No, Erickson and O'Brien did not share space. O'Brien had some sort of arrangement with Glenn's friend and riding buddy Peter Hiltner, I think Mike and Peter were roommates. Glenn told me about a time when Peter showed him around Mike's part of the garage or basement or whatever it was.

I visited Glenn's one-man shop many times, after he left R&E and worked out of a one-car garage. You wouldn't want to share that space, it was tiny. I don't know how he made tandems in there, maybe rolled his Park stand out in the alley? I lived around the corner from Glenn, our back yards were on the same alley. So close, I threw a pine cone from my back yard into his once.

Funny story about O'Brien and Gregg's Greenlake bike shop, told to me by Ross Shafer, who founded Salsa Bicycles and is in the MTB Hall of Fame. Ross and Bruce Gordon were on a motorcycle tour together and came through Seattle. One place they went was Gregg's, where they found a kiosk or some such, info about O'Brien frames. One of the things it said was that Mike had apprenticed under Bruce. According to Ross, Bruce blew up, started yelling about how he's never heard of this guy and he definitely didn't apprentice under Bruce, he would have remembered that! Made quite a scene until owner Stan Gregg came out and apologized, said he'd fix it, and next thing you know O'Brien and Gregg's were no longer affiliated.