Ridley Noah Fast size help

Hi everyone. Sorry, long post alert but hopefully lots of information is helpful!

Hoping some friendly Ridley owners will be able to help me with an upcoming purchase. I'm buying a frame from Merlin (£1999) and building up the bike over the winter for use next year. It will be used for club runs in flat southern England, some longer rides in Mallorca and the UK plus possibly some crits if I can bring myself to race such an expensive bike. I'm having a dilemma over sizing, though.

I'm 178cm tall with 80cm inside leg, so the Ridley calculator https://www.ridley-bikes.com/product/noah/#/catalogue/noah is saying I need a Medium. However, I've heard Ridleys run quite large and it looks like I'm at the bottom end of Medium sizing, so would rather go for Small if it would work for me.

A few other bits of info - the frame comes with an integrated cockpit which has 100mm stem and 400mm bars, I'd ideally run it without any spacers. I don't really want to have to buy a new cockpit so want to get it right. I'm currently riding a 2014/15 Boardman Elite Air 9.8 in I think Small - this is based on measurements of TT and ST and comparing to the size guide here: https://issuu.com/alexandrpanasovsky/docs/boardman_2015). I felt sure it was advertised to me as a medium but the ETT is 540mm and ST definitely 505mm from BB to where the seatpost goes in. I have a 120mm stem (10 degree) and 440mm bars on this, with 20mm of spacers. This was bought second hand from here and never fitted to me but seems to be good for me although I'm occasionally finding myself quite far forward on the saddle.

I like quite an aggressive position but equally don't want it to be too uncomfortable for century-plus rides. Any thoughts?


  • siddy1972
    siddy1972 Posts: 180
    I have this very frame. I got it from slanes with the 110mm stem rather than the 100mm.
    I’m 179cm tall, and went size M. 76cm saddle height. To be honest, wouldn’t want to go any smaller, I have 2 of the bigger spacers and the drop is still good enough to get low. With it slammed it would be seriously low at the front.
    I hope you’re going Di2, i built mine myself, I can’t imagine trying to get the mechanical gear cables in through the route required, it’d be a huge pain.
  • I’ve just built up this exact frame from Merlin for my wife. She is shorter than you at 173cm. Her winter bike is a Cervelo R2 in 54cm, when I compared geometry charts the 54cm Cervelo is almost exactly the same as the small Noah Fast. Which confirms that Ridley do appear larger than other brands for the same stated size. Sounds like a medium Noah would work for you.

    I can confirm routing mechanical through the integrated bar and stem and onwards through the frame is a pain, even with a internal routing tool!
  • wongataa
    wongataa Posts: 1,001
    Get the geometry details for your current bike that suits you and draw it out. Get the geometry details of the Ridley and draw it out. Overlay the two drawings and see how they match. Line up the bottom brackets when comparing the drawings. You can now add/remove spacers, change stem length/angle etc and see what happens.

    You can do this with online tools, bits of paper, or CAD software.
  • Thanks everyone for your advice. I'm going for a Medium, and noted re. the groupset!