Bike Sizing - Previous Gen XC versus Latest

[MORNE]

I’m 197cm, 1:1 ape ratio….and i can promise you that you don't need an XL. In fact..as @ChrisF alluded to, modern Geo means you might be lucky enough to try M or L bikes depending on brand and also what your preference is ito bike handeling.

A smaller bike will feel less cumbersome ito handeling. I should probably be riding an XXL…but i’m not a dentist and dont have Santa Cruz money. There are only a few brands sold locally in these sizes…spez S6’s being one and SC being the other. Trek mskes small bijes so i dont regard their XxL too big.
 

That being said, i prefer to ride XL bikes, with some caveats - knowing full well they are probably on the ‘smaller’ side for me. They are still massive bikes though and will never be as nimble in the twisties as L and M bikes. 480mm reach vs 520mm is huge.
Then, ask any tall rider and they will all moan about how low the stack is on most modern bikes. Bike brands design bikes in size M/L and compromise all the others. Proportional sizing is rare.
I want a frame with 680mm stack…instead i have to accept that 630-640 ish which is in most cases the same as a size M/L. I want longer chain stays, instead i get the same ones that are on a size S,M,L.

Low stack automatically means 50mm risers to get a better seated position and more comfort with less strain on my hands. If a 300mm dropper post existed and could fit in a frame, i would be able to use one lol! I have some noticable saddle to bar drop even with 20mm spacers under a 50mm riser bar.

Before droppers i had a hard time finding seat posts long enough (410-450mm to get minimum insertion)

i currently ride a bike in XL that feels great…but its in the smaller side of the XL spectrum imo (495mm reach and a pathetic 637mm stack)..i mean there are size large bikes close to those numbers out there. BUT, it has proportionally sized rear triangle, as in..rear center grows with larger sizes…so its actually as long as an XL bike is supposed to be and it gets me in the center of the bike where others have me hanging off the rear. It rides great. Its still a boat (big long XL bike) but just rides so much better than many other compromised XL’s ive ridden in the past.

In conclusion: Try a M and a L. 

Edited January 31 by MORNE

[ajnkzn]

Thanks Morné - yes stack seems to be the final frontier for brands to get right and for tall guys it’s still a disaster 🥴. 
 

That’s what’s been weird with my Roscoe - higher stack than all my bikes before (including a SC Tallboy 4) but I’m having this issue with hand fatigue and loss of grip strength control.

[MORNE]

1 hour ago, ajnkzn said:

Thanks Morné - yes stack seems to be the final frontier for brands to get right and for tall guys it’s still a disaster 🥴. 
 

That’s what’s been weird with my Roscoe - higher stack than all my bikes before (including a SC Tallboy 4) but I’m having this issue with hand fatigue and loss of grip strength control.

Look Im not a bike fit expert by any stretch lol, but i’m very in tune with how i like my own bikes to feel when i’m on them and i know my preferences well enough by now that i can look at a Geo chart and know exactly what i would need in terms of components to make it fit me right. I can and do replicate that feeling as close as possible across many bikes, road-gravel-mtb. This is partly because I used to CAD them out on the computer haha.  This made it possible to overlay different bikes to see how touch points were affected and what i needed to do to get the fit right.

it could be as simple a saddle shape/position/height issue. Or even armpump depending on what trails you ride, which is very much a suspension and or tyre pressure related. It could also be a combo between reach and bar width. A 800mm bar on 450mm reach puts you in a different position than say a 760mm bar on the same reach. Backsweep, roll, rise too. Wider bars pull you forward. Many variables.  

But I’ll say If your saddle height measured to the floor is roughly the same as your grips to the floor, you should be relatively neutral and centerer on the bike which means the sizing is pretty close. 

Your arms are longer as you stated, that means you have room to play with in this regard. Lucky! 

It SOUNDS like your weight is slightly biased to the front which could mean you are keeping yourself up with your hands off the bar - leading to the issues you are describing. 

Negating someone with a washboard core and monster abs, you should be able to hold yourself up and have the grips float loosely between your fingers without wanting to ‘fall’ forward while seated and freewheeling along. “Heavy feet, light hands”. That has always been my gauge and how i know my bars/reach/stem are close to being in the right position. 

A very tall saddle combined with slammed bars or too long a stem will put your weight forward naturally, meaning you will be holding yourself up more with your hands than you probably should. Ofcourse some people want this too, as it results in more grip on the front wheel. 

Go feel both sizes out, move the bars around. Look for that heavy feet light hands feel. Avoid feeling stretched out. You’ll be pretty close then.
 

Edited January 31 by MORNE

[DieselnDust]

Stack is a problem at both ends of the spectrum.

for rider shorter than 165cm its often too high to accommodate 29er wheels.

for rider taller than 185cm its too low because the head tube length is being limited to minimize the number of head tube moulds required (economic choice)

The only way to get the head tube higher is too make bespoke frames since a complete revision of the geometry I needed.

With the more modern bikes I find myself sizing down from M to S due to length of these new bikes. A 2024 Scalpel in size small is bigger than my 2018 Scalpel Medium in all important metrics

A 2021-2023 Scalpel medium is slightly bigger than my 2018 small. Same applies across other brands

I'm 172cm btw

Edited January 31 by DieselnDust

[MORNE]

5 minutes ago, DieselnDust said:

Stack is a problem at both ends of the spectrum.

for rider shorter than 165cm its often too high to accomodate 29er wheels.

for rider taller than 185cm its too low because the head tube length is being limited to minise the number of head tube moulds required (economic choice)

The only way to get the head tube higher is too make bespoke frames since a cmplete revision of the geometry i needed.

With the more modern bikes Imy find myself sizing down from M to S due to length of these new bikes. A 2024 Scalpel in size small is bigger than my 2018 Scalpel Medium in all important metrics

A 2021-2023 Scalpel medium is slightly bigger than my 2018 small. Same applies across other brands

Im 172cm btw

Yea you have the same problem but at the other end of the spectrum. Size S bikes are also considered a niche size - at least in SA. And Rare!. My wife is 170cm and i built up n medium Hyrax for her, but literally had to build it as the smallest medium size bike I possibly could so it could fit her right. Modern bikes are long.