I would like to start biking to work which is about 9 miles one way. There is a shower facility at work along with an indoor room to lock and store the bike during the day. Essentially, the bike storage room has a basic outdoor style bike rack that everybody uses. My dilemma is I own a Trek Domane 5.2 and I'm not sure I trust storing my bike there without getting abused with nicks, bumps and scratches. Not that anybody would do this on purpose but accidents happen.

Would I be better off buying a used bike for the commuter and keeping my Trek for my training rides? What have others done in a similar situation?

Have you asked if you can park the bike inside? That may be an option. If not, then I think you should get yourself an inexpensive commuter of CL or the like, and ride a bike that you can enjoy, and not worry about. Sounds like you love your Trek. Happy commuting!

You clearly aren't aware of the N+1 rule, where N+1 is the number of bikes you need, and N is the number you currently own.

It's up to you. A bike that gets ridden will show some wear. I ride my nicer road bike daily. I try to be careful with it, but if it gets a scuff now and then. Hanging it in the garage and looking at it is not an option.

#FirstWorldProblems

A secondary, heavier bike may make you stronger. It will definitely make you appreciate the Domane.

All good points above.

I'll add that every scratch and nick on all my bikes, I've put there. They're accidental, of course, but there's nothing on any of them that I haven't put there myself. Even out front in the public bike parking racks, (which are right outside a glass wall behind me as I work) I've never seen anyone damaging someone else's bike. I have seen attempted thefts, though. Even the thieves don't want to wreck their target.

I think you may be giving your co-workers less credit than they're due WRT to respecting others' property. Everyone's in the same boat.

That said, I like having a choice of bikes for commuting. I have two dedicated to the task, and my Litespeed makes the trip when I don't have things to tote and the weather cooperates.

Neither of my commuters is an old POS beater. That's key for me. I like what I like, and it's contemporary drivetrains, frames, and carbon forks. I've put a lot of thought and dollars into my rides to make them so that I never feel "less than" on any of them. I'm equally happy commuting on any of the three, even though they're three completely different geometries and two are fully fendered, with rack and dynamo lights.

That may be something to consider as you examine the N+1 question. Why buy something you really don't want to have to ride? Put as much care into the purchase of a commuter that you have into the Domane, and you'll enjoy the ride as much on either bike--even though they're different. Plus, if it's equipped for foul weather, you may find yourself on the bike more often.

Plus-as alluded to- it-nice pricy bike-will get stolen(maybe)
There are sooo many cheap mid late 1990's cromo steel framed Trek-not really MTB MTBs 700,800,900 series(700 have 700c wheels if it matters)
for $50-$200
and low RR tires-1 to 1.5"
Why bother risking the super bike-leaving it out of your sight for hours?
Yeah-get a inexpensive CRMO steel or aluminum framed rigid suspension "MTB"
all brands made them- 21 speeds-decent bikes-sturdy
Might add 10-15% to actual ride time-

I'm with TSL, ride it, enjoy it! Every time I see my 30 year old Cannondale frame with the original paint and all the battle scars on it, it takes me back to all the good times we had together, going all over the world with it! I know I've been blessed with the longevity of the bike, but no bike last forever (accident, stolen, failure, sell). We may think it does but nothing last forever and you paid good money to enjoy it, so ride, take care of it the best you can and let the chips fall.

Flat tire this AM, rode my backup bike.

If I could park it inside, of course I'd ride it. I'm able to park inside, so it eases my mind a bit knowing my bike is safe while I'm working.

but I love bikes ... so it'd be nice to have an excuse to get another ...

Me personally, I own a Trek 1.2, a far cry below a Domane, but it's my roadie and I love that bike ridiculously. I didn't want to submit it to the daily rigors of a 24 mile commute, so I bought a cyclocross bike, swapped out the knobbies and ride it primarily as my commuter. Ironically, today I rode the Trek instead of the CX bike.

It's nice to have options

OP, your Domane probably needs some character added to it. An indoor lockup site is about as good as it gets. Once you get past that first scratch or paint chip, the rest are much easier to deal with... Plus, that's what they make stickers for.

Personally, I have no interest in riding a bicycle that is not my favorite. There's only one bicycle that I want to ride. It has all the stuff that I've personalized it with. I have another couple of bicycles that I really need to get rid of. I thought I'd want to ride them but never do.

Between the indoor room with a rack and the showers with lockers, isn't there some place you can store a thick blanket? I keep a lock at work, clothes, why not something to drape over the expensive bike?

^great idea

Is your bike a tool or a jewel? (Hint: a Domane 5.2 is not a jewel)

If you commute by bike long enough, you will get sweaty, wet and dirty, you'll fall down and get hurt, your bike parts will wear out, your bike will get dinged, scratched and dirty. Comes with the territory. What's the dilemma again?

Ride it, lock it in the bike room. Hasn't it gotten scratches and dings already? First time I fell, my new bike got a scuff. It builds character.

I wish I had a shower room and indoor secure bike parking.

Dude, commuting is the best excuse to ride and enjoy a nice bike.

Apply N+1. Just you asking says you should.

Since it's "what would *I* do" - I don't worry about nicks and scratches, on bikes or cars or anything else. Heaven forbid that my vehicle looks like someone ever used it.

It's a bike, for chrissake. It'll be just as fast and comfortable when it's scratched.

Your OP question "What would I do?" Well, over a period of years I've invested plenty in 6 bikes that I currently own and ride. All of them spec'ed the way I want them, all can and have been commuted upon, and none are beaters, I hate riding beaters. So if you are going to buy another one buy something you'll love, or forget it and ride the TREK.

any questions.

If you are serious about commuting, you should get a better bike for commuting on. The Trek Domaine is a fine bike for racing, but for commuting you want something that you can easily hang stuff on like bags, lights etc.
I have an almost identical situation to you - I have an 8 mile commute to work, at work we have a gym, with showers etc, and a room where we can store bikes, which has tools, air etc. I ride in to work hard enough to work up a sweat, and then shower and get dressed at work. I park the bike in the storage room. There are power outlets in the bike storage room to recharge batteries etc. After work, I ride home slowly enough to be able get home without being too hot and sweaty.
My bike (which cost about 50% more than the Trek Domaine 5.2) has a rack, fenders, lights, beefy tires (one flat in the past 13000 miles). I have another bike that is for fun fast rides, but I don't commute on it.

My suggestion would be to ride to work with what you have. If you are constantly worrying about damage or realize it is not ideal for commuting then get something else.

I used to have a Trek Y-Foil (see below) that I commuted to work on a few times since I could store it inside. However I soon noticed I wouldn't ride it anywhere else because I did not feel comfortable locking it using a cable lock (also I couldn't carry anything unless I had a back pack). After a while I sold it to a bike shop and bought a different bike that I would ride more often and better suited my needs.