Frame size for 5’10 man

Apologies but what mountain bike frame size would suit me at 5 ft 10 please. I used to know frame sizes in my youth. Do they go up in twos eg 17 then. 19 inch

Likely to be just Medium these days dude, but check the size guide for the bike. 

it depends.  I’m just under 5’10” and am sometimes medium and some times large.  The inches measurements are very variable depending on frame design so not terribly reliable as a guide.  I just measured up a couple of bikes.  My Shand is a medium with an 18.5 inch seat tube. My cube is a large with a 17″ seat tube, My salsa fatbike is a medium with a 17″ seat tube.  All are a good fit.  Mrs TJ had a 17″ that was tiny for me

New or Secondhand?

TJ makes sense. Sometimes manufacturers intentionally spec short seat tubes to allow big droppers now. I am 178cm or just over your height at 5-10 and a bit. I ride a large sc chameleon. Look at reach and stack. Maybe look to see if a manufacturer’s suggested size puts you bang in the middle or on the border between 2 sizes.

Edit: incidentally there is (or was) a reasonably priced chameleon in the classifieds. No connection.

I’m 5’11” and it is a bit of a pain. Medium for more playful and longer for more stable seems to be the rule. I can fit both

As another 5’10”-er, I repeat the answer.

I can fit a medium or a large although it really depends on bike design.  Generally though I’d plump for  a medium and then consider why a large would be better, particularly if it’s got bigger wheels and/or lots of suspension travel.

I have medium and large bikes depending on the brand and type of bike.

I’d go demo some you like, borrow from friends etc. 

I size down on drop bars 54cm typically. I’ve got one medium MTB and two large. The medium is longer than one of the larges?

If you sit on some you can find the geometry and then compare. I’d probably recommend reading about reach and stack as these are good indicators. Typically I look at effective top tube, reach and stack when comparing. Often seat tube too as I have long legs and on drop barred bikes can end up with a 400mm post on some models.

Same as @tjagain, I’ve a medium frame and a large frame. Both fit just fine. You just have to pay attention to the geometry charts 

Thanks all. It’s a second hand trek 18 inch. It would just be a rough renovation project.

I’m 5’10 long body, stumpy legs (30″ inside).
In the olden times (well 8 years ago when I last bought a new mountain bike) I went for a large because I wanted more reach and I compromised on having less standover.
A modern bike is more likely to have a much shorter seat tube that takes away that standover issue so you can more easily size for how long you want it not how long your legs are.
My gravel bike is a medium.
My older 2009 hardtail is also a medium (18″ in old money).
I like a bit more reach / length on the MTB for stability so I’d consider sizing up when on a size crossover by default but I’ve yet to ride a properly slack recent bike. YMMV.

I’m 5’10” and seem to vary between ‘Medium’ and ‘Large’ depending on manufacturers. I’m seemingly of very ‘average’ dimensions, with a 33″ inside leg and moderate ape index, I can technically fit on lots of bikes, but it’s quite easy to pick something that’s either a bit of a stretch or makes me feel a bit bunched up…

My advice, Ignore seat tube sizes (stand over tends not to be such an issue these days). Figure out if you are more torso or leg and then look at reach, see if you can try a few bike of differing reaches just to see how you personally get along with each of them.

I’m 5’10” with short legs. Ride a large HT (reach is good, standover not), ML bird Aether (Loooong but perfect) and a large road bike with almost none of the setback seat post showing.  All about the stack and reach for me.

I’m 5’10” with short legs. Ride a large HT (reach is good, standover not), ML bird Aether (Loooong but perfect) and a large road bike with almost none of the setback seat post showing. All about the stack and reach for me.

Exactly the same here. The Bird was the first mtb I’ve ever had that actually felt long enough whilst keeping space over the top tube. I’ve recently built up a Ragley Big Al which is also nicely long with decent standover (I can just fit a 170mm dropper).

5ft10 here too, another Mr Average.

First point – completly ignore ‘medium’ or ‘large’ as its absolutely meaningless, as some manufacturers medium frames are larger than anothers large.

My advice, Ignore seat tube sizes (stand over tends not to be such an issue these days).

See. this is the the problem with us all being the same – we are all different. I’m all body, 30inch jean legs here. Seat tube length is absolutely critical to correct fit on a new trail/MTB frame and the first thing I look at on the geo chart!

430mm centre to top (the old, nominal 17 inch frame) is absolute maximum – any more, and I wont get a decent length (150+) dropper in. Reach 460-480ish, touch longer if possible depending on intended usage.

Its quite normal to look at a manufacturers reccomended sizing, where they would put me on their ‘large’ with a 445mm seat tube – the bike build comes with a 170mm dropper, and my feet would be 3 inches off the pedals at the bottom of the stroke, with the dropper slammed in the frame.

The introduction of the ‘Medium Long’ size by people such as Bird is brilliant, Trek do one too now which is quite good. Medium sized seat tubes and large size reaches.

Ratio of SeatTube:Reach discussed a bit more here when I was last looking https://singletrackworld.com/forum/topic/trail-bike-frames-with-shortest-seat-tubes-relative-to-reach/ and https://singletrackworld.com/forum/topic/trail-bike-with-low-standover-height-designed-for-dropper/

It tends to be the more progressive/radical manufacturers that are better at this. My newly bike has a 420mm ST and 490mm reach 😀