That’s an awesome idea/gesture. Personally, I’d set it up as a “business” for liability and tax reasons, even if the shop use fee is something like $10/day and you choose to waive it for more than a few folks.
Things I’d be interested in if I were a guest would be:
1. A place to ship things and someone who could confirm they had arrived and were actually the right parts. Nothing like them sending you a 19” tire for an 18” wheeled bike, or a pair of 525 sprockets with a 520 chain…
2. A place to securely store things while exploring locally or on shorter trips. Colorado is a place where guys working and traveling across the country might want to stash their laptop and street clothes and spend 4-5 days in the backcountry. CA, OR, WA and Canada are also less than firearm friendly if you’d be comfortable storing a pistol for somebody for a bit.
3. General maintenance stuff on hand, in addition to tools. Tubes, grips, filters, bolts, master links, wiring connectors, oil, and dump station for waste oil. It might also be helpful to stock some inexpensive stuff like gloves, beanies, riding socks, phone chargers, etc. A lot of that is readily available but you don’t want to waste time hunting for it or realize it would be nice to have until you’re looking at it.
4. Local knowledge. Obviously a lot of this would come from talking to you, which would be the point, like “where’s a good wing place around here?”. A lot of things get forgotten when put in the spot though, and it might be nice to have a few print outs of local rides with distance, difficulty level, things to see on the route, and so on.
5. Bunk, shower, laundry, grub, booze. If guys are coming in after limping along bikes with mechanical failures or just got all of their gear poured on, it’s awesome to get everything cleaned up and a meal and drink at the same spot. This could be as simple as some frozen burritos and beer in the fridge, or throwing steaks on the grill and making old fashioneds. An electric pressure washer and gravel area where it’s clearly ok to wash the bike and make a bit of a mess would be appreciated also.
I’d try to set things up where it can be semi-autonomous if necessary. You might enjoy hanging out with guys traveling a bunch of the time, but if it gets busy enough at some point you’ll be sick, out of town, or with the wife/gf, and want to help people without being involved. Maybe a “text this number, I’ll send you the door code, let me know when you’ve left” which unlocks the bunk area, kitchenette, and small service bay with $200 worth of Harbor Freight tools. All the more involved stuff is kept locked where you control and oversee things.
On the growing/advertising I‘d just offer it up on forums and let it grow organically. Maybe a small sign out by the road if you get riders passing through. I don’t see a reason to push it to get big fast if you’re not trying to generate revenue. The word of mouth approach will probably keep things to the type of guys you want around and give you time to sort out issues as they pop up.
Downsides would be liability and guys getting in over their heads with repairs/projects getting abandoned. Liability wise I’d want insurance and a waiver, even if it’s not 100% ironclad in court. You’re hoping guys will be decent enough that if they knock their own bike off the stand and crush their leg they won’t try to sue you, but it seems less certain these days unfortunately.
You might not mind helping a newer rider rivet a master link on their chain, (again stock some clip style spares), but when a guy breaks a spark plug off in the head and doesn’t know how to handle it, I’d want to be able to throw it on a trailer, take it to a reputable shop for them, and let it be someone else’s problem.
Same deal when you’ve got a kid from Maine in that thinks they need their valves adjusted, only to find out the piston and cylinder are shot and the kid is broke. They fly back home and are unreachable for a year, then you eventually give the project to a buddy who has asked about it several times. A few months down the road said kid pops up on a forum talking about how you stole their bike when they were down and out but planning to come get it, etc.
Have rules and conditions written and posted, you can always make exceptions.