UK and Europe · Public discussion

Pedersen problem v2.0

Started by Tim Hall · · Last activity · 8 posts · 580 views

This thread is locked and is currently read-only.

Thread navigation

Jump through the discussion

Go to the original post, the replies on this page, or the latest preserved contribution.

Thread details

What we know about this thread

Original section
UK and Europe
Published
24 April 2008
Last activity
25 April 2008
Original author
Tim Hall
Posts
8
Discussion status
Public discussion
Total views
580
Views / 30 days
0

The navigation and discussion metadata provide context. Posts remain in their original chronological order.

Showing posts 1–8 of 8
Posts remain in their original chronological order.

Text size
  1. I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Bugger.

    Any Pedersen owners out there with a clue as to what's going on?

    --

    Tim

    I understand very little of what's being discussed
    but for some reason it's fascinating.

    (Jon Thompson, urs)

  2. Tim Hall said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Bugger.

    Any Pedersen owners out there with a clue as to what's going on?

    I'd be looking at the other joints, starting with the ones closest. If
    they are bad you could get that one failing as it tries to take more than
    it was supposed to.

    Plastic coating will be trouble though - it probably will be flexible
    enough that you won't see cracking. What did that cost?

  3. In article <[email hidden]>, Tim Hall
    [email hidden] says...

    Quoted message said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Bugger.

    Any Pedersen owners out there with a clue as to what's going on?


    I wonder if a vent hole is blocked (or missing) so the bronze didn't
    fill the joint properly. Probably unlikely, as this is normally evident
    when you make the joint. It could be that there was some corrosion or
    contamination to the end of the bridge tube that didn't get cleaned off
    before the joint was remade - it would be trickier to get in there than
    to clean the main strut. I think you really need to take the bridge out
    and examine the surfaces of the joint to get some indication of what's
    going on, rather than just trying to rebraze it in situ and hoping for
    the best.

  4. In article <[email hidden]>, _
    [email hidden] says...

    Quoted message said:
    Tim Hall said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Bugger.

    Any Pedersen owners out there with a clue as to what's going on?

    I'd be looking at the other joints, starting with the ones closest. If
    they are bad you could get that one failing as it tries to take more than
    it was supposed to.

    Plastic coating will be trouble though - it probably will be flexible
    enough that you won't see cracking.

    All he has to do is remove the seat posts and wiggle the seat tubes for
    any other fracture to become apparent, but as the only other joints are
    where the seat tubes join the bottom bracket[1] I don't think anything
    will show up. It's notable that on the original Pedersens the two seat
    tubes were joined at the top, thus triangulating them - I wonder if the
    provision of separate adjustable seat posts has compromised the rigidity
    of the structure, subjecting the bridge in question (which originally
    just held the seat tubes apart) to too much (mostly shear) stress. If
    that's the case I'd be inclined to braze a plate or crossed tubular
    bridges between the seat tubes near the top (not very pretty, but should
    work) to control the movement, or replace the failed bridge with such an
    arrangement (maybe neater but it would place more stress on the seat
    tubes).

    [1] I'm assuming the front mech mount is just a bolt-on.

  5. Tim Hall said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Bugger.

    Any Pedersen owners out there with a clue as to what's going on?

    sorry no idea, but
    <http://www.flickr.com/photos/timintheshed/505944431/in/set-721575945092
    57998/> that looks rather simular to the handle bars on the old racer i
    picked up.

    Which has that detail on them as well as Sakae custom on the other side,
    which is the brand i guess. Is the Pederesen from the 80's? i've dated
    my old racer to 1986 from the suntour's derailer stamps. though i have
    no idea what the bike is it's self as it has a rather funky paint job at
    some point.

    google doesn't seem to bring up much or rather much useful any way.

    roger
    --
    www.rogermerriman.com

  6. [email hidden] (Roger Merriman)typed

    Quoted message said:

    Tim Hall <[email hidden]> wrote:

    Quoted message said:
    Quoted message said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Bugger.

    Any Pedersen owners out there with a clue as to what's going on?

    Quoted message said:

    sorry no idea, but
    <http://www.flickr.com/photos/timintheshed/505944431/in/set-721575945092
    57998/> that looks rather simular to the handle bars on the old racer i
    picked up.

    Quoted message said:

    Which has that detail on them as well as Sakae custom on the other side,
    which is the brand i guess. Is the Pederesen from the 80's? i've dated
    my old racer to 1986 from the suntour's derailer stamps. though i have
    no idea what the bike is it's self as it has a rather funky paint job at
    some point.

    Quoted message said:

    google doesn't seem to bring up much or rather much useful any way.

    Quoted message said:

    roger

    I wonder if the stress on the joint coud be relieved by fasioning a
    brace between the seat tubes to hold them RIGID.

    --
    Helen D. Vecht: [email hidden]
    Edgware.

  7. Rob Morley said:

    In article <[email hidden]>, _
    [email hidden] says...

    Quoted message said:
    Tim Hall said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    Riding it theother night, I noticed the joint has sprung again.

    Any Pedersen owners out there with a clue as to what's going on?

    I'd be looking at the other joints, starting with the ones closest.

    Quoted message said:

    All he has to do is remove the seat posts and wiggle the seat tubes for
    any other fracture to become apparent, but as the only other joints are
    where the seat tubes join the bottom bracket[1] I don't think anything
    will show up. It's notable that on the original Pedersens the two seat
    tubes were joined at the top, thus triangulating them - I wonder if the
    provision of separate adjustable seat posts has compromised the rigidity
    of the structure, subjecting the bridge in question (which originally
    just held the seat tubes apart) to too much (mostly shear) stress. If
    that's the case I'd be inclined to braze a plate or crossed tubular
    bridges between the seat tubes near the top (not very pretty, but should
    work) to control the movement, or replace the failed bridge with such an
    arrangement (maybe neater but it would place more stress on the seat
    tubes).

    Hmm. Looking at it from an intuitive persecrtive I would think that
    joining the seat tubes rather more robustly at their ends is a Good
    Idea [TM] The loading on the bridge from the riding motion must be
    beyond it.
    --
    Phil Cook looking north over the park to the "Westminster Gasworks"

  8. Tim Hall said:

    I'm the guardian of Helen Vecht's Pederesen, since she is no longer
    able to ride it. A couple of years ago, one of the joints came apart,
    so I got it repaired at Chas Roberts. This knackered the slightly
    tatty paintwork so I then got it plastic coated. Photos are here:
    http://www.flickr.com/photos/timintheshed/sets/72157594509257998/

    I have a secret yearning for one of those. I must resist...

Active in the last 60 minutes

Active in this thread

0 users · 0 guests ·0 bots ·0 total

No signed-in users are active right now.

No known search crawlers active right now.