Listen up, you're asking about optimal tire pressure for a Trek Checkpoint SL 6? Well, let me tell you, it's not rocket science, but you'd be surprised how many riders get it wrong. For a bike like that, you're looking at 38-42 PSI for the front and 40-45 PSI for the rear, assuming you're around 150-170 lbs. But, let's be real, that's just a starting point.
Trek's own guidelines recommend 35-45 PSI, but that's a pretty broad range. You need to factor in the terrain, your riding style, and the conditions. For example, if you're riding on rough roads or carrying a heavy load, you'll want to bump up the pressure. But, if you're on smooth roads or racing, you can go lower.
Now, I've seen guys on group rides running 50 PSI or more, and I'm thinking, "What are you doing, man?" You're sacrificing comfort and traction for a negligible gain in efficiency. And don't even get me started on under-inflated tires. It's like riding a flat tire, you're just asking for a blowout.
So, do your research, read up on the guidelines, and experiment to find your sweet spot. And for goodness' sake, don't be afraid to ask questions or seek advice from more experienced riders.