Cyclocross - Building an all-purpose cross-type bike?

Hello everyone. Im new to the forums and biking in general. I just traded my electric bike for a road bike, and am looking to buy a cheap used mountain bike for some light trail riding.

However, my girlfriend wants to get into riding as well, and she would prefer to not have two bikes. So I was thinking we could convert a used road or mountain bike off craigslist or ebay to serve her needs. She wont EVER be racing the bike, or beating it up on hard terrain, or riding in the mud. It would be for light trails, and mostly city riding.

Would it be a good idea to buy her a cheap mountain bike frame, put on drop bars, narrower tires, etc? I know there is more to it than that regarding cantilever brakes, shifting levers and all that. I would plan to work with my LBS to make sure it all is done properly.

I am just wondering if this would be:
- Mechanically possible
- Cost efficient (under $200 for used/cheap parts on ebay or craigslist for the conversion, not including the original bike)
- or, just a bad idea.

Anyone with any suggestions, it would be GREATLY appreciated. I am hoping to get much more into cycling, and eventually cross riding, and would love if my girlfriend could start down that path with me.

Thanks guys.

Daniel

for cost effectiveness you should decide which kind of bike to buy based on the kind of handlebars she wants. switching the style of bars requires new bars, brake levers, shifters, grips/tape and often a new stem. and that's assuming everything's compatible. most beginners are more comfortable with flat or riser bars.

if she wants flat bars, i'd get a mountain bike with a rigid fork and throw some 1.5 inch slicks on. if she wants drops go with a road/cross/touring bike and throw the fattest slicks the frame and brakes will allow.

a few other notes from a guy who's been down this road. make sure the fit is good, if it doesn't fit it's never a good deal. most beginners are not very sensitive to problems regarding fit and many get turned off right from the start because they don't know what a good fitting bike is supposed to feel like.

the other thing is to keep it fun, you may luck out and your girlfriend may love riding as much as you do. but you have to accept the fact that she might have a much lower interest level. my girlfriend doesn't care to ride any more than to the farmer's market once every couple weeks and that's ok. we have fun and then later i go ride as far as i want.

Buy an 80s touring road bike for like $100-150 (NYC price, may be lower). Add bigger wheels. Drink $100+ you saved in beer.

...for cost effectiveness you should decide which kind of bike to buy based on the kind of handlebars she wants....

.. make sure the fit is good, if it doesn't fit it's never a good deal. most beginners are not very sensitive to problems regarding fit and many get turned off right from the start because they don't know what a good fitting bike is supposed to feel like...

the other thing is to keep it fun, you may luck out and your girlfriend may love riding as much as you do.
but you have to accept the fact that she might have a much lower interest level.

"switching the style of bars requires new bars, brake levers, shifters, grips/tape and often a new stem" isn't necessarily true, because you can put trigger shifter/ brakes on the flats of your drop bars, but it wouldn't be super effective ir comfortable, but you can run them with aero levers and have them interleave to the top mounted brakes.

can you do it for under 200$ yes, but find other bikes you can rip apart, the easiest way to go about your thoughts is just take a road bike and put knobby tires on... or go the other way and take an mtb and put slicks on it... both work fine and go with what you have the parts to do easier.

+1 on the fit
+2 on keep it fun

beware, road handlebars typically have a 15/16" diameter (not at the stem, but over the rest of the handlebar). mountain handlebars typically have 7/8" diameter, meaning that brake levers and shifters designed to fit on flat/riser bars are going to be too small to fit on most road drops.

if they're downtube shifters, then you'd only need a new bar, levers, grips/tape and maybe stem. but it still makes financial sense to buy a bike that's already got what you want and just switch the tires.

Or you could buy a brand new Surly Cross Check :)

Cycling Plus had an article on the exact scheme you have planned in 05/06. They used a Dawes Mtb frame, rebrazed the canti posts and home painted the frame, got some cheap 700c wheels and used bar end shifters. I think it came to less than 200 pounds. The trick would be finding a cheap frame repair workshop in the USA!

thank you guys so much for your responses. I appreciate al the tips and input. I definitely think I will look into going the used road bike route as she wants the drop bars. there's one for sale on craigslist here for $100 bucks with downtube shifters, so I am hoping the conversion wont be too big of a deal.

and i hear you guys on keeping it fun. im not planning on making her train with me or anything. we just want to be able to ride around the lake together and do some small trails around here. thanks again to everyone.