Originally Posted by stdennis
Right now I'm riding a 12" mtb which suits me well, the Milano comes in 16.5 and the Birea in 18". Are those frame sizes significantly larger? My Jamis fits neatly in the empty cube next to me, I'd like my next bike to also be equally inconspicuous.
Thanks in advance for your help.
This is going to sound strange... but it's not seat height that affects whether you can put a foot down or not. The bottom bracket height is a much bigger factor, because it dictates how high up you are, and how large a foot you need to have to touch the ground. Most bikes have a bottom bracket at least 26 cm above the ground. 30 cm is not unusual. They do this so that 170mm (aka 17cm) cranks won't touch the ground in turns. Having a pedal or crank arm hit the ground is a great way to have a fall, so the design makes sense.
Thing is, crank arms don't *have* to be 170mm long. And for a shorter person, shorter crank arms can be helpful. And *that* means the shorter person can have a lower bottom bracket, so they can stop safely.
So before you go replacing your Jamis, take a bit of time with it and a tape measure. Then you'll have a baseline of what works for you, so you can comparison shop easily. At your height, it may turn out that none of the "adult sized" bikes you look at are a good fit. There are some "youth" or "kids" bikes that have 26" wheels and smaller frame sizes... if you find one of those in your shopping, it might be well worth a look.
And just to give you a comparison point, my legs are about 29" long, with size 9 us women's feet (which makes my bare foot about 25cm long). My Breezer Villager has a 26cm high bottom bracket and 26" wheels, and I can touch the ground easily for a dismount. I ride the smallest frame size Breezer makes. I can't stay seated and have a foot flat on the ground, but I can't do that even on an Electra Townie.