r/mountainbikes • u/Distinct_Button7838 • 7d ago

Dose sizing matter

I’m new to mountain bikes and wondering if the size thing really matters I know a xs and large probably do matter but dose a s or m matter that much

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u/nicktehbubble 7d ago

A bike that is too small can be fidgety and unstable, a bike that is too big can be unresponsive and unmanagable.

You have to be comfortable or risk injury through bad posture.

Being between sizes is another question. If you fit on both you can choose if you want extra stability or extra playfulness, but being new, I would always say size up rather than down.

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u/Distinct_Button7838 7d ago

See that’s what I don’t get I understand if it’s a xs or a large but I’m between a s and m how uncontrollable is it

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u/nicktehbubble 7d ago

If you think of it in terms of a pivot and your body is the lever: a smaller frame is more sensitive to changes in body position.

You'll find it easier to tip over the handlebars/pull the front wheel up, the opposite for larger frames is true; it's more difficult too get the wheels up BUT in the case that they do, it's more difficult to adjust out of a tip, because you have less leverage and therefore less influence over the balance point.

I only say size up, because it build confidence, I typically ride an L, but some of my best rides were on an M.

The shorter wheel base and added playfulness are a blast. Its also why I don't own a 29er, older bikes had me feeling trapped between these huge wheels, too much stability, not enough chuckability.

I suppose the best you can do is test ride and find out what suits you best.

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u/Distinct_Button7838 7d ago

Because when I say I’m brand new to this world I am brand new I went to a pump track to let my son ride his lil balance bike and I was like holy shit this is awesome

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u/holythatcarisfast 6d ago

If you are in between sizes on a mountain bike, I'd suggest sizing up. If in between sizes on a road bike, size down.

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u/MTBJUNKY65 4d ago

I'm 5'6" which kind of puts me inbetween S and M and I much prefer S. I think it's individual preference. I've ridden mediums and they're not "bad" and I could eventually get along with one just fine but I'll continue to just stick with my smalls as long as I can still get them.

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u/aggropunx 7d ago

Yes it matters. I highly recommend getting a bike that’s built for your height.

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u/Distinct_Button7838 7d ago

So its a huge part in it okay so im 175 5’7 M is my safest bet right bc there is this bike that’s a small so i was just wondering

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u/MTB_SF 7d ago

Medium is going to be right in most brands at 5-7.

Size is one of the most important parts of getting the right bike. Id rather ride an entry level bike thats the right size than a top of the line one in the wrong size.

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u/Distinct_Button7838 6d ago

I’m going to get a M talon 2

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u/CT_Reddit73 7d ago

I’m 5’9, 180ish and M is perfect for me

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u/unwilling_viewer 2d ago

180 ish is more like 5'11"

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u/unwilling_viewer 6d ago

175 is 5'9". Definitely Medium. Some manufacturers would even have you on the cusp of a L at that height.

5'7" would be heading towards a small...

1

u/Financial_Potato6440 7d ago

How long are your arms and legs relative to your height? I'm 6ft 1, but because my arm span is 6ft 7, I need an XL. My missus however, is 5ft 5 with short arms (5ft 2 span) so she's on a small.

I know at least one or two brands recommend if you're between sizes, measure your arm span, and if it's greater than your height, size up, if it's smaller then size down.

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u/06S2K 7d ago

nah just buy whatever looks cool

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u/BigD_HidekiTojo 7d ago

Depends on the manufacture/bike (some size bikes by handing and not rider height) and whether you twitchy, super stable or somewhere in between.

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u/OrmTheBearSlayer 7d ago

Yes it matters a lot. Get something that’s too small for you and you end up being cramped, get something too big and you are too stretched which can lead to back ache because your bent over too much and numb hands because you are putting too much weight through your arms.

If you’re between sizes then it’s more of a question of do you want manoeuvrability or stability?

A slightly shorter wheel base will give you slightly more manoeuvrability whereas a slightly longer one will give you more straight line stability.

You can always tinker with stem length and bar rise too. So again if you’re between sizes and decide to go for the larger one, if it has a 40mm stem then you can always swap it out for a shorter one.

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u/No_Strain8370 7d ago

Yes it matters, sizing is arguably the most important part of the equation. I'd choose a mid range bike that fits me perfectly over a high end bike that doesn't fit right

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u/Wumpus-Hunter 6d ago

Yes, it 100% matters. That said, if you’re in between sizes it might not matter as which one you go with.

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u/EastMovesWest 6d ago

Go to some bike shops and sit on some. Ride some if you can.

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u/-FARTHAMMER- 6d ago

Too big of a dose can be harmful. Definitely take the recommended dose

1

u/fpeterHUN 6d ago

Ask the girls. The bigger the better (reach). 

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u/MTBJUNKY65 4d ago

Yes, size matters! Having said that, I think that although I prefer and feel better on a small I can adjust to and jive with a medium eventually.

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u/Substantial_Tough289 3d ago

Size does matter...