Sizing

[madcyclist09]

I have 2 hardtails large frame and a road bike also large and I am thinking of getting a graval bike.
I was thinking large frame would this be right
TIA

 

[Legs]

I have 2 hardtails large frame and a road bike also large and I am thinking of getting a graval bike.
I was thinking large frame would this be right
TIA

No! On the basis of what information you've given, I'd recommend an XXS!

The serious answer is that sizing - particularly the subjective S/M/L type of sizing - varies enormously between brands, so without telling us a few more specifics, we're not in a position to advise. Best would be to go to a shop and put your leg over a few.

 

[wafter]

Ignore such frame sizing convention as it can be all over the place.

Best bet is to measure the reach and stack of your road bike (assuming you find it comfortable and can ride for hours with pain) then compare these numbers to the published values of your intended purchase.

You can measure reach by pushing the front wheel up against a straight, vertical wall, measuring horizontally from the wall to the top centre of the frame's head tube and subtracting this from the distance between the wall and bottom bracket. Stack can be deduced on a flat floor, measuring to the bottom bracket and subtracting this from the distance to the top centre of the head tube.

Reach and stack have their limitations but are a pretty universal measurement, will get you a lot closer than subjective and hugely variable size-labels and factors that affect effective reach and stack (such as stem length) can relatively easily be changed.

The acid test after you've made your selection is of course a test ride..


EDITED for the usual attention-deficient cockups and some bits being the wrong way around...

 

[vickster]

Do you have your eye on any specific bikes? Most manufacturers will give a range based on height and dimensions of the normal adult male (longer arms, longer torso, shorter legs). Go and try them out even if only on a turbo trainer in a decent shop

 

[vickster]

This looks a good deal if you are the right fit for a L gravel bike
https://winstanleysbikes.co.uk/genesis-fugio-10-2023-bike#187=4581

Here's the geo...looks like it'll come up pretty large as Genesis often do (reckon you'd need to be over 6ft) https://geometrygeeks.bike/bike/genesis-fugio-2020/

 

[N0bodyOfTheGoat]

If your existing bikes fit nicely, measure their stack and reach and look for similar numbers in a gravel bike.

Just remember that reach is for the frame only, you then get extra reach from the stem (which will often change a bit depending on whether flipped upwards or downwards) and the bars (especially on drop bars).

My road bike ("58cm" Cube Attain GTC Disc) is 388mm reach, 610mm stack, with -30 degree 110mm stem and ~&5mm reach bars.

My gravel ebike (med GT eGrde Bolt) is 405mm reach and 577mm stack, with a 90mm stem and ~80mm bars reach. I'm tempted to try a 100/110mm stem to stretch me out a bit more for the aero gains.

 

[madcyclist09]

I'm 5'11
The bike I'm looking at below

 

[vickster]

I'm 5'11
The bike I'm looking at below

There's a sizing section on the Trek website
https://www.trekbikes.com/gb/en_GB/.../F224-2/checkpoint-alr-4-gen-3/49973/5332853/
Suggests an ML for 5'11. L will be too big most likely. You can make a drop bar bike larger if a little small, but it's much harder to shrink a frame that's too big! Even tumble drying doesn't work

 

[Sharky]

I'm 5'9" and most of my bikes are large, with quite a large showing of seat post. But my Giant is a medium, however all my bikes are set so the riding positions are very similar.

As said above, try a few bikes at your LBS or even Halfords, to get an idea of what you need.

 

[Animo]

Go to Geometry Geeks and compare your existing road bike and the intended new one. You can check multiple sizes. Just remember to factor in stem lengths if different.