Ok I know sitting on one is the ultimate test but checking things out online for bike for partner and his inside leg and height don't fit in the same category! 36" inside leg but only 5'9 to 5'10". One puts him in one size bracket, the other puts him in the other. Should we be looking at height as the decider or inside leg?
Any ideas?
Find something that you can try out. at those proportions is the reach a lot shorter? that would make a massive difference and a lot more than height
I personally think you need to consider inside leg and upper body length too. I've got a 30" inside leg and am 5'9" tall, a mate of mine is 6'2" with a 30" inside leg too, so he's much taller than me and it's all in his upper body than me. so not sure how you'd size a bike for our two very different body proportions. We both want a bike with similar seat tube length but very different reaches.
I'm not sure that even sitting on a bike helps much. I've just got a new road bike and had a full bike fit before hand and they sized me for the particular bike I was after as a 52 where normally I would have thought and have always had a 54. Sat on a bike in the shop and it felt fine, but once I got it and went on the first ride it doesn't quite feel right. Not massively out and probably because I've got used to what I've ridden before, but now looking at longer stems and layback seat posts, but might just give it a few more rides to give it more of a chance.
Doesn't really help I'm afraid, I think you're taking a risk when you buy a new bike unless you get the opportunity to get a bit of time on the bike you're interested in. It also doesn't help that across brands the sizing is different with some sizing up, some sizing down and some sized for complete freaks.
Yup sizing does seem erratic of bikes. I guess hiring something might help to try out. 36" leg is quite long and I reckon his arms are almost that long too lol. Well maybe not quite. But he has long arms.