Top tube length / reach

judith_sw Posts: 101
edited May 2010 in MTB buying advice

I realise that there isn't a magic formula for fit, and there is no real alternative other than to try out a bike. However, when assessing the "fit" of the bike, is there any advice on what the "bum to handlebars" ratio should be? Angles, bend of arm, etc?

The reason I ask is that Iam unsure whether to include femal=specific models in my search. I am not particularly small - 5'7, long in the arms and legs, but quite short in the back. I tried a Specialized man's bike yesterday (M) and the assistant thought it was too long in the top tube as my arms were too straight. (TBH I didn't want to lean too far forwards, as he would have had a good view down my t-shirt :oops: ).

Any idea on how to gauge best fit without embarrassing myself and the shop assistant gratefully received!


  • nicklouse
    nicklouse Posts: 50,675
    Fun fun fun. next time go correctly dressed.

    really you need to have a look at your current bike and then use that as a base to compare figures. BUT please be aware that not all bike companies measure the same way.

    but bums on leather is still the bestway to start out looking.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • crankface
    crankface Posts: 45
    I too have found some bikes have a longer reach than others. I have found this not just with certain manufacturers but also the type of bike. For eg. a race mtb might have a longer reach than a xc frame and certain companies prefer a particular geometry like cannondale.

    I had a badboy (hybrid) which I thought the top tube was too long on. In the end I think it depends on what you are going to use it for. I would try a few and see what fits you best - thats what matters most imo
  • judith_sw
    judith_sw Posts: 101
    I will wear a sensible blouse buttoned all the way to the top next time :lol:

    Not sure the assistant was embarrassed actually ... I was.

    Seriously though, is there a point at which the angle of lean is too much? I'm not really sure I know when this would be, and there will need to be enough leeway for it to be comfortable for both ascent and descent ... I don't suppose there is any sort of magic formula?

    I'm interested in an all-round bike for long trails and fun singletrack. I'm not into brutal descents and like stuff like Marin Penmachno in North Wales. I think I'm probably more XC than anythin else.
  • The Spiderman
    The Spiderman Posts: 5,625
    Arms should be bent at the elbow,also get the shop to try a shorter stem.
    To find what ballpark you should be in try one of the fit calculators such as that on the competitive cyclist website.

    Still no susbstitute to trying a few bikes out though.
    2006 Giant XTC
    2010 Giant Defy Advanced
    2016 Boardman Pro 29er
    2016 Pinnacle Lithium 4
    2017 Canondale Supersix Evo