Hi All,
Back in the free-for-all early 90's mountain bike component cottage industry, there were at least two of these conversion kits for MTB's. Avid made it's Microadaptor to facilitate a fourth 'granny' chainring, and Mountain Tamer made one called the 'Quad', which is what I believe the one in the ebay auction is, and it did indeed use a Suntour cog. Actually I think it replaced the original small ring with two Suntour cogs, but folks would sometimes modify the mounts on the crank so they could reinstall their original style third ring, usually doing this because it was lighter than a freewheel cog.
To lean this back toward on topic, we installed several of each of these on road touring bikes here in the Rocky Mountain region. And I'm sure some of those touring bikes were pre '83.
There was no shortage of 'innovation' in that round of the good old days.
Greg Overton near Denver, Colorado
Quoting Jay S <jvs@sonic.net>:
> This looks like a mountain bike triple with an adapter in place of the
> small chain ring spacers, allowing for a threaded freewheel cog, in
> this case a 16. If it is a Suntour adapter, very clever indeed. Wonder
> how many were made?
>
> Jay (wishing I could go to cirque) Sexton
> Sebastopol, CA
>
>
> Message: 12
> Date: Mon, 26 Apr 2010 22:33:21 -0400
> From: "Howard Darr" <hdarr@embarqmail.com>
> Subject: Re: [CR] interesting quad crank and conversion
> To: "'Jon Spangler'" <jonswriter@att.net>, "'Dale Brown'"
> <classicrendezvous@bikelist.org>
> Message-ID: <5A3DD506CF2645A2BA4FAD75AD174E40@UserPC>
> Content-Type: text/plain; charset="us-ascii"
>
> Someone mentioned that it was a Suntour conversion that used a screw on free
> wheel cog.
>
> Howard Darr
> Kinsman OH USA
> -----Original Message-----
> From: classicrendezvous-bounces@bikelist.org
> [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of Jon Spangler
> Sent: Monday, April 26, 2010 10:07 PM
> To: Dale Brown
> Subject: Re: [CR] interesting quad crank and conversion
>
>
>
> Howard and all,
>
> Odd, indeed. But I can't figure out how the 4th 16t ring (!) is attached to
> the "normal" inner/granny ring.
>
> Can anyone explain this to me?
>
> Jon Spangler
> stumped this time in Alameda, CA USA
>
>
> Message: 8
> Date: Sun, 25 Apr 2010 18:14:36 -0400
> From: "Howard Darr" <hdarr@embarqmail.com>
> Subject: [CR] interesting quad crank and conversion
> To: "'Classic Rendezvous'" <classicrendezvous@bikelist.org>
> Message-ID: <6AC9CFD3467A46C798BA3B5A460A6704@UserPC>
> Content-Type: text/plain; charset="us-ascii"
>
> EBay Item
> http://ebay.com/
> 0426824342?cmd=ViewItem
> http://ebay.com/
> 90426824342?cmd=ViewItem&pt=Cycling_Parts_Accessories&hash=item439ec9a696>
> &pt=Cycling_Parts_Accessories&hash=item439ec9a696
>
>
>
> ODD
>
>
>
> Howard Darr
>
> Kinsman OH USA
>
>
>
> Jon Spangler
> Writer/editor