bcd for "custom" crank?

[futrino]

I have a old 1982 trek, with a double crank with "custom" stamped on the
arm. Is this an odd BCD? I get about 68-69 mm between center of holes.
according to Sheldon's BCD chart, x 1.7 = 115-117? closest is the
"obsolete campagnolo".
Am I missing something, or should I just use a newer crank?














I want to have a single chainring up front.

[A Muzi]

futrino wrote:
> I have a old 1982 trek, with a double crank with "custom" stamped on the
> arm. Is this an odd BCD? I get about 68-69 mm between center of holes.
> according to Sheldon's BCD chart, x 1.7 = 115-117? closest is the
> "obsolete campagnolo".
> Am I missing something, or should I just use a newer crank?
> I want to have a single chainring up front.

SR Apex 118mm most probably. They exist yet, what size?
http://www.yellowjersey.org/esoteric.html
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[Andrew W]

On 1 Mar, 19:31, A Muzi <a...@yellowjersey.org> wrote:
> futrino wrote:
> > I have a old 1982 trek, with a double crank with "custom" stamped on the
> > arm. Is this an odd BCD? I get about 68-69 mm between center of holes.
> > according to Sheldon's BCD chart, x 1.7 = 115-117? closest is the
> > "obsolete campagnolo".
> > Am I missing something, or should I just use a newer crank?
> > I want to have a single chainring up front.
>
> SR Apex 118mm most probably. They exist yet, what size?http://www.yellowjersey.org/esoteric.html
> --
> Andrew Muziwww.yellowjersey.org
> Open every day since 1 April, 1971

Would these be the same as for "Silstar" cranks (another SR product)?

[A Muzi]

>> futrino wrote:
>>> I have a old 1982 trek, with a double crank with "custom" stamped on the
>>> arm. Is this an odd BCD? I get about 68-69 mm between center of holes.
>>> according to Sheldon's BCD chart, x 1.7 = 115-117? closest is the
>>> "obsolete campagnolo".
>>> Am I missing something, or should I just use a newer crank?
>>> I want to have a single chainring up front.

> , A Muzi <a...@yellowjersey.org> wrote:
>> SR Apex 118mm most probably. They exist yet, what size?http://www.yellowjersey.org/esoteric.html

Andrew W wrote:
> Would these be the same as for "Silstar" cranks (another SR product)?

Silstar have pressed outer ring, many versions at various diameters for
the inner ring. Including, yes, 118mm.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971