I think it depends on what you are aiming for. If you just want a bike to get you around for some light exercise I think you can get by with a cross country bike. But, if your goal is really hard riding you'll want to go with a real road bike. There is a reason they are designed very differently than mountain bikes. You can do things to improve a mountain bikes ability to ride on the road, but I don't feel you could ever get it to be a good road rider, just good for a mountain bike.

I can say the breaking isn't as good as the disc brakes on my mountain bike, but I don't need that kind of stopping power on the road bike. It isn't like single-track where it is common to turn a blind corner and have another rider coming the other way.

These days I get more time and miles on the road bike because it is more convenient and faster than driving out to a trail. It mostly takes care of the riding itch and keeps me in riding shape for when I do hit the trails.

 

I like the analogy of a mtn bike being like an off-road jeep and a road bike being a Ferrari. Sure you can get the jeep to work on the road, but its a pig, and the efficiency of the road bike on the road can be awesome.

 

Thanks for the comments guys. I do understand that the two bikes are totally different beasts and am just trying to gauge just HOW different in real world riding I guess.

For example, take two hypothetical riders of exact matching fitness/ability. One's on a road bike and ones on an mtb with slicks. Both riders are told to ride for two hours at a comfortable level of exertion. How much further ahead is the rider on the road bike going to be? 10%? 50%?

Long term I'm try to figure out whether my best option is to have a pure road bike (which is very tempting) or something like a Salsa Vaya which could be set up nicely for road riding, but be parts compatible with my Niner Sir 9. My Niner is my main bike and I like the idea of keeping future bikes parts compatible. I'm weighing this up with efficiency/speed advantages of a road bike.

I hope I make sense!

 

Thanks for the comments guys. I do understand that the two bikes are totally different beasts and am just trying to gauge just HOW different in real world riding I guess. ...

I ride a 30 lb mtb with aggressive tread on the road at around 15 mph. I can average 18 mph on my 20 lb road bike on the same 21 mile course with around 1100 ft of elevation gain.

A friend of mine rides a 29'r mtb with lugged tires that are road friendly (lugs always touch to form a constant contact patch on the road). He is about my same fitness level and is about 1-2 mph slower on the road than I am on my road bike.

 

I originally put slicks on an old (but very good condition) MTB and it was a definite improvement.

Eventually I got a road bike and it was a huge step up. No comparison at all.

Get a road bike.

 

I know a guy who did a century last weekend on a hardtail mtb. I think he said he did around a 6.5hr pace for the 100mi ride (just over 15mph) with a bunch of guys on road bikes. He's a pretty fit guy, but said he was cooked at the end and it's the last time he'll do that.

I'm in the process of building up a road bike right now. I want a faster, more efficient commute. It's not going to be a super light road bike, but it'll be faster than using an old mtb to commute.

 

A mountain bike is geared lower than a road bike, so when you ride it on the road, you'll top out and wish you had a higher gear. This is accentuated by putting skinny slicks on a 26" wheel because they roll faster, with less effort, while simultaneously lowering your gearing because they reduce the outside diameter of the wheel.

Get a road bike. They're very different.

 

I am a 30 year crit racer who just recently came into the mtb world - I love it!!! If I go down on the mtb, it's prob a result of my riding beyond my skills set. Road bike, most likely to have an encounter with a car and, sorry to say...bike usually loses!!! Stick with the dirt!!

 

Trying to quantify that it's x% more efficient won't do the experience justice. Many shops have rental or demo bikes that they can loan out, give that a try and then you can find out for yourself if you think the difference is worth the cost. Maybe you know someone with a road bike that would loan it to you for a while to check out, if you're curious enough you'll find a way to try one out.

 

There really isn’t a good comparison. I used to commute on an old hardtail then switched to a ‘cross bike riding single track to a rail-trail.

The Jeep to Ferrari is a great analogy. How much faster really depends on too many factors, gearing, distance, terrain etc. If you are just talking pavement, a low-mid priced road bike will make even a high-end mtb seem slow in comparison over any significant distance.

 

When I first hopped on my road bike, it felt like I was on a rocket. No kidding. I used to ride my hardtail on mostly pavement, and then I bought a road bike instead. It helps leaps and bounds in terms of fitness too.

As long as your brakes are set up correctly, there should be no issues (Note: I've never ridden discs). The brakes on a road bike are more for trimming speed and maintaining a safe/reckless speed on descents and such, not necessarily for actually slamming on the brakes for a sudden stop.

 

Be careful, some people feel differently about road bikes.

http://forums.mtbr.com/california-norcal/does-crosstraining-make-you-gay-734372.html

Riding a road bike makes me a better mountain biker.

 

On the road I averaged 14.5 mph on my hardtail 26" XC bike.

On my cyclocross bike (Surly Cross Check) I average 17 mph by myself.

The biggest difference to me is comfort. I don't ever ride my mtb sitting down all the time. You stand to climb, go over obstacles, etc... The roadie is much more comfortable in the saddle for long periods of time. And quite a bit faster.

That said, I usually have knobbies on the cyclocross bike in case I want to bomb some singletrack.

If the above analogy is true, and a MTB is a jeep, and a roadie is a ferrari, the cyclocross is the Subaru WRX. Fast on road, and decently capable offroad.

 

IMHO it has a lot to do with the speed you ride. At 15mph the aerodynamic advantage of a road bike position is not going to make much of a difference. However, at 20mph or with a significant headwind it makes a HUGE difference. If you are talking about a 40-50 mile ride it just compounds the difference.

You can certainly gear an MTB for higher speeds and change out the bars for a more aero riding position, but it will always be a bike built for the trail. It's the whole "jack of all trades, master of none" argument. I started commuting on my road bike a couple years ago instead of my MTB with 1.5" semi-slicks and the difference was amazing. I picked up 2-3mph with the same effort and found I was able to maintain speeds over 20mph for longer distances. This made longer rides of 20+ a LOT more fun!

 

Before getting a road bike, I had a second set of wheels for my rigid MTB. The road wheels were super light, with 1" slicks at 120 PSI and a set of road gears (11-21). The riding position was very aggressive like a road bike. It was fast, but still not as fast as the road bike. Part of the difference was my MTB was 26" wheels and my road bike is 700c. Also, the biggest chainring on the MTB was a 48, compared to a 54 on my road bike.

I ride as little pavement as possible, but when the trails are wet, I have to ride road. For the road, it is hard to beat the road bike. I picked up a decent road bike on e-bay during the off season for less than the cost of the front wheel on my mountain bike, and it has not problem keeping up with the fanciest Dura-ace equipped full carbon rides of my buddies.

We have some pretty fast winding mountain roads around here on which we regularly get over 50mph and the braking never seems to be an issue on my cheap road bike

 

Find someone that has a road bike that you can borrow, or see if any shops have a demo you can try.

Even the parking lot test can show you how much more efficient the road bike is over the mountain bike.

Even a heavy road bike(19/20 lbs) will climb much better than a light mountain bike (25+ lbs).

I resisted riding a road bike for a long time. Was more into DH and FR. However, that group kept getting smaller and smaller. My other group of riding buddies, started riding road bikes more and more.

Finally gave in and bought one. Never rode one outside of a parking lot test.

First ride out, I was climbing hills in a huge gear compared to having to spin an easy gear on the mtb. The road bike responded much quicker to pedal input. Average speed was much higher than I thought was possible.

I still prefer to ride my mtb bike 95% of the time. However, once on the road bike, I remember why it is fun to ride.

 

I hate riding a MTB on the road. If you commuting it has advantages but if your goal is to go for a road ride get a road bike and be done with it. I remember getting my first cross bike 10 years ago and being like whoa this is so much faster than my MTB. I didn't think the same thing would happen when I got a true road bike having ridden the CX bike with slicks a fair bit. But the change from a CX bike to a true road bike was also pretty notable.

 

Perhaps the best advice isn't going to be from those who ride road bikes.

Despite loving riding bikes ever since I took off my stabalisers in 1975, and from the mid 80's to the early noughties I was never off my bike, I don't consider myself a cyclist.

I don't commute on a bike,when i'm cycling,i'm out there for fun, I don't particularly like road bikes, they're just not for me I ride a mountain bike,I always will, if i'm riding on a road it's because i'm heading somewhere offroad.

Riding a mountain bike for me is awesome,through parks and woods, down trails etc, the best.

And my advice to you if you are thinking about lots of road biking is get a road bike, and get a decent one, the difference is huge , and if you like riding on roads you won't need to ask advice, you will soon know the difference in performance and may even become addicted to it, it really is a huge difference from riding a mountain bike on the road with slicks.

 

Thanks for all the comments everyone; I really appreciate it. A couple of people mentioned test riding a road bike. I do hope to do that eventually, but I do not know anyone with a road bike. In my experience the bike shops around where I live are pretty reluctant to allow test rides. And even if I convince them to they probably won't have a frame my size (183cm in Japan).

It all sounds very tempting if I can ever get the money together!

 

I used to do a loop of about 30 miles on my road bike it was about 2:15, on the mountain with slicks it was about 2:20. For longer rides a road bike is the way to go.

 

There is this one guy on the MUP that rides a road bike....I chase him on my XC bike and while I once got within 6 foot of his back tire....I couldn't hold my ground...I'd be spinning my legs so fast that I just give out feeling like having a heart attack. and he is just merely cruising..not even pushing it all the way.

 

I'm actually thinking about getting a DB Wildwood, hybrid for the paved MUP and roads.

 

I have and ride MTB's, a road bike and a cyclocross bike.

Like others have said, a mountain bike on the road sucks. I even did the true test and did a pretty big group road ride on a rigid MTB with Schwalbe Big Apples, and it was noticeably slower than others with road bikes. I did a local road climb that ascends 3000 ft. and I was getting dropped by guys on road bikes who I for sure knew I would've hanged with if I was on the right equipment.

For tooling around the urban sprawl... sure, a slicked MTB is fine. But for any serious road work... not so much.

The 'cross bike is the great equalizer, because it's plenty fast on the road and does great for dirty work. I personally set up my 'cross bike with an off road slick in back and a knobby front and I've done full on road centuries with it. I've also ridden full on rocky single track, too. I have "CX training routes" that consist of road climbs and dirt descends - total fun.

I'm sorry, but I would argue that no matter how light and slick you set up a MTB, it will never compare to a road bike on the road. Believe me, I've done it and tried my best to make a MTB road worthy; my Surly Pacer still knocks my socks off for pure road riding and is significantly faster.

As far as braking goes, the guys on the Tours seem to be fine hitting 60mph on those twisty roads under hard braking. I totally trust my Tektros to keep me out of trouble and I've never felt the need for discs at all.

 

On paved road I average 3 mph faster on a road bike. Drop bars give more hand positions on longer rides and make it more comfortable. Better in the wind too. Braking is fine. On pavement I take a road bike.

 

Do it. There is nothing like the freedom and effortlessness of riding a road bike on smooth pavement for long distances. The ability to go right out your front door for a training ride is unmatched. If you are getting a road bike, I HIGHLY recommend going with carbon. If you have to, get steel but I'd avoid aluminum like the plague, MHO.

 

...but I'd avoid aluminum like the plague...

Yes. It seems the carbon chain stays and fork seems to help when they combine it with aluminum, but a straight up aluminum frame & fork is ridiculously rough, especially on 700 X 23 tires.

I like my steel bike. Just put on a carbon fork to save some weight.

 

i recently bought a decent road bike. its a 92 specialized epic . it has a carbon frame and a full 105 7 speed group with downtube shifters lol