Is it normal for someone to compliment your bike and then go quiet?

Message her. Worst case you get a 'sure, sometime' and nothing happens, and you're exactly where you are now. Best case she's been waiting to hear from you because she told you to look her up and you never actually did, you just showed up at her group ride instead, which from her side might have looked like you ignored what she said. That right there is probaly why the ride felt off. She gave you an opening, 'look her up sometime,' and instead of following up on it you appeared at her hobby group a week later with no contact in between. Some people would read that as confident, others as a little odd. Then you maybe hovered or felt awkward because you were trying to gauge her interest, and she picked up on that and kept her distance. Rides are also just a bad place to chat anyway, you're doing a rider's meeting, checking your tank, getting staged, and half the group is strangers to everybody. Five minutes at a gas pump is worth more than an hour of waving at each other across a parking lot. For what it counts for, gas station conversations about bikes are usally just bike people being bike people. But the part that separates yours from a normal pump chat is that she asked about group rides and told you to find her. That's not a compliment about the bike, that's an invitation. She also showed up to a beginner ride after posting about it, so the learning to ride thing seems real, not just something she said to be polite. I met my riding buddy of eight years the exact same way, he commented on my bike at a car wash and said he'd been wanting to get his license. If I'd waited for him to chase me down we'd both still be riding solo. Just keep the message simple. Something like 'hey, good seeing you at the ride Saturday, still thinking about learning? Happy to show you the basics before the next beginner run.' One message, no pressure, and let her answer tell you everything.

New rider here so this might be a dumb thing to ask, but what does 'look her up' actually mean? I would've taken that as find her online or somethig, not just show up where she hangs out. If that's the case then I get why the ride felt wierd, she was probably waiting for a message that never came. Also don't stress the quiet part too much, those rides are hard for talking anyway. Everyone's got helmets on, gloves on, and you're busy checking the bike and getting in line before you leave. Did you at least go say hi when you got there?

Agreeing with the reply above, the simple message is the whole play here. I sat on something like this for two weeks once because I kept overthinking it, then finally sent three lines about meeting up at the next beginner ride and she replied within the hour asking what day worked. All that agonizing for nothing. One thing I'd add is keep it about the riding, not about the gas station chat. Leading with the bike stuff gives her an easy way to say yes without it feeling like a date ask, and if she's actually serious about learning that's the part she cares about anyway.

Update: took the advice and just messaged her. The reply about 'look her up' meaning find her online, not show up at her ride, kind of stung because that's exactly what I did. Anyway I sent a short note about the beginner rides and she answered same day, said she'd been wondering if I'd ever reach out. We're meeting at the next one.