Hi, I'm trying to build a hybrid, it's my first build. My budget is around $800. Is there any advice you guys have or anywhere I should start? What would be your recommendation in terms of frames? Thanks.

Welcome to the Forums .

You could get some decent complete bikes with your budget, but if you are really set on doing a frame up build (which can get pricey rather quickly if you don't have a well stocked parts bin or lack patience), then I would suggest you figure out what type of riding you plan on first and take it from there.

Thanks for the speedy reply! I'd mostly be on pavement and some gravel. I was thinking about going for a more upright/relaxed geometry for the frame. Knowing my budget, how much should I spend in each area of the bike? (Probably go used for much of it)

I was also thinking about possibly going for a thin mountain bike frame with 700c wheels. Is that possible?

Thin? Do you mean CroMo? I'd be all for that but if the frame isn't a 29er you would be pushing poo poo up hill to fit 700mm rims.
Just buy a used rigid framed hybrid like a Surly and don't worry about building one. If you want a project just strip it and rebuild it with new cables, grease and pads etc.

Unless you pretty much know what you want, there is a risk that even building with "all the right parts" that what you build will not be ideal for you.

I enjoy the challenge of building, and don't want to discourage you too heavily, but you need to keep one point in mind... You can't test ride a bike that hasn't been assembled.

What I did for under your price point was to buy a 2011 Trek 7.3 fx (used obviously). I then bought new wheels to be sure to hold my excessive weight, some higher volume tires that looked good (which worked out great) and some other minor parts to tweak it a little bit for my needs.Had I started from scratch, it would have taken longer, and it would have cost about the same.

I would look for a 90s steel hybrid and update the components and position according to budget / requirements

pros: cheap, available, quality frames (some), retro, recycle, some in pristine condition
cons: outdated specs (canti only, threaded fork), research needed to identify better frames, low spec components

Some to look for are: Bianchi Boardwalk, Specialized Crossroads, Trek Multitrack, Diamondback Overdrive, and Giant Innova.

If you want new, I would start at the wheels first because that would dictate your frame requirements and usually require something handspun if you want 135mm QR, disc, and narrow 700 rims.

Thanks guys! Unfortunately I'm pretty set on building it (summer project), would going to a bike shop to try out some frames help with the fit issue? Also, I was wondering on your opinion on Unknown frames?

Since you are sold on building, then the first question you need to decide is whether to lean toward a mountain frame or a road frame. I don't think you will ever find a bare frame listed as a hybrid, since rarely do hybrid riders build from scratch when compared to roadies or mountain bikers... Limited market means fewer available options.

I have converted many mountain bikes to rail trail and light road use, and they work for me. If I wanted something a little more toward the road direction, I would go for a road frame with relaxed geometry... I would personally look for a touring frame, but there are other good choices as well, possibly cyclocross.

Riding something could help you narrow your choices, but then in your search you would have to determine how the geometry of available frames compares to the bikes you like... plus you will be using a shop employee's time without any intent to buy from them... Depending on your stance on such things, that may or may not be a problem for you.

You can also just start with what you ride now. You could take some measurements, and use them when choosing a frame and component mix. You would of course have to adjust for any, "I like my bike except for..." items.

You really need to get some decisions made before anyone can provide real good information on specifics, but I think in general, you have a couple of decisions points here to get you started.

Awesome! That was very helpful, thank you!

Knowing that mountain bike frames and 700c wheels are not very compatible, would a cyclocross frame be better for my needs? I plan to go on bike paths and sidewalks/roads. I've never ridden a road bike, so I imagine I should try one out

Both my hybrid and my MTB have 700 (622mm) rims. You just have make sure you buy a 29er frame. Easy easy.