Birdbikes

I am 5'10.


​​​​​​i currently have an old 19 inch mountain bike that doesnt fit right. I measured it with a 22.5 inch top tube length (from the seat post to the head tube), 34 inch seat height for full pedal extension (measured from bottom pedal stroke), and 39 inch high handlebars (measured from ground).

that bike is very uncomfortable because I feel like I have to lean too much to grab the handlebars, and it feels like there is too much weight on my hands. The handlebars feel way too low.

I can't tell if that means I need a bigger bike or a smaller bike.

i feel like its too hard to get a comfortable bike since I have long legs but short arms.


what size do I need? I've been looking at something like the trek fx1 or the radmission ebike.

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argulator

I don't think anyone can give you an answer. 19s or 20s or Ls or Ss are all going to vary by brand and/or model and no one knows what it feels like to be you. Go sit on some at the dealer if you're lucky enough to find some in stock and see what feels best.

hokiefyd 

Few new bikes sold today will fit like an older mountain bike; older mountain bike geometry featured just what you have -- a much longer top tube than seat tube...and often, a pretty long stem as well. This puts you in a relatively aggressive position (to attack the trails!) that's not all that comfortable to ride. Modern hybrids (like the FX) will have a higher head tube (and longer head tube) that puts the handlebar much higher in relation to the pedals (called "frame stack"). Additionally, most modern bikes have sloping top tubes such that the seat tube is shorter than what you might be used to.

For example, your current bike has a 19" (48cm) seat tube and a 22.5" (57cm) top tube. Your effective top tube is likely just a hair longer than this, but it should be close. A medium Trek FX has a 17.5" (44.5cm) seat tube and a 21.9" (55.7cm) effective top tube. This should give you a shorter reach and it may be quite a bit more comfortable because the handlebar will likely be higher than your current bike. A large Trek FX has a 20" (50.8cm) seat tube and a 22.5" (57.1cm) effective top tube. This will be closer to what you have now and probably NOT what you want. Although the handlebar will still likely be higher than your current bike, you'll still likely feel leaned over the front bars more than you like.

You really need to visit a bike shop and see what fits. It's difficult right now due to the current inventory situation but, in the end, your body has to like the fit, and different bikes, and even different brands with the "same size", will fit differently.