Want to know what SIZE bike to get? READ THIS.

supersonic

S,M, L, XL only has relevence in the context of the same frame as with a different one can be totally different. At least a sit on the bike or a ride round the car park gives some feel for size and riding position, and is far better than buying blind unless you know the numbers and how they work.

Pains in the back - depends on a few factors, may find a shorter top tube and higher stem/bars relieves pressure.

Daz555

Here's my dilema:

5'11" and interested in a bike that comes in S,M,L,XL. I have sat on the M and the L in the shop and to be honest the L felt a bit big but when I sat on the M, it felt a bit small.

Better to be a tiny bit too small than a than a tiny bit too big? (talking about bikes here of course!).

supersonic

Best to err for the small size. But I'd try a few more brands and bikes out.

sq225917

Two things count, height and reach, moving the post up and down and saddle back and forth and tinkering with stems is relatively easy. Seat position and stem length options can comfortably give you a 4-6" reach adjustment, and as for pedal to saddle height, max extension is the limit.

Small is better than too big, too big will never be right, too small can be made big...

KnightofCydonia

would it be possible if you found a bike that almost felt right to easily chance the geometry in addingor taking away maybe 20mm or 30mm of stem without affecting the end result?

supersonic

You are only changing the stem aspect, none of the frame aspect - but it will make a difference. You will be more upright, weight a little further back and faster steering.

Some shops will let you try a shorter stem.

KnightofCydonia

as i thought, a few mm won't make a difference, but perhaps going from a stumpy one to a 130mm might? Fortunately I'm not at the point where I have the money to buy yet, but will be in the next few weeks and am just thinking on my feet as to get it perfectly comfortable asap rather than buy blind & be fed up with the result!

wastelander

I started out riding off-road but moved across to road bikes and I've been pro fitted for my road frame size with the result being for me and ideal top tube length of 550mm with a 110mm stem. Getting back onto my MTB (2003 Specialized Enduro in large) recently everything that used to seem right now feels a little stretched out. A quick check with the tape measure showed a virtual top tube length of 620 with an 80mm stem - an increase of 40mm - that's 1.75 inces give or take. I know that the sweep back of the MTB bars will also give a little back but I guess that the large frame is definitely, well, too large!

Does anyone know if there's a relationship between ideal road and MTB top-tube length e.g. road top tube length + 10% or somesuch rule of thumb?

BlackSpur

Daz555 wrote:

Here's my dilema:

5'11" and interested in a bike that comes in S,M,L,XL. I have sat on the M and the L in the shop and to be honest the L felt a bit big but when I sat on the M, it felt a bit small.

Better to be a tiny bit too small than a than a tiny bit too big? (talking about bikes here of course!).

I was in exactly the same situation as you a while back! I went for the M, rammed the saddle back on it's rails, rolled the bars forward a bit and it's great! I could have gone for a different stem too, my current one is fairly short and steep - 90mm and 25 degress rise I think.

The Spiderman

Daz555 wrote:

Here's my dilema:

5'11" and interested in a bike that comes in S,M,L,XL. I have sat on the M and the L in the shop and to be honest the L felt a bit big but when I sat on the M, it felt a bit small.

Better to be a tiny bit too small than a than a tiny bit too big? (talking about bikes here of course!).

I am just under 6ft,with a 33" inside leg.My Giant XTC,is a 19" or what Giant call medium.I would say it`s a fraction too small,but I preferred the medium to the large,so have a layback post,and the saddle back on its rails.

Whilst the front can get a bit light on climbs, I must say I like the more chuckable feel of the medium.

I have since tried,other bikes and know that size wise a Specialized Rockhopper or Kona Kula in a 19" frame (Large in Specialized) would be spot on.My ideal is a tt length of 590-600mm.I would then get an inline post/and/or shorter stem.

At somepoint I might get an 18" On One Scandal frame,which again has a decently long top tube,but still has plenty of standover.

Just goes to show the importance of trying them,unless you know your ideal geometry from experience.

Even then,manufacturers quote figures slightly differently and I know my bike`s quoted tt length doesn`t quite stack up to what I have measured it to be.20mm shorter by my reckoning!

Dr Tinkle

I have read all the advice above and now at 6' 2" ride a M sized Whyte e120. Felt great at the shop but the more I ride and the more often I go over the bars, the more convinced I am that when I'm out of the saddle my weight is too far over the wheel.

If i increase the angle of the stem will this alleviate this problem or, as I am new to full sussing, is this just the way its supposed to be?

Sorry if this is obvious but i dont have the experience of you guys

supersonic

Dr Tinkle

Certainly worth trying. Full suss bikes are very dynamic - with travel at either end, angles can change rapidly and take some getting used to.
A slightly shorter, higher rise stem will give you a more upright position and take a bit of weight of the front end. Not talking much here - an inch is very noticable (or so she said ;-))

N0bodyOfTheGoat

I would really appreciate some guidance from the Commencal owners out there!

Height: 5'10"
Inseam: 31"
Reach (top of arm to handlebar grip): ~27"

I could be a medium or a large... which would help stretch me out to a familiar road bike position, please?

If this sizing is correct, the 594mm top tube of the large maight be too big...
http://www.allseasonssport.com/images/c ... _multi.pdf

My Felt F5C is a 540mm top tube with a 100mm stem.

Thanks in advance

Mad Dawg

I am 6'2" and have always more or less ridden an 18" frames no more than 19" ever... i was used to it from the BMX days back in the 80's getting use to small frames. Smaller frames are easier to dismount in a hurry without cracking your nuts in a hurry.

If it means setting the bike up in a way that makes it more adaptable for you, do so... all manafactures have different geometries these days, due to the many different styles that are out there. It's not all the usual 71 head tube; 73 seat tube that we were use too all the time. Though that geometry did make the best XC frame (personnel thoughts) tight and agressive very responsive, did the job. Also let you crank down the pedals when needed. Different frame angles will predict the length of top tubes depending on what size you want, try a few out and see how you feel.

Just look for about at least 3-4 inches clearance from the top bar, to your crown jewels. Main thing when sizing yourself against a bike, is dont feel to cramped up on it when sititting on it and dont feel to over stretched. Get that happy medium where you yourself are comfy, then get dialled in to it and go for it.

Mad Dawg

JxL

Thought il post this, might be of use to someone!

Im 6.2

Inseam 34"

I ride a 22.5" Genesis Core 10 frame.

Feels great!

hughesb

Hi

Im looking at buying a 'Giant' Mountain bike off the internet. However I am unsure what the sizes of the frame are as they are in S,M and L. Could anyone tell me what inch frame these sizes would be?

Thanks

REMF

6' tall (180cm)
34" leg

91 kilos

I ride a large frame Specialised 2009 FSR XC Comp, and it feels great.

i tried a large frame 2009 Stumpy and that felt great too.

Gideon

5'9/10
34.5" leg

Had a Cannondale F6 disc 2008 Large....had to adjust the saddle to feel right for me.....unfortunately some barsteward half inched it last week

The bike itself was fantastic....i'm looking to replace it for the same model (2008) but can only find it in XL....now in theory going by the cannondale geometry it should fit me fine...



I've found evans cycles have it in XL and their woking branch is only 10 miles away so trying to see if they have the XL at that branch for me to test out but thought i'd see what you guys thought as in theory measurements add up fine for me

The Spiderman

hughesb wrote:

Hi

Im looking at buying a 'Giant' Mountain bike off the internet. However I am unsure what the sizes of the frame are as they are in S,M and L. Could anyone tell me what inch frame these sizes would be?

Thanks

S=16"
M=18"
L=20"

I`d still advise you find a Giant dealer first,and go swing your leg over one first.

The Spiderman

Gideon wrote:

5'9/10
34.5" leg

Had a Cannondale F6 disc 2008 Large....had to adjust the saddle to feel right for me.....unfortunately some barsteward half inched it last week

The bike itself was fantastic....i'm looking to replace it for the same model (2008) but can only find it in XL....now in theory going by the cannondale geometry it should fit me fine...



I've found evans cycles have it in XL and their woking branch is only 10 miles away so trying to see if they have the XL at that branch for me to test out but thought i'd see what you guys thought as in theory measurements add up fine for me

You`ll find that far too much of a reach to the bars. :shock:

simon44

Adding my experience which sounds very similar. I am 5'10 with a 32" inside leg. I've ridden the 17" Orange P7 which felt great yet the dealer is saying definately go up a size. So after visiting another dealer that had a 19" to sit on, this also felt good...confusing. However in terms of the tackle test on the 19" there was no clearance and with the 17" there was some clearance of maybe 1-2 inches.

As I am intending to be mainly off road and hope to ride in a variety of different environments I think that the slightly smaller 17" frame will be more chuckable and more fun.

Cheers,

Simon

nick1986

hi there im looking at getting a marin wolfridge, im 6ft 3 and have tried the medium and large and don't know which to get. the guy in tne shop said i would be better off on the large but i think that the medium would be easier to throw about and therefore more fun, when im sat on the medium the seat post needs to be extended quite far and dont know wether this would look daft on the trails with a big guy on a small bike. i would prefer the medium as im looking to ride some short downhill and 4xbut also like to go to the tril centres . i dont want to spend all that money and regret it. was just wondering if any of you had this problem and what you decided to get. cheers

Dave Loasby

I'm 6'1" with a 35" inside leg, i ride a 19" frame. Always go small. imagine riding up hill and running out of steam. fall off the back or step forward ?? step forward with a large frame and you might as well have fallen off the back.
as i say in all my posts with regards buying its personal preference,
go and try before you buy, even if its a cheeky try on a shops bike if your internet buying.

nby

i'm 5"8 with a 32" inside leg and ride a 16" fury am 08, its perfect for me with 2" knackergap!

I took the advice mentioned here and tried from the top downwards so a 20" (tip toes) and then an 18" (no gap between myself and the frame) then ploughed for a 16" (perfect).

a mate has a GT Avalanche 2.0 08 disk in a "small" and hes the same height/build as me but theres no clearance at all!! he made the mistake of buying it online without trying at a LBS ... thinking "small" would be fine when its clearly unrideable!

he even cut the seatpost by a few inches so that its the smallest it can go

clwydian_rider92

I'm 5ft 11 and I really don't know what size to get. I went to look at the Trek 6700 and the 19' frame fitted perfectly. However Ive just seen the Cube LTD Race. However the only sizes they do are 18' and 20'. However my riding style is to sit really far back on the saddle to get maximum power all of the time. Would this mean Id need to go for a frame an extra inch bigger or so anyway? (Would my reach (arms) effect sizing?) Thanks!

supersonic

As it says in the first post, you can't really equate one model or brand with another.
So unless you understand all the numbers then it is a case of trying it out.

waynej

I recently bought a new bike - I'm 5' 11" and bought a 22" bike - big for me but for a reason.

I know that the top tube is too high but..

I have a history of back problems and the found that the top tube length on smaller frames does reduce (it feels considerable in some cases, probably isn't but does feel like a big reduction). Having more length gives increased stretch meaning that I can get more comfortable, go out, cover good miles and have no reaction. If too upright I can feel my back stiffen and actually go into spasm - not nice.

May seem like a strange reason, but it works for me and if you don't have back problems trust me - you'll take a crack in the nuts that passes in a couple of minutes for relief from a cripplingly sore back that can last days - if not weeks.

To be honest, I haven't cracked my nuts yet and I've been off a couple of times.

In a nutshell - yes get something that fits but make sure you can get comfortable. Don't buy something that is technically the correct size but is cripplingly uncomfortable - the payback could be worse than you think. Shop around and try different sizes.

Some may dispute this but it works for me.

dgw15

Im looking at buying a boardman pro, ive tried a M 18.5" & S 16.5" in the shop - both felt ok in their own way. Was hoping that 1 would be obviously better than the other but just left confused. I have a 18" GT 3.0 at the moment, it seems fine but the top tube of the M boardman is 2" longer than the GT so I think all in all small would be the best shot.

Seems reading through forums etc that if stuck on 2 sizes swing the direction of the smaller size. Im 5'6" with 30" leg.

Steve_b77

Just thought I'd add my 2p's worth.

I had a Medium Specialized Pitch (17.5" frame) with a 65mm stem on it and a layback Joplin seat post and it was nice and chuckable.

I now ride a large Nicolai Helius CC which is classed as a 19", however the top tube is only 11mm longer, the bottom bracket is 8mm higher @ 14" and it feels alot better for trail riding but not for throwing off stuff (it's a XC FS afterall), I much prefer the ride.

On another note I also ride a 17.5" Cove Handjob, this is much shorter than the Nicolai but with a 90mm stem and a lay-back post it feels great, really respoinsive handling and great for twisty single track and XC rides alike. It however has quite a low BB @ 12.75" with a 115mm fork on there, probably why the 170mm cranks suit the bike down to the ground.

BTW, I'm 5'11" with a 33" inside leg.

Clarkii

Well the whole thing is confusing me.

I havent had a bike for so long I thought I better go and check the sizes out before purchasing over the internet. I went to Halfords and looked at the GT Aggressor hoping this will be a good comparison for an 08 Avalanche I have my eye on. I have around a 35" inside leg ( another issue - how do you measure the inside leg for cycling.... another story :-) ) I jumped on a 20" GT and found it feel ok, unfamilier due to not riding for some time but generally ok. I then got on the 18" with the seat up, I was leaning forward a little more but and this also felt ok. I couldnt go any distance on them but hope I can tomorrow if they allow me but I am stumped to know which one to get.

If I follow the guides I see then it would be inside leg removing 13-14 " so for me would be 21-22" frame. I think this would be way, way to big personally. I looked at the geometry of the GT to try and work out a rough guide from the bottom bracket clearance measurement and frame height which would be around 11.7" + 20" frame size giving 31.7 + around 3-4" clearance for the crown jewels which is around 34.7 - 35.7 inside leg or for the 18" frame 32.7 - 33.7.

What do all the figures mean, well after actually getting on the bike I can tell they mean nothing, you need to try them. No calculation gives you the feel of the bike. I am still stuck between the 18 and the 20" GT, going for another look tomorrow to try and decide.

Can anyone tell me why GT use s, m, l, xl, xs sizing. Is this just another way of confusing people ? I guess it has little consequence if you are actually going to test them, the proof is in the riding not the size naming convention I suppose.