I ride a lot and am going to differ a bit from the advice from others. If your son is younger and just learning it doesn’t really matter what type of bike you buy because he’s going to be doing around the block rides. You could follow him on a road bike, cross bike, mountain bike or beach cruiser and be just fine. The important thing is that if you are spending time with him you’re being a good dad. If he’s a little older he is going to want to hit the trails and so you would indeed want a mountain bike.
Either way my advice is always to spend enough that you’ll enjoy riding the bike. If you hit WalMart* and buy a cheap bike it’s going to be heavy, fragile and unreliable. It may or may not be the right size for you. It could very easily end up being ridden a few times and then retired to a corner in the garage. That doesn’t ever feel like a good investment to me. On the other hand, if you find a bike that puts a smile on your face every time you throw a leg over you’ll ride it a lot, improve your health and set a great example for your son. I get asked “What bike should I buy” often and here is the process I recommend:
- Figure out how much you can spend. I generally say you should plan on $800-$1000 to get a good mountain bike new that will work well and last years.
- Visit every bike shop in your area. Tell them your budget and where you plan to ride and then test ride every bike they have in your price range. Wear good shoes and shorts. If you are hoping to ride a ton buy a $40 pair of bike shorts and wear them on the test ride. Ask the person helping you to help you get the saddle setup properly, in a well run shop you won’t need to ask. Go around the block more than once. Ride over the curb and on the grass.Shift the gears and spend time pedaling from the saddle and standing up.
- One of the bikes will put a bigger smile on your face than the others. Buy that bike. Size matters, but it’s easier in a mountain bike than a road bike as there are fewer sizes so I’d feel OK letting the shop tell you what size to test/buy.
- Ride. Often.
I don’t think brand matters a ton as long as you are in a good shop. I’ve owned Giant, Trek, Specialized, Cannondale, Felt and others and love them all. I’ve owned hard tails, fat bikes and full suspension bikes and am currently spending most of my dirt time on a hard tail that I currently have setup with a rigid fork. It’s all good and the only really important thing is that you are excited every time you get on the bike.
There are a few places where I’d feel good letting you buy used, but as a newby I generally tell folks to buy new. If you are local to Utah there is are a couple of good Facebook groups that will have bikes that are well cared for and not stolen. (MBEU / Parking Lot Deals)
As others have said, if you are in Utah and about my size (5’10" also!) I’d be happy to loan you a bike and even give you a tour of a local trail system. I’m in Herriman and there are trails close that are beginner compatible. I’d also recommend Eagle Mountain, Corner Canyon in Draper, Valley Vista in Lehi, Lambert Park in Alpine or Temple Quarry in Sandy as being beginner friendly.
Man, this turned out to be a long post, here’s the TL;DR: Biking is awesome, spend enough that you’ll enjoy the ride. I’m happy to help. Get out and ride!