Mountain Biking - Should I ask shops to swap stems & adjust setback for test rides on cheaper bikes?

I've been test riding a few bikes but quite frankly, except for adjusting height I haven't bothered "dialing" them in. I looked in the beginner thread and saw nothing, except to ride bikes before asking questions. I'm fairly settled on the two bikes below, it's more of a question of figuring out which size is best for me.

I'm going to buy a bike this weekend. Both bikes(Gary Fisher Marlin, Specialized Rock Hopper; I expect it will come down to 29'er vs. good brakes and lighter weight), they both fit a little "longish" compared to others I've ridden in size 17"(usually having a 580mm top tube) such that I've thought about going with the smaller models, with the 15.5" models having about a 570mm top tube, and the 17.5" models having a 600mm top tube.

Before making the final decision, I'd actually like to ride them like I will when they are mine, i.e. a good fit. So to me, that would be a 10cm stem on the 15.5" and a shorter stem on the 17.5". I'm only looking at $600 bikes, but will shops swap the stem for me before a test ride and allow me to adjust the setback for test rides?

I would hope so........ If not, buy from a shop that will.

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I would hope so........ If not, buy from a shop that will.

Sure, there are $3000 bikes there, but you're still dropping $600 dollars. Not exactly a piddly cash, every day purchase. Just ask them flat out. If they won't, maybe say "Ok, Thanks, I might be back. I'm gonna shop around a bit before I make any decisions." They should get the hint. You shouldn't really have to do that, though. They should be fine with it from the start if you're serious about buying a bike from them.

Yes, you should ask them to swap the stem. Explaining that you're going to buy the one that fits the best should have them interested in setting it up as best as possible. It's a no-brainer.

If you didn't have any intention of buying one, but were still just looking around, then I would say no, that's a lot to ask for a maybe sale way down the road. However, since you're trying to decide between only two bikes, and you will most likely buy one of them, then yes, a good shop should have no problem helping you make that decision. 10 minutes of swapping a stem is pretty good trade-off to keep $600 merchandise moving.

Bingo.

I had one shop swap a stem free of charge. They pulled a different stem out of their "stem drawer," and threw the stem that came with the bike that I was buying into the drawer for someone else.

I had another shop cut a carbon seatpost for a test ride, despite my telling them not to worry about it because it wasn't even my first choice bike and it may take me a few visits to make a final decision. Their response was that they had a great relationship with the company and the company would happily send them a new seatpost, and that there was no way I could actually test the bike without it fitting properly. That's a good shop. I wish the bike fit, because they would have had my business based on that (unfortunately, it did not, and no amount of tweaking was going to do it).

Out of the bikes I've bought from shops rather than off Craigslist or the internet, 3 out of 5 involved the shop employee doing a fitting with the bike mounted on a trainer. Minor tweaking was up to me, but all the major stuff was done by them.

Moral of the story is that it shouldn't be a problem. They may or may not buy back the stem that comes with the bike so you may have to pay full price for a new one, as I've had experiences both ways, depending on whether or not the shop thinks it can sell whatever it is that you want to get rid of. However, they should put it on for the test ride, as long as you're serious about buying.

Thanks for the input.

I honestly can't wait to finish shopping and just get a bike to ride.