stykthyn

When I ride road I have no issues whatsoever. On my MTB I finish the day with neck and shoulder pain. Frame is a 17.5 and I'm 6' tall. I sat a 19" frame and the stand over height was a little uncomfortable(32" inseam). Would raising the bars help? I also find myself unsteady when leaning over the bars during a technical climb. I originally thought this was just me being a novice but I'm starting to feel that the bike may not fit me that well.

jimincalif

It could be the different handlebars. Let your arms hang comfortably then bend up 90 degrees at the elbow, note your hand orientation is similar to how you would ride the hoods on a drop bar. With flat bars you have to rotate your hands, this can cause shoulder issues. My wife was experiencing this to the point of getting medical treatment and PT. The therapist pointed this out. We got her a drop bar bike and the issue is much improved.

Obviously lots of people ride MTBs so you might just need to condition yourself. Try doing "yes no maybe" neck stretches and shoulder shrug exercises. I will occasionally get neck and between shoulder pain while riding my road bike, I can do a set of the YNMs while waiting at a traffic light. Almost immediate relief.

grubetown

17.5 seems small for 6’
Off road is going to use different muscles. I recommend a good fit as top tube height isn’t as much of a factor off road as most people think.

trailgumby

Get a bike fit from a professional fitter. People do it all the time for road, but sometimes seem a bit weird about doing the same for MTB. I've done it twice and it made for a dramatic improvement in my comfort and power output. Just make sure you get it done a few weeks before any major rides or races. This is to give your body time to adapt by doing a few light to moderate spins...

tajar66

I have a tendancy to tense my shoulders more on my mountain bike I really have to think about relaxing my shoulders while riding.