 
rBoTM Winner
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legrandefromage wrote:
a 25.4mm wedge would need machining down but I cant see a problem. match the angle of the wedge to the post and off you go. its no different to fitting a quill stem at the front.


This is basically what I have done in the past. You do however need to be careful that you do not cause expansion of the seat tube. A quill stem exerts much less stress on the steer tube than does a seatpillar on a much weaker (generally thinner gauge) seat tube. So do be careful but it does work. Theoldfm's suggestion is another way of doing it.


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