Advertise on Bikeforums.net



User Tag List

Results 1 to 15 of 15
  1. #1
    Large Member realestvin7's Avatar
    Join Date
    Nov 2010
    Location
    Tejas
    Posts
    2,736
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Vintage OVAL chainring ... What can you guys tell me about it?

    Couldn't pass this NOS oddity up. It features 54 teeth and a 144 BCD. What would have been its intended purpose? And in which position would it mount?



    Build a drop bar do-it-all MTB!
    For Sale / Trade:
    1985 Cannondale Road F/F - 56cm ST/56cm TT
    1988 Cannondale SM1000 MTB F/F 20" ST/ 56cm TT
    Kuwahara Puma MTB F/F - 19" ST/56cm TT
    Trek 7000 MTB F/F -17" ST/55cm TT
    Alpine MTB F/F - 23" ST/59cm TT
    Ross Hi-Tech MTB F/F - 20" - 21" ST/57cm TT
    Peugeot PR10 Road F/F - 62.5cm ST/60cm TT

  2. #2
    Senior Member ftwelder's Avatar
    Join Date
    Apr 2010
    Location
    vermont
    My Bikes
    Many
    Posts
    3,087
    Mentioned
    4 Post(s)
    Tagged
    1 Thread(s)
    Yours was made by Roger Durham in the 70's. Roger is the guy we have to thank for Bullseye cranks. He is an old friend of mine, living in Scottsdale az. Awesome find!
    1886 Surrey machinists Invincible, 1900 Nashua, 1937 Raleigh Golden Arrow, 1938 Raleigh Silver Record, 1951 Armstrong tourmalet, 1970 Motobecane Grand Record, 1971 Raleigh Professional, 1971 Gitane TDF, 1972 Legnano Gran Primio, 1973, Peugeot PX-10, 1975 Roberts, 1984 Battaglin Giro, 1985 Grandis Speciale, 2012 FTW

    frankthewelder@comcast.net

    le prix s'oublie,la qualité reste ,(michel audiard)

  3. #3
    Senior Member rothenfield1's Avatar
    Join Date
    Jun 2009
    Location
    Montereyish
    Posts
    2,326
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Uh? That’s way past crazy. I’ve never understood the ovalized chain ring era thing. Nerdy engineers seeking their PHDs were obviously involved. ‘Damn you PHD seeking smart people’.
    Half of the time I fear I may not know what the hell I’m doing; the other half, I’m sure of it.

  4. #4
    Large Member realestvin7's Avatar
    Join Date
    Nov 2010
    Location
    Tejas
    Posts
    2,736
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Is it road, MTB, something else?
    Build a drop bar do-it-all MTB!
    For Sale / Trade:
    1985 Cannondale Road F/F - 56cm ST/56cm TT
    1988 Cannondale SM1000 MTB F/F 20" ST/ 56cm TT
    Kuwahara Puma MTB F/F - 19" ST/56cm TT
    Trek 7000 MTB F/F -17" ST/55cm TT
    Alpine MTB F/F - 23" ST/59cm TT
    Ross Hi-Tech MTB F/F - 20" - 21" ST/57cm TT
    Peugeot PR10 Road F/F - 62.5cm ST/60cm TT

  5. #5
    Freewheel Medic pastorbobnlnh's Avatar
    Join Date
    Oct 2005
    Location
    Trying to Ride in the NH Mountains!
    My Bikes
    Vintage Schwinns, Classy Cannondales, & an '83 Santana Tandem
    Posts
    8,743
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    That ring has to have the longest, meanest, most intimidating looking teeth of any chainring I've ever laid eyes on! A competitor looking at it, would probably flinch, miss a shift, and immediately fall back!

    I have seen one (in a picture) once before, and IIRC, when the crank arms were horizontal or East-West on a compass, the ring was pointing North-South.

    Found these pictures online:



    Last edited by pastorbobnlnh; 01-11-12 at 03:47 AM.
    Bob
    Dreaming of Summertime in NH!

    Visit my websites:
    FreeWheelSpa.com orpastorbobnlnh.com

  6. #6
    Senior Member LesterOfPuppets's Avatar
    Join Date
    Sep 2008
    Location
    Vancouver, USA
    My Bikes
    My War
    Posts
    18,397
    Mentioned
    16 Post(s)
    Tagged
    6 Thread(s)
    Wonder what the two extra holes are for. Bold holes for some kinda ramps? Pins to keep the chain from wedging in between ring and crank arm?
    1980ish Free Spirit Sunbird fixed * 1996 Mongoose IBOC Zero-G * 1997 KHS Comp * 1990-ish Scapin * Olde Western Auto Cruiser.

  7. #7
    Senior Member randyjawa's Avatar
    Join Date
    Apr 2007
    Location
    Thunder Bay, Ontario, Canada - burrrrr!
    My Bikes
    1982 Tomassini, 1963 Peugeot PX10, and eight special issue Canadian lightweights...
    Posts
    5,584
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I have one of those chain rings on a Motobecane Mirage. What a POS! I rode the bike once or twice and the feel was horrible. The bike felt like it was bouncing as soon as my rpms started going up...

    Motobecane_Durham_Crank_4.jpg Motobecane_Durham_Crank_6.jpg

    Motobecane_Durham_Crank_5.jpg
    Learn how to find, restore and maintain vintage road bicycles at... MY "TEN SPEEDS"

  8. #8
    Freewheel Medic pastorbobnlnh's Avatar
    Join Date
    Oct 2005
    Location
    Trying to Ride in the NH Mountains!
    My Bikes
    Vintage Schwinns, Classy Cannondales, & an '83 Santana Tandem
    Posts
    8,743
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by randyjawa View Post
    I have one of those chain rings on a Motobecane Mirage. What a POS! I rode the bike once or twice and the feel was horrible. The bike felt like it was bouncing as soon as my rpms started going up...
    Now that I see Randy's post again, I'm pretty certain this is where I remember the picture from.



    Again, look at those huge teeth! Scary!

    Quote Originally Posted by LesterOfPuppets
    Wonder what the two extra holes are for. Bold holes for some kinda ramps? Pins to keep the chain from wedging in between ring and crank arm?
    Mounting holes for an emergency cut off release!
    Bob
    Dreaming of Summertime in NH!

    Visit my websites:
    FreeWheelSpa.com orpastorbobnlnh.com

  9. #9
    Old fart JohnDThompson's Avatar
    Join Date
    Nov 2004
    Location
    Appleton WI
    My Bikes
    Several, mostly not name brands.
    Posts
    11,841
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by pastorbobnlnh View Post
    That ring has to have the longest, meanest, most intimidating looking teeth of any chainring I've ever laid eyes on! A competitor looking at it, would probably flinch, miss a shift, and immediately fall back!
    I think that was intended to prevent derailment.

  10. #10
    Senior Member LesterOfPuppets's Avatar
    Join Date
    Sep 2008
    Location
    Vancouver, USA
    My Bikes
    My War
    Posts
    18,397
    Mentioned
    16 Post(s)
    Tagged
    6 Thread(s)
    Yes, there must have been a couple of chain jumping incidents during prototyping
    1980ish Free Spirit Sunbird fixed * 1996 Mongoose IBOC Zero-G * 1997 KHS Comp * 1990-ish Scapin * Olde Western Auto Cruiser.

  11. #11
    Senior Member
    Join Date
    Feb 2011
    Posts
    422
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I remember when these things showed up in the seventies and then when Shimano tried to force them down our throats in the late eighties or early nineties. I'm pretty sure they made an appearance in the thirties or sometime around then. Anybody know the history of oval chainrings? I'm always fascinated by ideas like this that keep being brought back from the dead just when everybody has forgotten about them.

  12. #12
    Large Member realestvin7's Avatar
    Join Date
    Nov 2010
    Location
    Tejas
    Posts
    2,736
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I want to WATCH somebody ride a bike with these on it. I don't want to try it myself. Lol.
    Build a drop bar do-it-all MTB!
    For Sale / Trade:
    1985 Cannondale Road F/F - 56cm ST/56cm TT
    1988 Cannondale SM1000 MTB F/F 20" ST/ 56cm TT
    Kuwahara Puma MTB F/F - 19" ST/56cm TT
    Trek 7000 MTB F/F -17" ST/55cm TT
    Alpine MTB F/F - 23" ST/59cm TT
    Ross Hi-Tech MTB F/F - 20" - 21" ST/57cm TT
    Peugeot PR10 Road F/F - 62.5cm ST/60cm TT

  13. #13
    Senior Member
    Join Date
    Nov 2005
    My Bikes
    Cinelli, Paramount, Raleigh, Carlton, Zeus, Gemniani, Frejus, Legnano, Pinarello, Falcon
    Posts
    5,770
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I remember those from the 70s. Seems like an idea that rears its head every 15-20 years through the course of bicycling history. Never used one, but I hated BioPace.

  14. #14
    Senior Member ftwelder's Avatar
    Join Date
    Apr 2010
    Location
    vermont
    My Bikes
    Many
    Posts
    3,087
    Mentioned
    4 Post(s)
    Tagged
    1 Thread(s)
    I think it's for people who ride around at 40 RPM.

    I would love to add it to my collection. I have most of rogers stuff except the chainring.
    1886 Surrey machinists Invincible, 1900 Nashua, 1937 Raleigh Golden Arrow, 1938 Raleigh Silver Record, 1951 Armstrong tourmalet, 1970 Motobecane Grand Record, 1971 Raleigh Professional, 1971 Gitane TDF, 1972 Legnano Gran Primio, 1973, Peugeot PX-10, 1975 Roberts, 1984 Battaglin Giro, 1985 Grandis Speciale, 2012 FTW

    frankthewelder@comcast.net

    le prix s'oublie,la qualité reste ,(michel audiard)

  15. #15
    Senior Member randyjawa's Avatar
    Join Date
    Apr 2007
    Location
    Thunder Bay, Ontario, Canada - burrrrr!
    My Bikes
    1982 Tomassini, 1963 Peugeot PX10, and eight special issue Canadian lightweights...
    Posts
    5,584
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I think it's for people who ride around at 40 RPM.
    Though I did not try to estimate my rpm, I am pretty sure I was lower than that. Honestly - the feel is unmistakable and scary. None the less, I have had the bloody bike for about ten years and still resist the urge to do something with it. Perhaps I should make a video of the mechanism in action.
    Learn how to find, restore and maintain vintage road bicycles at... MY "TEN SPEEDS"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •