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Frame advice needed

tordistordis Posts: 51
edited May 2013 in Road buying advice
Hi all,

Last year I found plenty of valuable advice here when I was looking for a bike; I'm afraid I need your help again.

I had an accident last week and my frame was badly damaged. I'm getting some money through insurance, but instead of buying a new bike, I decided to look for a new frame (and save the rest for my summer holidays 8) ). Trouble is, I still don't know much about frame geometry and sizing.

My damaged frame was a 48cm Jamis Ventura Race Femme:
http://www.jamisbikes.com/usa/thebikes/ ... aracef.pdf

Until yesterday, I was sure I wanted a Ribble 7005 Sportive (which was one of my options last year). I believe I'd need a 44cm one, as it's a different geometry - correct me if I'm wrong:
http://www.ribblecycles.co.uk/sp/road-t ... ibbfrar230

But yesterday I found this:
http://www.chainreactioncycles.com/Mode ... A+Frameset
If I'm not mistaken, I should go for XS with this one. I tried to do a quick comparison, but I'm confused by all the numbers and dimensions.

Any advice?

Posts

  • Ben6899Ben6899 Posts: 9,543
    Based solely on the TT (or effective TT) measurements, I would concur with your thoughts. That Ridley frame looks lovely and appears to be the "raciest" geometry of the three (short headtube).

    Disclaimer: I am not a geometry expert either.
    Ben

    Bikes: Donhou DSS4 Custom | Condor Italia RC | Gios Megalite | Dolan Preffisio | Giant Bowery '76
    Instagram: https://www.instagram.com/ben_h_ppcc/
    Flickr: https://www.flickr.com/photos/[email protected]/
  • MichaelWMichaelW Posts: 2,164
    edited April 2013
    Top Tube or effective top tube is the correct dimension for comparison....as long as the seat-tube angle is the same.
    The Ridley frame is 1/2 degree off which is really nothing so they are both 505mm long and will fit the same.
    Check the seatpost diameters Ridley is 31.6mm . You can get shims to make smaller posts fit into larger holes but you can't make a big post fit into a small hole. Just checked, they are both the same and the external diameter is the same for the front mech clamp.
  • Ben6899Ben6899 Posts: 9,543
    MichaelW wrote:
    Top Tube or effective top tube is the correct dimension for comparison....as long as the seat-tube angle is the same.
    The Ridley frame is 1/2 degree off which is really nothing so they are both 505mm long and will fit the same.
    Check the seatpost diameters. You can get shims to make smaller posts fit into larger holes.

    I wish I'd known that when I was 16.
    Ben

    Bikes: Donhou DSS4 Custom | Condor Italia RC | Gios Megalite | Dolan Preffisio | Giant Bowery '76
    Instagram: https://www.instagram.com/ben_h_ppcc/
    Flickr: https://www.flickr.com/photos/[email protected]/
  • arlowoodarlowood Posts: 2,538
    Out of the 2 options you have listed, the Ribble is going to be closest to the geometry of your Jamis. The Jamis must have quite a sloping top tube as the seat tube length on your 48cm bike is listed at 417mm. The effective Top tube on the 48 Jamis is 505mm and the head tube length is 120mm.

    On the 44cm Ribble the seat tube is a bit longer at 440mm but the effective TT is pretty close at 498mm and the head tube length is the same at 120mm. The top tube discrepency can be addressed by choosing a suitable stem length to get you to an ideal reach.

    As mentioned above, the Ridley frame has a much shorter head tube so will give you a lower (more racey) position compared to your Jamis. Just depends how comfortable you are with that.
  • tordistordis Posts: 51
    Thanks for all your help! I've checked the seatpost on Ridley and yes, it's 31.6mm, so looks like it would fit :) Sent an e-mail to Ribble, too, to make sure their seatpost is the same size, just to be on the safe side.
    I'm still a bit hesitant, though. Is it hard to adjust to a lower position after years of riding in a more relaxed one?
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