I'm 175 cm (5′9″) tall and have a 26" hardtail MTB. This bike is apparently small for my size because bike manufacturers do not recommend 26" bikes for my height. However I had gotten this bike frame many years ago and built the bike without knowing nothing about bike fit at that time. I made some modifications to make it fit to my size by adding 3 spacers under the stem and opting for a 120mm stem.
When I reach the handlebar in upright position there is very little flexion on my elbows. I don't feel comfortable and relaxed in this position. I think replacing the stem with a shorter one would not help as my sitting position is higher than the handlebar. What do you think I should do?