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29ers and frame size.

avalanche_expertavalanche_expert Posts: 177
edited September 2017 in MTB buying advice
Quick question my current bikes are both medium frames. One is a 27.5 inch wheel hatrdtail, the other is a 700c hybrid. Both bikes fit me perfectly.

I'm 5ft 6 with a 29" inside leg, I'm right in between sizes on sizing charts between small/medium.

I'm concerned a 29er MTB may lack stand over clearance. I'm thinking though being a comfortable medium on other bikes should mean a 29er would be no different?

I'm looking at a few options of bike and not all are available in local stores so online purchases may be my only option.

Just looking for any advice from people who ride multiple bikes of difffering wheel sizes.

Thanks.

Posts

  • Wheel size makes no difference to fit or stand over height.
  • Wheel size makes no difference to fit or stand over height.
    What he said - however I have found that where I am a large in 26 and 27.5s, I'm a medium for 29ers.
    Definitely 'try before you buy' if you have the opportunity.
    2007 Felt Q720 (the ratbike)
    2012 Cube Ltd SL (the hardtail XC 26er)
    2014 Lapierre Zesty TR 329 (the full-sus 29er)
  • The RookieThe Rookie Posts: 27,748
    29ers still have a similar BB height to a 26er (greater BB drop from axle height), the seat-tube is a similar length 9for the same size frame) so the standover is similar, the only caveat is that the longer forks tend to angle the top tube up a bit more steeply.

    Standover isn't (shouldn't be) part of size selection anyway of course.
  • Thanks for the replies, the thing which is concerning me is that some brands supply their bikes with either 27.5 or 29 depending on either medium or small.
  • I'm a similar height to the OP and from my recent test rides at Evans (Norco & Pinnacle bikes) there was definitely more standover height on the bikes with 27.5" wheels than those with 29" wheels. I ended up going for a small Pinnacle Ramin 4 with 29" wheels in the end as I preferred the ride with the bigger wheels. The standover clearance is pretty "snug" but hopefully it shouldn't matter. Haven't got the bike yet though, still waiting for my Ride-to-Work voucher to come through.
  • 02gf7402gf74 Posts: 1,163
    Having a larger front wheel is going to raise the front of the top tube unless either the head tube is shortened or the top joins lower down. Neither of these is desirable so sadly 29in bikes suit the taller rider.

    If you are on border of s/m frame size for 26 in then 27.5 may be the better choice.
  • mugensimugensi Posts: 558
    If you intend using the bike for mainly trails and fire roads then go for the larger size or if you plan on using it for more technical trails and descents then the smaller frame should be more chuckable.

    I ride 56cm or Medium in road bikes but bought an XL (21") 29er as I found it considerably more comfortable for the use I put it too (trails/fire roads with very little technical stuff) I fitted a 60mm stem to tighten up the steering and decrease the reach on the larger frame. I tried out a 19" before buying but found it too cramped and uncomfortable.
  • I would buy based on the position you need. I have mine set up something close to my road bike position because there is no reason why I cant have the same seat post to handlebar distance, similar saddle to handlebar drop, the same seat height, similar length stems. and it works.

    I would not buy a frame too small for it to be more chuckable. the frame has to be the right size.

    If you ride a medium bike and use a XL 29er something is not right about your sizing. A 19" 29er frame should not feel uncomfortable if it was set up right. shorter stems do change steering charateristics but so does changing the wheel base which can be done by changing the forks or the frame. I have never liked the short stem trend maninly because if I put a 60mm stem on my 29er's I would be too upright and the larger frame size is not so much bigger that it would compensate.

    Of course this depends on the kind of terrain you ride on. My advise is to do what I do, pick the frame not by the size but by the virtual top tube length. For me that around 620 to 625mm with a 120mm or 130mm stem. For the OP it will be a lot shorter. What should determine the stem length you use is not how qucik you want the steering to be but how upright you want to be because your seat height should be fixed for a your leg length. If you need to drop it for technical stuff that what dropper posts are for.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • Thanks for the replys. I've been doing some geometry comparisons against my current 650B medium GT and other bikes I'm looking at and some do come out as small with 29" rims.

    I think the one I may decide on will be a medium though. It's geometry measuremts and angles are very close to my GT which I like a lot.
  • 02gf7402gf74 Posts: 1,163
    I
    . I have mine set up something close to my road bike position because there is no reason why I cant have the same seat post to handlebar distance, similar saddle to handlebar drop, the same seat height, similar length stems. and it works.
    .

    Not sure how you manage that as road bike bars are 30cm narrower than on a typical 29er
    If you ride a medium bike and use a XL 29er something is not right about your sizing.
    .

    Yeah, that's a massive jump of 2 sizes.
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