I like Sids Bike Shop (34th, west of 2nd). Ask for Tim, he's special (he's off on Sunday & Mondays). I bought my bike and love their service. I've also sent many people there who were satisfied by their service.

If you have transport, pay a visit to Jason at Piermont Bike in Tenafly, NJ (Exit 1 off the Palisades Parkway). They do a lot of custom jobs for Merlin, Litespeed and Independent Fabrications and also sell Specialized, Cannondale, et al. Jason's spoken a few times at NYCC events and will do a nice bike fit.

If you have a bike and want the fit adjusted, I'd suggest contacting Craig Upton (www.nyvelocity.com).

i personally think renaissance is hit or miss. interesting selection of bikes, ancillary gear, but oftentimes difficult to get someone's attention. distracted is probably the best way of describing salespeople. i went there a number of times with the intention of buying a new bike (i used to live in the neighborhood), but decided ultimately to purchase a bike elsewhere (a shop where the service appeared great but the fitting and after sales support was terrible, also on the west side) because the salespeople were unresponsive. perhaps when i went was an issue (on weekends) but like many others i was unable to go there other than on weekends due to work commitments. where to go has been a common question on this site and, i suspect, despite people having favorites, it's been unfortunately hit or miss for most. when the question is asked, though, all the old war horses come out. my own war horse is conrad's, but others would disagree. depending on the bike you wish to purchase, conceivably you could get a fitting elsewhere (also a frequent thread topic) and then have renaissance make the bike up for you. good luck, regardless.