Seanna5169

Hi all yes I’m a Newbie. Just got back into cycling after almost 15 years. Very long story but been adding things to my Giant Defy. Last thing was a power meter. I trusted guy I got bike from and ordered 175 mm crank meter. My Lbs installed it and 30 seconds later a second mechanic said you gotta a problem. He could immediately see my cranks were 172.5 not 175. Place I got Stages power meter from said it was my fault and I’m stuck with it. Called Stages and they were super but couldn’t help me as I didn’t buy it from them. So long story but bought the the drive side in 175 had it installed today. I had read many articles about length and majority of them say makes no difference, just adjust saddle height. My fitter didn’t even have to do that. Looked at my knee position and said it looks ok and to try it for a while. So paired it to my Garmin 830 did zero reset and just threw my shoes on and went for a ride around block 1.8 kilometers. Since back riding it’s been a pure pleasure no pain no burn, until I did my heart rate threshold test lol but in this short trip around my block my thighs were burning. Do you guys think I need to get use to new length or could this jump in size be a problem. Possibly since the arc is longer my legs need to get use to it ??
thanks for help
I’m 6 foot tall. I’ve gone from 172.5 to 175 mm cranks