Bike size – medium vs large

Got my eye on a bargain bike which I won’t name in case I get gazumped. Its last years model and only available in large. I’m 5’11 so generally on the cusp between medium and large. Looking on the manufacturers site, there’s virtually no difference between the medium and large. Seat tube, chain stay and BB height are exactly the same. Only differences are

Top tube – 585mm vs 610mm

And

Wheelbase – 1181mm vs 1204mm

Both my other bikes are mediums but with so little difference on this bike, would the extra inch on the top tube really be noticeable???

Yes.

measure the top tubes on your existing bikes, then decide.

a bike that doesn’t fit is never a bargain.

ps top tube and head tube are the 2 things I look at first for gauging size.

Head tube length is exactly the same on both

Longer top tube affects reach and has a big impact on climbing.
Head tube length will have impact on handling in a variety of ways and ideally should grow with frame size. If it doesn’t the triangle pretty much has to be different.
I’ve tended to buy larger sizes in borderline cases for longer top tubes.
Your mileage may vary and a lot depends on what you plan to do with it. Climbability is less important for an uplift bike, for example…

Its a downhill bike…

I thought many DHers preference was to go down a size for chuckability or whatever.

Measured my bikes.

Full susser TT length = 560mm

Hard tail TT length = 580mm

So if I add the stem length on the hard tail: 580 + 70 = 650mm total length

On the bike I’m looking at

610mm TT + 50mm stem = 660mm

So basically 10mm difference between my HT and this bike. HtT feels perfect so I doubt I’d notice an extra 10mm?

I had the same quandry once – a half price large that I never could afford the 2k for a med. Borderline between the two sizes. It did come with a long stem that obviously was a shortening candidate. I got on fine with it – loved it even. Then a few months later it snapped and I asked the shop for a med as the warranty replacement which the happily arranged. It did feel slightly better, but not 1k better.

Anyhow, consider seat tube length (for your height you may not get a reverb in a large for example), the cranks the same length? Otherwise, try and get a spin on it before paying?

Bigger bike may be slacker then. Smaller bike may get in way less.
If materials are the same and no fancy strengthening methods involved the smaller bike may be stiffer at the steerer interface and more positive under big loads.
There are a lot of ‘maybes’ here.
If you don’t dislike your mediums, I’d be inclined to stick with them unless you can try comparable larger frames to see if you prefer…

Has to be large 🙁
On account of my in-feasibly long legs.

Riding a large bike when you yourself can easily be compared with a giant is not fun. You are a really long way off the ground and when going down steep hills it can feel like death is on the horizon

You will certainly notice the extra inch. Whether this is a good thing or a bad thing depends on the bike, the wrong size is wrong regardless, best to get it right (although IME I would err on too short rather than too long) Can you get a ride on one? Or at least a sit on one?