I’ve been trying a few road bikes recently and I’m now a bit baffled by sizing; I’m 5’11” and seem to fit any bike between 54cm – 60cm (i.e. medium to XL). Is this normal across the different manufacturers?

It’s years since I’ve ridden road – do compact frames measure up differently? Is there a rule of thumb I can work against?

Virtual Top Tube (horizontal distance from seat tube to head tube) is the best gauge. I ride a 56 VTT and am 5’10.5″ and normal proportions (32″ inside leg). For some brands this is a L, others a M/L. You’re probably the about same.

5’11 and you can ride a 60cm??

Crikey..

I’m the same height & I ride a 56cm..

Mind, I’ve stumpy legs at 31″…

That’s quite a broad range of sizes. As a gut reaction I’d say in a traditional frame you’re looking at around 58cm (c-t) frame if you’re 5’11. Of course that can vary depending on what you want the bike for and what your leg length and ape index is.

If it’s any re-assurance…my old training partner is a couple of inches taller than me, yet has his saddle 80mm lower than mine. So that in itself indicates a certain ammount of variation!

i’m 180 cm & ride bikes with 555 & 570 mm ett. i reckon this is the shortest and longest practicle for me.

I’d imagine you’d be similar.

54cm – 60cm

is this naming convention? some manus seem to use seat tube length, other use virtual seat tube length if the frame wasn’t comact (when it is) or are you actually comfortable on medium & XL bikes?

I’m 5’11 and have a 56cm road bike and 49cm TT bike. Both feel fine, just rty some and see what you like.
MTBs are 17″, 17″, 17.5″, 19″ and medium, bit of a range there too.

5ft 11 and riding an M/L. (Giant Defy)
Had a 58 Trek before but that was a little too big.A 56 Trek felt a tad too short.Try lots before you buy!

I’m a smidge taller and fine on a 56cm, a 57 might be better but no one makes them.

Why do pro’s use mahooosive stems? Everyone else seems to use 110mm stems +/-10mm to tweak the fit, but some pro’s use 140mm stems, surely that just means they’re riding bikes 2 sizes too small?

and no mention of stem length in these sizing anecdotes from people with different flexibility/limb/torso lengths and height.*

Effective top tube is the key, once you know this + your ideal stem length (110-130) you can size any bike just from looking at the geometry chart (taking into account how seat angle and head tube can change the effective TT)
best way is to get fitted in a shop rather than guessing from what other people ride.

565+130 6ft1 here which is no use to you whatsoever. 🙄 different manufacturers frames that fit me are anything from 55-58 or M to L.

*written while the above was posted

I’m a smidge taller and fine on a 56cm, a 57 might be better but no one makes them.

Why do pro’s use mahooosive stems? Everyone else seems to use 110mm stems +/-10mm to tweak the fit, but some pro’s use 140mm stems, surely that just means they’re riding bikes 2 sizes too small?

i ride a 57 from a manufacturer that does 49-60 in cm increments.
long stems are better as they mean more weight over the front and better weight distribution, cornering and handling.

6ft and 58 is bang on

The couple of bikes that feel the nicest are a kuota Korsa Lite and a Scott CR1 (2010). The kuota is badged up as a 56 & the Scott a 54cm. I haven’t measured anything yet just had a play around & they feel identical in fit, with the only difference being a bit more post showing on the scott. I think they’re both standard spec so I’ll try to dig out geomery charts.

I’m just confused and wondering whether there’s a number of different sizing conventions that are muddying the water a tad.

You can ignore the seat tube length XXcm as it’s just what I’d call the ‘name’ size, ie what the brand refers to. 2 56’s can vary a lot. Compacts are usually described by the size they would be if level, not always though.

Reach and stack is useful info for road bike fitting, or effective top tube plus seat angle for most frames.

I can fit on a 53m frame but I would not want to ride it. I ride a 59cm traditional frame (59x59m) and I am 6ft with a 34″ inside leg. If you are 5ft11 and have a 33″ inside leg then a 56 or 57 m would work well in compact frame. 57cm should work better if your inside leg is 33 1/2″.

Effetive top tube length is important though, however what is more important your total reach which inludes the stem length.