Correct saddle height v correct frame size

Question

This is something that has always intrigued me. I expect there are numerous answers to this here. Apologies in advance!

I'm 178cm tall with a 73cm inside leg. I've cycled for more years than I'd like to admit to. I'm more of an everyday cyclist than an athlete,although I am relatively fit for my age.

I mostly ride 2 bikes. One with a touring frame, rack, mudguards etc(56cm) and the other an old 531 framed road bike pared down to the essentials (60cm frame).

According to most height /inside leg frame recommendations then a 56 to 58cm frame should be correct for me. However, I have not really noticed any difference when swapping between my two frames. I normally ride distances in excess of 40 miles. (saddle height is correct in both cases)

Is this more an issue relating to the relationship between leg length and arm length and the reach necessary to operate the handlebars? Perhaps my arms are longer than average, but I've never felt like I'm stretching on the larger frame. Alternatively, is it simply more efficient to ride a frame in your correct frame size bracket?

The road bike frame is wearing out, so I want to replace it with something similar and wondered whether to keep to the 60cm size.

Answer 1

Size charts and your existing bikes provide no more than a rough guide, as geometry varies between manufacturers and models and has changed over the years.

Top tube length, along with stem length as well as saddle position and seat tube angles all play their part in fitting a bike correctly. I would not rely on the comfortable fit of any bike you currently ride to be certain the same size in a new bike, that is not the same make, model and year, will be comfortable.

If you are flexible (particularly in the lower back) then the range of bike sizes you can comfortably ride is more than someone who is not as flexible. Also if you have been riding a larger than ideal frame for a long time, your body will have adapted, hence it feels comfortable (which is a good thing).

I suspect a 58cm frame would be more suited to you, and if you must buy without trying both sizes, 58cm would be a safer bet. You would need to ride both sizes to know for certain which is best for you.