Hey all, I'm brand new to the forum, and figured I would ask some advice from those in the know before I go out and spend a lot of money...

I used to bike a lot as a kid and teen, but have been off of two wheels for well over ten years now. My girlfriend recently bought a Rans (man is that thing weird), and wants me to get something to accompany her on weekend rides. My idea was this (and you guys tell me if this is even feasible): to buy a mountain bike and then get a narrower rim and some road tires and swap the two, when necessary, for a "jack of all trades" (master of none) kind of bike. Can this be done? Is it advisable? A lot of my riding will be in town, but I feel that a mountain bike with road tires would do a lot better on the road than a road bike with knobby tires would on a trail. Am I right? Are there any kinds/brands of bikes that would be more suitable to this kind of setup. Any help would be appreciated? -J

Spot on. Just don't go full suspension if it's going to see road duty.

My primary mountain bike, an upgraded 2003 GT Zaskar, is also my Jack of All Trades travel bike. With the race wheels and slicks, it's almost as fast as an entry level road bike at 22 lbs. With the sturdier wheels and big knobbies, I can ride just about any trail. It can't do big drops, requires pretty good technical skills, and there are a few trails, like the Portal Trail in Moab, that it's not up to but it gets the job done. I'm not about to kid myself and try maintaining a Cat. 4 race pace on it either.

Why not get a cross bike like the Surly Cross Check (or many others)? Bigger wheels and (I think) higher gearing than a mountain bike, plus drop bars. You can get a pair of 700c slicks and a pair of knobbies or something in between. It'd be a bike with off-road capability and none of the huge on-road disadvantages of a mountain bike.

What RANS?
Yes you can do it, and you don't need to swap the rims.
Just get some slick tires about 1.5 inches wide, get tubes to fit them (tubes come in different widths too!) and you're good to go. The narrower tires will work fine on the rims you've got.

And I disagree with the other poster in that you can get a suspended bike for pavement riding, too. The suspension makes riding over bumps easier on your various parts--just like it does off-road. The weight difference will cost you next to nothing in practical terms, but the comfort difference you will feel with every bump you roll over.
~

I disagree with this.

My primary bike had a front shock only, because I was going to do a combination of road and trail riding. I found I was doing only road and very light trail riding, so I switched to a rigid fork, and the handling of the bike improved immensely. I like riding the bike a lot more.

I see people half my size and half my age pushing their fully suspended bikes up hills I ride up all the time... I suspect that at least part of it is because the suspension sucks just enough energy to make it too hard to climb them.

Unless your primary time on the bike is hard core down hill riding, and unless you spend the big bucks for GOOD suspension, don't bother with suspension on a bike, especially on the rear. Go hard tail.

My last road ride on the Zaskar was 50 miles from one end of the South Rim of the Grand Canyon to the other and back. My buddy who always packs like he's driving an RV had to bring a road bike because one of the six rides we were planning happened to be on pavement. He got beat. If I had been riding my full suspension bike, and it's not a cheap one, that extra 1-2 mph would not have been there. I guess that means I'll stick to my original assertion, hardtail all the way, especially if you're looking at 50% road.

If you are old enough to recall when the first suspension forks for MTB's came out, the things that skeptics said-

"Oh my god, how dumb, they're too heavy, they don't work right, they cost too much, you don't need them, who would ever pay for such a thing?"

And look at what MTB's are now.
Go into your local bike shops, and count up all the MTB's on the floor that have no suspension, and compare that with the number of the ones that do.

-----------

Someday in the not-too-distant future--it will be difficult to walk into a bike shop and buy a bicycle that doesn't have full suspension. And I'm including road and touring bikes in that prediction.

In fact, if you consider suspension seatposts to be generally equivalent to rear suspension, then a lot of "comfort" bikes sold for "pavement riding" already are full-suspension.
~

Errr... that doesn't mean it's right. It just means that's what the market demands, ( or the manufacturers think it demands. )

I mean, look at the cr^p they sell for cars these days? ( though that's starting to change )

I pretty well do exactly what you want to do. I have what is presumably a XC bike which has a front headshock (which can be turned on or off) and no rear suspension (though I installed a suspension seatpost to soften the riding a bit). I can easily switch between 1" slicks for the road, 1.5" touring tires or much wider knobby tires for trail riding. In my case, I use it mostly on-road and have installed a drop bar with bar-end levers and brake levers for an upcoming tour.

Oh, and I'm happy with the results.

'Blarney,

One more opinion supporting NOT swapping rims, just use the mountain bike rims with a tire with more of a "road-type" lug* pattern. This way you only need to swap tires (and not rims; $$)when going from road to mountain biking. This works really well and gives you the "Jack-at-all-Trades" thing you mentioned. If you are at all tentative about how this is done or what to buy, talk to your Local Bike Shop.

Ciao, bello!

* - Technical term for "treads", those bumpy things on mountain bike tires that grab rocky, muddy, and uneven surfaces off-road.

What kind of brakes? Everything on a bike works together. If your bike has rim brakes, switching to narrower rims will make it necessary to readjust your brakes every time that you switch wheels. I'd recommend getting identical hubs too or you might get sloppy shifting with one or the other wheelset.

Frankly, if your objective is to ride with the lady, I'd get a bike that's similar to hers. The more similar the bikes are the more fun it is to ride together.

Thanks for all the input guys. The one thing I've learned over the last couple of days is that it is absolutely astounding how much I don't know about bikes. I didn't know about the existence of something called cyclocross... and while I'm never gonna be doing any bike racing, it sounds like it might fit the bill better than a MTB with slicks. Can anyone suggest one worth buying for less than $800 (or am I just dreaming?)