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So I'm (hopefully) looking to replace my full suspension later this year but struggling to understand what I should be looking at on geometry and sizing.
Looking at newer bikes reach seems a bit less relevant with steeper seat angles.
Below is the goe of my current 2014 Mega TR (large), my 2017 Scout (medium) and the L & m 2019 Mega.
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The 2019 Large has 30mm longer reach than my 2014 Large and the 2019 Medium has 6mm less reach, but the seat angle is 2.5 degrees steeper on the newer bikes and the head angle 2 degrees slacker.
The ett on the medium is shorter than my Scout but has longer reach....
Looking on the Nukeproof site it recons I should be on a Medium being around 5'10".
I know the best policy is to sling a leg over both sizes and see which one feels better but it's all very confusing lol
Out of interest, what's that bike comparison website you're using?
Looking at newer bikes reach seems a bit less relevant with steeper seat angles.
Reach is very relevant. It's the increase in reach that has mandated the steeper seat angle so that you're not too stretched out when seated climbing
Reach is more relevant to how long it will feel standing. Effective toptube is more relevant to how it will feel seated.
Reach is very relevant. It’s the increase in reach that has mandated the steeper seat angle so that you’re not too stretched out when seated climbing
Reach is more relevant to how long it will feel standing. Effective toptube is more relevant to how it will feel seated.
Thanks both, in that case then probably the Medium as I feel I wouldn't want to go any longer then I already am when seated.
Don't forget to factor in stem length.
Fair enough, I assumed the older geo bikes might be running a longer stem
That’s s good little website. Just for comparison I’m 5’9 with a 32” leg and quite a short torso / arms. I’m riding an ML Bird Aeris 145LT and it’s about right. I think I was on the cusp of the m and ml but Bird recommended the ml. Compared the geo’s below. I’d almost be tempted to go large on the Mega at 5’10 - if it gives enough standover height and enough room to fit the length dropper you want. Seems like it has quite a long seat tube for the given size.
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Longer reach won't necessarily mean it feeling more stretched out when seated. Hence the current trend for steeper seat angles to keep your weight centred when climbing rather than hanging off the back and having to be perched on the nose of the saddle to keep the front wheel down.
Is there anywhere local or a mate that have a newer bike that you can have a spin on to get an idea of which would feel better?
A good way of looking at it is in terms of ratios - the ratio between length (reach and ett, both have gone up) and seat tube height has increased. Typically for a given size, the former have gone up whilst the latter has come down*. This allows for the bigger range droppers that folk now like. If you like a shorter frame, get one, but the seat tube will be shorter than an equivalent length older design. So factor in seat tube actual height and how big a dropper you can fit in with your preferred max saddle height. Also, watch out for frames where a bend or pivot bolt restricts the depth you can drop your dropper into the frame.
Manufacturers seem reasonably similar in what size of rider should ride a medium etc., but they do vary (from "long" to "bloody long") in how long they think a medium etc. should be.
*leading to some bizarre size designations, eg until recently Trek stuck with calling their large frames "19.5 inch" although the seat tube height on the Slash was actually 18.5". They have now gone over to small medium large etc.
This needs a bit of time.I've had good results with it. Especially nice is the fact that you can overlay one bike on the other which is been super useful for me in terms of understanding reach and contact points between my bikes.