My bikeposts were well received and I plan to do more, but I'd like to reach out as to whether there's a topic or maybe specific questions about the whole ordeal that interests the users of this site specifically?
Like do you want to learn about tools you need for more than basic maintenance? Tips on riding in winter conditions and/or in the street with car traffic? Maybe which of the marketing buzzwords are actually important? How to train for longer rides? How to bike commute / when to bike commute?
Hit me up, I'll try to answer any question and/or do another bikepost about any topics that you're interested in and I feel qualified to answer.
Why does my bike always feel like the tyres are deflated? It's a mountain bike and I should probably buy road or gravel tyres but still. I inflate them up to 70 psi or something and they feel hard for a bit, then they feel way too soft a few minutes into riding. So now I'm just constantly inflating my wheels every time I need to go for a ride. I find that to be lame. I had a fixie that I bought for really cheap and it never felt too soft to ride. It got stolen, but is there any way to make a mountain bike feel solid like that? obviously it's not going to feel like a road bike, but I feel like I'm sitting on top of an air mattress to squeeze the air out when I'm on my mountain bike.
You probably have a slow leak in your tubes. You're going to have to get the tubes out and check, inflate them a bit and put them under water to see if there's bubbles rising somewhere. You either need to patch the holes or get new tubes.